Dr. S. Sathianarayanan

Abstract Tunable pH and redox responsive polymer was prepared using γ-polyglutamic acid (γ-PGA) with linker 3-mercaptopropionic acid (3-MPA) (γ-PGA_SH) via oxidation to obtain redox responsive disulfide (γ-PGA_SS) backbone and adipic acid dihydrazide (ADH) (γ-PGA_SS_ADH) with hydrazide functional group for pH responsiveness. Further curcumin (Cur) was conjugated through hydrazone bond of the γ-PGA_SS_ADH via Schiff base reaction to obtain (γ-PGA_SS_ADH_Cur). The prepared systems were characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, Electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-Qq-TOF-MS/MS) and Solid state nuclear magnetic resonance (SS NMR) techniques. γ-PGA_SS_ADH_Cur formed self-assembled core shell nanoparticles (NPs) in existence of stabilized aqueous medium. γ-PGA_SS_ADH_Cur NPs maintained its stability in physiological condition. NPs tunable Cur release and cytotoxicity were observed for γ-PGA_SS_ADH_Cur NPs in both acidic and redox conditions mimicking the cancer microenvironment. γ-PGA_SS_ADH_Cur NPs uptake study showed via endocytosis mechanism resulted in the lysosomal entrapment of these NPs within the cell. γ-PGA_SS_ADH_Cur NPs exhibited a dual stimuli responsive drug delivery and can be used as a smart and potential drug delivery system in cancer microenvironment.

Pancreatic cancer is a class of disease characterized by uncontrolled cell growth that begins in the pancreas. Heat shock proteins (Hsps) are chaperone proteins that on inhibition can prove to be effective in pancreatic cancer treatment. In cancer cells, Hsp90 significantly displays a proliferative potential of the malignant cells, so the inhibition of the protein can prove to be valuable to combat pancreatic cancer. Computer Aided Drug Designing (CADD) was instrumental to find out the effective constituent among the 35 plant sources selected. The Phytochemicals used for the present study were Curcumin, Allicin, Pinene, Tetrahydrocannabinol, Astragalin, Arginine, Scopoletin, Baicalin, Stylopine, Carvacrol, Quercetin, Thymol, Guaiaretic acid, Coumarin, Chlorogenic acid, Taraxacin, Ascorbic acid, Protocatechuic acid, Withaferin A, Triptolide, Ursolic acid, Cucurbitane, Thymoquinone, D-Carvone, Eugenol, Ellagic acid, Lapachol, Genistein, Emodin, Chelidonine, Caffeine, Catechin, Geraniol, Myrcene and Niacin. The preliminary studies such as the Primary and Secondary structure analysis of the protein were carried out. Molecular property based on Lipinski rule of 5, bioactivity parameters as well as Protein-Ligand Dynamic interaction were analyzed to determine the drug likeness of the ligands with the protein 4L94. The results of the in silico docking analysis indicate the selection of natural compounds such as Cucurbitane, Myrcene and Pinene as they elicited significant binding interaction in inhibiting Heat shock proteins for targeting pancreatic cancer which was comparable with that of the standard drug Gemcitabine. Further in vivo studies may be carried out to prove the same.

Helicteres isora linn, an ayurvedic herb, is distributed widely in forest throughout India. Almost its all parts are used traditionally. The fruits are useful in diarrhoea, dysentery, wounds, ulcers, hemorrhages and diabetes. The fruit after collection, authentication and drying, was extracted with petroleum ether, chloroform, methanol and water using soxhlet extractor. The present study was aimed to isolate the constituents and evaluate the antimicrobial properties of isolated constituents of methanolic extract of fruits of Helicteres isora linn. Isolation of alkaloids, flavonoids and phenolic compounds was done by using HPTLC technique. The invitro antimicrobial activities of methanolic extract, isolated alkaloids, flavonoids and phenolic compounds were investigated against Escherichia coli, Pseudomonas aeruginosa, Salmonella abony and Staphylococcus aureus by cup-plate diffusion method. The methanolic extract showed activity against Escherichia coli, Pseudomonas aeruginosa, Salmonella abony and Staphylococcus aureus., isolated phenolic compounds against Escherichia coli, Pseudomonas aeruginosa and Salmonella abony., isolated flavonoids against Pseudomonas aeruginosa and Staphylococcus aureus., and isolated alkaloids against Escherichia coli and Staphylococcus aureus. Minimum inhibitory concentration was determined by liquid broth method. Minimum inhibitory concentration of methanolic extract against Pseudomonas aeruginosa was found to be 10μg/ml and that against Staphylococcus aureuswas found to be 8μg/ml.