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At least 19 recordsLinked to original sources
PubMed1995

The inducible 9, 10-dihydrophenanthrene pathway: characterization and expression of bibenzyl synthase and S-adenosylhomocysteine hydrolase.

Tricyclic 9,10-dihydrophenanthrenes originate from phenylpropane derivatives by chain elongation and cyclization according to the polyacetate rule. Bibenzyls are bicyclic intermediates, and O-methylation is a prerequisite for their conversion into dihydrophenanthrenes. cDNA clones encoding bibenzyl synthases and S-adenosylhomocysteine hydrolase of the orchid Phalaenopsis sp. were isolated from a cDNA library representing the stage of elicitor-induced plants. The deduced amino acid sequences of two clones, pBibSy811 and pBibSy212, indicated that we obtained two full-length sequences of bibenzyl synthases characterized by their homology to stilbene synthases previously investigated. That indeed bibenzyl synthase cDNAs rather than a homologous stilbene synthase cDNA or chalcone synthase cDNA have been isolated was demonstrated by expression of two enzymatically active bibenzyl synthase proteins in Escherichia coli. These proteins showed virtually the same selectivity towards m-hydroxyphenylpropionyl-CoA as substrate as the enzyme isolated from orchid plants. In young sterile Phalaenopsis plants, the formation of both bibenzyl synthase mRNAs and S-adenosylhomocysteine hydrolase mRNAs was increased upon elicitation more than 100-fold. The time courses of gene expression exhibited transient profiles, reaching maximum mRNA levels 20 h after onset of fungal infection followed by a rapid decline to 40 h.

Adenosylhomocysteinase↗
PubMed2005

Bibenzyls and dihydroisocoumarins from white salsify (Tragopogon porrifolius subsp. porrifolius).

A phytochemical investigation of three accessions of Tragopogon porrifolius L. subsp. porrifolius (Asteraceae, Lactuceae) yielded three new bibenzyl derivatives, 5,4'-dihydroxy-3-alpha-l-rhamnopyranosyl-(1-->3)-beta-d-xylopyranosyloxybibenzyl, 2-carboxyl-3,4'-dihydroxy-5-beta-d-xylopyranosyloxybibenzyl, tragopogonic acid (2'carboxyl-3',5',4''-trihydroxyphenylethanone) and three dihydroisocoumarin derivatives, including the new natural product 6-O-methylscorzocreticoside I. One of the isolated bibenzyl derivatives is considered to be a precursor to the biosynthesis of dihydroisocoumarins. Structures of new compounds were established by HR mass spectrometry, extensive 1D and 2D NMR spectroscopy, and CD spectroscopy. Moreover, radical scavenging activities of the polyphenolic compounds were measured using the 2,2-diphenyl-1-picrylhydrazyl assay; two of the bibenzyls showed moderate and two of the dihydroisocoumarins showed weak radical scavenging activities. The chemosystematic impact of bibenzyls and dihydroisocoumarins is discussed briefly.

Bibenzyls↗
PubMed2005

Phytotoxic activity of bibenzyl derivatives from the orchid Epidendrum rigidum.

A whole plant chloroform-methanol extract of the orchid Epidendrum rigidum inhibited radicle growth of Amaranthus hypochondriacus seedlings (IC50 = 300 microg/mL). Bioassay-guided fractionation furnished four phytotoxins, namely, gigantol (1), batatasin III (2), 2,3-dimethoxy-9,10-dihydrophenathrene-4,7-diol (9), and 3,4,9-trimethoxyphenanthrene-2,5-diol (11), along with the known flavonoids apigenin, vitexin, and isovetin and the triterterpenoids 24,24-dimethyl-9,19-cyclolanostane-25-en-3beta-ol (14) and 24-methyl-9,19-cyclolanostane-25-en-3beta-ol (15). Stilbenoids 1, 2, 9, and 11 inhibited radicle growth of A. hypochondriacus with IC50 values of 0.65, 0.1, 0.12, and 5.9 microM, respectively. Foliar application of gigantol (1) at 1 microM to 4 week old seedlings of A. hypochondriacus reduced shoot elongation by 69% and fresh weight accumulation by 54%. Bibenzyls 1 and 2, as well as synthetic analogues 4'-hydroxy-3,3',5-trimethoxybibenzyl (3), 3,3',4',5-tetramethoxybibenzyl (4), 3,4'-dihydroxy-5-methoxybibenzyl (5), 3'-O-methylbatatasin III (6), 3,3',5-trihydroxybibenzyl (7), and 3,4',5-trihydroxybibenzyl (8), were tested for phytotoxicity in axenic cultures of the small aquatic plant Lemna pausicostata. All bibenzyls derivatives except 7 and 8 inhibited growth and increased cellular leakage with IC50 values of 89.9-180 and 89.9-166 microM, respectively. The natural and synthetic bibenzyls showed marginal cytotoxicity on animal cells. The results suggest that orchid bibenzyls may be good lead compounds for the development of novel herbicidal agents.

