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

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

A New Chromene Derivative and a New Polyalcohol Isolated From the Fungus Xylaria sp. 111A Associated With Garcinia polyantha Leaves

Tegha HF, Jouda J-B, Dzoyem JP, et al. A New Chromene Derivative and a New Polyalcohol Isolated From the Fungus Xylaria sp. 111A Associated With Garcinia polyantha Leaves. Natural Product Communications. 2021;16(1).From the crude extract of the plant-associated fungus Xylaria sp. collected in Cameroon, a new 2H-chromene derivative, hexacycloxylariolone (1), and a new polyalcohol, xylatriol (2), were isolated, in addition to 3 known compounds, 2,3-furandiol (3), 1,8-dimethoxynaphthalene (4), and 1-palmitoyl-rac-glycerol (5). Their chemical structures were established on the basis of the interpretation of spectroscopic data. Hexacycloxylariolone (1), 1,8-dimethoxynaphthalene (4), and 1-palmitoyl-rac-glycerol (5) showed antiproliferative activity by inhibiting the growth of Raw 264.7 and THP-1 cancer cell lines

Cytotoxicity of a new tirucallane derivative isolated from Stereospermum acuminatissimum K. Schum stem bark.

Leutcha BP, Sema DK, Dzoyem JP, et al. Cytotoxicity of a new tirucallane derivative isolated from Stereospermum acuminatissimum K. Schum stem bark. Natural product research. 2020:1-6.One new tirucallan derivative, leutcharic acid (1) was isolated from Stereospermum acuminatissimum stem bark together with the known compounds 3-oxo-22-hydroxyhopane (2), 3,4-secotirucalla-4(28),7,24-trien-3,21-dioic acid (3), 3-oxotirucalla-7,24-dien-21-oic acid (7), lupeol (4), beta-sitosterol (5) and stigmasterol (6). The structures of the isolated compounds were elucidated using 1D and 2D NMR spectroscopy in combination with literature data. To the best of our knowledge, this is the first report on the cytotoxic properties' constituents of S. acuminatissimum. Cytotoxicity of compounds 1 and 2 was assessed invitro with the WST-1 assay on human lung adenocarcinoma A549 and THP-1 human monocytic leukaemia cell lines. Both compounds showed antiproliferative activity on the cancer cells. Compound 2 was more active against THP-1 with an IC50 value of 26.83M. The sensitivity of THP-1 cells to compounds 1 and 2 indicated that these compounds might be potential leads for anticancer agent development against leukaemia

A new flavonol derivative and other compounds from the leaves of Bauhinia thonningii Schum with activity against multidrug-resistant bacteria

Nouemsi GRS, Jouda J-B, Leutcha PB, et al. A new flavonol derivative and other compounds from the leaves of Bauhinia thonningii Schum with activity against multidrug-resistant bacteria. Natural Product Research. 2022.Investigation of the leaves of Bauhinia thonningii Schum led to the isolation and identification of a new flavonol derivative, 6-C-methylquercetin-3,4'-dimethyl ether (1) together with eleven known compounds (2-13), with two of them (10 and 11) obtained as a mixture. Their structures were established by extensive spectroscopic analyses. Antibacterial activity of compound 1 as well as the reference antibiotic, ciprofloxacin was tested on Gram-negative multidrug-resistant bacteria overexpressing active efflux pumps, and against methicillin-resistant strains of Staphylococcus aureus (MRSA). Samples were tested alone and in combination with an efflux pump inhibitor (EPI), phenylalanine-arginine-beta-naphthylamide (PASSN). Results show that when compound 1 was tested alone, its inhibitory effects were obtained on 7/10 tested bacteria with the highest MIC value of 128g/mL whilst in the presence of EPI, this activity significantly increase in all the 10 bacteria. An interesting antibacterial activity was obtained with compound 1 against Klebsiella pneumoniae ATCC11296 (MIC of 4g/mL), KP55 and Staphylococcus aureus MRSA6 in the presence of the PaSSN

