Shiva Shanker Kaki

Hypocholesterolemic effects of low calorie structured lipids on rats and rabbits fed on normal and atherogenic diet

The hypocholesterolemic effects of two low calorie structured lipids (SL1 and SL2) containing essential fatty acids, prepared by lipase catalysed interesterification of ethyl behenate respectively with sunflower and soybean oils were studied in rats and rabbits. The feeding experiment conducted on rats as well as rabbits, fed on normal and atherogenic diet containing 10% of SL1 and SL2 (experimental) and sunflower oil (control) indicated no adverse effects on growth and food intake. However, the structured lipids beneficially lowered serum and liver lipids, particularly cholesterol, LDL cholesterol, triglycerides and also maintains the essential fatty acid status in serum and liver. The lipid deposition observed in the arteries of rabbits fed on atherogenic diets was significantly reduced when structured lipids were included in the diet. These observations coincided with reduced levels of serum cholesterol particularly LDL cholesterol observed in experimental groups. Therefore the structured lipids, designed to have low calorific value also beneficially lower serum lipids and lipid deposition in animals fed on atherogenic diets.

Synthesis and in vitro antioxidant and antimicrobial studies of novel structured phosphatidylcholines with phenolic acids

Novel phenoylated phosphatidylcholines were synthesized from 1,2-dipalmitoyl phosphatidylcholine/egg 1,2-diacyl phosphatidylcholine and phenolic acids such as ferulic, sinapic, vanillic and syringic acids. The structures of phenoylated phosphatidylcholines were confirmed by spectral analysis. 2-acyl-1-lyso phosphatidylcholine was synthesized from phosphatidylcholine via regioselective enzymatic hydrolysis and was reacted with hydroxyl protected phenolic acids to produce corresponding phenoylated phosphatidylcholines in 48-56% yields. Deprotection of protected phenoylated phosphatidylcholines resulted in phenoylated phosphatidylcholines in 87-94% yields. The prepared compounds were evaluated for their preliminary in vitro antimicrobial and antioxidant activities. Among the active derivatives, compound 1-(4-hydroxy-3,5-dimethoxy) cinnamoyl-2-acyl-sn-glycero-3-phosphocholine exhibited excellent antioxidant activity with EC50 value of 16.43μg/mL. Compounds 1-(4-hydroxy-3-methoxy) cinnamoyl-2-acyl-sn-glycero-3-phosphocholine and 1-(4-hydroxy-3,5-dimethoxy) cinnamoyl-2-palmitoyl-sn-glycero-3-phosphocholine exhibited good antioxidant activity with EC50 values of 36.05 and 33.35μg/mL respectively. Compound 1-(4-hydroxy-3-methoxy) cinnamoyl-2-palmitoyl-sn-glycero-3-phosphocholine exhibited good antibacterial activity against Klebsiella planticola with MIC of 15.6μg/mL and compound 1-(4-hydroxy-3-methoxy) benzoyl-2-acyl-sn-glycero-3-phosphocholine exhibited good antifungal activity against Candida albicans with MIC of 15.6μg/mL.

An anti-oxidant, α-lipoic acid conjugated oleoyl-sn-phosphatidylcholineas a helper lipid in cationic liposomal formulations

Development of safe non-viral carrier systems for efficient intra-cellular delivery of drugs and genes hold promise in the area of translational research. Liposome based delivery systems have emerged as one of the attractive strategies for efficient delivery of drugs and nucleic acids. To this end, number of investigations was carried on liposomal formulations using lipids for achieving higher efficiency in transfection with lower cytotoxicities. In our efforts to develop safer and efficient liposomal delivery systems, we synthesized a novel anti-oxidant lipid, α-lipoyl, oleyl-sn-phosphatidylcholine (LOPC) and used as a helper lipid in combination with a cationic amphiphile, Di-Stearyl Dihydroxy Ethyl Ammonium Chloride (DSDEAC) and 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) at varying concentrations of LOPC. DNA binding properties of the liposomal formulations (DS, DS LA1, DS LA2 and DS LA3) revealed that increasing the percentage of single aliphatic chain lipid LOPC, did not affect the DNA binding properties. But, transfection profiles of these liposomal formulations in 3 different cell lines (HeLa, HEK 293 and MCF7) showed difference in their efficacies. Results showed that optimal percentage of LOPC i.e. 25% in DSDEAC and DOPC at 1:1 molar ratio (DS LA1) enhanced transfection as compared to DSDEAC:DOPC alone. The endosomal escape studies with NBD labelled lysotracker and Rhodamine labelled liposomal formulations revealed that DS LA1 and DS LA2 facilitated the release of genetic cargo with a better efficiency than their counter parts. Reactive Oxygen Species (ROS), a key modulator of necroptosis were lowered with the treatment of DS LA1 than other liposomal formulations. Here in, we present a novel liposomal formulation using DSDEAC and DOPC at 1:1 molar ratio doped with 25-50% (mole ratio) LOPC as an efficient delivery system for enhanced transfection with quenching of ROS levels compared to formulations without LOPC.

