Biomedical subjects
Publications and source records attributed to Bernard Bodo.
Fractionation of the methanolic extract of Ochna afzelii stem bark has resulted in the isolation of two biflavonoids afzelones A and B along with five known flavonoids, calodenins A and B, afzelone C, 4',5-dimethoxy-6,7-methylenedioxyisoflavone, 4',5,7-trimethoxyisoflavone and the glucoside lanceoloside A. Their structures were determined using spectroscopic and chemical methods.
Phytochemical analysis of the root bark of Bauhinia variegata Linn yielded a new flavanone, (2S)-5,7-dimethoxy-3',4'-methylenedioxyflavanone (1) and a new dihydrodibenzoxepin, 5,6-dihydro-1,7-dihydroxy-3,4-dimethoxy-2-methyldibenz [b,f]oxepin (2) together with three known flavonoids (3-5). The structures of the new compounds were determined on the basis of spectral studies.
Four new cephalotaxus alkaloids, cephalotaxine alpha-N-oxide (1), cephalotaxine beta-N-oxide (2), 11-beta-hydroxycephalotaxine beta-N-oxide (3), and isocephalotaxine (4), were isolated, together with several known alkaloids from an EtOAc extract of the fruits of Cephalotaxus fortunei. The structures were determined by spectral analysis including mass spectrometry and 2D NMR. Compounds 1, 2, 3, and 4 displayed cytotoxicity against nasopharynx KB cells with IC50 values of 30, 14, 31, and 15 micro g/mL, respectively.
Three new 2'-oxygenated flavonoids, (2S)-5,7,2',3',4'-pentamethoxyflavanone (1), 5-hydroxy-7,8,2',5'-tetramethoxyflavone (2), and echioidinin 2'-O-beta-d-(6' '-O-acetyl) glucopyranoside (3), together with four known flavonoids, 7-O-methyldihydrowogonin, 7-O-methylwogonin, skullcapflavone I 2'-methyl ether, and skullcapflavone I, and two diterpenoids, andrograpanin and 14-deoxy-11,12-didehydroandrographolide, were isolated from the whole plant of Andrographis affinis. The structures were elucidated by spectral and chemical studies.
A new naphthoquinone, 2,7-dihydroxy-8-formyl-5-isopropyl-3-methyl-1,4-naphthoquinone (1) together with a known naphthoquinone, 8-formyl-7-hydroxy-5-isopropyl-2-methoxy-3-methyl-1,4-naphthoquinone (2), has been isolated from the heartwood of Ceiba pentandra. The structures of 1 and 2 have been elucidated by extensive 1D and 2D NMR experiments.
Two new flavonoids, 5, 7, 2', 5'-tetramethoxyflavanone (1) and 5-hydroxy-7, 2'-dimethoxyflavone (2), together with two known flavones, skullcapflavone I (3) and echioidin (4) were isolated from the whole plant of Andrographis rothii. The structures of the new compounds were established by extensive one- and two-dimensional (1D- and 2D-) NMR spectral studies.
A new coumestan, tephcalostan (1) has been isolated from the whole plant of Tephrosia calophylla BEDD. together with two known flavonoids, 7-O-methylglabranin (2) and kaempferol 3-O-beta-D-glucopyranoside (3). The structure of tephcalostan was elucidated as 5'-(R)-8, 9-methylenedioxy-5'-isopropenyl-4', 5'-dihydrofurano[2', 3':2, 3]coumestan by extensive one-and two-dimensional (1D- and 2D-)-NMR techniques including (1)H-(1)H correlation spectroscopy (COSY), heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond connectivity (HMBC) and nuclear Overhauser enhancement spectroscopy (NOESY) experiments.
A new sesquiterpene lactone, 5-isopropyl-3-methyl-2,4,7-trimethoxy-8,1-naphthalene carbolactone (1) together with a known naphthoquinone, 8-formyl-7-hydroxy-5-isopropyl-2-methoxy-3-methyl-1,4-naphthoquinone (2) were isolated from the root bark of Bombax malabaricum. The structures of these two compounds were established by extensive one- and two-dimensional (1D- and 2D)-NMR spectral studies.
