Browsing by Author "Kumar, Rakesh"

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Chitosan-supported copper as an efficient and recyclable heterogeneous catalyst for A3/decarboxylative A3-coupling reaction
(Elsevier Ltd, 2018) Kaur, Pavneet; Kumar, Bhupinder; Kumar, Vinod; Kumar, Rakesh
Chitosan-supported copper (chit@copper) based heterogeneous catalysts have been explored for A3-coupling and decarboxylative A3-coupling. The developed protocol employs low catalyst loading, solventless condition and easy work-up for the synthesis of diversely substituted propargylamines. More importantly, the catalyst could be recovered and reused without any significant loss in the activity. This offer huge advantages as recyclability issues are rarely addressed in decarboxylative A3-coupling. Leaching studies were carried out using AAS and ICPMS analysis. It is envisaged that chit@copper catalysts can have potential applications in terms of efficiency and recyclability in the emerging area of decarboxylative C?H bond activation/functionalization strategies. ? 2018 Elsevier Ltd
Chitosan-supported FeCl3 catalyzed multicomponent synthesis of tetrahydroisoquinoline-indole hybrids with promising activity against chloroquine resistant Plasmodium falciparum
(Elsevier B.V., 2022-10-26T00:00:00) Kaur, Pavneet; Sharma, Priyanka; Kumar, Vinod; Sahal, Dinkar; Kumar, Rakesh
An operationally simple three-component coupling of tetrahydroisoquinoline (THIQ), aldehydes and indoles or indole-3-carboxylic acids has been achieved using chitosan-ionic liquid supported FeCl3 (chit-IL@FeCl3) as a recyclable heterogeneous catalyst. The developed waste-free approach provided rapid access to biologically important THIQ-indole hybrids without the use of any additive or ligand. The synthesized THIQ-indole hybrids were evaluated as antiplasmodial agents against chloroquine-sensitive (Pf3D7) and chloroquine-resistant (PfINDO) strains of Plasmodium falciparum. Compounds 4b (most potent against Pf3D7) and 4g (most potent against PfINDO) showed IC50 values of 1.32 and 0.26 �g/mL respectively. Also, 4g showed strong cytocidal action against both rings and trophozoite stages. Furthermore, cytotoxic study against human liver HUH 7 cells revealed that the most potent compound 4g with an excellent resistance index of 0.07 is also relatively non-toxic. The results of this study suggest that THIQ-indole hybrids hold an enormous potential for developing new antimalarial agents with novel mechanism of action. � 2022 Elsevier B.V.
Co-transport and deposition of fluoride using rice husk-derived biochar in saturated porous media: Effect of solution chemistry and surface properties
(Elsevier B.V., 2023-02-10T00:00:00) Kumar, Rakesh; Sharma, Prabhakar; Rose, Pawan Kumar; Sahoo, Prafulla Kumar; Bhattacharya, Prosun; Pandey, Ashok; Kumar, Manish
Fluoride (F?) contamination in water is a global health concern, threatening the well-being of millions. This study investigated the role of ZnCl2/FeCl3-rice husk-modified biochar (Zn-BC and Zn/Fe-BC) in treating F?-contaminated surface and groundwater under the influence of varying solution chemistry, co-existing ions, and biochar-amended through column transport experiments. Modified biochar showed maximum F? adsorption, 99.01% and 91.90% using Zn/Fe-BC and Zn-BC, respectively, than 85.87% using raw biochar (R-BC). Raw/modified biochars were characterized with FESEM-EDAX, FTIR, XRD, particle size, surface area, electro-kinetic potential, and point of zero charge analyses. Langmuir and pseudo-second-order kinetic could explain that F?-biochar interactions are dominated by chemisorption at ambient temperature while physisorption at higher temperatures. The influence of salt concentrations and co-occurring ions reduced F? sorption using Zn/Fe-BC. Increased salt strengths led to reduced electrophoretic mobility of biochar particles, i.e., biochar�biochar particles attract each other and increase the hydrodynamic diameter, which ultimately reduces the active sites on biochar for F? adsorption. Co-transport and deposition of biochar and F? in saturated porous media revealed lower mobility of biochar, and maximum F? adsorption was observed at 10 mM salt strength. Biochar transport is governed by electrostatic interactions, whereas F? transport mainly occurs through chemisorption. In rural areas, hand pumps and tube wells are generally used as source of potable water for drinking and cooking purposes; thus, biochar-mediated sand columns can be utilized for defluoridation. Thus, Zn/Fe-BC can be utilized as a potential bio-adsorbent for F?-contaminated natural surface and groundwater with optimum preparation and treatment costs. � 2023 The Authors
Copper catalysed regioselective synthesis of pyrimidine substituted Indolizino[8,7-b]indole derivatives via cascade A3 annulation
(Elsevier Ltd, 2023-07-08T00:00:00) Kumar, Sunit; Kumar, Rakesh; Malakar, Chandi C.; Singh, Virender
Cu(II) salt has been found to be an efficient catalyst for the regioselective synthesis of a series of novel indolizino [8,7-b]indole derivatives with pyrimidine tethers via three-component annulation of 1-formyl-9H-?-carbolines (Kumujian C), 2-amino-pyrimidines and terminal alkynes. The reactions proceeds through Cu-catalysed A3-coupling followed by intramolecular cyclisation in a cascade manner. The scope of strategy has been exemplified with a library of biologically interesting 25 indolizino [8,7-b]indoles with pyrimidine tethers which mimics several natural products. � 2023 Elsevier Ltd
Efficient synthesis and mechanistic insights for the formation of imidazo[1,2-a]pyridines via multicomponent decarboxylative coupling using chitosan-supported copper catalysts
(Elsevier B.V., 2023-10-03T00:00:00) Kaur, Pavneet; Gurjar, Kamlesh K.; Arora, Tania; Bharti, Divya; Kaur, Manpreet; Kumar, Vinod; Parkash, Jyoti; Kumar, Rakesh
An efficient multicomponent decarboxylative coupling of 2-aminopyridines, aldehydes and alkynoic acids for the synthesis of imidazo[1,2-a]pyridines was developed using recyclable chitosan-supported copper (chit@CuSO4) as a heterogeneous catalyst. Computational and experimental evidence revealed that in situ generated propargylamine undergoes cyclization to the desired imidazopyridine via prototropic isomerization involving allene type intermediates. Control experiments on isolated propargylamine demonstrated that cyclization could proceed without any metal catalyst. In literature, the cyclization step is assumed to be facilitated by metal catalyst and experimental proof for the involvement of actual intermediates is not available. The synthesized imidazopyridines were further evaluated for antiproliferative activity against human neuroblastoma cells (SHSY-5Y) using MTT assay. � 2023 Elsevier B.V.
