Sanjit Kanjilal

Synthesis and estimation of calorific value of a structured lipid-potential reduced calorie fat.

The majority of reduced calorie fats and fat substitutes avaiable, today, though similar in texture and flavor to natural fats, contain fatty acids that are not usually present in edible oils and fats and thus do not fully match the chemistry and functions of natural fats. For example, such products do not provide nutritionally important essential fatty acids (EFA). In this investigation, we prepared and evaluated a reduced calorie fat, prepared entirely from natural fats, taking advantage of the fact that long-chain saturated fatty acids (LCSFA), such as behenic acid (22∶0), are poorly absorbed. Mustard oil (MO) and sunflower oil (SO) were used as substrates to yield a structured lipid (SL). The product, being derived from a natural vegetable oil, would thus provide EFA, as would a native fat, a feature not provided by the low-calorie fats available in the market. Erucic acid (22∶1) was isolated from MO by a lipase (EC 3.1.1.3)-catalyzed reaction. It was then hydrogenated to behenic acid, the ethyl ester of which was subsequently enzymatically transesterified with SO to yield a plastic fat containing about 30–35% behenic acid. Absorption of this fat was studied in Wistar rats. In a preliminary single oral dose experiment, rats were fed equal amounts (2 mL) of SO and the SL. Plasma triacylglycerol (TAG) levels were estimated after 1, 2, and 3 h of feeding. The significantly lower concentration of plasma TAG in the 2-h sample, observed in the SL-fed group compared to the SO-fed group (P<0.001), indicated poor absorption of the SL. In order to estimate the calorific value of the SL, we conducted a restricted diet growth experiment over 21 d on weanling Wistar male rats with SO as caloric control. Diets for the test groups were modified by adding 5, 10, and 15% SO for the control groups, and 5 and 10% SL for the experimental groups. Food consumption of the test groups was restricted to 50% of the feed containing 5% SO that had been consumed by the ad libitum group the previous day. Body weights were recorded during the experiment. Calorific value of the SL was estimated by comparing the 21st-d mean body weight gain of the control group with that of the experimental group. Estimated calorific value of the SL was 5.36 kcal/g. Most of the behenic acid fed was excreted, as indicated by the analysis of the fatty acids of plasma and fecal total lipid. A second growth experiment on ad libitum diet was conducted over 21 d on weanling Wistar male rats to compare the absorption behavior of the SL with that of natural oil. SO (10%) was added to the diet of the control group, and SL (10%) was added to the diet of the experimental group. Feed consumption, as well as body weights, was recorded during the experiment. The growth pattern of the experimental group was identical to that of the control group during the period of study. The mean feed intake (9.8 g/d/rat for the control group vs. 9.9 g/d/rat for the experimental group) indicated good palatability of the product. In conclusion, the enzymatically synthesized SL containing EFA and natural antioxidants has nutritional properties almost identical to those of natural fats, and can be used as a reduced calorie fat.

Evaluation of the antioxidant activity of capsiate analogues in polar, nonpolar, and micellar media.

Synthesis of 10 capsiate analogues was conducted by lipase-mediated (Novozyme 435) esterification of vanillyl alcohol with different fatty acids. The antioxidant activity of the synthesized capsiates was evaluated using three in vitro assays: DPPH radical scavenging assay (polar medium), Rancimat assay (nonpolar medium), and autoxidation of linoleic acid (micellar medium). The objective of this study is to find the influence of structural characteristics of the alkyl chain of capsiate analogues on their antioxidant activity. In these assays, BHT and α-tocopherol were used as reference compounds. Both DPPH and Rancimat assays did not show any specific trend of antioxidant activity with the increase in lipophilicity and also with the type of fatty acids grafted to the phenolic moiety. In the Tween 20 micellar system for the inhibition of autoxidation of linoleic acid, vanillyl ester attached to a C18 alkyl chain (vanillyl stearate, oleate, and ricinoleate) exhibited maximum inhibition of autoxidation of linoleic acid.

Synthesis and evaluation of antioxidant and antifungal activities of novel ricinoleate-based lipoconjugates of phenolic acids.

