stilbenes and diphenyl

The cis-stilbene, combretastatin A4 (CA4), is a potent microtubule targeting and vascular damaging agent. Despite promising results at the pre-clinical level and extensive clinical evaluation, CA4 has yet to be approved for therapeutic use. One impediment to the development of CA4 is an inherent conformational instability about the ethylene linker, which joins two aromatic rings. We have previously published preliminary data regarding structurally simplified biphenyl derivatives of CA4, lacking an ethylene linker, which retain anti-proliferative and pro-apoptotic activity, albeit at higher doses. Our current study provides a more comprehensive evaluation regarding the anti-proliferative and pro-apoptotic properties of biphenyl CA4 derivatives in both 2D and 3D cancerous and non-cancerous cell models. Computational analysis has revealed that cytotoxicity of CA4 and biphenyl analogues correlates with predicted tubulin affinity. Additional mechanistic evaluation of the biphenyl derivatives found that their anti-cancer activity is dependent on prolonged mitotic arrest, in a similar manner to CA4. Lastly, we have shown that cancer cells deficient in the extrinsic pathway of apoptosis experience delayed cell death following treatment with CA4 or analogues. Biphenyl derivatives of CA4 represent structurally simplified analogues of CA4, which retain a similar mechanism of action. The biphenyl analogues warrant in vivo examination to evaluate their potential as vascular damaging agents.

Topics: Antineoplastic Agents; Apoptosis; Biphenyl Compounds; Cell Cycle Checkpoints; Cell Proliferation; DNA Damage; Humans; Jurkat Cells; Membrane Potential, Mitochondrial; Mitosis; Models, Molecular; Protein Conformation; Stilbenes; Tubulin

Chemical investigation of Flickingeria fimbriata (Bl.) Hawkes (Orchidaceae) resulted in the isolation and identification of one new dihydrophenanthrene, 1,2,5,6,7-pentamethoxy-9,10-dihydrophenanthrene (1), together with seven known dihydrophenanthrenes, erianthridin (2), coelonin (3), 4-methoxy-9,10-dihydrophenanthrene-1,2,7-triol (4), lusianthridin (5), ephemeranthol A (6), flavanthridin (7) and hircinol (8), four known phenanthrenes, epheranthol B (9), nudol (10), denthyrsinin (11) and confusarin (12), and one known bibenzyl, batatasin III (13). The structure of the new compound was elucidated by spectroscopic analysis (HRMS, 1D and 2D NMR). All the compounds were isolated from F. fimbriata for the first time except for compounds 5 and 12, and compounds 1, 3, 4, 8, 10, 11 and 13 were obtained from this genus for the first time. Compounds 1-4 showed moderate cytotoxic activity against HepG2 cells.

Topics: Biphenyl Compounds; Cytotoxins; Hep G2 Cells; Humans; Magnetic Resonance Spectroscopy; Molecular Structure; Orchidaceae; Phenanthrenes; Phenols; Plant Stems; Stilbenes

The photoinduced intramolecular excited-state energy-transfer (EET) process in conjugated polymers has received a great deal of research interest because of its important role in the light harvesting and energy transport of organic photovoltaic materials in photoelectric devices. In this work, the silylene-bridged biphenyl and stilbene (SBS) system was chosen as a simplified model system to obtain physical insight into the photoinduced intramolecular energy transfer between the different building units of the SBS copolymer. In the SBS system, the vinylbiphenyl and vinylstilbene moieties serve as the donor (D) unit and the acceptor (A) unit, respectively. The ultrafast excited-state dynamics of the SBS system was investigated from the point of view of nonadiabatic dynamics with the surface-hopping method at the TDDFT level. The first two excited states (S1 and S2) are characterized by local excitations at the acceptor (vinylstilbene) and donor (vinylbiphenyl) units, respectively. Ultrafast S2-S1 decay is responsible for the intramolecular D-A excitonic energy transfer. The geometric distortion of the D moiety play an essential role in this EET process, whereas the A moiety remains unchanged during the nonadiabatic dynamics simulation. The present work provides a direct dynamical approach to understand the ultrafast intramolecular energy-transfer dynamics in SBS copolymers and other similar organic photovoltaic copolymers.

Topics: Biphenyl Compounds; Electrons; Energy Transfer; Kinetics; Models, Molecular; Molecular Conformation; Photochemical Processes; Polymers; Quantum Theory; Stilbenes

Isoriccardin C (1) and riccardin D (2), isolated from the liverwort Reboulia hemisphaerica, were first characterized to be a mixture of two enantiomeric atropisomers by online chiral high-performance liquid chromatography-circular dichroism (HPLC-CD) analysis. Exemplarily for bisbibenzyls of the diarylether-biphenyl type, the absolute atropisomeric configurations of compunds 1 and 2 were determined by the analysis of their CD data coupled with quantum chemical CD calculations.