From 2011 to 2022: The development of pyrazole derivatives through the ?,?-unsaturated carbonyl compounds
(HeteroCorporation, 2023-11-25T00:00:00) Sharma, Shubham; Singh, Virender; Vaishali; Kumar, Rakesh; Jamra, Rahul; Banyal, Naveen; Jyoti
The synthesis of pyrazole derivative using ?,?-unsaturated carbonyl compounds has attracted increasing attention of the synthetic organic chemist community. Interestingly, the simplicity of the synthetic method, high reactivity, and ease of incorporating diversity into the desired prototype have contributed a lot toward the exploration of ?,?-unsaturated carbonyl compounds by various research groups. Due to the tremendous pharmacological significance of pyrazole derivatives, their synthesis has been one of the leading research frontiers in recent years. As prime examples, sildenafil, zometapin, Celebrex, and rimonabant have been successfully commercialized in the market to treat various life-challenging diseases. Considering the great profile of ?,?-unsaturated carbonyl compound in the synthesis of biologically active pyrazole derivatives, this review incorporates contemporary literature (2011�2022) on the synthesis of pyrazole and its derivatives using ?,?-unsaturated carbonyl compound as a starting precursor. � 2023 Wiley Periodicals LLC.
Global, regional, and national burden of diabetes from 1990 to 2021, with projections of prevalence to 2050: a systematic analysis for the Global Burden of Disease Study 2021
(Elsevier B.V., 2023-06-23T00:00:00) Ong, Kanyin Liane; Stafford, Lauryn K.; McLaughlin, Susan A.; Boyko, Edward J.; Vollset, Stein Emil; Smith, Amanda E.; Dalton, Bronte E.; Duprey, Joe; Cruz, Jessica A.; Hagins, Hailey; Lindstedt, Paulina A.; Aali, Amirali; Abate, Yohannes Habtegiorgis; Abate, Melsew Dagne; Abbasian, Mohammadreza; Abbasi-Kangevari, Zeinab; Abbasi-Kangevari, Mohsen; ElHafeez, Samar Abd; Abd-Rabu, Rami; Abdulah, Deldar Morad; Abdullah, Abu Yousuf Md; Abedi, Vida; Abidi, Hassan; Aboagye, Richard Gyan; Abolhassani, Hassan; Abu-Gharbieh, Eman; Abu-Zaid, Ahmed; Adane, Tigist Demssew; Adane, Denberu Eshetie; Addo, Isaac Yeboah; Adegboye, Oyelola A.; Adekanmbi, Victor; Adepoju, Abiola Victor; Adnani, Qorinah Estiningtyas Sakilah; Afolabi, Rotimi Felix; Agarwal, Gina; Aghdam, Zahra Babaei; Agudelo-Botero, Marcela; Arriagada, Constanza Elizabeth Aguilera; Agyemang-Duah, Williams; Ahinkorah, Bright Opoku; Ahmad, Danish; Ahmad, Rizwan; Ahmad, Sajjad; Ahmad, Aqeel; Ahmadi, Ali; Ahmadi, Keivan; Ahmed, Ayman; Ahmed, Ali; Ahmed, Luai A.; Ahmed, Syed Anees; Ajami, Marjan; Akinyemi, Rufus Olusola; Al Hamad, Hanadi; Al Hasan, Syed Mahfuz; AL-Ahdal, Tareq Mohammed Ali; Alalwan, Tariq A.; Al-Aly, Ziyad; AlBataineh, Mohammad T.; Alcalde-Rabanal, Jacqueline Elizabeth; Alemi, Sharifullah; Ali, Hassam; Alinia, Tahereh; Aljunid, Syed Mohamed; Almustanyir, Sami; Al-Raddadi, Rajaa M.; Alvis-Guzman, Nelson; Amare, Firehiwot; Ameyaw, Edward Kwabena; Amiri, Sohrab; Amusa, Ganiyu Adeniyi; Andrei, Catalina Liliana; Anjana, Ranjit Mohan; Ansar, Adnan; Ansari, Golnoosh; Ansari-Moghaddam, Alireza; Anyasodor, Anayochukwu Edward; Arabloo, Jalal; Aravkin, Aleksandr Y.; Areda, Demelash; Arifin, Hidayat; Arkew, Mesay; Armocida, Benedetta; Arnlov, Johan; Artamonov, Anton A.; Arulappan, Judie; Aruleba, Raphael Taiwo; Arumugam, Ashokan; Aryan, Zahra; Asemu, Mulu Tiruneh; Asghari-Jafarabadi, Mohammad; Askari, Elaheh; Asmelash, Daniel; Astell-Burt, Thomas; Athar, Mohammad; Athari, Seyyed Shamsadin; Atout, Maha Moh'd Wahbi; Avila-Burgos, Leticia; Awaisu, Ahmed; Azadnajafabad, Sina; Darshan, B.B.; Babamohamadi, Hassan; Badar, Muhammad; Badawi, Alaa; Badiye, Ashish D.; Baghcheghi, Nayereh; Bagheri, Nasser; Bagherieh, Sara; Bah, Sulaiman; Bahadory, Saeed; Bai, Ruhai; Baig, Atif Amin; Baltatu, Ovidiu Constantin; Baradaran, Hamid Reza; Barchitta, Martina; Bardhan, Mainak; Barengo, Noel C.; Barnighausen, Till Winfried; Barone, Mark Thomaz Ugliara; Barone-Adesi, Francesco; Barrow, Amadou; Bashiri, Hamideh; Basiru, Afisu; Basu, Sanjay; Basu, Saurav; Batiha, Abdul-Monim Mohammad; Batra, Kavita; Bayih, Mulat Tirfie; Bayileyegn, Nebiyou Simegnew; Behnoush, Amir Hossein; Bekele, Alehegn Bekele; Belete, Melaku Ashagrie; Belgaumi, Uzma Iqbal; Belo, Luis; Bennett, Derrick A.; Bensenor, Isabela M.; Berhe, Kidanemaryam; Berhie, Alemshet Yirga; Bhaskar, Sonu; Bhat, Ajay Nagesh; Bhatti, Jasvinder Singh; Bikbov, Boris; Bilal, Faiq; Bintoro, Bagas Suryo; Bitaraf, Saeid; Bitra, Veera R.; Bjegovic-Mikanovic, Vesna; Bodolica, Virginia; Boloor, Archith; Brauer, Michael; Brazo-Sayavera, Javier; Brenner, Hermann; Butt, Zahid A.; Calina, Daniela; Campos, Luciana Aparecida; Campos-Nonato, Ismael R.; Cao, Yin; Cao, Chao; Car, Josip; Carvalho, Marcia; Castaneda-Orjuela, Carlos A.; Catala-Lopez, Ferran; Cerin, Ester; Chadwick, Joshua; Chandrasekar, Eeshwar K.; Chanie, Gashaw Sisay; Charan, Jaykaran; Chattu, Vijay Kumar; Chauhan, Kirti; Cheema, Huzaifa Ahmad; Abebe, Endeshaw