Dienoic Acid Research Articles

Clerodendrumol, A New Triterpenoid from Clerodendrum yaundense Gürke (Lamiaceae)

AbstractA new lupane‐type triterpene named clerodendrumol (1), i.e., (16α)‐lupa‐12,20(29)‐dien‐16‐ol, together with five known compounds, octacosa‐(5Z,9Z)‐dienoic acid (3), tetracosanoic acid (4), genkwanin (5), (12S)‐hydroxyoctadeca‐(9Z,13E,15E)‐trienoic acid (6), and (9S)‐hydroxyoctadeca‐(10E,12E)‐dienoic acid (7), were isolated from the twigs of Clerodendrum yaundense. O‐Acetylclerodendrumol (2), a derivative of 1, was prepared by a standard acetylation procedure applied to compound 1. The structure of the new compound was elucidated using spectroscopic analysis (NMR and MS) data, and chemical conversions (acetylation and deacetylation). The human breast cancer cell line (MDA‐MB‐231) was sensitive to all test samples, and clerodendrumol (1) as well as its derivative 2 had good activity (IC50 values 7.5 and 13.2 μM). Genkwanin (5) exhibited strong activity on HeLa cell line with IC50 7.8 μM.

Effects of pH on the rates of lipid oxidation in oil–water system

The effect of pH on the oxidative stability in oil–water systems was determined at 40 °C for 18 days by monitoring headspace oxygen depletion and concentration of conjugated dienoic acids (CDAs). Two types of pH solutions were prepared: a buffer solution and a mixture of NaOH and HCl. When the pH of the mixture of NaOH and HCl increased from 1 to 13, the oxidative stability in oil decreased significantly in the order of pH 1 > 10 > 7 > 4 > 13. In case of the buffer solution, the oxidative stabilities of oils were in the order of pH 4 = 7 > 10. Depending on the pH and buffering capacities, oxidative stability of oils were greatly influenced.

An Unprecedented Occurrence of Δ5,9- and Δ9,15-Dienoic Fatty Acids in Ovaries of the Archaeogastropod Limpet Cellana toreuma.

A detailed structural diversity of dienoic fatty acids (FA), including non-methylene-interrupted dienoic FA, of triacylglycerols and polar lipids in ovaries of Cellana toreuma was clarified for the first time by using capillary gas chromatography-mass spectrometry of their 3-pyridylcarbinol esters and argentation thin-layer chromatography. Interestingly, in addition to 5,9-octadecadienoic (18:2Δ5,9), 5,9-eicosadienoic (20:2Δ5,9), 5,9-heneicosadienoic (21:2Δ5,9), 5,9-docosadienoic (22:2Δ5,9), 5,9-tricosadienoic (23:2Δ5,9), and 5,9-tetracosadienoic (24:2Δ5,9) acids, previously identified in ovaries of C. grata, rare FA 5,9-hexadecadienoic (16:2Δ5,9), 5,9-nonadecadienoic (19:2Δ5,9), and 21-methyl-5,9-docosadienoic (iso 23:2Δ5,9) were newly recognized in ovaries of C. toreuma. Detectable amounts of four Δ9,15-dienoic FA were present in the ovary lipids. The FA identified were one novel 9,15-heneicosadienoic (21:2Δ9,15) acid and known 9,15-docosadienoic (22:2Δ9,15), 9,15-tricosadienoic (23:2Δ9,15), and 9,15-tetracosadienoic (24:2Δ9,15) acids. The findings help to explain the broad evidence of the structural diversity in marine gastropods and suggest biomarkers to evaluate marine food web relations.

