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PubMed1983

Simple enzymatic detection method for urinary sulfated 7 alpha-hydroxy bile acids in normal subjects and in patients with acute hepatitis.

Urinary sulfated primary bile acids, 7 alpha-hydroxy bile acids, are detected by an enzymatic method using 7 alpha-hydroxysteroid dehydrogenase (EC 1.1.1.-, 7 alpha-HSD) after chromatographic fractionation on Sephadex G-25. Urinary sulfated or glucuronated bile acids are hydrolyzed by beta-glucuronidase/sulfatase (EC 3.2.1.31/EC 3.1.6.1) from Helix pomatia and then released 7 alpha-hydroxy bile acids are detected with 7 alpha-HSD in the presence of beta-ND+, diaphorase (EC 1.6.99.2, from Clostridium kluyveri) and 2-p-iodophenyl-3-p-nitrophenyl-5-phenyltetrazolium chloride. The absorbance of formazan formed during the enzymic reaction is measured at 500 nm. Excretion values of 7 alpha-hydroxy bile acids in normal subjects and in patients with acute hepatitis were compared. This enzymatic detection method for the excretion pattern of urinary 7 alpha-hydroxy bile acids may be useful for clinical diagnosis.

Bile Acids and Salts↗
PubMed2001

Conjugated linoleic acid accumulation via 10-hydroxy-12-octadecaenoic acid during microaerobic transformation of linoleic acid by Lactobacillus acidophilus.

Specific isomers of conjugated linoleic acid (CLA), a fatty acid with potentially beneficial physiological and anticarcinogenic effects, were efficiently produced from linoleic acid by washed cells of Lactobacillus acidophilus AKU 1137 under microaerobic conditions, and the metabolic pathway of CLA production from linoleic acid is explained for the first time. The CLA isomers produced were identified as cis-9, trans-11- or trans-9, cis-11-octadecadienoic acid and trans-9, trans-11-octadecadienoic acid. Preceding the production of CLA, hydroxy fatty acids identified as 10-hydroxy-cis-12-octadecaenoic acid and 10-hydroxy-trans-12-octadecaenoic acid had accumulated. The isolated 10-hydroxy-cis-12-octadecaenoic acid was transformed into CLA during incubation with washed cells of L. acidophilus, suggesting that this hydroxy fatty acid is one of the intermediates of CLA production from linoleic acid. The washed cells of L. acidophilus producing high levels of CLA were obtained by cultivation in a medium containing linoleic acid, indicating that the enzyme system for CLA production is induced by linoleic acid. After 4 days of reaction with these washed cells, more than 95% of the added linoleic acid (5 mg/ml) was transformed into CLA, and the CLA content in total fatty acids recovered exceeded 80% (wt/wt). Almost all of the CLA produced was in the cells or was associated with the cells as free fatty acid.

Aerobiosis↗
PubMed1975

Fluorescent demonstration of basement membranes with hydroxy-naphthoic acid hydrazide.

The hydroxy-naphthoic acid hydrazide (HNAH) procedure can be employed not only for selective fluorochroming of side chain carboxyl groups of proteins, but also for demonstration of certain exoplasmic structures---particularly basement membranes. The demonstration of basement membranes by the HNAH procedure is likely related to the relatively high levels of available side chain carboxyl groups in the noncollagen glycoproteins of basement membranes.

Animals↗
PubMed1989

2-Hydroxy fatty acids from marine sponges. 2. The phospholipid fatty acids of the Caribbean sponges Verongula gigantea and Aplysina archeri.

The alpha-hydroxy fatty acids 2-hydroxy-eicosanoic (1) acid, 2-hydroxyheneicosanoic (2) acid, 2-hydroxydocosanoic (3) acid, 2-hydroxytetracosanoic (4) acid, 2-hydroxy-23-methyl-tetracosanoic acid and 2-hydroxypentacosanoic (5) acid were isolated from the Caribbean sponges Verongula gigantea and Aplysina archeri. The very long chain fatty acids 5,9-nonacosadienoic acid (29:2) and 5,9,23-tricontatrienoic acid (30:3) were also identified together with the iso-prenoid fatty acid 3,7,11,15-tetramethylhexadecanoic (phytanic) acid that seems to be common in the Aplysinidae. A. archeri contained an extremely long chain fatty acid tentatively characterized as dotricontaenoic (32:1) acid. These acids were found to occur in phosphatidylserine, phosphatidylinositol, phosphatidylethanolamine, phosphatidylcholine and traces of phosphatidylglycerol.

