Identification and total synthesis of novel fatty acids from the Siphonarid limpet Siphonaria denticulata.
The novel fatty acids 17-methyl-6(Z)-octadecenoic acid and 17-methyl-7(Z)-octadecenoic acid were identified for the first time in nature in the mollusk Siphonaria denticulata from Queensland, Australia. The principal fatty acids in the limpet were hexadecanoic acid, octadecanoic acid, and (Z)-9-octadecenoic acid, while the most interesting series of monounsaturated fatty acids was a family of five nonadecenoic acids with double bonds at either Delta(7), Delta(9), Delta(11), Delta(12), or Delta(13). The novel compounds were characterized using a combination of GC-MS and chemical transformations, such as dimethyl disulfide derivatization. The first total syntheses for the two novel methyl-branched nonadecenoic acids are also described, and these were accomplished in four to five steps and in high yields.
Carballeira
N M
NM
Department of Chemistry, University of Puerto Rico, Rio Piedras, Puerto Rico 00931, USA. ncarball@upracd.upr.clu.edu
Cruz
H
H
Hill
C A
CA
De Voss
J J
JJ
Garson
M
M
D000818:Animals; D001315:Australia; D005229:Fatty Acids, Monounsaturated / Q000138:chemical synthesis / Q000737:chemistry / Q000302:isolation & purification; D008401:Gas Chromatography-Mass Spectrometry; D015394:Molecular Structure; D008974:Mollusca / Q000737:chemistry*; D019308:Palmitic Acid / Q000138:chemical synthesis / Q000737:chemistry / Q000302:isolation & purification*; D013229:Stearic Acids / Q000138:chemical synthesis / Q000737:chemistry / Q000302:isolation & purification; D013237:Stereoisomerism
C443280:17-methyl-6-octadecenoic acid; C443279:17-methyl-7-octadecenoic acid; D005229:Fatty Acids, Monounsaturated; D013229:Stearic Acids; D019308:Palmitic Acid; C031183:stearic acid