Isolation and identification of antifungal fatty acids from the basidiomycete Gomphus floccosus

Bioautography of extracts of the fruiting bodies of the basidiomycete Gomphus floccosus (Schw.) Singer indicated the presence of fungitoxic compounds in the ethyl acetate fraction against the plant pathogens Colletotrichum fragariae, Colletotrichum gloeosporioides, and Colletotrichum acutatum. Bioassay-guided fractionation of this fraction resulted in the isolation of the bioactive fatty acids (9 S,10 E,12 Z)-9-hydroxy-10,12-octadecadienoic acid (1), (9 E,11 Z)-13-oxo-9,11-octadecadienoic acid (2), and (10 E,12 E)-9-oxo-10,12-octadecadienoic acid (3). These three oxylipins were further evaluated for activity against a greater range of fungal plant pathogens (C. fragariae, C. gloeosporioides, C. acutatum, Botrytis cinerea, Fusarium oxysporum, Phomopsis obscurans, and Phomopsis viticola) in in vitro dose-response studies. Phomopis species were the most sensitive fungi to these compounds. At 120 h of treatment, the IC50 values for compounds 1, 2, and 3 for P. obscurans were 1.0, 4.5, and 23 microM, respectively, as compared to 1.1 microM for the captan positive control.     

Fate of fatty acids derived from biogas residues in arable soil

Biogas residues are rich in microbial biomass and contribute to organic matter formation when applied to soils. Here we present a detailed analysis of the fatty acids derived from ¹³C-labelled biogas residues applied to arable soil and incubated for 378 days. We applied a differential approach using phospholipid fatty acids and total fatty acids to evaluate the carbon dynamics in living biomass and non-living soil organic matter. Biogas residue addition increased the microbial biomass in soil. The sum of ¹³C-labelled phospholipid fatty acids decreased to ∼60% during incubation whereas the decrease of t-FA was higher (to 33%). Compound-specific fatty acid analysis showed fatty acid specific incorporation or loss of ¹³C, indicating hints for the carbon flow within the microbial food web. Overall, microbial biomass in biogas residues may be a significant contributor to soil organic matter formation.     

Oxidation process affecting fatty acids and cholesterol in fried and roasted salmon.

Salmon was processed by three different culinary techniques: pan-frying with olive oil, pan-frying with soya oil, and roasting. Roasting did not modify the fat content from that of raw samples. Frying increased the fat content 2-fold, with no difference between samples fried with different oils. Total cholesterol oxidized products (COPs) were 0.74, 2.98, 3.35, and 7.38 microg/g fat in raw, fried with olive oil, fried with soya oil, and roasted salmon, respectively, which represent 0.01, 0.08, 0.09, and 0.15% of cholesterol. A significant correlation (r = 0.902, < or = 0.01) was found between acidity index and total COPs. The most abundant COPs were 7-ketocholesterol, which appeared in all the samples, and cholestanetriol (one of the most citotoxic COP), which appeared only in cooked samples (1.05-1.33 microg/g fat). All cooked samples supplied more omega-6 polyunsaturated fatty acids (PUFAs) than raw samples and showed higher omega-6/omega-3 ratios. Roasted salmon showed the lowest omega-3 content and the highest PUFAs/(SFAs)-C18:0 and MUFAs+PUFAs/(SFAs-C18:0) ratios.     

Impact of fatty acyl composition and quantity of triglycerides on bioaccessibility of dietary carotenoids

A carotenoid-rich salad meal with varying amounts and types of triglycerides (TG) was digested using simulated gastric and small intestinal conditions. Xanthophylls (lutein and zeaxanthin) and carotenes (alpha-carotene, beta-carotene, and lycopene) in chyme and micelle fraction were quantified to determine digestive stability and efficiency of micellarization (bioaccessibility). Micellarization of lutein (+zeaxanthin) exceeded that of alpha- and beta-carotenes, which was greater than that of lycopene for all test conditions. Micellarization of carotenes, but not lutein (+zeaxanthin), was enhanced (P < 0.05) by addition of TG (2.5% v/w) to the meal and was dependent on fatty acyl chain length in structured TG (c18:1 > c8:0 > c4:0). The degree of unsaturation of c18 fatty acyl chains in TG added to the salad purée did not significantly alter the efficiency of micellarization of carotenoids. Relatively low amounts of triolein and canola oil (0.5-1%) were required for maximum micellarization of carotenes, but more oil (approximately 2.5%) was required when TG with medium chain saturated fatty acyl groups (e.g., trioctanoin and coconut oil) was added to the salad. Uptake of lutein and beta-carotene by Caco-2 cells also was examined by exposing cells to micelles generated during the simulated digestion of salad purée with either triolein or trioctanoin. Cell accumulation of beta-carotene was independent of fatty acyl composition of micelles, whereas lutein uptake was slightly, but significantly, increased from samples with digested triolein compared to trioctanoin. The results show that the in vitro transfer of alpha-carotene, beta-carotene, and lycopene from chyme to mixed micelles during digestion requires minimal (0.5-1%) lipid content in the meal and is affected by the length of fatty acyl chains but not the degree of unsaturation in TG. In contrast, fatty acyl chain length has limited if any impact on carotenoid uptake by small intestinal epithelial cells. These data suggest that the amount of TG in a typical meal does not limit the bioaccessibility of carotenoids.     

