Five New C₁₉‐Diterpenoid Alkaloids from Delphinium tianshanicum W.T.Wang

Abstract

Five new diterpenoid alkaloids, tianshanitines A-E (1 - 5), along with ten known compounds (6 - 15), were isolated from the EtOH extracts of the whole plant of Delphinium tianshanicum W.T.Wang. Their structures were determined based on extensive spectroscopic analyses, including 1D- and 2D-NMR, HR-ESI-MS, and the structure of tianshanitine C (3) was confirmed by X-ray diffraction analysis. Tianshanitine A (1) is the first example of natural diterpenoid alkaloid containing a benzoyl group at C(1) position. Tianshanitine B (2) is a rare natural diterpenoid alkaloid bearing a OH group at C(16) position. Compounds 1 - 5, 6, 8, 10, 12 and 14 were evaluated for cytotoxicity against HCT116, MCF-7 and HepG2 human cancer cell lines.

An overview of the chemical constituents from the genus Delphinium reported in the last four decades

“…[33][34][35][36][37] Budelphine (36) from D. buschianum possesses a rare 1,2-epoxy group. 36 There are 12 alkaloids (39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50) with an N-CHO formamide group formed from a C-21 aldehyde. 4,[38][39][40][41][42][43][44][45] Among these compounds, alkaloids 41-45 are DAs that have no oxygen-containing group at C-16.…”

“…5). Nine of these DAs (53-61) contain a 7,8-methylenedioxy group, 29,[45][46][47][48][49][50][51] and of these, caerunine (60) from D. caeruleum possesses a 9-OH group. 50 Another ve imine DAs (64-68) contain a 7,8-diol group along with an anthranoyl group at C-18.…”