[Isolation and identification of three new alkaloids from the roots of Alstonia yunnanensis Diels Indiana, USA].

In a previous paper, the isolation and identification of six known indole alkaloids form Alstonia Yunnanensis Diels was reported. This paper reports the isolation of nine other indole alkaloids and a nonalkaloidal component. They are lochnerinine (Ⅰ), 11-methoxy-19-hydroxytabersonine (Ⅱ), pseudoakuammigine (Ⅳ), picrinine (Ⅴ), deacetylpicraline 3, 4, 5- trimethoxybenzoate (Ⅵ), corynanthine (Ⅸ), yohimbine (Ⅹ), 17-acetylsarpagine (Ⅺ), 16-episarpagine (Ⅻ) and methyl 3, 4, 5-trimethoxycinnamate. Their structures were elucidated by spectroeopic analysis (UV, IR, NMR, MS), physical constants and preparation of derivatives. It has been shown that Ⅵ, Ⅺ and Ⅻ are new indole alkaloids.