Pharmaceutical Sciences and Natural Products - Master Dissertation
Permanent URI for this collectionhttps://kr.cup.edu.in/handle/32116/53
Browse
3 results
Search Results
Item Phytochemical investigation of natural sweetener from stevia rebaudiana (Bartoni)(Central University of Punjab, 2014) Mayank; Jaitak, VikasS. rebaudiana is an important plant because of the high concentration of steviol glycosides (SGs). Sugars and artificial sweeteners, which are used in general as well as in pharmaceutical field have shown multiple toxic effects. On the other hand SGs have shown sweetness profile many fold compared to sucrose along with many health benefits.The substitution of SGs as sweeteners seems to be a reasonable solution towards the safety issues. The antidiabetic activity of S. rebaudiana extract as well as SGs is well documented in literature. The association of diabetes with cancer is also well known factor. Taking in consideration the above mentioned factors we have investigated the anticancer potential of extracts of S. rebaudiana. Extracts was prepared using petrolieum ether, ethyl acetate, methanol, aqueous methanol and water. Three cell lines (A-549, H-460 and MCF-7) have been used to evaluate the anticancer potential using MTT assay. In case of A-549, MVE-5 showing IC50 value of 10 ?g/ml. Moreover, IC50 values of MVE-2 was also comparatively better and found to be less than 50 ?g/ml and MVE-4 had shown IC50 value of 90 ?g/ml. In case of H- 460 reasonably better IC50 have been observed for MVE-4 and MVE-5 which is 88 ?g/ml and 92 ?g/ml, respectively. In H-460 reasonably better IC50 have been observed for MVE-4 and MVE-5 which is 88 ?g/ml and 92 ?g/ml, respectively. But in case of MCF-7 breast cancer cell line MVE-1 and MVE-2 have shown IC50 value of 90 ?g/ml and 53 ?g/ml, respectively. Thus, various extracts have shown good antiproliferative activity and S. rebaudiana can be further investigated for its anticancer potential. Furthermore docking study on EGFR, v PI3K and mTOR receptor revealed that SGs have good binding affinity towards all the three mentioned receptors and can be suitably modified to explore its anticancer potential. Moreover unfavourable ADME profile can be overcome by structure modification. Thus on the basis of in-vitro and in-silico data we can conclude that S. rebaudiana extracts have promising anticancer potential. Further isolation of compounds have also been done successfully and total seven compounds have been isolated. Two compounds MVR-1 and MVR-5 have been successfully characterized and found to be quercetin and stevioside respectively which are already known compounds. Many reported SGs have shown poorer taste quality. Moreover taste quality of all SGs are different from one another. Thus docking studies were performed on SGs by constructing homology models of T1R2 and T1R3 subunits of human sweet taste receptors to explore the sweetness mechanism. Ramachandran plot, PROCHECK results and ERRAT overall quality factor indicated the acceptable quality of models. The binding pattern indicated that Asn 44, Ans 52, Ala 345, Pro 343, Ile 352, Gly 346, Gly 47, Ala 354, Ser 336, Thr 326 and Ser 329 are the main interacting amino acids residues of T1R2 and Arg 56, Glu105, Asp 215, Asp 216, Glu 148, Asp 258, Lys 255, Ser 104,Glu 217, Leu 51, Arg 52 of T1R3 respectively. Amino acids interact with SGs mainly by forming hydrogen bonds with hydroxyl group of glucose moieties. Maximum binding affinity has been obtained with SGs having total four glucose molecules attached with it and increase or decrease in glucose molecules reduced the binding afinityThere is significant variation in docked poses of all SGs. Taking in consideration the diverse binding patterns of various SGs as well as their structural features, we have proposed the mechanism of sweetness in the form of multiple point stimulation model. The present study will be helpful to know the proper mechanism of sweetness as well as binding patterns of SGs to sweet taste receptor. It will further helpful in understanding the difference in taste quality and will be used in improving the taste of SGs using semisynthetic approaches.Item Anticancer activity of cassia fistula linn through invitro and insilicoapproach(Central University of Punjab, 2014) Sharma, Akanksha; Jaitak, VikasCassia fistula L. (Leguminoseae) is a plant species called "Aragvadha" that means "disease killer". C. fistula consists of plethora of medicinal properties. A detailed discussion is depicted of the therapeutic potential and chemical composition of C. fistula that is responsible for its highly important medicinal properties. C. fistula contains many chemical components like anthraquinones, anthocyanindins, proanthocyanidins, flavanoids, polyphenols, alkaloids, saponins, coumarins, tannins, etc. These constituents are reported to possess various biological properties such as antioxidant, antimicrobial, antidiabetic, antitumor, antimelasmic