Syntheses of four castor oil fatty acid-based novel lipoconjugates of phenolic acids were carried out following Mitsunobu methodology. The lipid part consists of methyl ricinoleate and its saturated analogue, methyl-12-hydroxystearate and the phenolic moieties are ferulic and vanillic acid. Synthesised compounds are evaluated for antioxidant activity using three in vitro assays (DPPH radical scavenging assay, DSC studies for oxidative induction temperature of linoleic acid and autoxidation of linoleic acid in Tween 20 micellar medium) and compared with three widely used antioxidants in the food industry, BHT, α-tocopherol, and dodecyl gallate. Synthesised compounds are found to exhibit good antiradical activity. These compounds also exhibited very good antifungal activity against studied fungal strains. All these results suggested the applicability of the synthesised compounds as potent lipophilic antioxidants for combating oxidative stress.

Cationic Amphiphiles with Fatty Acyl Chain Asymmetry of Coconut Oil Deliver Genes Selectively to Mouse Lung

Recent structure-activity studies have revealed a dramatic influence of hydrophobic chain asymmetry in enhancing gene delivery efficacies of synthetic cationic amphiphiles (Nantz, M. H. et al. Mol. Pharmaceutics2010, 7, 786-794; Koynova, R. et al. Mol. Pharmaceutics2009, 6, 951-958). The present findings demonstrate for the first time that such a transfection enhancing influence of asymmetric hydrocarbon chains observed in pure synthetic cationic amphiphiles also works for cationic amphiphiles designed with natural, asymmetric fatty acyl chains of a food-grade oil. Herein, we demonstrate that cationic amphiphiles designed with the natural fatty acyl chain asymmetry of food-grade coconut oil are less cytotoxic and deliver genes selectively to mouse lung. Despite lauroyl chains being the major fatty acyl chains of coconut oil, both the in vitro and In vivo gene transfer efficiencies of such cationic amphiphiles were found to be remarkably superior (>4-fold) to those of their pure dilauroyl analogue. Mechanistic studies involving the technique of fluorescence resonance energy transfer (FRET) revealed higher biomembrane fusibility of the cationic liposomes of the coconut amphiphiles than that of the symmetric dilauroyl analogue. AFM study revealed pronounced fusogenic nonlamellar structures of the liposomes of coconut amphiphiles. Findings in the FRET and cellular uptake study, taken together, support the notion that the higher cellular uptake resulting from the more fusogenic nature of the liposomes of coconut amphiphiles 1 are likely to play a dominant role in making the coconut amphiphiles transfection competent.

Biotransformation of ferulic acid to acetovanillone using Rhizopus oryzae

Microbial transformation of ferulic acid to acetovanillone was studied using growing cells of Rhizopus oryzae. Ferulic acid was added to the growing medium (0.5 g L−1) and incubated for 12 days. The progress of formation of metabolites was monitored by GC and GC-MS after extraction with ethyl acetate. The major metabolite was acetovanillone with minor metabolites formed, such as dihydroferulic acid, coniferyl alcohol and dihydroconiferyl alcohol. Traces of metabolites (≤1–3%), such as vanillin, vanillyl alcohol, vanillic acid and phenyl ethyl alcohol, were also produced. Formation of 4-vinyl guaiacol increased from day 1 (12.4%), reaching a maximum on day 4 (31.7%), and reducing to a minimum on day 12 (3.1%). The formation of acetovanillone increased only from day 2 onward, and reached a maximum (49.2%) on day 12. The optimum concentration of ferulic acid to be added into the medium was found to be only 0.5 g L−1, as any increase in concentration (0.75 and 1.0 g L−1) precipitated the precursor, resulting in no further degradation.

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.