Multifunctional lubricant additives derived from natural amino acids and methyl oleate

Novel multifunctional additives were synthesized from methyl oleate via thioglycolic acid addition followed by condensation with different amino acid methyl esters. Seven additives were synthesized and the structures of all the additives were fully characterized by mass, IR and NMR spectral studies. The tribological properties were evaluated using laboratory tribotests in biolubricant base oil, which suggest that all the prepared compounds act as antiwear and extreme pressure additives. Among the synthesized additives, heterocyclic containing compounds exhibited superior performance compared to others. Antioxidant properties evaluated using differential scanning calorimetry reveal that all the additives improved the oxidation stability of base oil with heterocyclic based additives exhibiting better performance compared to commercial antioxidant BHT. The synthesized amino acid-based derivatives have potential as biodegradable multifunctional additives in biolubricant formulations.

Synthesis, characterization, antimicrobial and biofilm inhibitory studies of new esterquats.

Novel esterquats (monoesterquats and diesterquats) were synthesized from 11-bromo undecanoic acid (11-BUA) and different alkyl amines. The prepared compounds were characterized by FT-IR, (1)H NMR, (13)C NMR and mass spectral analysis. 11-BUA was converted into methyl 11-bromo undecanoate which was further converted into amine ester (amine monoester and diester) by reacting with different aliphatic amines (hexyl, dodecyl, octadecyl, dioctyl and dicyclohexyl amine). Finally, the obtained amine esters were converted into esterquats (monoesterquat and diesterquat) by reacting with methyl iodide followed by ion exchange to afford chloride counter ion esterquats (5a-h). The synthesized esterquat products were studied for their antimicrobial and biofilm inhibitory activities. Among all the compounds, amine ester 3a and esterquat 5d showed potent antimicrobial activity towards pathogenic Gram-positive bacterial strains with minimum inhibitory concentration (MIC) values in the range of 3.9-15.6 μg mL(-1) and 1.9-7.8 μg mL(-1), respectively. The esterquat 5d also showed promising antifungal activity against Candida albicans MTCC 3017, Candida albicans MTCC 4748 and Candida aaseri MTCC 1962 strains with MIC value of 7.8 μg mL(-1) which was identical to standard Miconazole. The compounds which exhibited antimicrobial activity were also effective in anti-biofilm activity and it was found that compound 5d exhibited excellent biofilm inhibitory activity with IC50 value of 0.9 μg mL(-1) against Staphylococcus aureus MLS16 MTCC 2940.

Synthesis, characterization, antimicrobial and biofilm inhibitory activities of new N-oxide esters

Novel N-oxide esters were synthesized from tertiary amine esters, which in turn were obtained from the reaction of 11-bromoundecanoic acid and different alkyl amines. The synthesized N-oxide esters were characterized by fourier transform infrared, proton nuclear magnetic resonance, carbon-13 nuclear magnetic resonance, and mass spectral analysis. The synthetic route involved three steps; initially, 11-bromoundecanoic acid was converted into methyl 11-bromoundecanoate, which was further converted into tertiary amine (mono and di) esters by reacting with different aliphatic amines (hexyl, dodecyl, octadecyl, dioctyl, and dicyclohexyl amine). Finally, the obtained amine esters were converted into N-oxide esters by treating with m-chloroperbenzoic acid. The synthesized N-oxide esters (4a–e) were studied for their antimicrobial and anti-biofilm activities. Among all the synthesized N-oxide esters, compounds 4a and e showed good antimicrobial activity especially towards pathogenic gram-positive bacterial strains with minimum inhibitory concentration values in the range of 7.8–31.2 μg mL−1. The compounds which exhibited antimicrobial activity were also effective in anti-biofilm activity and it was found that the compound 4e exhibited promising biofilm inhibitory activity with IC50 value of 6.4 μg mL−1 against Bacillus subtilis MTCC 121. Further, compound 4e showed increased levels of intracellular reactive oxygen species accumulation, which may be contributing to the bactericidal activity in B. subtilis MTCC 121.

