Three new 11-hydroxyburnamine (1) and rauvoyunnanines A-B (2-3), and fourteen known (4-17) monoterpenoid indole alkaloids were isolated from the total alkaloids extract of Rauvolfia yunnanensis, which exhibited promising immunosuppressive activity on T cell proliferation in preliminary screening. Their structures were determined by analysis of high-resolution electrospray ionization mass (HRESIMS), ultraviolet (UV) and nuclear magnetic resonance (NMR) data, and by comparison with the literature. All the alkaloids were evaluated for inhibitory activity on T cell proliferation. Among them, one new compound (1) and reserpine (6) exhibited moderate immunosuppressive activity, with IC50 values of 5.9 μM and 5.0 μM, respectively.

https://www.mdpi.com/1420-3049/24/24/4574/pdf

Bioactivity-Guided Isolation and Identification of New and Immunosuppressive Monoterpenoid Indole Alkaloids from Rauvolfia yunnanensis Tsiang.

Rauvolfia yunnanensis Tsiang are commonly used as a folklore herb to treat hypertension,snake bites,and insanity in the southwest of China,and an important industrial raw material of reserpine and verticalBut the wild resources of it reduced gradually in recent years,thus we have introduced and cultivated it to the arid-hot valley region of Yunnan Province,China,and investigated the chemical constituents variety of it for the sustainable utilizationThe dried leaves powder(80 kg) of Ryunnanensis was extracted with 95%(volume fraction) EtOH(40 L×5,8 h each) ,and led to the isolation of eleven indole alkaloids by column chromatography(silica,alumina and Sephadex LH-20 gel) methodsTheir structures were identified as caberine(1) ,19-ethoxyl-1-demethyl-Δ1-17-acetylajmaline(2) ,vellosimine(3) ,β-yohimbine(4) ,yohimbine(5) ,vinorine(6) ,picrinine(7) ,nareline(8) ,akuammicine(9) ,strictamine(10) ,reserpine(11) by spectral analysis(UV,IR,MS and 1D,2D NMR) ,respectivelyAmong them,compound 2 was a new indole alkaloids,compounds 1,8 and 9 were firstly isolated from this plant

Geng Chang

Papers

Indole Alkaloids from the Leaves of Rauvolfia yunnanensis