The lipid class and fatty acid composition of a little-known and rarely collected alga Exophyllum wentii from Bali Island, Indonesia were determined for fresh and frozen-thawed samples using thin-layer chromatography, gas-liquid chromatography, and high-performance liquid chromatography. Glycoglycerolipids, which mainly consisted of mongalactosyldiacylglycerols (MGDG) and digalactosyldiacylglycerols (DGDG), were the predominant lipid components, accounting for 67% and 56% of the total polar lipid content in the fresh and frozen-thawed samples, respectively. Phospholipids, including phosphatidylcholines (PC) and phosphatidylglycerols (PG), were detected with lesser amounts in both samples (16 - 17% of the total polar lipid content). Free fatty acids (FFA), sterols and triacylglycerols (TAG) were also detected in minor quantities; however, the FFA content in the frozen-thawed sample increased to up to 20% of the total lipid content, suggesting that hydrolysis of the membrane lipids had occurred. A crude enzyme preparation from the alga showed activities for hydrolyzing the acyl groups of the phospholipids and glycoglycerolipids. Palmitic acid (16:0) and arachidonic acid (20:4n-6) were the major fatty acids in both the total lipid and in individual polar lipid classes as well as the dominant fatty acids released from the membrane lipids by enzymatic hydrolysis. The high level of 20:4n-6 (29%) in the total lipid and the presence of considerable amounts of PC (11% of the total polar lipid) and PG (6.2%) support classification of E. wentii into the Division Rhodophyta.
Recent studies have shown that dietary phospholipids, especially phosphatidylcholine and phosphatidylserine, have various beneficial biological effects. However, there are not enough data concerning the physiological function of dietary phosphatidylinositol (PI). The metabolic syndrome, a cluster of metabolic abnormalities such as dyslipidemia, diabetes mellitus, and hypertension, is widespread and increasingly prevalent diseases in industrialized countries. In the present study, we evaluated that the effect of dietary PI on cholesterol metabolism in metabolic syndrome model Zucker (fa/fa) rats. For 4 weeks, rats were fed semisynthetic diets containing either 7% soybean oil or 5% soybean oil plus 2% PI. Dietary PI prevented the mild hypercholesterolemia and hepatic cholesterol accumulation in Zucker (fa/fa) rats. These effects were attributable to an increased fecal bile acid excretion and to the tendencies of decreased ACAT1 mRNA level and increased CYP7A1 mRNA level in the liver. Additionally, dietary PI markedly increased microsomal PI content in the liver of Zucker (fa/fa) rats. Our study suggests that dietary PI normalizes cholesterol metabolism through the enhancement of fecal bile acid excretion in the metabolic syndrome model rats.
The volatile constituents of the essential oils from the flower, leaf, and stem of Verbascum wiedemannianum were analysed by GC and GC-MS. A total of forty-three compounds were identified, constituting over 99.1%, 94.3%, and 98.7% of oil composition of the flower, leaf, and stem of V. wiedemannianum, respectively. Hydrocarbons were shown to be the main group of constituents of the flower and stem part in the ratio of 83.3% and 32.1%, respectively. But, the major group in the leaf oil was found to be aldehydes (46.8%). The main components of the flower, leaf and stem oils of V. wiedemannianum were pentadecane (58.2%), (2E)-hexenal (33.2%), and hexadecanoic acid (24.6%), respectively.
The Lipase-catalyzed transesterification method is utilized as a safe and effective method for preparing various structured oils. As each lipase shows different fatty acid specificity, it is important to select an appropriate lipase according to fatty acid species incorporated into oils. In the present study fatty acid specificities of lipases obtained from different origins were evaluated by transacylation between oils and various fatty acids. Of 12 kinds of lipases used, 5 lipases have 1,3-regio specificity and 7 lipases have non-regio specificity for hydrolysis of oils. Fatty acid substrates of transacylation were 8 saturated fatty acids with 6 to 18 carbon numbers, and C18 unsaturated fatty acids with different double bonds such as oleic, linoleic and linolenic acids. As results shown below, most lipases used gave high transacylation ratios for lauric acid when saturated fatty acids are compared and a different tendency in C18 unsaturated fatty acids. Regarding the fatty acid specificity of different lipases, fatty acid specificity of each lipase differed by its origin. Almost all lipases with or without regio specificities showed high selectivity for C10 and C12, especially C12 saturated fatty acid, and a little selectivity for C14-20 saturated fatty acids. On the other hand, C6 saturated fatty acid was little incorporated into TAG, and C18 fatty acids with higher unsaturation were incorporated easily into TAG. Transacylation activity defined as an acydolysis unit (AU) of an activity which is able to incorporate 1 μmol of C12 saturated fatty acid into TAG for 24h represents high relationship with the known hydrolysis activity. It is considered that structured lipids can be prepared effectively by transacylation based on the proper selection of lipase with higher transacylation or hydrolysis activities for specific fatty acids.
