(20S*,24S*)-25-Hydroxy-20,24-epoxy-A-homo-4-oxadammaran-3-one (Chrysura) isolated from the leaves ofWalsura chrysogyne

Abstract

The title dammarane triterpenoid, C30H50O4, assigned the name chrysura, was isolated from an ethyl acetate extract of Walsura chrysogyne leaves (Meliaceae). It has 20S*,24S* relative stereochemistry and an oxepanone ring with two methyl groups at position 4. The two cyclo­hexane rings adopt chair conformations. The cyclo­pentane and tetra­hydro­furan rings have envelope conformations; their mean planes make a dihedral angle of 13.1 (3)°, indicating that the rings are only slightly tilted with respect to each other. There is an intra­molecular C—H⋯O hydrogen bond in the mol­ecule, which forms S(6) and S(7) ring motifs. In the crystal, mol­ecules are linked via O—H⋯O and C—H⋯O hydrogen bonds, forming chains propagating along [001] which stack along the b-axis direction.

Walsogynes H–O from Walsura chrysogyne

“…Walsura, a genus belonging to Meliaceae, is composed of about 16 species distributed from Sri Lanka to the Himalaya and Indochina through Malaysia, Indonesia to New Guinea, and Walsura chrysogyne is distributed in Peninsular Malaysia [1]. The plants of this genus have been reported to produce limonoids, dammarane, tirucallane and apotirucallane triterpenoids [2][3][4][5][6][7]. In our search for new bioactive compounds [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27], we have reported the isolation of new limonoids and triterpenoids from plants of this genus [3,4,19], and alkaloids showing antimalarial activity [22,26,27].…”

“…In our search for new bioactive compounds [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27], we have reported the isolation of new limonoids and triterpenoids from plants of this genus [3,4,19], and alkaloids showing antimalarial activity [22,26,27]. Continuation of the bioassay-guided investigation on the extract of W. chrysogyne bark led to the isolation of eight new limonoids, walsogynes H-O (1)(2)(3)(4)(5)(6)(7)(8) showing antimalarial activity (Fig. 1).…”

A New Apotirucallane from Walsura trichostemon Leaves and Its Antibacterial and α‐Glucosidase Inhibitory Activities

“…The genus Walsura is an evergreen tree belonging to the family Meliaceae, which includes approximately 40 species widely distributed in Southeast Asia. Phytochemical and pharmacological studies of genus Walsura have been reported, and over 60 compounds have shown a wide range of biological activities, including antibacterial, antimicrobial, antimalarial, antioxidant, antifeeding, and cytotoxic activities [3–17] . Moreover, the crude extracts of Walsura species reportedly exhibit antidiabetic activity; [18] however, the antidiabetic activity of secondary metabolites has not been reported.…”

Apowalsogynes A and B, Two Highly Oxidized 3,4-Seco-Apotirucallane Triterpenoids from Walsura chrysogyne

“…[1] The plants of this genus have been reported to produce limonoids, dammarane, tirucallane and apotirucallane triterpenoids. [2][3][4][5][6][7][8][9][10] In our search for new bioactive compounds, [11][12][13][14][15][16] we isolated several 11,12-seco limonoids, walsogynes A-G, from Walsura chrysogyne (Miq.) Bakh.f.…”