Chekol; Chen, Simiao; Cherbuin, Nicolas; Chichagi, Fatemeh; Chidambaram, Saravana Babu; Cho, William C. S.; Choudhari, Sonali Gajanan; Chowdhury, Rajiv; Chowdhury, Enayet Karim; Chu, Dinh-Toi; Chukwu, Isaac Sunday; Chung, Sheng-Chia; Coberly, Kaleb; Columbus, Alyssa; Contreras, Daniela; Cousin, Ewerton; Criqui, Michael H.; Cruz-Martins, Natalia; Cuschieri, Sarah; Dabo, Bashir; Dadras, Omid; Dai, Xiaochen; Damasceno, Albertino Antonio Moura; Dandona, Rakhi; Dandona, Lalit; Das, Saswati; Dascalu, Ana Maria; Dash, Nihar Ranjan; Dashti, Mohsen; Davila-Cervantes, Claudio Alberto; De la Cruz-Gongora, Vanessa; Debele, Gebiso Roba; Delpasand, Kourosh; Demisse, Fitsum Wolde; Demissie, Getu Debalkie; Deng, Xinlei; Denova-Gutierrez, Edgar; Deo, Salil V.; Dervi�evi?, Emina; Desai, Hardik Dineshbhai; Desale, Aragaw Tesfaw; Dessie, Anteneh Mengist; Desta, Fikreab; Dewan, Syed Masudur Rahman; Dey, Sourav; Dhama, Kuldeep; Dhimal, Meghnath; Diao, Nancy; Diaz, Daniel; Dinu, Monica; Diress, Mengistie; Djalalinia, Shirin; Doan, Linh Phuong; Dongarwar, Deepa; dos Santos Figueiredo, Francisco Winter; Duncan, Bruce B.; Dutta, Siddhartha; Dziedzic, Arkadiusz Marian; Edinur, Hisham Atan; Ekholuenetale, Michael; Ekundayo, Temitope Cyrus; Elgendy, Islam Y.; Elhadi, Muhammed; El-Huneidi, Waseem; Elmeligy, Omar Abdelsadek Abdou; Elmonem, Mohamed A.; Endeshaw, Destaw; Esayas, Hawi Leul; Eshetu, Habitu Birhan; Etaee, Farshid; Fadhil, Ibtihal; Fagbamigbe, Adeniyi Francis; Fahim, Ayesha; Falahi, Shahab; Faris, MoezAlIslam Ezzat Mahmoud; Farrokhpour, Hossein; Farzadfar, Farshad; Fatehizadeh, Ali; Fazli, Ghazal; Feng, Xiaoqi; Ferede, Tomas Y.; Fischer, Florian; Flood, David; Forouhari, Ali; Foroumadi, Roham; Koudehi, Masoumeh Foroutan; Gaidhane, Abhay Motiramji; Gaihre, Santosh; Gaipov, Abduzhappar; Galali, Yaseen; Ganesan, Balasankar; Garcia-Gordillo, M.A.; Gautam, Rupesh K.; Gebrehiwot, Mesfin; Gebrekidan, Kahsu Gebrekirstos; Gebremeskel, Teferi Gebru; Getacher, Lemma; Ghadirian, Fataneh; Ghamari, Seyyed-Hadi; Nour, Mohammad Ghasemi; Ghassemi, Fariba; Golechha, Mahaveer; Goleij, Pouya; Golinelli, Davide; Gopalani, Sameer Vali; Guadie, Habtamu Alganeh; Guan, Shi-Yang; Gudayu, Temesgen Worku; Guimaraes, Rafael Alves; Guled, Rashid Abdi; Gupta, Rajeev; Gupta, Kartik; Gupta, Veer Bala; Gupta, Vivek Kumar; Gyawali, Bishal; Haddadi, Rasool; Hadi, Najah R.; Haile, Teklehaimanot Gereziher; Hajibeygi, Ramtin; Haj-Mirzaian, Arvin; Halwani, Rabih; Hamidi, Samer; Hankey, Graeme J.; Hannan, Md Abdul; Haque, Shafiul; Harandi, Hamid; Harlianto, Netanja I.; Mahmudul Hasan, S.M.; Hasan, Syed Shahzad; Hasani, Hamidreza; Hassanipour, Soheil; Hassen, Mohammed Bheser; Haubold, Johannes; Hayat, Khezar; Heidari, Golnaz; Heidari, Mohammad; Hessami, Kamran; Hiraike, Yuta; Holla, Ramesh; Hossain, Sahadat; Hossain, Md Shakhaoat; Hosseini, Mohammad-Salar; Hosseinzadeh, Mehdi; Hosseinzadeh, Hassan; Huang, Junjie; Huda, Md Nazmul; Hussain, Salman; Huynh, Hong-Han; Hwang, Bing-Fang; Ibitoye, Segun Emmanuel; Ikeda, Nayu; Ilic, Irena M.; Ilic, Milena D.; Inbaraj, Leeberk Raja; Iqbal, Afrin; Islam, Sheikh Mohammed Shariful; Islam, Rakibul M.; Ismail, Nahlah Elkudssiah; Iso, Hiroyasu; Isola, Gaetano; Itumalla, Ramaiah; Iwagami, Masao; Iwu, Chidozie C. D.; Iyamu, Ihoghosa Osamuyi; Iyasu, Assefa N.; Jacob, Louis; Jafarzadeh, Abdollah; Jahrami, Haitham; Jain, Rajesh; Jaja, Chinwe; Jamalpoor, Zahra; Jamshidi, Elham; Janakiraman, Balamurugan; Jayanna, Krishnamurthy; Jayapal, Sathish Kumar; Jayaram, Shubha; Jayawardena, Ranil; Jebai, Rime; Jeong, Wonjeong; Jin, Yinzi; Jokar, Mohammad; Jonas, Jost B.; Joseph, Nitin; Joseph, Abel; Joshua, Charity Ehimwenma; Joukar, Farahnaz; Jozwiak, Jacek Jerzy; Kaambwa, Billingsley; Kabir, Ali; Kabthymer, Robel Hussen; Kadashetti, Vidya; Kahe, Farima; Kalhor, Rohollah; Kandel, Himal; Karanth, Shama D.; Karaye, Ibraheem M.; Karkhah, Samad; Katoto, Patrick D. M. C.; Kaur, Navjot; Kazemian, Sina; Kebede, Sewnet Adem; Khader, Yousef Saleh; Khajuria, Himanshu; Khalaji, Amirmohammad; Khan, Moien A. B.; Khan, Maseer; Khan, Ajmal; Khanal, Saval; Khatatbeh, Moawiah Mohammad; Khater, Amir M.; Khateri, Sorour; Khorashadizadeh, Fatemeh; Khubchandani, Jagdish; Kibret, Biruk Getahun; Kim, Min Seo; Kimokoti, Ruth W.; Kisa, Adnan; Kivimaki, Mika; Kolahi, Ali-Asghar; Komaki, Somayeh; Kompani, Farzad; Koohestani, Hamid Reza; Korzh, Oleksii; Kostev, Karel; Kothari, Nikhil; Koyanagi, Ai; Krishan, Kewal; Krishnamoorthy, Yuvaraj; Defo, Barthelemy Kuate; Kuddus, Mohammed; Kuddus, Md Abdul; Kumar, Rakesh; Kumar, Harish; Kundu, Satyajit; Kurniasari, Maria Dyah; Kuttikkattu, Ambily; Vecchia, Carlo La; Lallukka, Tea; Larijani, Bagher; Larsson, Anders O.; Latief, Kamaluddin; Lawal, Basira Kankia; Le, Thao Thi Thu; Le, Trang Thi Bich; Lee, Shaun Wen Huey; Lee, Munjae; Lee, Wei-Chen; Lee, Paul H.; Lee, Sang-Woong; Lee, Seung Won; Legesse, Samson Mideksa; Lenzi, Jacopo; Li, Yongze; Li, Ming-Chieh; Lim, Stephen