Structural Revision of the Stemona Alkaloids Tuberostemonine O, Dehydrocroomines A and B, and Dehydrocroomine

Abstract

The structural revision of four Stemona alkaloids from Stemona tuberosa is reported. The misassignment of the tuberostemonine O structure (1) was recognized when a new alkaloid, tuberostemonine P, was isolated and unambiguously assigned structure 1 in this work. Reinvestigation of the spectroscopic data and NMR calculations led to the revised structure 1a for tuberostemonine O. The structural misassignment of dehydrocroomine A as 2 was corrected by reinterpreting the X-ray crystal structure, which was consistent with 2a. The structural reassignments of dehydrocroomine B (3 to 3a) and dehydrocroomine (4 to 4a) were confirmed by X-ray crystallography and NMR calculations, respectively.

Isolation and Bioactivities of Stemona Alkaloid: A Review

“…32 Kil et al 33 separated tuberostemonine O (43) from the roots of Stemona tuberosa (Figure 3). Recently, Jiang et al 34 roots of Stemona tuberosa (Figure 3). Dong et al 36 discovered 2 new alkaloids, dehydrostenines A (46) and B (47) from the roots of Stemona sessilifolia (Figure 3).…”

“…24 Recently, the structure of dehydrocroomine was revised as 132 . 34 Sessilifoliamine A ( 133 ) also known as stemona-amine A was obtained from the roots of Stemona sessilifolia . 70 This compound possesses a lactone ring attached to C5 and C6.…”

“…32 Kil et al 33 separated tuberostemonine O ( 43 ) from the roots of Stemona tuberosa (Figure 3). Recently, Jiang et al 34 revised structure of tuberostemonine O as 44 , which differs in stereochemistry at C9. Zhang et al 35 isolated tuberostemonine D ( 45 ) from the roots of Stemona tuberosa (Figure 3).…”

“…These compounds have a hydroxy group at C9a and stemona-amine B possesses an ether linkage. Tuberostemonoxirine (34) containing an epoxy ring was obtained from the roots of Stemona tuberosa. 27 Lai et al 28 reported the isolation and structure determination of stenines A (35) and stenine B (36) from the roots of Stemona sessilifolia (Figure 3).…”