Prosojuliflavone and other constituents from Prosopis juliflora Swartz D.C (Fabaceae) and their chemotaxonomic importance

Yanda L, Tatsimo SJN, Tamokou J-D-D, et al. Prosojuliflavone and other constituents from Prosopis juliflora Swartz D.C (Fabaceae) and their chemotaxonomic importance. Biochemical Systematics and Ecology. 2022;105: 104508.The chemical investigation of ethyl acetate extracts of the roots and stem bark of Prosopis juliflora Swartz D.C (Fabaceae) led to the isolation of a new flavonoid, prosojuliflavone (1) and a new natural indole alkaloid dimer, N,N-Bis(2-(1H-indol-3-yl) ethyl) oxalamide (2) along with eight known compounds including three flavonoids, vitexin (3), a mixture of vitexin (3) and isovitexin (4), 4ʹ-O-methyl-ent-gallocathechin (5), two indole alkaloids, N-acetyltryptamine (6), tryptamine (7), a disaccharide, sucrose (8), two monoglycerides, hyloglyceride (9) and 1-(26-hydroxyhexacosanoyl)-glycerol (10). Their structures were elucidated by means of spectroscopic and spectrometric data, as well as by comparison with literature data. Compound 2 is described here for the first time as a natural product with complete 1H and 13C assignments. The antibacterial and antioxidant activities of the extracts and isolated compounds were evaluated. Compounds 1 and 5 (MIC = 8–64 μg/ml) were samples with most antibacterial activities while compound 1 (EC50 = 4.31 μg/mL; GEAC = 94.66 μg/mL) displayed the largest antioxidant activity. Interestingly, the tested samples showed bactericidal effects (MBC/MIC ≤4) with respect to sensitive bacteria. Compounds 1, 2, 6, 8 and 10 were isolated for the first time from the Fabaceae family. The chemotaxonomic significance of these compounds was also discussed. The overall results highlight the potential of P. juliflora as a sustainable source of antibacterial and antioxidant agents

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

Leutcha BP, Dzoyem JP, Jouda J-B, et al. Antimicrobial and Cytotoxic Activities of Constituents from the Fruit of Albizia lebbeck L. Benth (Fabaceae). Molecules. 2022;27(15): 4823.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

A New Unsaturated Aliphatic Anhydride from Aspergillus candidus T(12)19W1, an Endophytic Fungus, from Pittosporum mannii Hook f.

Juidzou GT, Anoumedem EGM, Sema DK, et al. A New Unsaturated Aliphatic Anhydride from Aspergillus candidus T(12)19W1, an Endophytic Fungus, from Pittosporum mannii Hook f. Journal of Chemistry. 2023;2023: 5938723.A new unsaturated aliphatic anhydride derivative (Z)-(12Z)-heptadec-12-enoic-2 '-hydroxypropanoic anhydride (1) and ten known compounds, three flavonoids (2-4), two terphenyllins (5-6), four triterpenoids (7-8, 10-11), and one n-fatty acid (9), were isolated from the EtOAc extract of Aspergillus candidus T(12)19W1, an endophytic fungus, inhabiting Pittosporum mannii. All the isolated compounds were characterized using 1D- and 2D-NMR and HR-EI experiments together with the reported literature. p-terphenyls are suggested to be the chemophenetic marker of the genus Aspergillus. The ethyl acetate crude extract as well as some isolated compounds of A. candidus was assayed for antibiofilm activity, anti-inflammatory (ROS) activity, and cytotoxicity on brine shrimps and the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) cytotoxicity assay on 3T3 cell lines. The tested sample showed good antibiofilm activity with the lowest MBEC50 obtained at 64 mu g/mL. Compounds showed low anti-inflammatory activity even at high concentration (250 mu g center dot mL(-1) with an IC50 of 59.6 +/- 0.1 mu g center dot mL(-1)) with moderate cytotoxicity on brine shrimps at high concentration (1000 mu g center dot mL(-1), with 46.67% mortality). However, no cytotoxic activity was observed against 3T3 cell lines