Synthesis of industrially important platform chemicals via olefin metathesis of palash fatty acid methyl esters

The study signifies the importance of olefin metathesis in developing industrially important platform chemicals from a non-edible renewable resource, palash oil using Grubb’s second generation catalyst. The reaction conditions were optimized by varying the concentration of the catalyst, 0.03-0.05 mM and the temperature, 45-100 °C of the reaction. Maximum yield of the metathesized products, as analysed using GC/GC-MS were obtained employing lower concentration of the catalyst, 0.03 Mm and temperature, 45 °C for 36 h. The metathesized products showed the formation of hydrocarbons namely 9-octadecene (10.9%) and cyclodecacyclotetradecene (27%) as major. The formation of cyclodecacyclotetradecene was observed for the first time. The study also describes the possible routes and the molecules involved in the formation of the metathesized products

Metathesis of 9-octadecenoic acid methyl ester: diversity and mechanism of product formation at various Grubbs’ catalyst concentrations

Self-metathesis of 9-octadecenoic acid methyl ester was carried out with varying the concentration of Grubbs’ second generation catalyst from 0.03 mmol to 0.18 mmol at 40-45 °C for 36 h. Only two products (9-octadecene 30%, and dimethyl-9-octadecene-dienoate 23%) resulted when 0.06 mmol of catalyst was employed, while at other concentrations four metathesized products were observed. 9-Octadecene generated at 0.03, 0.06 and 0.12 mmol completely disappeared and dimethyl-9-octadecene-dienoate (64%) was observed in major amounts at 0.18 mmol concentration

Synthesis and characterization of new fatty Schiff base ethers of 4-((pyridin-3-ylmethylimino)methyl)phenol

A series of ten new Schiff base ethers were synthesized by etherification of Schiff base-{4-(pyridine-3-methylimino) methyl phenol} with fatty alkyl bromides of different chain lengths (C4-C18) in the presence of base with 80-85% isolated yields. All the synthesized Schiff base ethers (2a-j) were characterized by FT-IR, 1H NMR, 13C NMR and Mass spectral studies. Presence of a characteristic peak for ether linkage, C-O at 1039 cm-1 in IR spectra; a triplet around 7.67 ppm in 1H NMR and a characteristic peak around 69.7 in case of  13C NMR further confirmed the structures of Schiff base ethers. The structure of all the compounds were further confirmed by their characteristic molecular ion peaks in ESI-MS

Phenolic content and antioxidant activity of young and mature mango (Mangifera indica) and avocado (Persea americana) leave extracts

Polyphenols are groups of secondary metabolites in plants, known with their various biological activities, including their ability to act as antioxidants. Due to the side effects of the use of synthetic antioxidants on human’s health, the search for natural less toxic compounds has significantly increased. This study was carried out to evaluate the phenolic content and antioxidant activity of young and mature avocado (Persea americana) and mango leaves (Mangifera indica). Different extracts were prepared by maceration in methanol, ethanol, cold and hot water. The phenolic content of the extracts was determined using the Folic-Ciocalteu Method. A total of three antioxidant tests were done on the extracts: the 2, 2-diphenyl-1-picrylhydrazyl test (DPPH test), the Ferric reducing antioxidant power and the Hydroxyl radical scavenging activity. Results of these investigations generally showed that the mature leaves of mango and young leaves of avocado exhibited the highest phenolic and flavonoid contents, as well as the antioxidant activity. They can be recommended as good sources of antioxidants to reduce the damages caused by free radicals and reactive oxygenated species in the body. They can also be recommended as a source of antioxidants for the preservation of oils, food containing lipids and pharmaceutical products

Synthesis of lactones from fatty acids by ring-closing metathesis and their biological evaluation