菜籽油皂脚中游离脂肪酸分子蒸馏分离模拟

该文利用分子蒸馏模型模拟分离皂脚中脂肪酸,进而为后续高效率制备生物柴油奠定基础.根据建立的分子蒸馏模型和物化参数的估算,对菜籽油皂脚中游离脂肪酸的分离进行模拟,并与实际试验数据进行了比较.研究结果表明:该模型在模拟分离菜籽油皂脚中游离脂肪酸时的结果与试验结果曲线趋势相近.随着蒸馏温度的增加,蒸馏量增大,蒸馏量模拟值与实验值的相对误差不超过16%.随着蒸馏温度的增加,重组分中游离脂肪酸含量不断降低,试验结果的脂肪酸浓度都大于模拟值,而相对误差随温度升高不断降低,蒸馏温度为453 K时较蒸馏温度为423 K时,相对误差降低近50%.     

Influence of fatty acids on wine foaming

The influence of fatty acids (free and bound as ethyl esters) on wine foaming was studied in different white wines and the corresponding sparkling wines. Moreover, from three of these wines the foam formed by CO(2) injection was separated, and two fractions were then obtained: foam wine (FW) and remainder wine (RW). In these fractions and the sparkling wines produced from them, foam properties and fatty acids were also determined. The free fatty acids C8, C10, and C12 were negatively correlated with foamability (HM), whereas the ethyl esters of hexanoic, octanoic, and decanoic acids were positively related to HM. The value of HM was directly proportional to the ratio of esterified to unesterified fatty acids. This was confirmed by the changes that occur in the esterification ratio during the second fermentation and aging. No influence was observed on either the Bikerman coefficient or the stability time of foam.     

果蔬垃圾重复批次发酵协同制备乳酸和短链脂肪酸

利用果蔬垃圾厌氧合成中链脂肪酸（medium-chain fatty acids,MCFAs）等化学品是厌氧技术高值化的重要方向。中链脂肪酸合成通常需要以乳酸/乙醇（电子供体）和短链脂肪酸（电子受体）为碳源进行碳链延长反应。因此,利用有机废弃物连续、稳定地协同制备乳酸和短链脂肪酸是中链脂肪酸合成的关键步骤。该研究考察了果蔬垃圾重复批次发酵协同制备乳酸和短链脂肪酸（short-chain fatty acids,SCFAs）的可行性,研究了不同置换率和进料浓度对果蔬垃圾重复批次发酵产酸特性的影响。结果表明,调控重复批次发酵的置换率和进料浓度是提高生产率、改善乳酸/SCFAs比例的有效方法。综合考虑酸化产物的生产率、乳酸/SCFAs比例和碳源浓度,在70%置换率和8%进料TS(total solid)浓度条件下获得的酸化产物相对更有利于MCFAs的合成。此时,酸化产物生产率达到（5.25±0.25）g/(L·d),乳酸/SCFAs的碳摩尔比例达到5±0.3,碳源浓度达到（985±29）mmol C/L。微生物群落分析显示,乳酸菌,如Lactobacillus和Enterococcus作为优势菌通过异型乳酸发酵协同制备乳酸和SCFAs。研究结果可为果蔬垃圾的高值化利用提供参考。     

Effect of diet and dietary fatty acids on the transformation and incorporation of C18 fatty acids in double-muscled Belgian Blue young bulls