S.; Lim, Lee-Ling; Liu, Xuefeng; Liu, Chaojie; Lo, Chun-Han; Lopes, Graciliana; Lorkowski, Stefan; Lozano, Rafael; Lucchetti, Giancarlo; Maghazachi, Azzam A.; Mahasha, Phetole Walter; Mahjoub, Soleiman; Mahmoud, Mansour Adam; Mahmoudi, Razzagh; Mahmoudimanesh, Marzieh; Mai, Anh Tuan; Majeed, Azeem; Sanaye, Pantea Majma; Makris, Konstantinos Christos; Malhotra, Kashish; Malik, Ahmad Azam; Malik, Iram; Mallhi, Tauqeer Hussain; Malta, Deborah Carvalho; Mamun, Abdullah A.; Mansouri, Borhan; Marateb, Hamid Reza; Mardi, Parham; Martini, Santi; Martorell, Miquel; Marzo, Roy Rillera; Masoudi, Reza; Masoudi, Sahar; Mathews, Elezebeth; Maugeri, Andrea; Mazzaglia, Giampiero; Mekonnen, Teferi; Meshkat, Mahboobeh; Mestrovic, Tomislav; Jonasson, Junmei Miao; Miazgowski, Tomasz; Michalek, Irmina Maria; Minh, Le Huu Nhat; Mini, G.K.; Miranda, J. Jaime; Mirfakhraie, Reza; Mirrakhimov, Erkin M.; Mirza-Aghazadeh-Attari, Mohammad; Misganaw, Awoke; Misgina, Kebede Haile; Mishra, Manish; Moazen, Babak; Mohamed, Nouh Saad; Mohammadi, Esmaeil; Mohammadi, Mohsen; Mohammadian-Hafshejani, Abdollah; Mohammadshahi, Marita; Mohseni, Alireza; Mojiri-Forushani, Hoda; Mokdad, Ali H.; Momtazmanesh, Sara; Monasta, Lorenzo; Moniruzzaman, Md; Mons, Ute; Montazeri, Fateme; Ghalibaf, AmirAli Moodi; Moradi, Yousef; Moradi, Maryam; Sarabi, Mostafa Moradi; Morovatdar, Negar; Morrison, Shane Douglas; Morze, Jakub; Mossialos, Elias; Mostafavi, Ebrahim; Mueller, Ulrich Otto; Mulita, Francesk; Mulita, Admir; Murillo-Zamora, Efren; Musa, Kamarul Imran; Mwita, Julius C.; Nagaraju, Shankar Prasad; Naghavi, Mohsen; Nainu, Firzan; Nair, Tapas Sadasivan; Najmuldeen, Hastyar Hama Rashid; Nangia, Vinay; Nargus, Shumaila; Naser, Abdallah Y.; Nassereldine, Hasan; Natto, Zuhair S.; Nauman, Javaid; Nayak, Biswa Prakash; Ndejjo, Rawlance; Negash, Hadush; Negoi, Ruxandra Irina; Nguyen, Hau Thi Hien; Nguyen, Dang H.; Nguyen, Phat Tuan; Nguyen, Van Thanh; Nguyen, Hien Quang; Niazi, Robina Khan; Nigatu, Yeshambel T.; Ningrum, Dina Nur Anggraini; Nizam, Muhammad A.; Nnyanzi, Lawrence Achilles; Noreen, Mamoona; Noubiap, Jean Jacques; Nzoputam, Ogochukwu Janet; Nzoputam, Chimezie Igwegbe; Oancea, Bogdan; Odogwu, Nkechi Martina; Odukoya, Oluwakemi Ololade; Ojha, Vivek Anand; Okati-Aliabad, Hassan; Okekunle, Akinkunmi Paul; Okonji, Osaretin Christabel; Okwute, Patrick Godwin; Olufadewa, Isaac Iyinoluwa; Onwujekwe, Obinna E.; Ordak, Michal; Ortiz, Alberto; Osuagwu, Uchechukwu Levi; Oulhaj, Abderrahim; Owolabi, Mayowa O.; Padron-Monedero, Alicia; Padubidri, Jagadish Rao; Palladino, Raffaele; Panagiotakos, Demosthenes; Panda-Jonas, Songhomitra; Pandey, Ashok; Pandey, Anamika; Pandi-Perumal, Seithikurippu R.; Stoian, Anca Mihaela Pantea; Pardhan, Shahina; Parekh, Tarang; Parekh, Utsav; Pasovic, Maja; Patel, Jay; Patel, Jenil R.; Paudel, Uttam; Pepito, Veincent Christian Filipino; Pereira, Marcos; Perico, Norberto; Perna, Simone; Petcu, Ionela-Roxana; Petermann-Rocha, Fanny Emily; Podder, Vivek; Postma, Maarten J.; Pourali, Ghazaleh; Pourtaheri, Naeimeh; Prates, Elton Junio Sady; Qadir, Mirza Muhammad Fahd; Qattea, Ibrahim; Raee, Pourya; Rafique, Ibrar; Rahimi, Mehran; Rahimifard, Mahban; Rahimi-Movaghar, Vafa; Rahman, Md Obaidur; Rahman, Muhammad Aziz; Rahman, Mohammad Hifz Ur; Rahman, Mosiur; Rahman, Md Mosfequr; Rahmani, Mohamed; Rahmani, Shayan; Rahmanian, Vahid; Rahmawaty, Setyaningrum; Rahnavard, Niloufar; Rajbhandari, Bibek; Ram, Pradhum; Ramazanu, Sheena; Rana, Juwel; Rancic, Nemanja; Ranjha, Muhammad Modassar Ali Nawaz; Rao, Chythra R.; Rapaka, Deepthi; Rasali, Drona Prakash; Rashedi, Sina; Rashedi, Vahid; Rashid, Ahmed Mustafa; Rashidi, Mohammad-Mahdi; Ratan, Zubair Ahmed; Rawaf, Salman; Rawal, Lal; Redwan, Elrashdy Moustafa Mohamed; Remuzzi, Giuseppe; Rengasamy, Kannan R. R.; Renzaho, Andre M. N.; Reyes, Luis Felipe; Rezaei, Nima; Rezaei, Nazila; Rezaeian, Mohsen; Rezazadeh, Hossein; Riahi, Seyed Mohammad; Rias, Yohanes Andy; Riaz, Muhammad; Ribeiro, Daniela; Rodrigues, Monica; Rodriguez, Jefferson Antonio Buendia; Roever, Leonardo; Rohloff, Peter; Roshandel, Gholamreza; Roustazadeh, Abazar; Rwegerera, Godfrey M.; Saad, Aly M. A.; Saber-Ayad, Maha Mohamed; Sabour, Siamak; Sabzmakan, Leila; Saddik, Basema; Sadeghi, Erfan; Saeed, Umar; Moghaddam, Sahar Saeedi; Safi, Sare; Safi, Sher Zaman; Saghazadeh, Amene; Sharif-Askari, Narjes Saheb; Sharif-Askari, Fatemeh Saheb; Sahebkar, Amirhossein; Sahoo, Soumya Swaroop; Sahoo, Harihar; Saif-Ur-Rahman, K.M.; Sajid, Mirza Rizwan; Salahi, Sarvenaz; Salahi, Saina; Saleh, Mohamed A.; Salehi, Mohammad Amin; Salomon, Joshua A.; Sanabria, Juan; Sanjeev, Rama Krishna; Sanmarchi, Francesco; Santric-Milicevic, Milena M.; Sarasmita, Made Ary; Sargazi, Saman; Sathian, Brijesh; Sathish, Thirunavukkarasu; Sawhney, Monika; Schlaich, Markus P.; Schmidt, Maria Ines; Schuermans, Art; Seidu, Abdul-Aziz; Kumar, Nachimuthu Senthil; Sepanlou, Sadaf