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.
No takes yet. Share an insight, caveat, or question.
Tajima et al. (2004) studied this question.
Synapse has enriched one closely related paper. Consider it for comparative context: