The saturated 2-methoxylated fatty acids 2-methoxytetradecanoic acid (1), 2
-methoxypcntadecanoic acid (2), and 2-methoxyoctadecanoic acid (3) as well
as the Delta (6) monoenoic methoxylated fatty acids (6Z)-2-methoxy-6-tetrad
ecenoic acid (4), (6Z)-2-methoxy-6-pentadecenoic acid (5), and (6Z)-2-metho
xy-13-methyl-6-tetradecenoic acid (7) were identified for the first time in
nature in the phospholipids from the Caribbean sponge Callyspongia fallax.
These findings expand the occurrence of 2-methoxylated fatty acids to C-14
-C-15 chain lengths and establish new fatty acid biosynthetic possibilities
for marine organisms. The novel methoxylated fatty acids could have origin
ated from the phospholipids of a bacterium in symbiosis with the sponge.