Comparative Chemical Characterization of Pigmented and Less Pigmented Cell Walls of Alternaria tenuissima

Alternaria tenuissima, the parasitic fungus, was obtained from the pruned upper-cut surfaces of mulberry stems. This fungus contains dark pigment because of the presence of melanin in the cell wall. To obtain less-pigmented cell walls, this fungus was grown under dark condition. When the pigmented and less-pigmented cell walls were chemically analyzed, no differences were observed in amino-acid composition, hexoses, or pentoses. However, in pigmented cell walls, higher contents of melanin (2.6%) were found than in less-pigmented cell walls (0.3%). Interestingly, a significant difference was observed in the relative fatty-acid compositions between these two types of cell walls. Among the major fatty acids, there were increased concentrations of tetradecanoic acid (C14:0), hexadecanoic acid (C16:0), 9-hexadecenoic acid (C16: 1,Δ9), and 9-octadecanoic acid (C18:1,Δ9) and a concomitant decrease in 9,12-octadecadienoic acid (C18:2,Δ9,12) in less-pigmented compared with pigmented cell walls. This difference in fatty-acid composition may be related to the higher percentage of melanin in the pigmented than the less-pigmented cell walls. Lesser amounts of 9,12-octadecadienoic acid in less-pigmented cell walls may have been caused by the growth of the fungus under environmental stress conditions. An interesting observation was the presence in pigmented cell walls only of methyl-substituted fatty acids with carbon numbers C14 to C17, but their occurrence could not be ascertained in the present study.

Synthesis and mosquito larvicidal activity of furanochalcones and furanoflavonoids analogous to karanjin

A series of furanoflavonoids analogous to karanjin have been synthesized starting from resacetophenone. Initially, resacetophenone was reacted with bromoacetaldehyde diethylacetal, and the resultant phenoxy acetal, on cyclization, produced linear, 5-acetyl-6-hydroxybenzofuran (3) and angular, 5-acetyl-4-hydroxybenzofuran (4). The linear and angular benzofuran on Claisen–Schmidt condensation with a series of substituted aryl aldehyde produced initially furanochalcones, which on cyclization in presence of alkaline hydrogen peroxide produced the corresponding furanoflavonoids. Synthesized compounds were assayed for mosquito larvicidal activity against Culex quinquefasciatus strain. The results showed enhanced toxic effect of analogues on mosquito larvae compared to karanjin. Angular furanochalcone with no substituent on the aryl moiety and its corresponding angular furanoflavonoid were found to be the most toxic among the studied compounds. Angular furanochalcones showed better activity than their corresponding linear counterparts. An interesting observation is higher toxicity towards the studied larval strain of precursor angular furanochalcones compared to their corresponding furanoflavonoids in most cases.

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.

Ferulic acid protects lipopolysaccharide-induced acute kidney injury by suppressing inflammatory events and upregulating antioxidant defenses in Balb/c mice

Sepsis-induced acute kidney injury (AKI) is responsible for 70-80% mortality in intensive care patients due to elevated levels of endotoxin, Lipopolysaccharide (LPS) caused by gram-negative infections. Ferulic acid (FA), a phenolic phytochemical is known for its renal protection on various induced models of nephrotoxicity. However, the curative effect of FA in LPS-induced AKI is not well studied. This study aimed to investigate the effect of FA on LPS-induced AKI in mice model and to understand the protective mechanisms involved, to provide evidence for FA in the treatment of AKI. Balb/c mice were treated with FA at 50 mg/kg and 100 mg/kg dosages after LPS stimulation (10 mg/kg). At the end of the intervention, we determined the concentrations of serum creatinine and blood urea nitrogen, inflammatory cytokines and histopathological changes in animals. Also, the relative protein expression level of TLR4 mediated NF-κB signaling pathway were studied in kidney tissues. FA treated animals showed upregulation of antioxidant defenses and suppression of inflammatory events by inhibiting TLR-4 mediated NFκB activation. However, LPS alone administered group, resulted in rapid renal damage with increased levels of blood urea nitrogen and modest increase in creatinine; decreased antioxidant defenses and release of inflammatory cytokines. The histopathological analysis also revealed the protective action of the FA against sepsis induced fibrosis and renal damage. Our findings demonstrated that FA exhibits marked protective effects on LPS-induced AKI in mice suggesting its chemopotential role for treating AKI in humans.