Long-chain acyl-homoserine lactones from Methylobacterium mesophilicum: synthesis and absolute configuration.
The acyl-homoserine lactones (acyl-HSLs) produced by Methylobacterium mesophilicum isolated from orange trees infected with the citrus variegated chlorosis (CVC) disease have been studied, revealing the occurrence of six long-chain acyl-HSLs, i.e., the saturated homologues (S)-N-dodecanoyl (1) and (S)-N-tetradecanoyl-HSL (5), the uncommon odd-chain N-tridecanoyl-HSL (3), the new natural product (S)-N-(2E)-dodecenoyl-HSL (2), and the rare unsaturated homologues (S)-N-(7Z)-tetradecenoyl (4) and (S)-N-(2E,7Z)-tetradecadienyl-HSL (6). The absolute configurations of all HSLs were determined as 3S. Compounds 2 and 6 were synthesized for the first time. Antimicrobial assays with synthetic acyl-HSLs against Gram-positive bacterial endophytes co-isolated with M. mesophilicum from CVC-infected trees revealed low or no antibacterial activity.
Pomini
Armando M
AM
Chemistry Institute, University of Campinas, CP 6154, 13083-970, Campinas, São Paulo, Brazil.
Cruz
Pedro L R
PL
Gai
Cláudia
C
Araújo
Welington L
WL
Marsaioli
Anita J
AJ
D054742:Acyl-Butyrolactones / Q000138:chemical synthesis / Q000737:chemistry* / Q000302:isolation & purification*; D020580:Methylobacterium / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D013237:Stereoisomerism
D054742:Acyl-Butyrolactones