Three groups of double-muscled Belgian Blue young bulls were fed during different stages of production diets differing in the proportions of linolenic and linoleic acid by including linseed in the concentrate or giving grass silage as main linolenic acid suppliers. Samples of rumen and abomasal contents and of the longissimus thoracis, subcutaneous fat, and liver were taken to analyze the fatty acid pattern with emphasis on the individual trans (t) C18:1 fatty acids and cis-9,trans-11 conjugated linoleic acid (c9t11CLA). Trans C18:1 isomers represented up to 20 g/100 g of total fatty acids in rumen and abomasal contents, whereas the accumulation of c9t11CLA was limited. Total trans C18:1 content in subcutaneous fat and intramuscular fat of the longissimus thoracis comprised 8.4 and 5.2 g/100 g of total fatty acids, respectively, with t11C18:1 being the most abundant one. Compared to rumen contents, subcutaneous and intramuscular fat were enriched in c9t11CLA and contained fewer tC18:1 isomers, resulting in a higher c9t11CLA/t11C18:1 ratio (0.04, 0.22, and 0.22, respectively). This result suggests that the endogenous synthesis of c9t11CLA in adipose tissue by the Delta(9)-desaturase was more important than its ruminal production.     

Studies on the bacteria isolated anaerobically from paddy field soil III. Production of fatty acids and ammonia by Clostridium species

The volatile fatty acids produced by the representative strains of clostridia isolated from paddy field soil were surveyed. All the strains, except Cl. tertium, utilized only amino acids as the sole source of energy for growth. All of them produced acetic and butyric acids, and some of them produced propionic acid in addition. Iso-valeric and iso-butyric acids were also produced, except by Cl. tertium. These results suggest that all the strains, except Cl. tertium, may carry out the STICKLAND reaction. The cells of each strain harvested from the culture in the VL medium were subjected to examination whether or not they carried out the STICKLAND reaction in the presence of leucine or glycine. All the strains, except Cl. tertium, catalyzed the STICKLAND reaction and some strains also metabolized leucine and glycine even when they were supplied singly.     

Incorporation and stabilization of omega-3 fatty acids in surimi made from cod, Gadus morhua

Surimi containing omega-3 fatty acids from algal oil was prepared by the addition of oil-in-water emulsions or bulk oil. Emulsion and bulk oil were added separately to surimi to provide approximately 500 mg of omega-3 fatty acids per serving of surimi (85 g). Addition of the emulsion had no effect on surimi gel strength, whereas bulk oil decreased gel strength an average of 31%. All surimi treatments containing algal oil increased in Hunter b values due to the presence of carotenoids in the oil. Among cryoprotectants, sodium tripolyphosphate was the major surimi additive responsible for retarding the formation of lipid hydroperoxides and thiobarbituric acid reactive substances (TBARS). Lipid hydroperoxide and TBARS formation was lower in surimi containing bulk oil compared to surimi with emulsified oil. Both EDTA and lipid soluble antioxidants were able to decrease lipid oxidation in surimi fortified with omega-3 fatty acids. This suggests that surimi containing nutritionally beneficial omega-3 fatty acids could be developed with good oxidative stability and gel strength.     

Isolation of two anti-inflammatory and one pro-inflammatory polyunsaturated fatty acids from the brown seaweed Undaria pinnatifida

Two anti-inflammatory omega-3 polyunsaturated fatty acids (PUFAs) of stearidonic acid (SA) and eicosapentaenoic acid (EPA) and one pro-inflammatory omega-6 PUFA of arachidonic acid (AA) were isolated from the edible brown seaweed Undaria pinnatifida. SA was active against mouse ear inflammation induced by phorbol myristate acetate, with IC50 values of 160, 314, and 235 microg per ear for edema, erythema, and blood flow, respectively. EPA was also active against edema, erythema, and blood flow, with IC50 values of 230, 462, and 236 microg per ear, respectively. Although AA at low concentrations showed anti-inflammatory activities when measured 10 h later, AA doses of more than 243 microg per ear induced inflammatory symptoms 1 h later. Mature thalli generally had larger amounts of PUFAs than young thalli. The algal blade contained more omega-3 PUFAs than were found in other parts, while the holdfast contained extremely high amounts of AA. Late-season thalli showed increased amounts of PUFAs, especially AA.     