Animals↗
PubMed1979

Direct hydroxylation in the biosynthesis of hydroxy fatty acid in lipid a of Pseudomonas ovalis.

It was found that Pseudomonas ovalis IAM 1177 had an abundance of hydroxy fatty acids such as 3-hydroxy-decanoic acid, 3-hydroxy-dodecanoic acid and 2-hydroxy-dodecanoic acid in the lipophilic part of the lipopolysaccharide fraction, which comprise 80% of total fatty acids. By using 18O2, it was shown that one oxygen atom from molecular oxygen was incorporated into 2-hydroxy-dodecanoic acid, but not into 3-hydroxy-decanoic acid. The incorporated oxygen atom was specifically located at the hydroxyl group of 2-hydroxy-dodecanoic acid. The biosynthetic pathways of these hydroxy fatty acids are discussed.

Fatty Acids↗
PubMed1976

Absolute configuration of 3-hydroxy fatty acids present in lipopolysaccharides from various bacterial groups.

The absolute configuration of 3-hydroxy fatty acids has been studied, which are present in the lipopolysaccharides of the following bacteria: Phodopseudomonas gelatinosa, Rh. viridis, Rhodospirillum tenue, Chromobacterium violaceum, Pseudomonas aeruginosa, Bordetella pertussis, Vibrio metchnikovii, Vibrio cholerae, Salmonella spp., Escherichia coli, Shigella flexneri, Proteus mirabilis, Yersinia enterocolitica and Fusobacterium nucleatum. The 3-hydroxy acids were liberated by strong alkaline hydrolysis, converted to 3-methoxy acid L-phenylethylamides and analyzed by gas-liquid chromatography. With the aid of authentic D-3-hydroxy fatty acids it was shown for all lipopolysaccharides that the 3-hydroxy acids, regardless of chain lengths, branching, 3-O-substitution or type of linkage, possess the D-configuration. 2-Hydroxydodecanoic acid, which is present in some lipopolysaccharides, was analyzed in an analogous way and shown to possess the L-configuration.

Binding Sites↗
PubMed1970

Fatty acids of glycosphingolipids from pig blood fractions.

Four glycolipids have been isolated from three fractions of pig blood. The glycolipids were presumably cerebroside, diglycosyl ceramide, triglycosyl ceramide, and globoside. The blood fractions were erythrocytes and plasma high and low density lipoproteins. Fatty acid distributions were determined for each glycolipid as a means to assist in identifying relationships among the several glycolipids. Normal fatty acids predominated in all glycolipids except the globosides from erythrocytes in which the amount of hydroxy acids was slightly greater than the amount of normal acids. Hydroxy acids appeared to be present in all the glycolipids, but the concentration was very low in cerebrosides isolated from high density lipoproteins and erythrocytes, and in diglycosyl ceramide and globoside of the low density lipoproteins. In general, the average fatty acid chain length increased from cerebroside to globoside. This was most apparent in erythrocytes and also greater for normal acids than for hydroxy acids. Fatty acid distributions of erythrocyte glycolipids had sufficient variation to make a metabolic relationship by simple addition of a hexose appear doubtful. While the fatty acid distributions found in plasma lipoproteins were more similar, some means of acyl group selection is probably present for either the synthesis or degradation of these glycolipids.

Animals↗
PubMed2001

A condensing enzyme from the seeds of Lesquerella fendleri that specifically elongates hydroxy fatty acids.

