title: Novel Fusicoccins R and S, and the fusicoccin S aglycon (phomopsiol) from Phomopsis amygdali niigata 2-A, and their seed germination-stimulating activity in the presence of abscisic acid.
abstract: Our search for new 3-hydroxyfusicoccins structurally related to cotylenin A from a culture of Phomopsis amygdali Niigata 2-A resulted in the isolation of novel 3-hydroxy fusicoccins, called fusicoccins R and S, and the fusicoccin S aglycon, called phomopsiol, together with known 3alpha-hydroxyfusicoccin J. The structure of phomopsiol was identified as that of O-demethyl-3-epicotylenol based on spectroscopic evidence. The structures of fusicoccins R and S were also determined to be those of 3'-deacetyl-3alpha-hydroxyfusicoccin A and 3beta-hydroxy-3-epifusicoccin H. The lettuce seed germination-stimulating activity of fusicoccins R and S, phomopsiol and 3alpha-hydroxyfusicoccin J was examined in the presence of ABA; fusicoccin R and 3alpha-hydroxyfusicoccin J were highly active, while fusicoccin S and phomopsiol were inactive. The possible biosynthetic relationships among these novel fusicoccins having a 3alpha- or 3beta-hydroxy group in their diterpene moiety are briefly discussed.
authors.affiliation: Course of the Science of Bioresources, The United Graduate School of Agricultural Sciences, Iwate University (Yamagata University), Morioka, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Tajima
authors.forename: Manabu
authors.initials: M
authors.lastname: Nukina
authors.forename: Nobuo
authors.initials: N
authors.lastname: Kato
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sassa
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology*; D001203:Ascomycota / Q000737:chemistry* / Q000187:drug effects; D034242:Cyclooctanes / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D004224:Diterpenes / Q000737:chemistry; D018525:Germination / Q000187:drug effects*; D005960:Glucosides / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D018545:Lactuca / Q000378:metabolism; D015394:Molecular Structure; D012639:Seeds / Q000187:drug effects / Q000378:metabolism
chemical_list: D034242:Cyclooctanes; D004224:Diterpenes; D005960:Glucosides; C423222:cotylenin A; C494856:fusicoccin R; C494857:fusicoccin S; C494858:phomopsiol; D000040:Abscisic Acid