Open Access(+)‐Geodin from Aspergillus terreus
Author(s) -
Rønnest Mads H.,
Nielsen Morten T.,
Leber Blanka,
Mortensen Uffe H.,
Krämer Alwin,
Clausen Mads H.,
Larsen Thomas O.,
Harris Pernille
Publication year - 2011
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
eISSN - 1600-5759
pISSN - 0108-2701
DOI - 10.1107/s0108270111005816
Subject(s) - aspergillus terreus , molecule , chemistry , stereochemistry , hydrogen bond , crystallography , ring (chemistry) , crystal structure , halogen , organic chemistry , alkyl , food science
The fungal metabolite (+)‐geodin [systematic name: (2 R )‐methyl 5,7‐dichloro‐4‐hydroxy‐6′‐methoxy‐6‐methyl‐3,4′‐dioxospiro[benzofuran‐2,1′‐cyclohexa‐2′,5′‐diene]‐2′‐carboxylate], C 17 H 12 Cl 2 O 7 , was isolated from Aspergillus terreus . The crystal structure contains two independent molecules in the asymmetric unit. Molecules denoted 1 interact through O—H...O hydrogen bonds creating chains of molecules parallel to the crystallographic 2 1 screw axis. Molecules denoted 2 interact through an O...Cl halogen bond, also creating chains of molecules parallel to the crystallographic 2 1 screw axis. Molecules 1 and 2 interact through another O...Cl halogen bond. The two molecules are similar but molecules 2 have a slightly more planar cyclohexadiene ring than molecules 1. The absolute structure of (+)‐geodin has been unequivocally assigned with the spiro centre having the R configuration in both molecules. The structurally related (+)‐griseofulvin has an S configuration at the spiro centre, a difference of potential biological and biosynthetic relevance.