The present study involves the synthesis of macrocyclic lactones by the esterification of unsaturated fatty acids (oleic acid, undecenoic acid, and erucic acid) with unsaturated alcohols (allyl alcohol, prop-2-ene-1-ol, oleyl alcohol, and undecenol) followed by a ring closing metathesis reaction employing Grubbs' second generation catalyst (1.0-1.5 mmol). The structure of the compounds was confirmed by 1H NMR, 13C NMR, FT-IR, and ESI-Mass spectral studies. The antibacterial activity of the synthesised lactones was evaluated. The larger ring-sized lactone, namely, erucic acid lactone, exhibited excellent antibacterial activity against three bacterial cell lines, namely, Staphylococcus aureus, Staphylococcus epidermidis, and Bacillus subtilis. Undecenoic acid-based lactones exhibited excellent antibacterial activity selectively against only Staphylococcus epidermidis. The assay of macrolactones for their in vitro anticancer activity was carried out by MTT for different cancer cell lines, namely, human prostate epithelial cancer cells (ATCC HTB-81), HepG2 derived from hepatic cancer cells (ATCC HB-8065), SKOV3 derived from human ovarian cancer cells (ATCC HTB-77), MDAMB-231 derived from human breast cancer cells (ATCC HTB-26) and Chinese hamster ovarian (CHO-K1) cell lines. The molecules selectively exhibited anticancer activity against Chinese hamster ovarian (CHO-K1) cell lines. Among macrolactones, (E)-oxacyclotridec-11-en-2-one (MALUN) was more active and its activity was much higher compared to others and on par with the reference standard Mitomycin C. This was followed by (E)-oxacyclotricos-14-en-2-one (MOLER) and (E)-oxacyclononadec-10-en-2-one (MOLOH). The fatty acid-based cyclic lactones with selective antibacterial and anticancer activities can be further explored for a variety of pharmaceutical formulations

Synthesis of industrially important platform chemicals via olefin metathesis of palash fatty acid methyl esters

The study signifies the importance of olefin metathesis in developing industrially important platform chemicals from a non-edible renewable resource, palash oil using Grubb’s second generation catalyst. The reaction conditions were optimized by varying the concentration of the catalyst, 0.03-0.05 mM and the temperature, 45-100 °C of the reaction. Maximum yield of the metathesized products, as analysed using GC/GC-MS were obtained employing lower concentration of the catalyst, 0.03 Mm and temperature, 45 °C for 36 h. The metathesized products showed the formation of hydrocarbons namely 9-octadecene (10.9%) and cyclodecacyclotetradecene (27%) as major. The formation of cyclodecacyclotetradecene was observed for the first time. The study also describes the possible routes and the molecules involved in the formation of the metathesized products

Optimization of Palm Olein Stability during Storage Using Natural Antioxidants from Cocoa Pods Extract

Aims: The objective of this study is an attempt to optimize palm olein stability during storage using natural antioxidants from Theobroma cacao pods. Study Design: Drying of fresh cocoa pods, extraction of natural antioxidants and its application as antioxidants to optimize oxidative stability of palm olein during storage. Place and Duration of Study: University of Dschang, Cameroon and Council for Scientific and Industrial Research-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad, India, from March 2016 to January 2017. Methodology: The plant material was extracted and its reducing power, metal ion chelating activity evaluated. The extract was added in refined palm olein. Peroxide, p-Anisidine and total oxidation (TOTOX) values were determined as response variables to evaluate the effect of storage time and extract concentration during storage of oil. Results: The outcomes showed cocoa pods extract to be efficient in metal ion chelating activity and have the ability to reduce Fe3+ to Fe2+. This extract was also found to be efficient in inhibiting peroxide formation and reducing, in the same way, the amount of secondary oxidation products. At 2000 ppm, Theobroma cacao pods extract has the ability to extend the shelf life (30 months) of palm olein during storage. Conclusion: Theobroma cacao pods can be exploited as an alternative source of synthetic antioxidants for stabilization of palm olein and other oil systems