G.; Sethi, Yashendra; Seylani, Allen; Shabany, Maryam; Shafaghat, Tahereh; Shafeghat, Melika; Shafie, Mahan; Shah, Nilay S.; Shahid, Samiah; Shaikh, Masood Ali; Shanawaz, Mohd; Shannawaz, Mohammed; Sharfaei, Sadaf; Shashamo, Bereket Beyene; Shiri, Rahman; Shittu, Aminu; Shivakumar, K.M.; Shivalli, Siddharudha; Shobeiri, Parnian; Shokri, Fereshteh; Shuval, Kerem; Sibhat, Migbar Mekonnen; Silva, Luis Manuel Lopes Rodrigues; Simpson, Colin R.; Singh, Jasvinder A.; Singh, Paramdeep; Singh, Surjit; Siraj, Md Shahjahan; Skryabina, Anna Aleksandrovna; Sohag, Abdullah Al Mamun; Soleimani, Hamidreza; Solikhah, Solikhah; Soltani-Zangbar, Mohammad Sadegh; Somayaji, Ranjani; Sorensen, Reed J. D.; Starodubova, Antonina V.; Sujata, Sujata; Suleman, Muhammad; Sun, Jing; Sundstr�m, Johan; Tabar�s-Seisdedos, Rafael; Tabatabaei, Seyyed Mohammad; Tabatabaeizadeh, Seyed-Amir; Tabish, Mohammad; Taheri, Majid; Taheri, Ensiyeh; Taki, Elahe; Tamuzi, Jacques J. L. Lukenze; Tan, Ker-Kan; Tat, Nathan Y.; Taye, Birhan Tsegaw; Temesgen, Worku Animaw; Temsah, Mohamad-Hani; Tesler, Riki; Thangaraju, Pugazhenthan; Thankappan, Kavumpurathu Raman; Thapa, Rajshree; Tharwat, Samar; Thomas, Nihal; Ticoalu, Jansje Henny Vera; Tiyuri, Amir; Tonelli, Marcello; Tovani-Palone, Marcos Roberto; Trico, Domenico; Trihandini, Indang; Tripathy, Jaya Prasad; Tromans, Samuel Joseph; Tsegay, Guesh Mebrahtom; Tualeka, Abdul Rohim; Tufa, Derara Girma; Tyrovolas, Stefanos; Ullah, Sana; Upadhyay, Era; Vahabi, Seyed Mohammad; Vaithinathan, Asokan Govindaraj; Valizadeh, Rohollah; van Daalen, Kim Robin; Vart, Priya; Varthya, Shoban Babu; Vasankari, Tommi Juhani; Vaziri, Siavash; Verma, Madhur Verma; Verras, Georgios-Ioannis; Vo, Danh Cao; Wagaye, Birhanu; Waheed, Yasir; Wang, Ziyue; Wang, Yanqing; Wang, Cong; Wang, Fang; Wassie, Gizachew Tadesse; Wei, Melissa Y. Wei; Weldemariam, Abrha Hailay; Westerman, Ronny; Wickramasinghe, Nuwan Darshana; Wu, YiFan; Wulandari, Ratna D. W. I.; Xia, Juan; Xiao, Hong; Xu, Suowen; Xu, Xiaoyue; Yada, Dereje Y.; Yang, Lin; Yatsuya, Hiroshi; Yesiltepe, Metin; Yi, Siyan; Yohannis, Hunachew Kibret; Yonemoto, Naohiro; You, Yuyi; Zaman, Sojib Bin; Zamora, Nelson; Zare, Iman; Zarea, Kourosh; Zarrintan, Armin; Zastrozhin, Mikhail Sergeevich; Zeru, Naod Gebrekrstos; Zhang, Zhi-Jiang; Zhong, Chenwen; Zhou, Jingjing; Zieli?ska, Magdalena; Zikarg, Yossef Teshome; Zodpey, Sanjay; Zoladl, Mohammad; Zou, Zhiyong; Zumla, Alimuddin; Zuniga, Yves Miel H.; Magliano, Dianna J.; Murray, Christopher J. L.; Hay, Simon I.; Vos, Theo
Background: Diabetes is one of the leading causes of death and disability worldwide, and affects people regardless of country, age group, or sex. Using the most recent evidentiary and analytical framework from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD), we produced location-specific, age-specific, and sex-specific estimates of diabetes prevalence and burden from 1990 to 2021, the proportion of type 1 and type 2 diabetes in 2021, the proportion of the type 2 diabetes burden attributable to selected risk factors, and projections of diabetes prevalence through 2050. Methods: Estimates of diabetes prevalence and burden were computed in 204 countries and territories, across 25 age groups, for males and females separately and combined; these estimates comprised lost years of healthy life, measured in disability-adjusted life-years (DALYs; defined as the sum of years of life lost [YLLs] and years lived with disability [YLDs]). We used the Cause of Death Ensemble model (CODEm) approach to estimate deaths due to diabetes, incorporating 25 666 location-years of data from vital registration and verbal autopsy reports in separate total (including both type 1 and type 2 diabetes) and type-specific models. Other forms of diabetes, including gestational and monogenic diabetes, were not explicitly modelled. Total and type 1 diabetes prevalence was estimated by use of a Bayesian meta-regression modelling tool, DisMod-MR 2.1, to analyse 1527 location-years of data from the scientific literature, survey microdata, and insurance claims; type 2 diabetes estimates were computed by subtracting type 1 diabetes from total estimates. Mortality and prevalence estimates, along with standard life expectancy and disability weights, were used to calculate YLLs, YLDs, and DALYs. When appropriate, we extrapolated estimates to a hypothetical population with a standardised age structure to allow comparison in populations with different age structures. We used the comparative risk assessment framework to estimate the risk-attributable type 2 diabetes burden for 16 risk factors falling under risk categories including environmental and occupational factors, tobacco use, high alcohol use, high body-mass index (BMI), dietary factors, and low physical activity. Using a regression framework, we forecast type 1 and type 2 diabetes prevalence through 2050 with Socio-demographic Index (SDI) and high BMI as predictors, respectively. Findings: In 2021, there