Neomacrophorin I, II, and III, novel drimenyl cyclohexanes with hydroxylated butanoates from Trichoderma sp 1212-03

Neomacrophorins I(1), II(2), and III (3) were isolated from the culture broth of Trichoderma sp. 1212-03, which was collected at Shirakami Mountainous area in Japan. Structural analyses disclosed that these resemble known macrophorins but possess axial-hydroxy group at C3 as well as different side chains at C7'. These are diastereomeric forms of macrophorins for 5',6'-epoxide functionality. The NMR analyses suggested their relative configurational relationship between the C1-C15 drimene and C1'-C7' epoxyquinone moieties. ECD spectral discussions verified them particularly for C5',C6'-epoxyquinone (1), C5',C6'-epoxysemiquinone (2 and 3), and 2,3-dihydroxybutanoate moiety in 1 and 2. The configuration of C3-stereocenter of 3 was determined by chiral GC MS after converting into methyl (S)-3-hydroxybutanoate by basic of 3 methanolysis. Biological assays disclosed that 1 induces hyphal branching of Cochliobolus miyabeanus as well as cytotoxicity against human colorectal cancer COLO 201. (C) 2014 Elsevier Ltd. All rights reserved.