Antimicrobial and Cytotoxic Activities of Constituents from the Fruit of Albizia lebbeck L. Benth (Fabaceae)

Abstract

Twenty-two compounds were isolated from the fruit of Albizia lebbeck including one unprecedented, rare amino acid-derived zwitterionic and one new flavone derivative. The isolation was performed on repeated column chromatography over silica gel and their structures were determined by 1D-, 2D-NMR and HR-ESI-MS spectra together with reported data in the literature. The chemophenetic significance is also discussed. Some isolated compounds were reported for the first time to be found in the species. Additionally, compound 2 showed antibacterial activity and compounds 1 and 2 revealed moderate cytotoxic activity against the Raw 264.7 cancer cell line with IC50 values of 37.19 µM and 29.36 µM, respectively. Furthermore, a proposed biosynthetic pathway of compound 1 is described.

Antiplasmodial and Antileishmanial Activities of a New Limonoid and Other Constituents from the Stem Bark of Khaya senegalensis

“…The protolimonoid compound (1abc) was found to be a mixture of a new limonoid 21βhydroxybourjotinolone A (1a) together with an epimeric mixture of 21α-melianodiol (1b) and 21β-melianodiol (1c). However, degraded triterpenoid-type limonoids (compounds 4-6), lupanes (3), oleanane (7) and steroids (11)(12)(13)(14), two flavonoids (8)(9) and one ceramide (10) were also identified here. Most of these compounds (2, 3-9 and 11-14) have been previously reported from K. senegalensis [8,11].…”

“…A mass of 275.0 g of the MeOH extract of K. senegalensis was partitioned into n-hexane (15.6 g) and EtOAc (160.8 g) fractions. Repeated column chromatography with Sephadex as well as silica gel as the stationary phase of the EtOAc (160.0 g) and n-hexane (15.0 g) extracts led to the isolation of 16 secondary metabolites, including nine triterpenoids (1abc-7), four steroids (11)(12)(13)(14), two flavonoids (8)(9) and one ceramide (10) (Figure 1). led to the isolation of 16 secondary metabolites (1abc-14).…”

“…The remaining 13 known compounds were identified as follows: bellericagenin B (2) [24,25], alphitolic acid (3) [26,27], methyl angolensate (4) [28], rohituka-3 (5) [11,29], khayanolide E (6) [30,31], oleanolic acid (7) [32], Belamcanidin (8) [25,33], catechin (9) [34], gynuramide IV (10) [35], a mixture of β-sitosterol (11) and stigmasterol (13) [36], and a mixture of β-sitosterol glycoside (12) and stigmasterol glycoside (14) [37,38].…”

“…The MeOH crude extract from Khaya senegalensis stem bark, the fractions, and the isolated compounds were evaluated for their antiplasmodial activity against chloroquine-resistant Dd2 and chloroquine-sensitive 3D7 strains of Plasmodium falciparum as well as antileishmanial and cytotoxicity activities against the Leishmania donovani strain and RAW 264.7 cancer cell lines, respectively (Figure 3, Table 2). According to a previ- The remaining 13 known compounds were identified as follows: bellericagenin B (2) [24,25], alphitolic acid (3) [26,27], methyl angolensate (4) [28], rohituka-3 (5) [11,29], khayanolide E (6) [30,31], oleanolic acid (7) [32], Belamcanidin (8) [25,33], catechin (9) [34], gynuramide IV (10) [35], a mixture of β-sitosterol (11) and stigmasterol (13) [36], and a mixture of β-sitosterol glycoside (12) and stigmasterol glycoside (14) [37,38].…”

“…Limonoids are reported to be the most abundant and chemophenetic taxon of K. senegalensis as well as the Khaya genus [3,13]. In our search for bioactive compounds from medicinal plants growing in Cameroon [11,14,15], we have undertaken a chemical investigation of the methanol extract of the stem bark of K. senegalensis. This study aimed to investigate the antimalarial and antileishmanial properties of the extract and fractions of the stem bark of the Cameroonian medicinal plant Khaya senegalensis as well as its isolated compounds.…”