Synthesis and Characterization of a Novel Phenolic Lipid for Use as Potential Lipophilic Antioxidant and as a Prodrug of Butyric Acid

Ferulic acid was modified to produce a novel phenolipid containing butyl chains. Ferulic acid was esterified with butanol to produce butyl ferulate which was further dihydroxylated followed by esterification with butyric anhydride to produce the phenolipid containing butyric acid. IR, NMR and MS techniques confirmed the structure of the synthesized structured lipophilic phenolic compound. The synthesized compound was tested for in vitro antioxidant and antimicrobial activities. The produced phenolipid showed moderate antioxidant activity in DPPH (2, 2-diphenyl-1-picrylhydrazyl) radical scavenging assay but in linoleic acid oxidation method, it exhibited good activity compared with the parent compound and the reference compounds. The prepared derivative could find applications as antioxidant in lipophilic systems and also as a potential prodrug of butyric acid. It also showed antibacterial effect against the four bacterial strains studied. The drug-likeness properties of the prepared molecule calculated were in the acceptable ranges according to Lipinskis rule of 5 and suggest that it has potential to cross the blood-brain barrier.

Physico-chemical characterization and biodiesel preparation from Ailanthus excelsa seed oil

ABSTRACT Ailanthus excelsa seed oil is identified as minor seed oil from forest origin for biodiesel production. The seed oil was initially characterized for various physico-chemical properties following standard protocols. The extracted oil was further refined and transesterified to produce biodiesel. The prepared biodiesel was evaluated for fuel properties such as the iodine value, free fatty acids, phosphorous content, flash point, cloud point, pour point, viscosity at 40°C, oxidative stability at 110°C, density, and trace metals. The properties were compared with international specifications and it was found that the oxidative stability of the prepared biodiesel was better compared to most of the biodiesels reported.

Synthesis, characterization and evaluation of antiproliferative activity of diisopropylphenyl esters of fatty acids from selected oils

The present investigation describes the synthesis, characterization and evaluation of antiproliferative activity of novel diisopropylphenol (propofol) conjugates of fatty acids. The fatty acids were obtained from oils of Jatropha curcas (jatropha) and Pongamia glabra (karanja) containing unsaturated-rich fatty acids, Sterculia foetida (containing cyclopropene-rich fatty acids), Samia cynthia (eri pupae, containing polyunsaturated-rich fatty acid, 18:3) and Cocos nucifera (coconut, containing medium-chain saturated-rich fatty acids). The synthesized conjugates viz. propofol-jatropha mixed fatty acid conjugates (2,4P-JTA and 2,6P-JTA), propofol-karanja mixed fatty acid conjugates (2,4P-KTA and 2,6P-KTA), propofol-sterculia foetida mixed fatty acid conjugates (2,4P-STA and 2,6P-STA), propofol-eri pupal mixed fatty acid conjugates (2,4P-EFA and 2,6-EFA) and propofol-coconut mixed fatty acid conjugates (2,4P-CCFA and 2,6P-CCFA) were obtained by esterification of the fatty acid mixture to propofol isomers (2,4-diisopropylphenol and 2,6-diisopropylphenol). The prepared derivatives were characterized by FT-IR, NMR (1H, 13C) and GC–MS and were tested for in vitro antiproliferative studies on A549, MDA-MB-231, HeLa, Mia-Pa–Ca and HePG2 cancer cell lines. All the synthesized propofol-mixed fatty acid conjugates showed good to moderate specific growth inhibition of cancer cells on studied cell lines. The results suggest that all the novel propofol-mixed fatty acid conjugates possess antiproliferative properties that reduce the proliferation of cancer cells in vitro.

Synthesis and biological evaluation of novel lipoamino acid derivatives.

Seven novel lipoamino acid conjugates were synthesized from methyl oleate and amino acids. Methyl oleate was grafted to different amino acids using thioglycolic acid as a spacer group. Seven derivatives (3a-g) were prepared and characterized by spectral data (NMR, IR and MS spectral studies). All the derivatives were studied for their antimicrobial, anti-biofilm and anticancer activities. Among all the derivatives, it was found that compound 3b was the most potent antibacterial compound which showed good activity against four Gram positive bacterial strains and also exhibited excellent antifungal activity against a fungal strain. In the anti-biofilm assay, compound 3b showed promising activity with IC50 value of 2.8μM against Bacillus subtilis MTCC 121. All the compounds showed anticancer activities with 3c showing promising anticancer activity (IC50=15.3-22.4μM) against the four cell lines tested.