Amaranthus↗
PubMed2004

Novel biologically active bibenzyls from Bauhinia saccocalyx Pierre.

Four new bibenzyls, bauhinols A-D (1-4), together with the two known bibenzyls 5 and 6, were isolated from the roots of Bauhinia saccocalyx, and their structures were elucidated by analyses of spectroscopic data. Bauhinol A (1) exhibits significant cytotoxicity towards NCI-H187 (small-cell lung cancer), BC (breast cancer), and KB (oral-cavity cancer) cell lines, with IC50 values of 2.7-4.5 microg/ml. Bauhinol B (2) is cytotoxic against NCI-H187 (IC50 = 1.1 microg/ml) and BC (IC50 = 9.7 microg/ml) cell lines, but inactive toward the KB cell line (at 20 microg/ml). Compound 2 also is mildly antifungal towards Candia albicans (IC50 = 28.9 microg/ml). Bibenzyl 6 is active against NCI-H187 (IC50 = 14.1 microg/ml) and BC (IC50 = 4.0 microg/ml) cells, but inactive (at 20 microg/ml) toward the KB cell line. Compounds 1, 2, and 6 show mild antimycobacterial activities, with MIC values of 25-50 microg/ml, but are inactive at 20 microg/ml against the K1 malarial parasite strain (Plasmodium falciparum). While bauhinol A (1) is inactive against cyclooxygenase 1 (COX-1) and cyclooxygenase 2 (COX-2), compounds 2 and 6 inhibit both COX-1 and COX-2, with IC50 values comparable to those of the standard drug, aspirin (Table 3).

Animals↗
PubMed1972

Physical state in which naphthalene and bibenzyl are utilized by bacteria.

The generation times of a strain of Pseudomonas grown on a mineral salts medium in the presence of various amounts of naphthalene did not vary with the amount of solid present, and these generation times were the same as the generation time on mineral salts medium containing only dissolved naphthalene. The generation time of a soil isolate grown on mineral salts medium in the presence of 0.5 g of solid bibenzyl per liter was the same as the generation time on a mineral salts medium saturated with bibenzyl. The evidence indicates that naphthalene and bibenzyl are utilized in the dissolved state.

Bacteriological Techniques↗
PubMed2002

New bibenzyl cannabinoid from the New Zealand liverwort Radula marginata.

The ether extract of the New Zealand liverwort Radula marginata afforded a new cannabinoid type bibenzyl compound named perrottetinenic acid, and two new bibenzyls, together with a known cannabinoid, perrottetinene. Their structures were established by two dimensional (2D) NMR spectral data. The structure of perrottetinenic acid was a similar to that of Delta(1)-tetrahydrocannabinol, a known hallucinogen. Cannabinoid type bibenzyls have been isolated from liverwort Radula perrottetii, though have not previously been reported from the liverwort R. marginata.

Bibenzyls↗
PubMed2003

Synthesis and fungicidal activity of novel 4,4'-bis(2' '-aryl-5' '-methyl/unsubstituted-4' '-oxo-thiazolidin-3' '-yl) bibenzyl.