Production of conjugated dienoic and trienoic fatty acids by lactic acid bacteria and bifidobacteria

The production of conjugated linoleic (CLA) and linolenic (CLNA) acids by lactic acid bacteria (LAB) and bifidobacteria strains was assessed. The initial selection was based on optical density measurements by the UV method and GC analysis. The LAB strains showed a lower ability to synthesise CLA and CLNA. Yet, two Lactobacillus sakei strains were the best producers. Moreover, the production of CLA and CLNA by Lactobacillus mucosae is reported here for the first time. In contrast, bifidobacteria strains were more efficient to synthesise CLA and CLNA. Among these, the t9, t11-CLA was the main isomer, which is a potent anticarcinogenic compound. All tested strains produced the c9,t11,c15-CLNA isomer. High substrate concentrations of LA and LNA negatively affected the conversion rate of CLA and CLNA by Bifidobacterium animalis subsp. lactis INL2, even though the bacterial growth was not affected.

Radical Solution to the Alkylation of the Highly Base-Sensitive 1,1-Dichloroacetone. Application to the Synthesis of Z-Alkenoates and E,E-Dienoates.

A simple radical-based route to gem-α-dichloroketones, relying on the degenerative addition transfer of (S)-[3,3-dichloro-2-oxopropyl]-O-ethyl dithiocarbonate (xanthate), is described. The adducts can then be converted into Z-enoates by exposure to Et3N in methanol. In the case of certain substrates, it was possible to form skipped dienoic acid and methyl E,E-dienoates.

NZ,(n + 4)Z-Dienoic fatty acids: a new method for the synthesis and inhibitory action on topoisomerase I and IIα

An original, effective approach to the stereoselective method for the synthesis of higher unsaturated acids containing a 1Z,5Z-diene group in 61–75 % yields and with >98 % selectivity based on the new intermolecular Cp2TiCl2-catalyzed cross-cyclomagnesiation of terminal aliphatic and O-containing 1,2-diene with Grignard reagents has been developed. The inhibitory action of the obtained dienoic acids on the human topoisomerase I and II was studied. Resorting to the data of molecular docking, a probable mechanism of inhibition was proposed.

A defensin fragment regulates CHO-K1 cell spreading and induces renewal of fatty acid composition in cell membrane phospholipids.

A tetrapeptide defensin fragment has been shown to stimulate the spreading of CHOK1 cells. The tetrapeptide investigated had virtually no effect on the composition of cell membrane phospholipids but participated in the regulation of the renewal of fatty acid composition of phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, and phosphatidylinositol. Incubation of cells with the peptide resulted in a change in the composition of the unsaturated fatty acid residues in the phospholipids investigated: specifically, the content of monoenoic and/or dienoic acids increased and that of polyenoic acids decreased. The possible role of the peptide investigated (1) in the regulation of the functional activity of integrin receptors, and (2) in changes in the packing density of the phospholipid acyl chains in cell membrane microdomains, which affects the rates of integrin clustering and adhesion complex formation, is discussed.

Effects of relative humidity and neutral emulsifier on oxidative stability of corn oil during room temperature storage

The effects of tween 20, one of neutral emulsifiers, on oxidative stability of corn oil were determined under a relative humidity (RH) range of 0–93 % at room temperature after 350 days of storage. The degree of oxidation was determined by headspace oxygen content and conjugated dienoic acids analyses. Moisture content and α-tocopherol were also analyzed. The degree of lipid oxidation was significantly influenced by the concentration of tween 20 and relative humidity. Samples without addition of tween 20 showed the highest oxidative stability in 11 % RH, whereas oxidative stability was lowest at 93 % RH. Adding 0.5 and 1.0 % tween 20 increased the rate of lipid oxidation in a concentration dependent manner. Samples containing tween 20 had higher moisture content than those without an amphiphilic compound. Stability of α-tocopherol was depending on the content of moisture and amphiphilic compounds in bulk oil.

Synergism of phosphatidylcholine on the antioxidant properties of α‐tocopherol in corn oils under different relative humidity

SummaryThe effects of phosphatidylcholine on the antioxidant properties of α‐tocopherol (84 ppm) were determined in stripped corn oil with various moisture contents at 60 °C. The degree of oxidation in the oils was determined by analysing headspace oxygen content and conjugated dienoic acids (CDA). Generally, phosphatidylcholine acted as an antioxidant in stripped corn oils, whereas it accelerated the rate of lipid oxidation in nonstripped corn oils. As the relative humidity and moisture content increased, the antioxidant properties of phosphatidylcholine increased significantly (P < 0.05). Strong synergistic antioxidant effects were observed in samples containing both phosphatidylcholine and α‐tocopherol compared to samples with only phosphatidylcholine or α‐tocopherol. Oils containing phosphatidylcholine or α‐tocopherol under different moisture contents had different oxidative stabilities.