activities etc. In the current dissertation work we limited our study to cancer; specifically, Lung cancer (LC) and Breast cancer (BC) which are spread all over the world to a threatening level. The present study is an effort to contribute to such a multi-targeting moiety from the plant C. fistula, on the basis of in vitro and simulated analysis. To explore the anticancer activity of C. fistula; in vitro (cytotoxicity studies) on different extracts and in silico studies using MMGBSA (Molecular Mechanics - the Generalized Born model and Solvent Accessibility) on the earlier reported molecules was performed; to study protein - ligand binding interactions on four different targets. The different extracts (Petroleum v ether (SVA-1) (for defatting), Ethyl acetate (SVA-2), Methanol (SVA-3), Hydro- methanolic (SVA-4) Extracts) were prepared in order of their increasing polarity. In- vitro cytotoxicity studies done using MTT (3-(4, 5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide) assay on the extracts of plant and their IC50 values were calculated. It was performed to identify plant's cytotoxic activity. Targets studied via performing in silico protein-ligand binding interactions of majorly mutated yet interlinked pathways of tyrosine kinase and serine/ threonine kinase family; that are namely EGFR, PI3K, Akt and mTOR receptors on which reported molecules of plant were studied. In silico studies were performed using maestro 9.6 Schrodinger software. MMGBSA and ADMET analysis were performed to discover and understand protein - ligand interactions between the chosen ligands of Cassia fistula and selected kinase receptors. On conducting MMGBSA (Molecular Mechanics ' the Generalized Born model and Solvent Accessibility) studies 5,3,4-tri-hydroxy-6-methoxy-7-O-?-L- rhamnopyranosyl-(1?2)-O-?-D-galactopyranoside along with few other moieties illustrated fine binding interactions against standard inhibitors of all the protein targets. From in vitro experiment, it was found that Hydromethanolic extract (SVA-4) showed prominent cytotoxicity against MCF-7, A-549 and H-460 cell lines particularly near 50?g/ml of concentration. Results were found in comparable with the NCI criteria limits for IC50 values of extracts obtained in assay. Also extracts were stable in DMSO solvent even when kept at the ambient temperature for 30 days and gave consistent results against cancer cell lines. As per the results of the in silico studies, the 5,3,4-tri- hydroxy-6-methoxy-7-O-?-L-rhamnopyranosyl-(1?2)-O-?-D-galactopyranoside (dG Bind score -98.7866kcal/mol) for EGFR in comparison to gefitinib (dG Bind score - 86.5585kcal/mol); (dG Bind score -87.3524kcal/mol) for Akt as compared to AZD 5363 (dG Bind score -76.5959); (dG Bind score -87.1051kcal/mol) for PI3K as compared to wortmannin (dG Bind score -79.0654kcal/mol) and for mTOR it has shown the (dG Bind score of -81.964kcal/mol) against sirolimus (dG Bind score -192.354kcal/mol) is reported to have fair pharmacokinetic profile along with attractive binding interactions with EGFR, PI3K, Akt and mTOR receptors.Item Anticancer potential of new n-acetyl pyrazoline derivatives of 1,3 diaryl/hetroaryl propenoes: Synethesis and evaluation(Central University of Punjab, 2013) Alex, Jimi Martin; Kumar, RajPyrazoles, categorized as nitrogen-containing heterocycles, are well known for their interminable participation in the field of perpetual research and development of therapeutical active agents. As a consequence pyrazoles became an inevitable core of numerous drugs having diverse activities. The broad spectrum of activities portrayed by the pyrazoles instigated the researchers to modify the pyrazole ring as 4,5-dihydro-1H-pyrazoles commonly known as 2-pyrazolines. This modification played a determining role in defining the biological activities of several compounds. The presence of aromatic/heterocyclic substituents on the pyrazoline ring only served to accentuate these activities. Literature survey also revealed that substitution such as amide group, acetyl groupetc.at N1 of the pyrazoline also played a decisive role in deciding the biological activity. The vast information obtained from literature survey stimulated us to synthesize compounds having 2-pyrazoline as the core moiety of which either the C3 or C5 was substituted with heterocyclic ring in addition to acetyl moiety at the N1 of the pyrazoline. The compounds were assessed for their anticancer potential against four cancer cell- MCF-7, H-460, T-47 D and A-549. MTT assay was carried out for testing the cell viability. The assay results revealed that certain compounds showed anticancer potential because these agents inhibited the proliferation of breast cancer cell lines but not against lung cancer cell line. Compounds showing good activity against the cancer cell lines were also evaluated for their antioxidant property especially against reactive oxygen species