Reduction followed by nitration of benzil I yielded 4,4'-dinitrobibenzyl (III) which by reduction furnished quantitatively and analytically pure 4,4'-diaminobibenzyl (IV) which on condensation with different carbonyl compounds gave 4,4'-bis (benzylideneamino) bibenzyls (Va-f). Compounds (Va-f) on cycloaddition with mercaptoacetic acid/2-mercaptopropionic acid yielded the corresponding 4-oxothiazolidin-3-yl bibenzyls (VIa-l). The compounds VIg-l have two chiral centers in each thiazolidinone moiety so two diastereomers are possible, but on crystallization and repeated chromatography, one diastereomer was obtained. The absolute configuration of the diastereomer was tentatively assigned on the basis of (1)H NMR spectra. (1)H NMR spectra of the product showed a distinct doublet at delta 1.22 for C(5)-CH(3) of thiazolidinone ring (22, 23) and a distinct quartet at delta 4.20 for the C(5)-H proton. Similarly, the C(2) proton showed an independent singlet at delta 5.95, so the diastereomers obtained were assigned trans configuration. Compounds Va-f and VIa-l were evaluated in vitro for their fungitoxicities against Fusarium oxysporium and Penicillium citrinum. All the compounds were found to be antifungal active. Some of the compounds displayed activities comparable with that of the commercial fungicide Dithane M-45. Structure-activity relationships for the screened compounds are discussed.

Bibenzyls↗
PubMed2004

Antimicrobial chlorinated bibenzyls from the liverwort Riccardia marginata.

Three new chlorinated bibenzyls 3, 4, and 5, have been isolated from the New Zealand liverwort Riccardia marginata. This is the first report of simple chlorinated bibenzyls from any natural source. Compounds 3-5 showed antimicrobial activity against Bacillus subtilis, Candida albicans, and Trichophyton mentagrophytes.

Antifungal Agents↗
PubMed2006

Neuroprotective bibenzyl glycosides of Stemona tuberosa roots.

Three new bibenzyl glycosides characterized as stilbostemin B 3'-beta-D-glucopyranoside (1), stilbostemin H 3'-beta-D-glucopyranoside (2), and stilbostemin I 2"-beta-D-glucopyranoside (3) were isolated from the roots of Stemona tuberosa. All three bibenzyl glycosides significantly protected human neuroblastoma SH-SY5Y cells from 6-hydroxydopamine-induced neurotoxicity.

Bibenzyls↗
PubMed2005

Simultaneous determination of phenols (bibenzyl, phenanthrene, and fluorenone) in Dendrobium species by high-performance liquid chromatography with diode array detection.

A new method of analysis of 11 phenols, including five bibenzyls, three phenanthrenes, and three fluorenones, using high-performance liquid chromatography (HPLC)-diode array detection (DAD) was described. The separation of 11 phenols was effected by RP-HPLC (Beckman Coulter ODS column, 5 microm, 250 mm x 4.6 mm) using linear gradient elution systems of acetonitrile-1/1000 trifluoroacetic acid (TFA). Satisfactory separation of these compounds was obtained in less than 45 min. The method was validated for linearity, repeatability, limits of detection (LOD) and limits of quantification (LOQ). Good results were obtained with respect to repeatability (relative standard deviation (RSD)<3.5%) and recovery (85.77-104.92%). The developed method was applied to the simultaneous determination of 11 phenols from totally 31 Dendrobium species (mainly of medicinal plants) as well as other four samples from the similar genera as Pholidota, Flickingeria and Bulbophyllum. The range of the total amounts of bibenzyl, phenanthrene and fluorenone were found to from trace: 4.00, not detected (nd): 0.42 and nd: 0.24 microg mg(-1), respectively.

Calibration↗
PubMed1981

Bifluranol, a novel fluorinated bibenzyl anti-androgen, its chemistry and disposition in different animal species.