Additive-free decarboxylative coupling of cinnamic acid derivatives in water: synthesis of allyl amines.

The first example of an additive-free decarboxylative coupling of cinnamic acid derivatives with formaldehyde and amines to afford the corresponding allyl amines is reported. This reaction is highly environmentally friendly because it was conducted in H2O and without any additives, releasing only CO2 and H2O as byproducts. This reaction showed a broad substrate scope including cyclic and acyclic amines and high functional group tolerance. Moreover, phenyl dienoic acid participated in this type of decarboxylative coupling reaction.

Threonine 286 of fatty acid desaturase 7 is essential for ω-3 fatty acid desaturation in the green microalga Chlamydomonas reinhardtii.

Omega-3 fatty acid desaturases catalyze the conversion of dienoic fatty acids (C18:2 and C16:2) into trienoic fatty acids (C18:3 and C16:3), accounting for more than 50% of the total fatty acids in higher plants and the green microalga Chlamydomonas reinhardtii. Here, we describe a Thr residue located in the fourth transmembrane domain of fatty acid desaturase 7 (FAD7) that is essential for the biosynthesis of ω-3 fatty acids in C. reinhardtii. The ω-3 fatty acid deficiency in strain CC-620, which contains a putative missense mutation at Thr286 of CrFAD7, was recovered by the overexpression of CC-125 CrFAD7. A Ser substitution in position 286 was able to partially complement the phenotype of the ω-3 fatty acid deficiency, but other substitution variants, such as Tyr, His, Cys, and Gly, failed to do so. Prediction of the phosphorylation target site revealed that Thr286 may be phosphorylated. Analysis of the structural conformation of CC-620 CrFAD7 via topology prediction (and bends in the helix) shows that this missense mutation may collapse the catalytic structure of CrFAD7. Taken together, this study suggests that Thr286 is essential for the maintaining the catalytic structure of CrFAD7.

Long-chain PUFA enrichment in microalgae and metabolic dynamics inTapes philippinarumlarvae

The possibility of increasing n-3 and n-6 long-chain polyunsaturated fatty acids (PUFA) content in microalgal mixtures used to feed Tapes philippinarum larvae was explored by lowering culture temperature from 26 to 14 °C. Although fatty acid composition of different microalgal species has a genetic basis, the algal cultures grown at 14 °C significantly increased the content of long-chain n-3 PUFA in Isocrysis galbana and in Thalassiosira pseudonana, while in Tetraselmis tetrathelo, the PUFA increase only involved shorter chain PUFA, namely 16:4n-3 and 18:4n-3. However, larvae fed on the PUFA enriched microalgal mixture did not show improvements in growth and survival performances with respect to the control group fed the microalgal mixture grown at 26 °C. From a biochemical perspective, two key aspects emerged from the results: (i) clam larvae have adequate biotransformation and selection skills to adjust fatty acid profile to their requirements as they can even modulate the incorporation of essential long-chain PUFA as 20:5n-3 and 22:6n-3 when the dietary supply exceeds the physiological requirements; (ii) bivalve can biosynthesize non-methylene-interrupted dienoic (NMID) fatty acids as confirmed by the constancy of relative proportion with larvae growth in spite of the NMID fatty acid absence in the diet.

ChemInform Abstract: Direct Synthesis of Stereodefined and Functionalized Dienes as Valuable Building Blocks

AbstractReview: 30 refs.