Basidiomycetous yeasts Cryptococcus humicola and Pseudozyma fusiformata secrete cellobiose lipids into the culture broth. In the case of Cr. humicola, 16-(tetra-O-acetyl-β-cellobiosyloxy)-2-hydroxyhexadecanoic acid was defined as major product and 16-(tetra-O-acetyl-β-cellobiosyloxy)-2,15-dihydrohexadecanoic acid was defined as minor product, while Ps. fusiformata secreted mainly 16-[6-O-acetyl-2’-O-(3-hydroxyhexanoyl)-β-cellobiosyloxy)-2,15-dihydroxyhexadecanoic acid. These compounds exhibit similar fungicidal activities against different yeasts including pathogenic Cryptococcus and Candida species. The cells of Filobasidiella neoformans causing systemic cryptococcosis completely died after 30-min incubation with 0.02 mg mL-1 of cellobiose lipids. The same effect on ascomycetous yeast, including pathogenic Candida species, is achieved at 0.1-0.3 mg mL-1 of cellobiose lipids depending on the test culture used. Cellobiose lipid of Ps. fusiformata inhibits the growth of phytopathogenic fungi Sclerotinia sclerotiorum and Phomopsis helianthi more efficiently than cellobiose lipids from Cr. humicola. Fully O-deacylated analogue, namely16-(β-cellobiosyloxy)-2-hydroxyhexadecanoic acid, and totally synthetic compound, 16-(β-cellobiosyloxy)-hexadecanoic acid, do not inhibit the growth of F. neoformans and Saccharomyces cerevisiae, while 16-(β-cellobiosyloxy)-2,15-dihydroxyhexadecanoic acid inhibits the growth of both test cultures but at higher concentrations than cellobiose lipids of Cr. humicola and Ps. fusiformata. The amide of 16-(β-cellobiosyloxy)-2,15-dihydroxyhexadecanoic acid possessed no fungicide activity. Thus, the structures of both the carbohydrate part and fatty acid aglycon moiety are important for the fungicidal activity of cellobiose lipids.
Petals from Coreopsis lanceolata L. were extracted in methanol and subjected to solvent-solvent partitioning to yield four fractions: hexane, diethyl ether, ethyl acetate, and aqueous. These fractions were screened using a 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay and an active oxygen inhibition assay. The ethyl acetate extract contained the highest level of active components. Four compounds isolated from this fraction by HPLC were screened for antioxidant activity and anti-allergic activity. Anti-allergic activity was assessed by measuring release of histamine from rat peritoneal mast cells. One compound, termed laceolin, was characterized by spectroscopic analysis, including extensive NMR and mass spectra. This compound had significant radical scavenging activity, with an SC50 (scavenging concentration of 50%) value of 2.6 μg/mL and superoxide dismutase activity of 46.2%.
Thirty-five glycerol-assimilating bacteria have recently been isolated from soil samples. Amplified ribosomal DNA restriction analysis revealed that these strains are grouped into four genetically different types of bacteria. Gas chromatography-mass spectrometry analysis of glycerol metabolites produced by the three selected strains (strains HH7, HH12, and HH31) revealed that extracts of culture liquid with ethyl acetate contains acetyl monoglyceride (monoacetin), which has not previously been reported as a glycerol metabolite and is used as a solvent, plasticizer, and food additive, as well as for other industrial purposes. The sequence analyses of the 16S rRNA genes from the selected strains showed that all of them belong to the Enterobacteriaceae.
The volatile oils from red and black rice bran were obtained by hydrodistillation using diethyl ester and the components of that oil were analyzed by capillary GC-MS. The volatile components of essential oil from red and black rice bran were analyzed by GC and GC-MS. One hundred twenty-nine (129) of volatile compounds were identified in red and black rice bran. Myristic acid, nonanal, (E)-β-ocimene and 6, 10, 14-trimethyl-2-pentadecanone were main compounds in red rice bran, whereas myristic acid, nonanal, caproic acid, pentadecanal and pelargonic acid were main compounds in black rice bran. Guaiacol, presented at 0.81 mg/100 g in black rice bran, is responsible for the characteristic component in black rice.