were 529 million (95% uncertainty interval [UI] 500�564) people living with diabetes worldwide, and the global age-standardised total diabetes prevalence was 6�1% (5�8�6�5). At the super-region level, the highest age-standardised rates were observed in north Africa and the Middle East (9�3% [8�7�9�9]) and, at the regional level, in Oceania (12�3% [11�5�13�0]). Nationally, Qatar had the world's highest age-specific prevalence of diabetes, at 76�1% (73�1�79�5) in individuals aged 75�79 years. Total diabetes prevalence�especially among older adults�primarily reflects type 2 diabetes, which in 2021 accounted for 96�0% (95�1�96�8) of diabetes cases and 95�4% (94�9�95�9) of diabetes DALYs worldwide. In 2021, 52�2% (25�5�71�8) of global type 2 diabetes DALYs were attributable to high BMI. The contribution of high BMI to type 2 diabetes DALYs rose by 24�3% (18�5�30�4) worldwide between 1990 and 2021. By 2050, more than 1�31 billion (1�22�1�39) people are projected to have diabetes, with expected age-standardised total diabetes prevalence rates greater than 10% in two super-regions: 16�8% (16�1�17�6) in north Africa and the Middle East and 11�3% (10�8�11�9) in Latin America and Caribbean. By 2050, 89 (43�6%) of 204 countries and territories will have an age-standardised rate greater than 10%. Interpretation: Diabetes remains a substantial public health issue. Type 2 diabetes, which makes up the bulk of diabetes cases, is largely preventable and, in some cases, potentially reversible if identified and managed early in the disease course. However, all evidence indicates that diabetes prevalence is increasing worldwide, primarily due to a rise in obesity caused by multiple factors. Preventing and controlling type 2 diabetes remains an ongoing challenge. It is essential to better understand disparities in risk factor profiles and diabetes burden across populations, to inform strategies to successfully control diabetes risk factors within the context of multiple and complex drivers. Funding: Bill & Melinda Gates Foundation. � 2023 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license
Green Synthesis of Imidazopyridines
(Central University of Punjab, 2018) Mehar, Nikhil Das; Kumar, Rakesh
A green synthesis of imidazopyridineusing environmentally friendly ionic liquids have been explored. The role of imidazolium based ionic liquids was evaluated. It was found that alkyl side chain of ionic liquid play an important role for product formation. The best optimized condition includes the use of ionic liquid [hmim]Br. Even the reaction was found to proceed under water. This is of significant importanceas solvent waste and their disposal is one of the major challenges faced by chemical industries.
Heck−Suzuki Tandem Reaction for the Synthesis of 3‑Benzazepines
(ACS Publications, 2015) Peshkov, Anatoly A.; Peshkov, Vsevolod A.; Pereshivko, Olga P.; Hecke, Kristof Van; Kumar, Rakesh; Eycken, Erik V. Van der
A novel procedure for the Heck−Suzuki tandem reaction suitable for the construction of nitrogen-containing medium rings was developed to provide access toward the 3-benzazepine framework.
Mechanisms of tubulin binding ligands to target cancer cells: Updates on their therapeutic potential and clinical trials
(Bentham Science Publishers B.V., 2017) Kumar, Bhupinder; Kumar, Rakesh; Skvortsova, Ira; Kumar, Vinod
Background: A number of chemically diverse substances bind to the tubulin and inhibit cell proliferation by disrupting microtubule dynamics. There are four binding sites for the ligands binding to the tubulin; taxane/epothilone and laulimalide/peloruside binding ligands stabilize microtubule while vinca and colchicine binding site agents promote microtubule depolymerization. Most of the tubulin binding ligands disturb the tubulin-microtubule dynamic equilibrium but these may exhibit anticancer activities through different mechanisms. Taxanes and epothilones are widely used cytotoxic agents and are found effective against different types of human malignancies. However, taxanes are susceptible to pgp mediated multi-drug resistance, dose limiting hematopoietic toxicity and cumulative neurotoxicity. Vinca alkaloids are already in clinical practice, but ligands binding to the colchicine site are still in the different stages of clinical trials. Objective: In the current review article, plausible mechanistic details about the interactions of ligands at the binding pocket and subsequent changes in the tubulin structure are described. The review article also illustrated different formulations of the tubulin binding agents in combination with other chemotherapeutic agents and their therapeutic potential against various human malignancies. Conclusion: Tubulin targeting agents emerged as one of the most successful anticancer drugs and a number of structurally different chemical compounds are in advance stages of clinical development. ? 2017 Bentham Science Publishers.
