Monohydroxy fatty acids

Ten barnacle species, including the two above, were assayed for hatching factor activity and the presence of monohydroxy fatty acids (MHFA) and THFA bands [147]. The other eight species were Balanus crenatus, B. balanus, B. hameri, B. amphitrite, B. perforatus, Chthalamus montagui, Pollicipes pollicipes, and Lepas anatifera. All ten showed both MHFA and THFA bands. 

Complete resolution and quantitation by HPLC of mixtures of monohydroxy fatty acids containing positional isomers of various chain lengths is a technical problem, because their separation occurs according to both chain length and the position of the hydroxyl group on both reverse-phase and silica adsorption HPLC columns. 

Bandi and Ansari (50) reported the use of 0-(p-nitrobenzyl)-A(,(V -(diisopropyl)-isourea (PNBDI) for the formation of PNB esters of monohydroxy fatty acids and the HPLC analysis of the derivatives on both reverse-phase and adsorption HPLC columns. They found that separation of positional isomers of PNB esters of monohydroxy fatty acids could be carried out successfully... 

To improve the purification by adsorption TLC and to reduce the separation of positional isomers by RP-HPLC, Bandi and Ansari (51) reduced the polarity of the hydroxyl groups forming ferf-butyldimethylsiloxy derivatives of PNB esters of monohydroxy fatty acids (PNB-TBDMS-OHFA) (with terr-butyldimethylimidazole in dimethylformamide). 

From the isolation of the O-deacylated but otherwise unmodified GPL from serovar 12, it was also shown that the structure of the lipopeptide core was identical to that accepted for glycolipids of this group with respect to D-amino acid configurations, but not of the alaninol unit, and of the mono-unsaturated monohydroxy fatty acid.48... 

Ziboh, V.A., Miller, C.C., and Cho, Y., Significance of lipoxygenase-derived monohydroxy fatty acids in cutaneous biology, Prostaglandins. Other Lipid Mediat., 63, 3, 2000. 

Kerwin, J.L. and Torvik, J.J. (1996) Identification of monohydroxy fatty acids by electrospray mass spectrometry and tandem mass spectrometry. Anal. Biochem., 237 (1), 56-64. 

Role of Lipoxygenase-Derived Monohydroxy Fatty Acids in Epithelial HyperproUferative Process Vincent A. Ziboh... 

Significance of 18-Carbon PUFA in the Epidermis Generation of Biologically Active Monohydroxy Fatty Acids... 

Functionally, this monohydroxy fatty acid has been reported to be an inhibitor of the generation of the proinflam-matory leukotriene (LTB ) from polymorphonuclear cells (PMN) and basophils (18). Consistent with this antiinflammatory potential, 155-HETE has been reported to improve the symptoms of human psoriasis vulgaris after in-tralesional injections (19). The extensive biological role and function of 155-HETE in the epidermis has not been investigated, and it remains a major challenge to discern the role... 

Role of Cutaneous Monohydroxy Fatty Acids (13S-HODEand 15S-HETrE) in Epidermal Skin Homeostasis... 

Monohydroxy Fatty Acid Production of 10-Hydroxystearic Acid... 

Aspirin acetylates a serine residue positioned in the catalytic site of the enzyme (Ser529 of COX-1 and Ser516 of COX-2) resulting in irreversible inhibition of COX-1/2 (Loll et al. 1995). However, the acetylated-COX-2 (ac-COX-2) retains part of its catalytic activity and can still act as a peroxidase forming R monohydroxy fatty acids such as 15R-HETE from AA, 18R-HEPE from EPA and 17/ -HDHA (Mancini et al. 1994 Serhan et al. 2008 Sharma et al. 2010). 

A wide choice of stationary phases is available for separation, such as reversed-phase or silver-ion impregnated phases. The separation of phenacyl derivatives of saturated, monoenoic, polyenoic, and monohydroxy fatty acids, and of the geometric isomers of fatty acids is possible. 

Derivatization of Monohydroxy Fatty Acids for HPLC Analysis... 

Ahmed, F., AI-Mutairi, E.H., Avery, K.L., CuIIis, P.M., Primrose, W.U., Roberts, G.C.K., and Willis, C.L. (1999) An unusual matrix of stereocomplementarity in the hydroxylation of monohydroxy fatty acids catalysed by cytochrome P-450 from Bacillus megaterium with potential application in biotransformations. Chem. Commun. (Camb.), 20, 2049-2050. 

Optical enantiomers of the methyl esters of monohydroxy fatty acids can be resolved by gas chromatography if they are first converted to the (-)-menthyl, D-phenylpropionyl or related derivatives [348,468] (reviewed briefly elsewhere [456,858]). Particularly good results were obtained with racemic methyl 2-hydroxy palmitate and stearate, after conversion to the (-)-a-methoxy-a-trifluoromethyl-phenylacetate derivatives, on a WCOT column coated with OV-1 as shown in Figure 5.17 [93] it is probable that the D-form elutes first. Some limited success has also been achieved in separating diastereoisomers of polyhydroxy fatty acids [988],... 

Hill EM, Holland DL. Identification and egg hatching activity of monohydroxy fatty acid eicosanoids in the barnacle Balanus balanoides. Proc R Soc Lond 1992 247 41-46. 

---