토스팅에 따른 김의 지방질 산화, 산화방지성분과 색소 변화

The effects of toasting, simulated gimgui (dried and toasted laver) manufacturing, on lipid oxidation and antioxidant and pigment contents of dried laver (Porphyra spp.) were evaluated by peroxide value (POV) and conjugated dienoic acid (CDA) value measurement, HPLC, and spectrophotometry. Dried laver was toasted for 40 or 300 s at 120℃, or for 2 or 5 s at 250℃. The POV and CDA contents were significantly higher in the toasted samples (0.60-0.69 mmol/kg and 2.17-4.20%, respectively) except in samples toasted at 120℃ for 40 s, compared to those in the non-toasted samples (0.43 mmol/kg and 1.21%, respectively). Chlorophyll was the most stable pigment during toasting (>90% retention), followed by carotenoids (50-77% retention) and phycocyanins and phycoerythrins (13-73% retention). Porphyran was the most stable antioxidant (>95% retention), and polyphenols, the most unstable antioxidant (24-75% retention). Despite the degradation of pigments and antioxidants during toasting, the dried laver still contained health-benefiting components after toasting.

Antioxidant properties of ascorbic acid in bulk oils at different relative humidity

The effects of relative humidity (RH) on the antioxidant properties of ascorbic acid (10, 20, 42, and 84ppm) were investigated in stripped corn oils stored at 60°C. The degree of oxidation in oils was determined by analysing headspace oxygen content and conjugated dienoic acids. The oxidative stability of bulk oils without addition of ascorbic acid was significantly different depending on the RH. As the concentration of ascorbic acid increased from 10 to 84ppm, oxidative stability increased significantly irrespective of RH (p<0.05). Generally, oils containing ascorbic acid at low RH had higher oxidative stability after storage at 60°C than those at high RH. The antioxidant properties of ascorbic acid were greatly influenced by both the moisture content in the oil and the ascorbic acid concentration.

Androgen-induced hypertension in angiotensinogen deficient mice: Role of 20-HETE and EETS

20-HETE is a potent inducer of endothelial ACE in vitro and administration of lisinopril or losartan attenuates blood pressure in models of 20-HETE-dependent hypertension. The present study was undertaken to further define the relationship between 20-HETE and the renin–angiotensin system in hypertension using an angiotensinogen-deficient mouse (Agt+/−). Treatment of male AGT+/− with 5α-dihydrotestosterone (DHT) increased systolic BP from 102±2 to 125±3mmHg; in comparison, the same treatment raised BP in wild type (WT) from 110±2 to 138±2mmHg. DHT increased vascular 20-HETE levels in AGT+/− and WT from 1.5±0.7 and 2.1±0.6 to 13.0±2.0 and 15.8±4.0ng/mg, respectively. Concurrent treatment with the 20-HETE antagonist, 20-hydroxyeicosa-6(Z),15(Z)-dienoic acid (20-HEDE) prevented the increases in BP in both AGT+/− and WT mice. Administration of 20-HEDE at the peak of the DHT-induced BP increase (12 days) reduced BP to basal levels after 48h. Interestingly, basal levels of renal microvascular EETs were higher in AGT+/− compared to WT (55.2±9.7 vs 20.0±4.1ng/mg) and treatment of AGT+/− with DHT decreased the levels of EETs (28.4±5.1ng/mg). DHT-mediated changes in vascular EET level were not observed in WT mice. Vascular Cyp4a12 and ACE protein levels were increased in both AGT+/− and WT by 30–40% and decreased with concomitant administration of 20-HEDE. Lisinopril was as effective as 20-HEDE in preventing DHT-mediated increases in BP in both AGT+/− and WT mice. This study substantiates our previous findings that the RAS plays an important role in 20-HETE-mediated hypertension. It also proposes a novel interaction between 20-HETE and EETs.