The synthesis of bifluranol, a new fluorinated bibenzyl anti-androgen, and of 3H-labelled bifluranol is described. The absorption, distribution and excretion of bifluranol has been studied in mouse, rat, ferret and dog; it is readily absorbed following oral administration, but blood concentrations of the drug are low due to hepatic uptake and biliary excretion. Enterohepatic re-circulation occurs, but the drug is excreted primarily in the faeces and only small amounts appear in urine. This pattern of disposition and excretion is similar to that reported elsewhere for the bibenzyl, hexoestrol, and for the stilbene, diethylstilboestrol.

Administration, Oral↗
PubMedDate not supplied

Molecular similarity analysis on biologically active macrocyclic bis(bibenzyls).

Conformational analysis of marchantin A (1), a bis(diarylether) type, and riccardin A (2), a diarylether-biphenyl type macrocyclic bis(bibenzyl) was carried out by systematic unbounded multiple minimum search (SUMM). Mobility of the macrocyclic rings was analysed by variable temperature 1H-NMR study. Molecular similarity analysis was performed on the minimum energy conformers of 1 and 2 comparing their steric, electrostatic and hydrophobic properties. Correlation between complexation properties and calmodulin inhibitor activity was established. Differences in steric and electrostatic profiles may be responsible for the reduced Ca2+ affinity and activity of 2.

Bibenzyls↗
PubMed2006

Antifungal bis[bibenzyls] from the Chinese liverwort Marchantia polymorpha L.

Bioassay-guided separation of the antifungal constituents of the Chinese liverwort Marchantia polymorpha L. (Marchantiaceae) led to the isolation of seven bis[bibenzyl]-type macrocycles. On the basis of NMR and MS analyses, the three new compounds plagiochin E (1), 13,13'-O-isoproylidenericcardin D (4), and riccardin H (7) were identified, together with four known compounds: marchantin E (2), neomarchantin A (3), marchantin A (5), and marchantin B (6). Their antifungal activities against Candida albicans were determined by TLC bioautography.

Antifungal Agents↗
PubMed1995

Bibenzyls from Stemona tuberosa.

Three new bibenzyls were isolated from the roots of Stemona tuberosa. Their structures were identified by spectroscopic methods as 3,5-dihydroxy-4-methylbibenzyl, 3,5-dihydroxy-2'-methoxy-4-methylbibenzyl and 3-hydroxy-2',5-dimethoxy-2-methylbibenzyl.

Animals↗
PubMed1995

The biological activity of cyclic bis(bibenzyls): a rational approach.

The biological activities reported for marchantin A (1), a natural cyclic bis(bibenzyl), were studied in comparison with cepharanthine (2), a therapeutically useful bisbenzylisoquinoline alkaloid. Based on the examination of steric, electrostatic, and hydrophobic similarity, as well as on the comparison of biological activities, the similar therapeutic properties of 1 and 2 can be attributed to binding on a common receptor. The wide range of activity of 1 can be interpreted by a mechanism of action based on a calcium binding.

Alkaloids↗
PubMed2001

Isolation of an anti-HIV diprenylated bibenzyl from Glycyrrhiza lepidota.

The organic soluble extract from the leaves of Glycyrrhiza lepidota showed moderate activity in the US National Cancer Institute in vitro anti-HIV-1 bioassay. Chromatographic separation of this extract resulted in the identification of a new diprenylated bibenzyl as the compound responsible for the observed anti-viral activity. Extensive spectroscopic experiments provide the complete 1H NMR and 13C NMR spectral assignments to support the proposed structure. Known compounds glepidotin B and glepidotin A were also isolated from the extract and shown to be inactive in the anti-viral assay.

Anti-HIV Agents↗
PubMed2005

Bis(bibenzyls) from liverworts inhibit lipopolysaccharide-induced inducible NOS in RAW 264.7 cells: a study of structure-activity relationships and molecular mechanism.

The inhibition of lipopolysaccharide-induced NOS by 19 bis(bibenzyls) isolated from liverworts in RAW 264.7 macrophages was evaluated. The presence of phenolic hydroxyls and saturation at 7,8 and/or 7'/8' are required for inhibition of NO production. Among the compounds tested, marchantin A was the most potent, and its inhibitory activity was consistent with the inhibition of LPS-induced iNOS mRNA.

Animals↗