Two New Alkaloids from the Rhizomes of Sinomenium acutum

is a deciduous shrub grown in Asia, particularly in Japan, China, and Korea. The stems and roots of the plant are wide-ly used to treat various rheumatic diseases, allergy, dropsy, dermatophytosis, and acesodyne in traditional Chinese prescriptions.1 Previous phytochemical investigations of S. acutum have isolated various alkaloids, e.g. protoberberin-type, aporphin-type, isoaporphin-type, morphine-type, and chlorine-contained alkaloids.2-12 Also, cyanoglucoside,13 butenolides,13,14 and lignan15 were isolated from this plant. The main alkaloid from this plant has been studied for its effects on anti-inflammation, anticancer, immunosuppre-ssion, arthritis amelioration, and protection against hepatitis induced by LPS for sinomenine.16-18 Column chromato-graphic purification of the MeOH extract of the rhizome of this source led to isolation of two new alkaloids (1 and 4), together with twelve known alkaloids (2, 3, 5-14). The structures of the new compounds (1 and 4) were established by spectroscopic and chemical means. Compound 1 was isolated as a colorless gum, −41.5 (c 0.5, MeOH). The molecular formula C21H26ClNO7 was determined by the HR-FAB MS m/z 440.1477 [M+H]+ (calcd. 440.1476). The UV, IR, 1H- and 13C-NMR spectra of 1 were very similar to those of 2, except for the presence of signals for an additional acetyl group (δH 2.12; δC 169.7, 21.3). The downfield shift of the signals of H-1 and C-1 (ΔδH +1.3; ΔδC +0.8) in 1, compared to the corresponding signals in 2, suggested that the acetyl group should be placed at C-1. The position of the acetyl group was established by an HMBC experiment, in which a long-range correlation was observed between the H-1 (δH = 5.93) and a carbonyl carbon (δC = 169.7) (Figure 2). The stereochemistry of 1 wa