Total synthesis of (−)-Sachalinol A and evaluation of its cytotoxicity

695-700(-)-Sachalinol A, a group of monoterpenoids, oxygenated derivatives of rosinidol, has been synthesized employing a simple, eight step procedure. The compound demonstrates excellent cytotoxicity against MDA-MB-231 derived from human breast adenocarcinoma cells (ATCC No. HTB-26) and HeLa derived from human cervical cancer cells (ATCC No. CCL-2). Good activity is observed against A549 derived from human alveolar adenocarcinoma epithelial cells (ATCC No. CCL-185) and Neuro2a derived from mouse neuroblastoma cells (ATCC No. CCL-131). Moderate activity is also observed against MCF-7 derived from human breast adenocarcinoma cells (ATCC No. HTB-22)

Oxidative stabilization of RBD palm olein under forced storage conditions by old Cameroonian green tea leaves methanolic extract

Background: Lipid oxidation is responsible for the deterioration of the nutritional and organoleptic qualities of foods. It also leads to the formation in these products of compounds which are harmful for the consumer's health. The synthetic antioxidants used by industries in order to solve this problem are also prone to be toxic and quite volatile at high temperatures. On the other hand, the trend among researchers to replace the synthetic antioxidants with natural ones is increasing because of their potential health benefits. In this study, old Cameroonian green tea leaf methanolic extracts were added in palm olein and its efficiency in delaying the oxidation of oil under forced storage conditions was assessed. Methods: The plant material was extracted with methanol and its total phenolics content evaluated by colorimetry, followed by the qualitative identification of some phenolic antioxidants by HPLC-DAD and ESI-MS. After preliminary antioxidant studies, the extract was added in oil at concentrations that ranged from 200 to 1800 ppm. Oil containing butylated hydroxytoluene (BHT) and oil without antioxidant served as positive and negative controls, respectively. The oxidative stability of these oil samples was evaluated by determining their oxidation induction times on Rancimat (at 110 °C) and measuring their oxidative state by the Schaal oven test method during 30 days of storage at 70 °C. Here, oil samples were collected every 10 days and their peroxide, p-anisidine, total oxidation, thiobarbituric acid, iodine values as well as changes in their linoleic acid profile gas chromatography coupled to flame ionization detector (GC/FID) were evaluated. Results: The outcomes showed the total phenolics content of the extract to be 53.5 mg GAE/g. Gallic acid, epicatechin gallate, gallocatechin and epigallocatechin gallate were the phenolic antioxidants detected. The induction times of palm olein supplemented with the extract (200–1800 ppm) were found to be in the range of 24.8–28.9 h, while those of control and oil containing BHT were 20.1 and 22.7 h, respectively. The extracts, at all concentrations, were also found to be efficient like butylated hydroxytoluene in inhibiting the oxidation of palm olein during 30 days of storage at 70 °C. Conclusion: The investigations showed that old Cameroonian green tea leaves are a viable source of natural antioxidants for delaying palm olein oxidation

Effects of Soursop flowers (Annona muricata L.) extract on chemical changes of refined palm olein stored at frying temperature

In this study, the antioxidant activity of soursop flowers extract in delaying palm olein oxidation at frying temperature was assessed. The oil was supplemented with the extract at concentrations 200–1800 ppm, and stored in the oven at 180 °C for 6 days (4 h heating per day). Palm olein containing butylated hydroxytoluene (BHT) served as positive control while the same oil without antioxidant (Control) served as negative one, in order to monitor changes in oils. After each two heating days, oil samples were collected, and their chemical indexes were determined. Peroxide, para-anisidine, TOTOX, thiobarbituric acid and iodine values were the parameters evaluated. Additionally, the evolution of the fatty acid composition of each oil sample during the storage was assessed by gas-chromatography using a flame ionization detector (GC/FID). Generally, palm olein samples containing the natural extract have exhibited the lowest rate of oxidation, and were efficient in limiting the destruction of unsaturated fatty acids in oil at frying temperature. The order of effectiveness in inhibiting oil oxidation was the following: PO + AnM1800ppm> PO + AnM1400ppm> PO + AnM1000ppm > PO + An.M600ppm> PO + An.M200ppm> PO + BHT200ppm = Control. From these results, it can be concluded that soursop flowers are a potent sources of natural antioxidants for stabilization of palm olein