Barnacle-hatching factor

Another barnacle species, Elminius modestus, was found to produce mono and trihydroxy fatty acids [146]. Analysis of the extract of whole animal homogenates by TLC provided two hatching factor active bands. The more polar band was tentatively identified as a trihydroxy fatty acid (THFA) band. The less polar band had an / r value similar to a 5-HETE standard. The compounds from this latter band were eluted from the TLC plate, methylated, and trimethylsilylated. GC-MS analysis detected several HEPE s and small amounts of monohydroxy derivatives of Ci8 1, C18 2, and C22 fatty acids. Hydrogenation and subsequent GC-MS analysis allowed identification of the major compound as 8-HEPE (ca. 70%). Five to ten percent of 9-, 11-, and 15-HEPE and minor amounts of 5-, 6-, 12-, and 13-HEPE were also detected. No stereochemical features of these oxylipins were determined. 

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. 

Holland DL, East J, Gibson H, Clayton E, Oldfield A. Identification of the hatching factor of the barnacle Balanus balanoides as the novel eicosanoid 10,11,12 trihydroxy-5,8,14,17-eicosatetraenoic acid. Prostaglandins 1985 29 1021-1029. 

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