Multi-Target-Directed Ligands as an Effective Strategy for the Treatment of Alzheimer�s Disease
(Bentham Science Publishers, 2021-05-12T00:00:00) Kumar, Bhupinder; Thakur, Amandeep; Dwivedi, Ashish Ranjan; Kumar, Rakesh; Kumar, Vinod
Alzheimer�s disease (AD) is a complex neurological disorder and multiple pathological factors are believed to be involved in the genesis and progression of the disease. A number of hypothesis including Acetylcholinesterase, Monoamine oxidase, ?Amyloid, Tau protein etc. have been proposed for the initiation and progression of the disease. At present, acetylcholine esterase inhibitors and memantine (NMDAR antagonist) are the only approved therapy for the symptomatic management of AD. Most of these single-target drugs have miserably failed in the treatment or halting the progression of the disease. Multi-factorial diseases like AD require complex treatment strategies that involve simultaneous modulation of a network of interacting targets. Since last few years, Multi-Target-Directed Ligands (MTDLs) strategy, drugs that can simultaneously hit multiple targets, is being explored as an effective therapeutic approach for the treatment of AD. In the current review article, the authors have briefly described various pathogenic pathways associated with the AD. Importance of Multi-Target-Directed Ligands and their design strategies in recently reported articles have been discussed in detail. Potent leads identified through various structure-activity relationship studies and their drug like characteristics are described. Recently developed promising compounds have been summarized in the article. Some of these MTDLs with balanced activity profile against different targets have the potential to be developed as drug candidates for the treatment of AD. � 2022 Bentham Science Publishers.
Recent advances for construction and late-stage diversification of indole core via C-H bond activation/functionalization
(Elsevier, 2021-02-26T00:00:00) Sinha, Arun Kumar; Kumar, Rakesh
Indole is an important structural motif of various drugs, therapeutic leads besides its prevalence in numerous natural products, agrochemicals, perfumery, and dyes. More than 200 indole derivatives have already been marketed as drugs or are under advanced stages of clinical trials. Owing to such a huge potential, continuous efforts are being put forward to construct or diversify this scaffold. This chapter provides an overview of various recently developed methodologies for the construction of indole core via C-H bond activation/functionalization. In particular, Pd- and Ru-mediated cyclization strategies involving Csp2-H functionalization of monofunctionalized arene substrates with the unsaturated bond of alkene and alkyne are highlighted herein. Also, late-stage diversification of indole system (C4-C7 position) via direct C-H activation is covered. Furthermore, the mechanistic aspects of some of these reactions are discussed as well. � 2021 Elsevier Inc. All rights reserved.
Recent advances in biochar amendments for immobilization of heavy metals in an agricultural ecosystem: A systematic review
(Elsevier Ltd, 2023-01-03T00:00:00) Sachdeva, Saloni; Kumar, Rakesh; Sahoo, Prafulla Kumar; Nadda, Ashok Kumar
Over the last several decades, extensive and inefficient use of contemporary technologies has resulted in substantial environmental pollution, predominantly caused by potentially hazardous elements (PTEs), like heavy metals that severely harm living species. To combat the presence of heavy metals (HMs) in the agrarian system, biochar becomes an attractive approach for stabilizing and limiting availability of HMs in soils due to its high surface area, porosity, pH, aromatic structure as well as several functional groups, which mostly rely on the feedstock and pyrolysis temperature. Additionally, agricultural waste-derived biochar is an effective management option to ensure carbon neutrality and circular economy while also addressing social and environmental concerns. Given these diverse parameters, the present systematic evaluation seeks to (i) ascertain the effectiveness of heavy metal immobilization by agro waste-derived biochar; (ii) examine the presence of biochar on soil physico-chemical, and thermal properties, along with microbial diversity; (iii) explore the underlying mechanisms responsible for the reduction in heavy metal concentration; and (iv) possibility of biochar implications to advance circular economy approach. The collection of more than 200 papers catalogues the immobilization efficiency of biochar in agricultural soil and its impacts on soil from multi-angle perspectives. The data gathered suggests that pristine biochar effectively reduced cationic heavy metals (Pb, Cd, Cu, Ni) and Cr mobilization and uptake by plants, whereas modified biochar effectively reduced As in soil and plant systems. However, the exact mechanism underlying is a complex biochar-soil interaction. In addition to successfully immobilizing heavy metals in the soil, the application of biochar improved soil fertility and increased agricultural productivity. However, the lack of knowledge on unfavorable impacts on the agricultural systems, along with discrepancies between the use of biochar and experimental conditions, impeded a thorough understanding on a deeper level. � 2023 Elsevier Ltd
Recent synthetic strategies for monocyclic azole nucleus and its role in drug discovery and development
(Bentham Science Publishers B.V., 2018) Neha; Dwivedi, Ashish Ranjan; Kumar, Rakesh; Kumar, Vinod
Background: In recent years, the development and diversification of heterocyclic compounds has become central to the discovery of bioactive compounds with novel or improved pharmacological properties. In particular, N-containing heterocycles are proved to be promising leads and drug candidates, and received huge attention of the medicinal chemists. Objective: Many drugs especially antibiotics are becoming obsolete due to the development of multidrug resistance. Moreover, toxicity and other side effects of some drugs necessitated the quest for safer and more potent drug candidates. The current review article described biological potential of various monocyclic azoles. Recent developments in the synthesis of azole derivatives have been also reviewed. Conclusion: The presence of N-heterocyclic rings can influence the pharmacokinetics, pharmacodynamics, pKa and bioavailability profile of the drug molecules. Compounds containing monocyclic azole rings showed various biological activities and number of molecules are in clinical practice. A number of important leads and potential drug candidates containing azole nucleus are in advance stages of drug developments. Thus, simple, atom economic and more efficient synthetic strategies are desired for the synthesis of new libraries of the compounds. ? 2018 Bentham Science Publishers.
A Review on the Arylpiperazine Derivatives as Potential Therapeutics for the Treatment of Various Neurological Disorders
(Bentham Science Publishers, 2022-01-18T00:00:00) Kumar, Bhupinder; Kumar, Naveen; Thakur, Amandeep; Kumar, Vijay; Kumar, Rakesh; Kumar, Vinod
Neurological disorders are disease conditions related to the neurons and central nervous system (CNS). Any structural, electrical, biochemical, and functional abnormalities in neurons can lead to various types of disorders, like Alzheimer�s disease (AD), depression, Parkinson�s disease (PD), epilepsy, stroke, etc. Currently available medicines are symptomatic and do not treat the disease state. Thus, novel CNS active agents with the potential to completely treat an illness are highly desired. A range of small organic molecules is being explored as potential drug candidates to cure different neurological disorders. In this context, arylpiperazinehas been found to be a versatile scaffold and indispensable pharmacophore in many CNS active agents. Several molecules with arylpiperazine nucleus have been developed as potent leads for the treatment of AD, PD, depression, and other disorders. The arylpiperazine nucleus can be optionally substituted at different chemical structures and offer flexibility for the synthesis of a large number of derivatives. In the current review article, we have explored the role of various arylpiperazine containing scaffolds against different neurological disorders, including AD, PD, and depression. The structure-activity relationship studies were conducted for recognizing potent lead compounds. This review article may provide important insights into the structural requirements for designing and synthesizing effective molecules as curative agents for different neurological disorders. � 2022 Bentham Science Publishers.
