We have developed a simple method for the quantification of milk fat in foods using 1,2-dipalmitoyl-3-butyroyl-glycerol (PPBu) as an indicator of milk fat content by high-performance liquid chromatography coupled with atmospheric pressure chemical ionization tandem mass spectrometry. The separation of the triacylglycerol positional isomer, 1,3-dipalmitoyl-2-butyroyl-glycerol (PBuP) and PPBu, was achieved using an octacocyl silylation (C28) column, and multiple reaction monitoring was employed. The milk fat contents in butter, butter-blended margarine, and butter cookies were quantified using two different sample preparation methods. In the first method (Method A), the lipid in the food was extracted with organic solvents and used for the preparation of a sample solution. In the other method (Method B), the sample solution was prepared by dissolving the food in organic solvents; the PPBu content in the fat and oil was corrected by the lipid content in the food obtained by the rapid NMR method. The calibration curve of standard PPBu was a first-order equation over the range of 1-250 μg/mL. The recovery rates of PPBu spiked into butter evaluated by Methods A and B were 99.9-105.0% and 106.5-110.1%, respectively. PBuP was not detected in milk fat. The milk fat contents in blends of butter and margarine determined by the method developed in this study were equivalent to the contents calculated with the butyric acid (Bu) method using GC-FID. The milk fat contents in butter-blended margarine analyzed by Methods A and B were almost the same. The PPBu content in blends of butter and margarine was correlated with the butter content. Thus, we succeeded in developing an efficient method for the rapid quantification of milk fat content and the detection of milk fat adulteration.
Hydrogen bonding between surfactant molecules plays an important role in self-assembly formation. For long alkyl chain amine oxide surfactants, the specific protonation degree dependence of some solution properties has been considered to be due to hydrogen bonding between protonated and deprotonated species. In addition to this type of hydrogen bonding, we introduced a pyridyl group into an alkylamine oxide molecule as a new hydrogen-bonding site. The pyridyl group has three different structural isomers based on the position of the substituent. An amine oxide group in pyridylamine oxides was preferentially protonated. In addition, protonation of the pyridyl group revealed a pronounced substituent position effect on the critical micelle concentration, micellar size, and solubilization of oil-soluble dye into micelles. The intermolecular or intramolecular hydrogen bond formation could be controlled by altering the substituent position.
Total glucocerebrosides of the sea cucumber Cucumaria frondosa (CFC) have been isolated from the less polar lipid fraction of the chloroform–methanol extract using high speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of petroleum ether-methanol-water (5:4:1, v/v). Three glucocerebroside molecular species (CFC-1, CFC-2 and CFC-3) were isolated from crude total cerebrosides with repeated column chromatography. The structures of these three glucocerebroside molecular species were determined on the basis of chemical and spectroscopic evidence: fatty acids were mainly saturated (C22:0 and C18:0), monounsaturated (C24:1 and C20:1) and α-hydroxyl fatty acids (C24:1h, C23:0h, C23:1h and C22:0h), the structures of long-chain bases were dihydroxy (d17:1, d18:2 and d18:1) and trihydroxy (t17:0 and t16:0), and the glycosylation was glucose. High purity long-chain bases of sea cucumber Cucumaria frondosa (CF-LCB) were prepared from total lipids by HSCCC with a two-phase solvent system composed of n-hexane-methyl tert butyl ether-methanol-water (1:1:2:1, v/v). Compare with traditional preparative methods, the method of HSCCC is short cycle, high yield and less solvent consumption. The composition analysis of CF-LCB showed that the ratio of d18:2 and d17:1 was approximately 2:1. The four glucocerebrosides and long-chain bases from sea cucumber Cucumaria frondosa were evaluated for activity in vitro assays for the cytotoxic activities against Caco-2 colon cancer cells. The results indicated that both glucocerebrosides and long-chain bases exhibited an inhibitory effect on cell proliferation. Moreover, CFC-3 was most effective in four glucocerebrosides to Caco-2 cell viability. The inhibition effect of CF-LCB was much stronger than glucocerebrosides.
