New Chemical Constituents from Borreria verticillata (Rubiaceae)

A phytochemical study on Borreria verticillata has led to the isolation of two novel simple indole alkaloids, 6‐methoxy‐4‐(3‐methylbut‐2‐en‐1‐yl)‐1H‐indole, named verticillatine A (1), and 1‐(1H‐indol‐6‐yl)‐3‐methylbutan‐1‐one, named verticillatine B (2), one new iridoid, 6′‐O‐(2‐glyceryl)scandoside methyl ester (3), with the glycerol unit linked to a glucose unit, and two known ones, asperuloside (4) and scandoside methyl ester (5). The structures of these compounds were elucidated on the basis of spectroscopic‐data analyses, mainly 1H‐ and 13C‐NMR, including 2D experiments (1H,1H‐COSY, NOESY, HMBC, and HMQC), and HR‐ESI‐MS.