title: Absolute stereochemistry of unusual biopolymers from Ascomycete culture LL-W1278: examples that derivatives of (S)-6-hydroxymellein are also natural fungal metabolites.
abstract: The new linear polyesters, W1278-A, B, and C, were isolated from culture extracts of a freshwater Ascomycete fungus. Their structures were elucidated on the basis of spectroscopic analyses and chemical transformations, with the absolute configuration established by the circular dichroism (CD) method using (R)-(-)-6-hydroxymellein as reference. Unexpectedly, W1278-A, B, and C contain (S)-6-hydroxymellein residues as concluded from the display of the opposite ellipticity than that of known (3R)-(-)-3,4-dihydro-6,8-dihydroxy-3-methylisocoumarin as revealed by CD.
authors.affiliation: Wyeth Research, Chemical and Screening Sciences, Natural Products Chemistry, Pearl River, New York 10965, USA. schling@wyeth.com
authors.forename: Gerhard
authors.initials: G
authors.lastname: Schlingmann
authors.forename: Deborah M
authors.initials: DM
authors.lastname: Roll
mesh_terms: D001203:Ascomycota / Q000378:metabolism*; D001704:Biopolymers / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D002942:Circular Dichroism; D003374:Coumarins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D006868:Hydrolysis; D049934:Isocoumarins; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D001704:Biopolymers; D003374:Coumarins; D049934:Isocoumarins; C070622:6-hydroxymellein