Lesquerella fendleri seed oil contains up to 60% hydroxy fatty acids, nearly all of which is the 20-carbon hydroxy fatty acid lesquerolic acid (D-14-hydroxyeicos-cis-11-enoic acid). Previous work suggested that lesquerolic acid in L. fendleri was formed by the elongation of the 18-carbon hydroxy fatty acid, ricinoleic acid. To identify a gene encoding the enzyme involved in hydroxy fatty acid elongation, an L. fendleri genomic DNA library was screened using the coding region of the Arabidopsis Fatty Acid Elongation1 gene as a probe. A gene, LfKCS3, with a high sequence similarity to known very long-chain fatty acid condensing enzymes, was isolated. LfKCS3 has a 2,062-bp open reading frame interrupted by two introns, which encodes a polypeptide of 496 amino acids. LfKCS3 transcripts accumulated only in the embryos of L. fendleri and first appeared in the early stages of development. Fusion of the LfKCS3 promoter to the uidA reporter gene and expression in transgenic Arabidopsis resulted in a high level of beta-glucuronidase activity exclusively in developing embryos. Seeds of Arabidopsis plants transformed with LfKCS3 showed no change in their very long-chain fatty acid content. However, when these Arabidopsis plants were crossed with the transgenic plants expressing the castor oleate 12-hydroxylase, significant amounts of 20-carbon hydroxy fatty acids accumulated in the seed, indicating that the LfKCS3 condensing enzyme specifically catalyzes elongation of 18-carbon hydroxy fatty acids.

Acetyltransferases↗
PubMed1993

Mechanism-based inhibitors of prostaglandin omega-hydroxylase: (R)- and (S)-12-hydroxy-16-heptadecynoic acid and 2,2-dimethyl-12-hydroxy-16-heptadecynoic acid.

12-Hydroxy-16-heptadecynoic acid has been shown to selectively inactivate cytochrome P450 4A4, a pulmonary cytochrome P450 enzyme that catalyzes the omega-hydroxylation of prostaglandins [Muerhoff, A. S.; Williams, D. E.; Reich, N. O.; CaJacob, C. A.; Ortiz de Montellano, P. R.; Masters, B. S. S. J. Biol. Chem. 1989, 264, 749-756]. Potent, specific inhibitors of this enzyme are required to explore its physiological role. In a continuing effort to develop such agents, the two enantiomers of 12-hydroxy-16-heptadecynoic acid have been stereospecifically synthesized, their absolute stereochemistry confirmed, and the dependence of enzyme inactivation on absolute stereochemistry determined using cytochrome P450 4A4 purified from the lungs of pregnant rabbits. The 12S enantiomer is roughly twice as active (KI = 1.8 microM, t1/2 = 0.7 min) as the 12R enantiomer (KI = 3.6 microM, t1/2 = 0.8 min), but the chirality of the hydroxyl group is not a major determinant of the specificity for the prostaglandin omega-hydroxylase. The flexibility of the acyclic skeleton of the inhibitor may account for the relatively low enantiomeric discrimination. 2,2-Dimethyl-12-hydroxy-16-heptadecynoic acid, an analogue that cannot undergo beta-oxidation, has also been synthesized as a potential in vivo inhibitor of the enzyme and has been shown to inactivate the purified enzyme with KI = 4.9 microM and t1/2 = 1.0 min. These acetylenic agents, particularly the dimethyl analog, are promising in vivo inhibitors of cytochrome P450 4A4.

Animals↗
PubMed1985

Studies of metabolites in diarrheal stool specimens containing Shigella species by frequency-pulsed electron capture gas-liquid chromatography.

