Constituents of the Rhizomes of Sansevieria cylindrica

Abstract

A new sappanin-type 3-benzyl chroman-4-one (homoisoflavanone), (3S)-3-(4′-methoxybenzyl)-3,5-dihydroxy-7-methoxy-6-methyl chroman-4-one (1), together with known congeners (3S)-3-(4′-methoxybenzyl)-3,5-dihydroxy-7-methoxy chroman-4-one (2), (3S)-3-(4′-hydroxybenzyl)-3,5-dihydroxy-7methoxy-6-methyl chroman-4-one (3), (3S)-3-(4′-hydroxybenzyl)-3,5-dihydroxy-7-methoxy chroman-4-one (4), 3-(3',4'-methyledioxybenzyl)-7-hydroxy-8methoxy chroman-4-one (5), and stigmasterol and ergosterol peroxide have been isolated from the rhizomes of Sansevieria cylindrica, collected in Myanmar. Moreover, the first isolation of the (-)-enantiomer of the dihydrochalcone trifasciatine C (7) from nature is described. The structures of the compounds have been established by extensive spectroscopic analysis. Compounds 4 and 7 showed no significant cytotoxicity against HeLa cells. Compounds 1-4 and 7 exhibited weak radical scavenging activity (DPPH). A new biosynthetic pathway has been proposed for the formation of homoisoflavanone 5 and dihydrochalcone 7.

Bioactive Constituents from the Rhizomes of Sansevieria cylindrica

“…The residue E from the EtOAc subextract of the MeOH extract of S. cylindrica rhizomes was subjected to flash column chromatography over octadecylsilanized silica gel (ODS) followed by repeated semipreparative HPLC separations to afford ten known compounds (1)(2)(3)(4)(5)(6)(7)(8)(9)(10). The physical and spectroscopic data of 1-10 nicely matched those reported in the literature.…”

“…While browsing literature reports, we found that a compound isolated from S. roxburghiana [22] was claimed to have the same structure as ()-cambodianol (2), isolated from Dracaena cambodiana [10]. However, upon carefully examining the 13 C NMR resonances determined for the homoisoflavanone from S. roxburghiana [22], we found that they were similar to the 13 C NMR signals of homoisoflavanone 11, which was previously isolated from Liriope muscari [23] and S. cylindrica [8]. In contrast, the 13 C NMR data of the compound isolated from S. roxburghiana [22] were significantly different from those determined for cambodianol (2) [10], although the solvents were not the same.…”

“…We reconfirmed that the structures of 2 and 11 are correct and are isomeric. In fact, the two compounds differ for the position of the methoxy group, which is at C-7 in compound 11 [8,23] and at C-4´ in cambodianol (2) [10]. Their location was confirmed by appropriate two bonds and three bonds correlations in the corresponding HMBC spectra (Figure 2) Moreover, comparison of the 13 C NMR spectra (Table 1) firmly indicated that the planar structure of the homoisoflavanone isolated from S. roxburghiana [22] must be revised from 2 to 11.…”

“…Their location was confirmed by appropriate two bonds and three bonds correlations in the corresponding HMBC spectra (Figure 2) Moreover, comparison of the 13 C NMR spectra (Table 1) firmly indicated that the planar structure of the homoisoflavanone isolated from S. roxburghiana [22] must be revised from 2 to 11. The 3S configuration was attributed to compound (+)-11 isolated from Liriope muscari [23] and S. cylindrica [8]. The 3R configuration has, instead, been proposed for the homoisoflavanone isolated from S. roxburghiana [22], whose stereostructure thus corresponds to that of ent-11.…”

“…In our ongoing research on new bioactive constituents from medicinal plants collected in Myanmar [7], a new homoisoflavanone, together with four known congeners and dihydrochalcone (-)-trifasciatine C, were recently isolated from the methanolic extract of S. cylindrica rhizomes [8]. Upon completion of our investigation on this plant, in this paper we describe the isolation and the structure identification of ten additional compounds.…”