Four New Compounds From Isodon eriocalyx

Four New Compounds From Isodon eriocalyx

Examination of the chemical constituents of the dried leaves of Isodon eriocalyx (Dunn.) Hara led to the isolation of four new diterpenoids, named maoecrystal Q-T (1-4). Their structures were elucidated as $16(R)-methoxymethyl-6{\beta},\;7{\beta}-dihydroxy-7{\alpha},20-epoxy-ent-kaur-2,3-ethenylene-1$, 15-dione(1), $1{\beta},18-diacetoxy-6{\beta},7{\beta}-dihydroxy-7{\alpha},20-epoxy-ent-kaur-16-en-15-one\;(2),\;6{\beta},\;7{\beta}-dihydroxy-15{\beta}-acetoxy-7{\alpha},20-epoxy-ent-kaur-16-en-1-one$ (3) and $7{\beta}-hydroxy-6{\beta},15{\beta}-diacetoxy-1{\alpha},11{\beta}-acetonide-7{\alpha},20-epoxy-ent-kaur-16-ene$ (4), respectively, on the basis of spectroscopic methods. Meanwhile, five known diterpeonids eriocalyxin B (5), maoecrystal B-D (6-8) and trichokaurin (9) were also obtained.