Rice husk biochar - A novel engineered bio-based material for transforming groundwater-mediated fluoride cycling in natural environments
(Academic Press, 2023-05-24T00:00:00) Kumar, Rakesh; Sharma, Prabhakar; Sharma, Pushpa Kumari; Rose, Pawan Kumar; Singh, Rakesh Kumar; Kumar, Nishant; Sahoo, Prafulla Kumar; Maity, Jyoti Prakash; Ghosh, Ashok; Kumar, Manish; Bhattacharya, Prosun; Pandey, Ashok
Biochar, a promising carbon-rich and carbon-negative material, can control water pollution, harness the synergy of sustainable development goals, and achieve circular economy. This study examined the performance feasibility of treating fluoride-contaminated surface and groundwater using raw and modified biochar synthesized from agricultural waste rice husk as problem-fixing renewable carbon-neutral material. Physicochemical characterizations of raw/modified biochars were investigated using FESEM-EDAX, FTIR, XRD, BET, CHSN, VSM, pHpzc, Zeta potential, and particle size analysis were analyzed to identify the surface morphology, functional groups, structural, and electrokinetic behavior. In fluoride (F?) cycling, performance feasibility was tested at various governing factors, contact time (0�120 min), initial F? levels (10�50 mg L?1), biochar dose (0.1�0.5 g L?1), pH (2�9), salt strengths (0�50 mM), temperatures (301�328 K), and various co-occurring ions. Results revealed that activated magnetic biochar (AMB) possessed higher adsorption capacity than raw biochar (RB) and activated biochar (AB) at pH 7. The results indicated that maximum F? removal (98.13%) was achieved using AMB at pH 7 for 10 mg L?1. Electrostatic attraction, ion exchange, pore fillings, and surface complexation govern F? removal mechanisms. Pseudo-second-order and Freundlich were the best fit kinetic and isotherm for F? sorption, respectively. Increased biochar dose drives an increase in active sites due to F? level gradient and mass transfer between biochar-fluoride interactions, which reported maximum mass transfer for AMB than RB and AB. Fluoride adsorption using AMB could be described through chemisorption processes at room temperature (301 K), though endothermic sorption follows the physisorption process. Fluoride removal efficiency reduced, from 67.70% to 53.23%, with increased salt concentrations from 0 to 50 mM NaCl solutions, respectively, due to increased hydrodynamic diameter. Biochar was used to treat natural fluoride-contaminated surface and groundwater in real-world problem-solving measures, showed removal efficiency of 91.20% and 95.61%, respectively, for 10 mg L?1 F? contamination, and has been performed multiple times after systematic adsorption-desorption experiments. Lastly, techno-economic analysis was analyzed for biochar synthesis and F? treatment performance costs. Overall, our results revealed worth output and concluded with recommendations for future research on F? adsorption using biochar. � 2023 Elsevier Ltd
Structural, kinetic and thermodynamic characterizations of SDS-induced molten globule state of a highly negatively charged cytochrome c
(Oxford University Press, 2019) Jain, R; Sharma, D; Kumar, Rakesh; Kumar, Rajesh
This study presents the structural, kinetic and thermodynamic characterizations of previously unknown submicellar concentrations of SDS-induced molten globule (MGSDS) state of a highly negatively charged basedenatured ferricytochrome c (U B -state) at pH ∼12.8 (±0.2). The far-UV CD, near-UV CD, ANS-fluorescence data of UB-state in the presence of different concentrations of SDS indicate that the submicellar concentrations of SDS (≤0.4mM) transform the UBstate to MG SDS -state. The MG SDS -state has nativelike α-helical secondary structure but lacks tertiary structure. The free energy change (ΔG° D) for U B → MG SDS transition determined by far-UV CD (∼2.7 kcal mol -1 ) is slightly higher than those determined by fluorescence (∼2.0 kcal mol -1 ) at 25°C. At very low SDS and NaCl concentrations, the MG SDS -state undergoes cold denaturation. As SDS concentration is increased, the thermal denaturation temperature increases and the cold denaturation temperature decrease. Kinetic experiments involving the measurement of the CO-association rate to the base-denatured ferrocytochrome c at pH ≈12.8 (±0.2), 25°C indicate that the submicellar concentrations of SDS restrict the internal dynamics of base-denatured protein. © The Author(s) 2018. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.
Study on Multicomponent Coupling of Aldehyde, Alkyne and Amine
(Central University of Punjab, 2018) Kumar, Rohtash; Kumar, Rakesh
The coupling of aldehyde, an amine and an alkyne (known as A3 -coupling) is a versatile strategy for the synthesis of propargylamine which are important precursors for various biologically active molecules. Various transition metal catalysts of Cu, Ag, Au, Fe, Ni, Zn, Co along with a variety of solvents have been reported for this reaction. However, metal/solvent waste and their disposal is one of the major challenges faced by chemical industries. Moreover, trapping of traces of metal impurity in the final product could be harmful. In this work, we have explored various environmental friendly solvents such as ionic liquids and water for the multicomponent coupling of hydroxybenzaldehyde with amine and alkyne. When there is OH group at ortho position of benzaldehyde, the reaction can be carried out without the presence of metal-catalyst. We found that this reaction can proceed even under solvent-less condition without the need of any metal catalyst. For comparison purpose, the effect of various molecule solvents on the yield of reaction has also been explored.
Synthesis and Evaluation of Antimicrobial Activity of N-Substituted Indole Derivatives and Molecular Docking Studies
(Bentham Science Publishers, 2022-11-18T00:00:00) Dwivedi, Ashish Ranjan; Kumar, Vijay; Neha; Jangid, Kailash; Devi, Bharti; Kulharia, Mahesh; Kumar, Rakesh; Kumar, Vinod
The increasing burden of microbial infection and emerging resistance against the available antimicrobial drugs drives the development of new agents. Two different series of indole-based compounds (VN-1 to VN-18) were synthesized and analyzed for antimicrobial activity by calculating the diameter of the inhibition zone using the broth dilution method and well diffusion method against Escherichia coli (E. coli) and environmental microbes. Most of the compounds displayed good to moderate activity against E. coli, and VN-4 and VN-9 displayed good inhibitory activity against the tested microbes. Molecular docking and binding energy calculation studies of all the synthesized compounds have been performed for targeting FabI, where most of the compounds showed significant interactions with the aromatic nicotin-amide moiety of NAD+. In molecular dynamics studies, VN-9 stays inside the binding cavity for sufficient time to induce antimicrobial activity. Thus, these indole-based derivatives may lead to the development of new antimicrobi-al agents that may act as FabI inhibitors. � 2022 Bentham Science Publishers.