Insecticidal components from field pea extracts: soyasaponins and lysolecithins

Extracts from field peas (Pisum sativum L.) have previously been shown to have a utility to control insect pests. To identify potentially new bioinsecticides in field crops, we describe the fractionation of impure extracts (C8 extracts) derived from protein-rich fractions of commercial pea flour. The activity of separated fractions was determined by a flour disk antifeedant bioassay with the rice weevil [Sitophilus oryzae (L.)], an insect pest of stored products. Bioassay-guided fractionation showed that the triterpenoid saponin fractions were partly responsible for the antifeedant activity of C8 extracts. Soyasaponin I (soyasaponin Bb), isolated from peas and soybeans, and mixtures of soyasaponins, comprised of soyasaponins I-III and isolated from soybeans, were inactive antifeedants, but dehydrosoyasaponin I (the C-22 ketone derivative of soyasaponin I), a minor component found in C8 extracts, was shown to be an active component. Dehydrosoyasaponin I (soyasaponin Be) and soyasaponin VI (soyasaponin betag) coeluted under conditions of silica gel thin-layer chromatography and C18 high-performance liquid chromatography. However, dehydrosoyasaponin I could be isolated from saponin-enriched fractions with a reversed phase column of styrene/divinylbenzene operated at alkaline pH. Phospholipids of the lysolecithin type were also identified in saponin fractions of C8 extracts from peas. Three of the lysolecithins were inactive alone against rice weevils, but mixtures of these phospholipids enhanced the insecticidal activity of dehydrosoyasaponin I.     

Insecticidal sesquiterpene from Alpinia oxyphylla against Drosophila melanogaster

In the course of screening for novel naturally occurring insecticides from Chinese crude drugs, an MeOH extract of Alpinia oxyphylla was found to possess insecticidal activity against larvae of Drosophila melanogaster Meigen. From the extract, an insecticidal compound was isolated by bioassay-guided fractionation and identified as nootkatone (1) by GC, GC-MS, and (1)H and (13)C NMR spectroscopy. In bioassays for insecticidal activity, 1 showed an LC(50) value of 11.5 micromol/mL of diet against larvae of D. melanogaster and an LD(50) value of 96 microg/adult against adults. Epinootkatol (1A), however, showed slight insecticidal activity in both assays, indicating that the carbonyl group at the 2-position in 1 was the important function for enhanced activity of 1.     

Antioxidant and cyclooxygenase activities of fatty acids found in food

Several commercially available C-8 to C-24 saturated and unsaturated fatty acids (1-29) were assayed for cyclooxygenase-I (COX-I) and cyclooxygenase-II (COX-II) inhibitory and antioxidant activities. Among the saturated fatty acids tested at 60 microg mL(-1), there was an increase in antioxidant activity with increasing chain length from octanoic acid to myristic acid (C-8-C-14) and a decrease thereafter. All unsaturated fatty acids tested at 60 microg mL(-1) showed good antioxidant activity except for undecylenic acid (12), cis-5-dodecenoic acid (13), and nervonic acid (29). The highest inhibitory activities among the saturated fatty acids tested on cyclooxygenase enzymes COX-I and COX-II were observed for decanoic acid to lauric acid (3-5) at 100 microg mL(-1). Similarly, among the unsaturated fatty acids tested, the highest activities were observed for cis-8,11,14-eicosatrienoic acid (25) and cis-13,16-docosadienoic acid (27) at 100 microg mL(-1).     

Lipophilization of lysozyme by short and middle chain fatty acids

Hen egg white lysozyme was lipophilized with short and middle chain saturated fatty acids (caproic, capric, or myristic acid). The yield, bactericidal properties, and structural properties of lipophilized lysozymes were investigated. The yield of lipophilization of lysozyme greatly increased with the decrease in the chain length of fatty acid. Lipophilization broadened the bactericidal action of lysozyme to Gram-negative bacteria with little loss of enzymatic activity. The bactericidal activity increased in proportion to the number of bound short chain fatty acids. The thermal stability of lipophilized lysozyme decreased in proportion to the chain length and number of bound fatty acids.     

Rapid extraction and analysis of volatile fatty acids in soil

Abstract

The concentrations of volatile fatty acids (VFA) in soils are important in studies involving phytotoxicity and fermentation processes. Concentrations of acetic, propionic, and butyric acids as low as 0.21, 0.14, and 0.10 mmol kg^‐1soil in water extracts were accurately determined. The extracts were filtered through 45 μm millipore disc filters and injected directly into a gas chromatograph following addition of purified formic acid. The formic acid eliminated ghosting of peaks. The gas chromatograph was equipped with a flame ionization detector and a 60/80 Carbopack C/0.3% Carbowax 20M/0.1% H₃PO₄packed precolumn (0.15 m) and column (1.83 m). The precolumn was changed after 150 to 200 sample injections when contaminated beyond acceptable limits. There was good separation of VFA with no interfering organic volatiles in extracts of soil containing glucose, cellulose or straw incubated anaerobically for as long as 4 weeks. The advantages of the procedure are relative rapidity and simplicity as well as improved sensitivity in measuring small quantities of volatile fatty acids in soil