Two new flavonoids, 2',4',6',2,3,4-hexamethoxychalcone (1) and 5-hydroxy-7,2',5'-trimethoxyflavone (2) together with a known flavone glycoside, echioidinin 5-O-beta-D-glucopyranoside (3) were isolated from the whole plant of Andrographis neesiana, and the structures were elucidated by electrospray ionization tandem mass spectrometry (ESI-MS/MS) and one- and two-dimensional (1D- and 2D)-NMR spectral studies including 1H-1H correlation spectroscopy (COSY), heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond connectivity (HMBC) and nuclear Overhauser enhancement spectroscopy (NOESY) experiments.
The fungus Trichoderma virens is a ubiquitous soil saprophyte that has been applied as a biological control agent to protect plants from fungal pathogens. One mechanism of biocontrol is mycoparasitism, and T. virens produces antifungal compounds to assist in killing its fungal targets. Peptide synthetases produce a wide variety of peptide secondary metabolites in bacteria and fungi. Many of these are known to possess antibiotic activities. Peptaibols form a class of antibiotics known for their high alpha-aminoisobutyric acid content and their synthesis as a mixture of isoforms ranging from 7 to 20 amino acids in length. Here we report preliminary characterization of a 62.8-kb continuous open reading frame encoding a peptaibol synthetase from T. virens. The predicted protein structure consists of 18 peptide synthetase modules with additional modifying domains at the N- and C-termini. T. virens was shown to produce a mixture of peptaibols, with the largest peptides being 18 residues. Mutation of the gene eliminated production of all peptaibol isoforms. Identification of the gene responsible for peptaibol production will facilitate studies of the structure and function of peptaibol antibiotics and their contribution to biocontrol activity.
Phytochemical investigation of the dichloromethane extract of Ochna calodendron leaves resulted in the isolation and identification of three known isoflavones, irilone, 3'-methoxyirilone and prunetin, one cyanoglucoside, menisdaurin, in addition to two new triflavonoid constituents, namely caloflavans A and B. The structures of the new compounds were established by spectroscopic methods (EI-MS, FAB-MS, 1H NMR, 13C NMR, HMBC and HMQC).
Two prenylated xanthone derivatives, named globulixanthones C and D and one bis-xanthone, designated globulixanthone E, have been isolated from the root bark of Symphonia globulifera. The structures of these compounds were elucidated by a detailed spectroscopic analysis. They have been shown to exhibit in vitro significant antimicrobial activity against a range of micro-organisms.
Bioassay-guided fractionation of a root bark extract of Symphonia globulifera has yielded, in addition to stigmasterol, two new xanthones with isoprenoid units, named globulixanthones A (1) and B (2). The structures of these compounds have been elucidated by spectroscopic means. They possess significant cytotoxicity in vitro against the KB cell line.
Two new 5-deoxyflavones, 7,8-dimethoxy-3',4'-methylenedioxyflavone (1) and 7,2',4'-trimethoxyflavone (2) together with a known flavone, 7,4'-dimethoxy-3'-hydroxyflavone (3) were isolated from the rootbark of Albizia odoratissima. The structures of these new compounds were elucidated by electrospray ionization mass spectrometry (ESI-MS) and 1D and 2D-NMR spectral studies including (1)H-(1)H correlation spectroscopy (COSY), heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond connectivity (HMBC) and nuclear Overhauser enhancement spectroscopy (NOESY).
Two new bisindole alkaloids, vingramine (1) and methylvingramine (2), were isolated from the seeds of Catharanthus roseus, Apocynaceae. The structures were determined by HRFABMS as well as one- and two-dimensional NMR experiments. They possess a new bisindole skeleton involving an indole alkaloid part B with loss of 5',6'-ethylene, a C7'-C16' linkage, a 14'-O-19'-tetrahydrofuran, and a N-4'-isobutyramide group. The 12-methyl vincorine part A and part B are connected via an 11,10'-biphenyl linkage. The relative configuration was determined by NMR analysis. Biogenetic considerations suggested a rearrangement and a double fragmentation at C6'/C7' and N4'/C5' for the formation of 1 from strictamine, further allowing deduction of the absolute configuration of 10 stereocenters: 2S, 7R, 15R, 16R, 3'R, 14'S, 15'S, 16'R, 19'S, and 20'R. The alkaloids 1 and 2 display, in vitro, cytotoxic activity against nasopharynx carcinoma KB cells, IC(50) 5 and 6 &mgr;M (4 and 5 &mgr;g/mL).