title: Curvularia lunata, a New Source of Cytochalasin B.
abstract: A biologically active metabolite was found in crude extracts of Curvularia lunata (Wakker) Boedijn (ATCC 34690) isolated from decayed tissues of litchi fruit (Litchi chinensis Sonn.). The fungus was grown on a shredded wheat-yeast extract-sucrose medium, and cultures were extracted with chloroform after 3 weeks of growth at 21 degrees C. Chloroform extracts were toxic to day-old cockerels and caused abnormal distortion of wheat coleoptile segments. The major toxin had a 50% lethal dose of 700 mg/kg (oral dose) and was a colorless crystalline material with a melting point of 218 degrees C. Elemental and high-resolution mass spectral analyses indicated a formula of C(29)H(37)NO(5) and a molecular weight of 479.62. The crystalline preparation was identified as 97% cytochalasin B and 3% cytochalasin A. The yield of cytochalasin B from C. lunata cultures grown on 4.5 kg of shredded wheat and 9 liters of yeast extract-sucrose medium was 6.24 g of purified material.
authors.affiliation: Southeastern Fruit and Tree Nut Research Laboratory, U. S. Department of Agriculture, Byron, Georgia 31008.
authors.forename: J M
authors.initials: JM
authors.lastname: Wells
authors.forename: R J
authors.initials: RJ
authors.lastname: Cole
authors.forename: H C
authors.initials: HC
authors.lastname: Cutler
authors.forename: D H
authors.initials: DH
authors.lastname: Spalding