Yh. Kuo et al., Three novel and one new lignan, chamaecypanones A, B, obtulignolide and isootobanone from the heartwood of Chamaecyparis obtusa var. formosana, TETRAHEDR L, 42(38), 2001, pp. 6731-6735
Three novel lignans, chamaecypanone A 1, chamaecypanone B 2, obtulignolide
4, and one new lignan, isootobanone 3, were isolated from the heartwood of
Chamaecyparis obtusa var. formosana, and were elucidated on the basis of 2D
NMR techniques. Compounds 1 and 2, derived from a phenyltetrahydronaphthal
ene-type lignan by cleavage and cyclization, are anthrone derivatives. Comp
ound 3 is a phenyltetrahydronaphthalene-type lignan, and 4 is a 3,4-secophe
nyltetrahydronaphthalene-type lignan. The absolute configurations of 3 and
otobanone 5 were elucidated by a modified Mosher's method. (C) 2001 Elsevie
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