A heterotrophic microalga, strain SD116, with the ability to produce high concentrations of docosahexaenoic acid (DHA, C22:6n-3) was isolated from Shuidong Bay, Guangdong Province, China. Nucleotide sequence analysis of the 18S rDNA of SD116 showed that the strain has a close phylogenetic relationship to Aurantiochytrium species. The highest rates for growth and DHA accumulation for SD116 were obtained in 6.0% glucose, 2.0% yeast extract, and 50% artificial seawater (ASW) at a pH of 7 at 28°C. The maximum total lipid content reached 56.3% of the dry cell weight (DCW), and the maximum DHA content accounted for 50.9% of the total fatty acid (TFA) content. It was further found that urea may be a potential nitrogen source for industrial fermentation because of its cheap price and ability to induce a relatively high biomass and lipid production capacity. Using 5 L fermenters, the DCW, total lipid content, and DHA yield were found to be 70.43 g L–1, 71.09% of the DCW, and 17.42 g L–1 (34.79% of the TFA), respectively. The results show that Aurantiochytrium sp. SD116 is a promising candidate for commercial DHA production and could be useful for the synthesis of biomass-related products.
Increased environmental awareness is slowly driving the industry to develop alternatives to chemical routes for synthesis. Lipase catalysed synthesis is one such alternative route that is environmentally more acceptable. In this study, immobilized Candida antarctica lipase (Lipozyme 435) was used for the esterification of ricinoleic acid and isopropyl alcohol. Molecular sieves were used to remove the water formed during esterification to drive the reaction in forward direction. The optimal conditions observed were 40°C temperature, 4% enzyme concentration, 1:1 acid: alcohol ratio and 4 hours time interval. Under the described conditions, the reusability of lipase was tested and it was found that above 80% esterification was observed for over three cycles.
We investigated the protective effects of sericin on corneal damage due to benzalkonium chloride (BAC) used as a preservative in commercially available timolol maleate eye drops using rat debrided corneal epithelium and a human cornea epithelial cell line (HCE-T). Corneal wounds were monitored using a fundus camera TRC-50X equipped with a digital camera; eye drops were instilled into the rat eyes five times a day after corneal epithelial abrasion. The viability of HCE-T cells was calculated by TetraColor One; and Escherichia coli (ATCC 8739) were used to measure antimicrobial activity. The reducing effects on transcorneal penetration and intraocular pressure (IOP) of the eye drops were determined using rabbits. The corneal wound healing rate and rate constants (kH) as well as cell viability were higher following treatment with 0.005% BAC solution containing 0.1% sericin than in the case of treatment with BAC solution alone; the antimicrobial activity was approximately the same for BAC solutions with and without sericin. In addition, the kH for rat eyes instilled with commercially available timolol maleate eye drops containing 0.1% sericin was significantly higher than that of eyes instilled with timolol maleate eye drops without sericin, and the addition of sericin did not affect the corneal penetration or IOP reducing effect of commercially available timolol maleate eye drops. A preservative system comprising BAC and sericin may provide effective therapy for glaucoma patients requiring long-term anti-glaucoma agents.
Anhydride copolymers were synthesized from acrylic acid and fatty alcohols (C12- C18, C18:1). These n-alkyl acrylates were treated with maleic anhydride in presence of hydrogen peroxide in second step, to form anhydride copolymer. The anhydride copolymer further reacted to n-butylamine to form poly (n-acrylate-co-nbutylmalemide). The compounds were used as pour point depressant (PPD) additive. The synthesized experimental pour point depressants were added in different concentrations to conventional base stock (150N and 500N), which had no other additive content before. Synthesized additives were effective as viscosity index improver but also lowered the pour point. These results were comparable with industrial product. Furthermore all additives showed antiwear (AW) and extreme pressure (EP) properties. The resultant anhydride copolymer can act as multifunctional additive, which is novelty of the work.
The components of the essential oil from the roots of Pueraria mirifica were analyzed by capillary gas chromatography-mass spectrometry (GC-MS). Eighty-two components, representing 88.5% of the total oil, were identified by GC-MS. The main component of the oil was 2-pentylfuran, followed by hexanal and hexadecanol. With regard to the odor components from the essential oil of P. mirifica as determined by gas chromatography-olfactometry and aroma extract dilution analysis, it was revealed that phenylacetaldehyde and (2E)-nonenal imparted the green odor of the oil, and geraniol contributed to the sweet odor.
Anti-oxidative, anti-tumor-promoting, and anti-carcinogenic activities of adonirubin and adonixanthin, which are biosynthetic intermediates from β-carotene to astaxanthin, were investigated. Both adonirubin and adonixanthin showed almost the same activities for inhibition of lipid peroxidation and quenching of singlet oxygen as those of astaxanthin. Furthermore, adonirubin and adonixanthin exhibited an inhibitory effect on Epstein-Barr virus early antigen activation in Raji cells and carcinogensis of mouse skin tumors initiated by 7,12-dimethylbenz[a]anthracene and promoted by 12-O-tetradecanoylphorbol-13-acetate.