| Research Abstract |
1. Bioorganically chemical research on Annonaceous acetogenins : Squamostanal-A, epoxyrollin A and diepomuricanin, which were proposed as biosynthetic intermediates for Annonaceous acetogenins, were synthesized by using stereoselective reactions. The spectral analysis of the synthesized epoxyrollin A showed that the structure proposed for natural epoxyrollin A is mistaken. Furthermore, (8^2R) and (8^2S)-corossoline and (+)-4-deoxygigantecin, Annonaceous acetogenins, were synthesized by the stereoselective methods using chiral bulding blocks. Separation and structural elucidation of biologically active components from Uvaria purpurea, a Chinese plant of Annonaceae species, was tried to separate new derivatives belong to zeylenol.
2. Studies on the chemical transformation of taxanediterpenoids.
1) Stereoselective deacetylation of taxinine, a major component of Japanese yew, using chemical (Mg(OCH_3)_2 )and enzymatic methods (pancreatine) gave 9,10-deacetyl taxinine.
2) Treatment of 2,5,7,9,10,13,20-heptaacetyl 3,8-secotaxa-3,8,11-triene with Pd(Ph_3P)_4 in acetic acid gave 2,5,10, 13,20-pentaacetyl-3,8-secotaxa-3,7-die-9-one. Which was identical with a new minor compound separated from Chinese yew, Taxus mairel.
3) Side chain elongation of 5-decinnamoyl taxinine with vinylethylether in the presence of Hg(OAc)_2 gave a new analog of taxanditerpenenoid with 20-formylmethyl group.
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