O-Methylation of phenylphenalenone phytoalexins in Musaacuminata and Wachendorfia thyrsiflora.
Biosynthetic O-methylation at various sites along the backbone of inducible phenylphenalenones in Musaacuminata var. "Williams" (Musaceae) and Wachendorfiathyrsiflora (Haemodoraceae) was investigated using 13C-labelled precursors. The inducibility of O-methylated metabolites was demonstrated in both species and the origin of methoxyl group from [methyl-13C]L-methionine was confirmed. In addition to known phenylphenalenones, a methoxylated metabolite, 4-(4-hydroxy-3-methoxy-phenyl)-benzo[de]isochromene-1,3-dione, was detected and its structure elucidated mainly by NMR spectroscopic techniques. The experiments were used to discriminate methionine-derived and artificial methoxy groups formed during methanolic extraction. Finally, demethylation of 4'-methoxycinnamic acid and subsequent conversion to 3',4'-methylenedioxycinnamic acid was demonstrated in M.acuminata.
Otálvaro
Felipe
F
Instituto de Química, Universidad de Antioquia, Calle 67# 53-108, A.A. 1226 Medellín, Colombia.
Jitsaeng
Kusuma
K
Munde
Tobias
T
Echeverri
Fernando
F
Quiñones
Winston
W
Schneider
Bernd
B
D002247:Carbon Isotopes; D019684:Magnoliopsida / Q000737:chemistry / Q000378:metabolism*; D008715:Methionine / Q000378:metabolism*; D008745:Methylation; D015394:Molecular Structure; D028522:Musaceae / Q000737:chemistry / Q000378:metabolism*; D043803:Phenalenes / Q000737:chemistry / Q000378:metabolism*; D012717:Sesquiterpenes / Q000737:chemistry / Q000378:metabolism*; D000094162:Phytoalexins
D002247:Carbon Isotopes; D043803:Phenalenes; D012717:Sesquiterpenes; D008715:Methionine; D000094162:Phytoalexins