Estimating the time of frying oils have been used for French fries based on profile changes of fatty acids derived from heated oil model systems

Time of use for frying oils recovered from French fries was estimated based on ratios of fatty acids and values of conjugated dienoic acid (CDA) and/or p-anisidine (p-AV) derived from oxidation data of oils heated to 180°C in model systems. Changes in CDA and p-AV values in oils occurred faster than changes in ratios of fatty acids (oleic to linoleic acids, O/L) and saturated to unsaturated fatty acids (SFAs/UFAs). Oil use times estimated by O/L SFAs/UFAs ratios, and on CDA and p-AV values in oil recovered from French fries were 1.38, 1.42, 0.36, and 0.22 h, respectively. The actual oil use time was 1.5 h. Although oxidation parameters from heated oil models may not accurately reflect changes in oils during deep-fat frying of French fries, ratios of fatty acids in oils may be more useful for predicting the use time of frying oils than CDA and p-AV values.

Effects of relative humidity on the antioxidant properties of α-tocopherol in stripped corn oil

The effects of relative humidity (RH) on the antioxidant properties of α-tocopherol (10, 20, 42, and 84ppm) were determined in stripped corn oil oxidised at 60°C. The degree of oxidation in oils was determined by analysing headspace oxygen content and conjugated dienoic acids (CDAs). Changes in moisture and α-tocopherol content were also monitored. The oxidative stability of stripped corn oil and stability of α-tocopherol differed significantly depending on the RH. As the concentration of α-tocopherol increased from 10 to 84ppm, oxidative stability decreased significantly irrespective of RH. The remaining α-tocopherol content decreased as RH increased, suggesting an important role for moisture content in the stability of α-tocopherol. Antioxidant properties of α-tocopherol were greatly influenced by both moisture content in oil and α-tocopherol concentration.

Effects of Phosphatidylcholine on Interaction of α‐Tocopherol and β‐Carotene in Photosensitized Oxidation of Emulsions

AbstractThe interaction between α‐tocopherol (500 mg/kg) and β‐carotene (10 mg/kg) during chlorophyll‐photosensitized oxidation of a sunflower oil emulsion was studied in the presence or absence of phosphatidylcholine (PC, 250 mg/kg) by determining peroxide (POV) and conjugated dienoic acid (CDA) values. Chlorophyll, α‐tocopherol, β‐carotene, and PC contents in the emulsion were also monitored. α‐Tocopherol and β‐carotene individually and interactively decreased the POV and CDA values of oil in the emulsion by singlet oxygen quenching. PC decreased the POV and CDA values of oil, however, the values of the emulsion with added α‐tocopherol, β‐carotene, and PC were not significantly different from those of the emulsion with added α‐tocopherol and β‐carotene without PC. Contents of α‐tocopherol did not change during 24‐h oxidation, whereas co‐present PC significantly caused α‐tocopherol and chlorophyll degradation. β‐Carotene and PC contents significantly decreased to 45.5 and 51.3 %, respectively, after 24 h, and α‐tocopherol protected β‐carotene from degradation. The results suggest that PC had no net effects on the interactive antioxidant activity of α‐tocopherol and β‐carotene during chlorophyll‐photosensitized oxidation of the emulsion through free radical generation, chlorophyll degradation, and lessening the potency of α‐tocopherol as a singlet oxygen quencher.

Light effects on lipid oxidation, antioxidants, and pigments in dried laver (Porphyra) during storage

Effects of light on lipid oxidation, antioxidants, and pigments in dried laver (Porphyra) were studied during storage at 40°C and at a water activity of 0.75 for 15 days. Lipid oxidation was evaluated by measuring peroxide value (POV) and conjugated dienoic acid (CDA) contents, whereas fatty acid composition was analyzed by gas chromatography. Contents of polyphenols, tocopherols, porphyran, chlorophylls, carotenoids, and phycobilins were also monitored. The POV and CDA contents of dried laver lipids increased during storage, whereas contents of eicosapentaenoic acid, pigments, and antioxidants decreased. Light accelerated lipid oxidation as well as degradation of antioxidants and pigments during storage of dried laver. Chlorophyll and polyphenols were the most rapidly degraded among all pigments and antioxidants, respectively, and light had the strongest effect on their degradation. Lipid oxidation of dried laver due to light was highly dependent on the content of a-tocopherol among all minor compounds.