Eleven diarrheal stool specimens and 10 control stool specimens from Cairo, Egypt, were studied by frequency-pulsed electron capture gas-liquid chromatography (FPEC-GLC). Four cases involving Shigella sonnei, three cases involving Shigella boydii, and four cases involving Shigella flexneri were studied. The aqueous stools were centrifuged, extracted with organic solvents, and derivatized to form specific electron-capturing derivatives of carboxylic acids, alcohols, hydroxy acids, and amines. Analyses were performed on high-resolution glass columns with an instrument equipped with an extremely sensitive electron capture detector that is specific for the detection of electron-capturing compounds. The diarrheal stools studied had specific FPEC-GLC profiles and contained metabolic markers that readily distinguished between the Shigella spp. studied and Escherichia coli producing heat-stable or heat-labile enterotoxins. S. sonnei stools contained hexanoic acid, 2-hydroxy-4-methylmethiobutyric acid, and some unidentified alcohols that distinguished this organism from other enteric pathogens. S. boydii produced an acid that was unique for this species, and S. flexneri produced alcohols that could be used to distinguish between it and other enteric organisms. The FPEC-GLC profiles obtained during this study were also very different from those reported earlier for Clostridium difficile and rotavirus. This study presents further evidence that the selectivity and sensitivity of FPEC-GLC techniques can be used to rapidly identify causative agents of diarrhea and detect physiological changes that occur in the gut during the course of diarrheal illness.

Chromatography, Gas↗
PubMed1995

Bioconversion of methyl ricinoleate to 4-hydroxy-decanoic acid and to gamma-decalactone by yeasts of the genus Candida.

The capacity of several strains of yeasts to do the bioconversion of methyl ricinoleate into gamma-decalactone, was studied in a medium containing this methylic ester of fatty acid as sole carbon source. Amongst the strains which are able to do this bioconversion, two types of behaviour are observed: some of the strains produce gamma-decalactone during all the incubation in bioconversion medium while others produce this aroma compound very quickly and then consume it fast too. The tested strains produce at the same time gamma-decalactone and the corresponding acid form (4-hydroxy-decanoic acid), and this, in variable proportions.

Biomass↗
PubMedDate not supplied

alpha-Hydroxy acid-based cosmetic procedures. Guidelines for patient management.

alpha-Hydroxy acid (AHA) peels and home regimens have recently been recognized as important adjunctive therapy in a variety of conditions including photodamage, actinic damage, melasma, hyperpigmentation disorders, acne, and rosacea. Overall in our experience and in the literature, AHAs have a proven level of safety and efficacy in a variety of skin types. Although their exact mechanism of action is unknown, it has been demonstrated that AHAs improve these disorders by thinning the stratum corneum, promoting epidermolysis, dispersing basal layer melanin, and increasing collagen synthesis within the dermis. In patients with photodamage, AHA peels and topical products are often combined with retinoids and other antioxidants for maximum benefit. Similarly, synergistic effects of fluorouracil and glycolic acid are observed in the treatment of diffuse actinic keratoses. For patients with melasma, AHA peels and combination products containing bleaching agents such as hydroquinone, kojic acid, and glycolic acid seem to have increased efficacy. Acne and rosacea patients can see improved results when standard regimens like antibacterials and topical retinoids are supplemented with AHA peels and lotions. However, care should always be taken prior to commencing treatment with AHA peels and topical products. By obtaining a thorough history and physical examination, the physician will identify any specific factors like medications, prior procedures and medical conditions which can affect the outcome of the peel. During the interview, there should be open discussion of patient questions and concerns so that realistic expectations can be made. Pre- and post-peel regimens should also be reviewed in full as patient compliance is essential to ensure the success of a series of AHA peels.

Acne Vulgaris↗
PubMed1986

Properties of the branched-chain 2-hydroxy acid/2-oxo acid shuttle in mouse spermatozoa.

Operation of the branched-chain 2-hydroxy acid/2-oxo acid shuttle for the transfer of reducing equivalents in mitochondria of mouse spermatozoa was studied in vitro in reconstituted systems. Results show that the branched-chain 2-oxo acids within the mitochondria are offered several metabolic pathways. (a) Decarboxylation: mouse sperm mitochondria possess high branched-chain 2-oxo acid decarboxylase activity. (b) Recycling to the cytosol by using a transport system which can be inhibited by alpha-cyano-3-hydroxycinnamate and pH 6.8. (c) Transamination to the corresponding amino acids: experiments presented indicate that leucine formed from 4-methyl-2-oxopentanoate may pass to the external phase, re-initiating the cycle. These two last possibilities would allow autocatalytic operation of the shuttle. The branched-chain 2-hydroxy acids apparently do not utilize the monocarboxylate carrier to penetrate the mitochondria.

Animals↗