Topics: Algorithms; Biphenyl Compounds; Catechols; Chromatography, High Pressure Liquid; Circular Dichroism; Drugs, Chinese Herbal; Hepatophyta; Molecular Structure; Phenyl Ethers; Spectrophotometry, Ultraviolet; Stereoisomerism; Stilbenes

Constitutive androstane receptor (CAR) and pregnane X receptor (PXR) are closely related orphan nuclear receptor proteins that share several ligands and target overlapping sets of genes involved in homeostasis and all phases of drug metabolism. CAR and PXR are involved in the development of certain diseases, including diabetes, metabolic syndrome and obesity. Ligand screens for these receptors so far have typically focused on steroid hormone analogs with pharmacophore-based approaches, only to find relatively few new hits. Multiple CAR isoforms have been detected in human liver, with the most abundant being the constitutively active reference, CAR1, and the ligand-dependent isoform CAR3. It has been assumed that any compound that binds CAR1 should also activate CAR3, and so CAR3 can be used as a ligand-activated surrogate for CAR1 studies. The possibility of CAR3-specific ligands has not, so far, been addressed. To investigate the differences between CAR1, CAR3 and PXR, and to look for more CAR ligands that may be of use in quantitative structure-activity relationship (QSAR) studies, we performed a luciferase transactivation assay screen of 60 mostly non-steroid compounds. Known active compounds with different core chemistries were chosen as starting points and structural variants were rationally selected for screening. Distinct differences in agonist versus inverse agonist/antagonist effects were seen in 49 compounds that had some ligand effect on at least one receptor and 18 that had effects on all three receptors; eight were CAR1 ligands only, three were CAR3 only ligands and four affected PXR only. This work provides evidence for new CAR ligands, some of which have CAR3-specific effects, and provides observational data on CAR and PXR ligands with which to inform in silico strategies. Compounds that demonstrated unique activity on any one receptor are potentially valuable diagnostic tools for the investigation of in vivo molecular targets.

Topics: Antifungal Agents; Biphenyl Compounds; Cell Line, Tumor; Constitutive Androstane Receptor; Drug Evaluation, Preclinical; Histamine Antagonists; Humans; Ligands; Phenolphthalein; Pregnane X Receptor; Protein Binding; Protein Isoforms; Quantitative Structure-Activity Relationship; Receptors, Cytoplasmic and Nuclear; Receptors, Steroid; Stilbenes; Substrate Specificity; Terphenyl Compounds

Fifty-one chemicals including derivatives of 16 flavonoids, three stilbenes, six pyrenes, seven naphthalenes, seven phenanthrenes, 10 biphenyls, 17beta-estradiol, and estrone were examined for their abilities to induce reverse type I binding spectra with human cytochrome P450 (P450) 1B1 and to inhibit 7-ethoxyresorufin O-deethylation (EROD) activities catalyzed by P450 1B1. Forty-nine chemicals showed reverse type I spectra with P450 1B1, and we found that 3,5,7-trihydroxyflavone, 3',4'-dimethoxy-5,7-dihydroxyflavone, 4'-methoxy-5,7-dihydroxyflavone, alpha- and beta-naphthoflavones, 2,4,3',5'-tetramethoxystilbene, pyrene, and several acetylenic pyrenes and phenanthrenes were strong inducers of the spectra and also potent inhibitors of EROD activities catalyzed by P450 1B1. The spectral dissociation constant (K(s)) and the magnitude of the binding (DeltaA(max)/K(s)) of 49 chemicals were correlated with the inhibition potencies of EROD activities by these chemicals [correlation coefficients (r) of 0.72 and 0.74, respectively]. The K(s) and DeltaA(max)/K(s) values were more correlated with IC(50) values when compared in a group of derivatives of flavonoids, stilbenes, and estrogens (r = 0.81 and 0.88, respectively) or a group of derivatives of pyrenes, naphthalenes, phenanthrenes, and biphenyls (r = 0.88 and 0.91, respectively). Among 14 flavonoids examined, 3,5,7-trihydroxyflavone and 4'-methoxy- and 3',4'-dimethoxy-5,7-dihydroxyflavone were more active than flavone in interacting with P450 1B1, but the respective 7,8-dihydroxyflavones were less active. Pyrene itself was highly active in interacting with P450 1B1, but its binding was slightly decreased when substituted with acetylenic groups. In contrast, substitution of naphthalene with methyl and ethyl propargyl ethers led to more interaction with P450 1B1 than with naphthalene itself. Similarly, substitution on phenanthrene or biphenyl with acetylenic groups and propargyl ethers increased affinities to P450 1B1. These results suggest that the reverse type I binding of chemicals to P450 1B1 may determine how they interact with and inhibit the catalytic activity of the enzyme. Substitutions on the compounds with various acetylenic groups and propargyl ethers cause an increase or decrease of their affinities to P450 1B1, depending on the parent compound used.

Topics: Aryl Hydrocarbon Hydroxylases; Biphenyl Compounds; Cytochrome P-450 CYP1B1; Cytochrome P-450 Enzyme Inhibitors; Cytochrome P-450 Enzyme System; Enzyme Inhibitors; Flavonoids; Humans; Hydrocarbons, Aromatic; Kinetics; Naphthalenes; Phenanthrenes; Protein Binding; Pyrenes; Spectrophotometry, Ultraviolet; Stilbenes; Structure-Activity Relationship

Topics: Anti-Inflammatory Agents; Biphenyl Compounds; Chemistry, Pharmaceutical; Ethers; Inflammation; Oxazoles; Phenyl Ethers; Research; Stilbenes

Topics: Amino Alcohols; Benzoin; Biphenyl Compounds; Ethanolamine; Stilbenes

Topics: Biphenyl Compounds; Parasympatholytics; Radiation; Radiation Injuries; Stilbenes

Topics: Biphenyl Compounds; Chlorides; Ions; Stilbenes; Tetrazolium Salts

Topics: Acetates; Biphenyl Compounds; Blood; Cholesterol; Diphenhydramine; Research; Stilbenes

Topics: Autonomic Agents; Biphenyl Compounds; Humans; Stilbenes

Topics: Biphenyl Compounds; Cardiovascular Agents; Curare; Diphenhydramine; Muscle Relaxants, Central; Stilbenes