Monohydroxy acids

Monohydroxy acids 8-Hydroxy C8 Psilotum nudum stem 0.7... 

From the sponge M. incrustans, two cerebrosides and a polar glycolipid were isolated.78 Both cerebrosides contain galactose and sphingosine, but differ in the nature of their fatty acids the less polar cerebroside contains normal, and the more polar, monohydroxy, acids. The structure of the polar glycolipid was not established, but it was shown to contain sphingosine, fatty acids, galactose, arabinose, fucose, and phosphorus.78... 

The formation of monohydroxy acids having chains of four, three, or two carbons can be rationalized with the same mechanism of oxidation of the corresponding enediol. The 1,2-enediol can rearrange to the 2,3- or 3,4-enolates, which undergo the oxidative cleavage. Alternatively, the enediol may undergo a retro-aldol condensation followed by oxidation. 

H-Bonding, Strongly Associative (HBSA) Water Primary amides Secondary amides Polyacids Dicarboxylic acids Monohydroxy acids Polyphenols Oximes Hydroxylamines Amino alcohols Polyols... 

Mid-chain hydroxy acids are also found. Mosses (Bryopsida, a class of the Bryophyta) contain monohydroxy acids, such as the 7- and 8-hydroxy CJ6 diacids... 

Borgeat P, Hamberg M, Samuelsson B. Transformation of arachidonic acid and homo-gammalinolenic acid by rabbit polymorphonuclear leukocytes. Monohydroxy acids from novel lipoxygenases. J Biol Chem. 251 (1976) 7816-7820. 

The bile acids may be isolated from the bile by eleaving the peptide linkage present in them by hydrolysis with alkali. From the resulting solution the bile acids are eonveniently isolated either by crystallization from organic solvent or by treating the ethereal solution of the aeids with various concentration of hydrochloric acid, for instance the trihydroxy, dihydroxy and the monohydroxy acids may be isolated by treating the ethereal solution with 15%, 25% and eoneentrated hydroehloric acid respectively. 

Diester type I a- or jS-monohydroxy acids Straight chain White stork, brown kiwi... 

Besides influencing the critical micellar temperature, the number and position of hydroxy groups also influence the critical micellar concentration. The critical micellar concentration of dihydroxy bile acids is significantly below that of trihydroxy acids (1,63), but no values have been reported for monohydroxy acids. Conjugation with glycine or taurine does not appear to have any particular effect on those properties of bile acids which are related to the steroid nucleus, provided that experiments are carried out at pH sufficiently alkaline that all bile acid molecules present are ionized (64). 

Natural monohydroxy acids which are either saturated or contain non-conjugated unsaturation are listed in Table 1.8. Ricinoleic acid (12-hydroxyoleic) is the best known being the major acid in castor oil. Isoricinoleic acid is an isomer with the double bond and hydroxyl group interchanged. Densipolic acid is... 

Citric acid n. C3H4(OH)(COOH)3. Tricarboxylic, monohydroxy acid. One molecule of water is normally included in the formula. It has an mp of 154°C, but decomposes on further heating See image). 

After intraperitoneal administration to the rat, 90% of this acid is recovered unchanged in bile (141) 0.6% was present in monohydroxy acids of which 60% was identified as 3/3-hydroxy allocholanoic acid. About 9% was converted to unidentified trihydroxy acids. In vitro experiments with liver homogenates indicate less extensive metabolism of this dihydroxy allo-acid in this case allolithocholate appears to be formed instead of the 3j9-isomer. 

Silver nitrate TLC is also useful for separation of monohydroxy acids. Dihydroxy or tetrahydroxy acids are best dealt with by TLC using borate or arsenate-impregnated silica gel. 

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