Search results for "STILBENES"
showing 10 items of 121 documents
Heterocyclic and Phenyl Double-Bond-Locked Combretastatin Analogues Possessing Potent Apoptosis-inducing activity in HL60 and in MDR Cell lines
2005
Two new series of combretastatin (CA-4) analogues have been prepared. The alkenyl motif of CA-4 was replaced either by a five-membered heterocyclic (isoxazoline or isoxazole) or by a six-membered ring (pyridine or benzene). The new compounds have been evaluated for their effects on tubulin assembly and for cytotoxic and apoptotic activities. Five compounds (18b, 20a, 21a, 34b, and 35b) demonstrated an attractive profile of cytotoxicity (IC501 microM) and apoptosis-inducing activity but poor antitubulin activity. The isoxazoline derivatives 18b, 20a, and 21a, demonstrated potent apoptotic activity different from that of natural CA-4. Their ability to block most cells in the G2 phase suggests…
Revised structure of trans-resveratrol: Implications for its proposed antioxidant mechanism
2015
The crystal structure of trans-resveratrol has been redetermined by X-ray diffraction. The newly refined structure demonstrates that the previously reported, dynamically disordered hydrogen-bonding network is rather the superposition of two crystallographically independent molecules of trans-resveratrol. This latter arrangement possesses a well-defined hydrogen-bonding network in a unit cell of double the previously reported volume. While not meant as a criticism of the proposed antioxidant mechanism itself, the present studies clearly show that the X-ray diffraction data should no longer be used for its additional support.
Structural determinants of resveratrol for cell proliferation inhibition potency: experimental and docking studies of new analogs.
2010
International audience; Resveratrol is the subject of intense research because of the abundance of this compound in the human diet and as one of the most valuable natural chemopreventive agents. Further advances require new resveratrol analogs be used to identify the structural determinants of resveratrol for the inhibition potency of cell proliferation by comparing experimental and docking studies. Therefore, we synthesized new trans/(E)- and cis/(Z)-resveratrol - analogs not reported to date - by modifying the hydroxylation pattern of resveratrol and a double bond geometry. We included them in a larger panel of 14 molecules, including (Z)-3,5,4'-trimethoxystilbene, the most powerful molec…
Topology and accessibility of the transmembrane helices and the sensory site in the bifunctional transporter DcuB of Escherichia coli.
2011
C(4)-Dicarboxylate uptake transporter B (DcuB) of Escherichia coli is a bifunctional transporter that catalyzes fumarate/succinate antiport and serves as a cosensor of the sensor kinase DcuS. Sites and domains of DcuB were analyzed for their topology relative to the cytoplasmic or periplasmic side of the membrane and their accessibility to the water space. For the topology studies, DcuB was fused at 33 sites to the reporter enzymes PhoA and LacZ that are only active when located in the periplasm or the cytoplasm, respectively. The ratios of the PhoA and LacZ activities suggested the presence of 10 or 11 hydrophilic loops, and 11 or 12 α-helical transmembrane domains (TMDs). The central part…
Design, synthesis and biological evaluation of novel stilbene-based antitumor agents
2008
A series of novel stilbene derivatives has been synthesized and studied with the main goal to investigate SAR of the amino compound 1a, as well as to improve its water solubility, a potentially negative aspect of the molecule that could be a serious obstacle for a pre-clinical development. We have obtained derivatives with good cytotoxic activity, in particular, the derivatives 5c and 6b could represent two novel leads for further investigation. Compound 8b, a morpholino-carbamate derivative, prodrug of 1a, has a very good solubility in water, and is active in suppressing growth of tumor cells at a concentration of 5000 nM, which is a concentration 100 times higher than the parent stilbene …
Novel antiproliferative chimeric compounds with marked histone deacetylase inhibitory activity.
2014
Given our interest in finding potential antitumor agents and in view of the multifactorial mechanistic nature of cancer, in the present work, taking advantage of the multifunctional ligands approach, new chimeric molecules were designed and synthesized by combining in single chemical entities structural features of SAHA, targeting histone deacetylases (HDACs), with substituted stilbene or terphenyl derivatives previously obtained by us and endowed with antiproliferative and pro-apoptotic activity. The new chimeric derivatives were characterized with respect to their cytotoxic activity and their effects on cell cycle progression on different tumor cell lines, as well as their HDACs inhibitio…
Occurrence of resveratrol and pterostilbene in age-old darakchasava, an ayurvedic medicine from India
2000
'Darakchasava' is a well known Indian herbal preparation of which the main ingredient is Vitis vinifera L. This 'ayurvedic' medicine is prescribed as a cardiotonic and also given for other disorders. HPLC analysis of this age old formulation revealed the presence of polyphenols like resveratrol and pterostilbene. These phenolic compounds are now known as antioxidants, cancer chemopreventive agents, and also known to reduce mortality from coronary heart disease by increasing high density lipoproteins like cholesterol and inhibiting platelet aggregation (Soleas, J.S., Diamandis, E.P., Goldberg, D.M., 1997. Resveratrol: a molecule whose time has come? and gone? Clin. Biochem. 30 (2), 91-113). …
Bioactive Polyphenols from Grapes and Wine Emphasized with Resveratrol
2013
Grape polyphenols are abundant. They play essential roles in the plant's life, particularly in defence mechanisms. Moreover, the grape, fresh or dried, is a widely consumed fruit by humans, as are its by-products, grape juice and wine. They also contain vast and highly varied quantities of polyphenols. Like other phytophenols, grape and wine resveratrol is considered a protective micronutrient. Resveratrol is a well known antioxidant, for example, a protector of low-density lipoproteins against oxidation. Its applications are therefore highly varied. Research supports the idea that wine consumed regularly, without excess, is a natural biological product possesses preventive properties, and …
Analysis of the Molecular Dialogue Between Gray Mold (Botrytis cinerea) and Grapevine (Vitis vinifera) Reveals a Clear Shift in Defense Mechanisms Du…
2015
Mature grapevine berries at the harvesting stage (MB) are very susceptible to the gray mold fungus Botrytis cinerea, while veraison berries (VB) are not. We conducted simultaneous microscopic and transcriptomic analyses of the pathogen and the host to investigate the infection process developed by B. cinerea on MB versus VB, and the plant defense mechanisms deployed to stop the fungus spreading. On the pathogen side, our genome-wide transcriptomic data revealed that B. cinerea genes upregulated during infection of MB are enriched in functional categories related to necrotrophy, such as degradation of the plant cell wall, proteolysis, membrane transport, reactive oxygen species (ROS) genera…
Pterostilbene and 3′-hydroxypterostilbene are effective apoptosis-inducing agents in MDR and BCR-ABL-expressing leukemia cells
2005
Pterostilbene and 3,5-hydroxypterostilbene are the natural 3,5-dimethoxy analogs of trans-resveratrol and piceatannol, two compounds which can induce apoptosis in tumor cells. In previous studies we demonstrated the importance of a 3,5-dimethoxy motif in conferring pro-apoptotic activity to stilbene based compounds so we now wanted to evaluate the ability of pterostilbene and 3,5-hydroxypterostilbene in inducing apoptosis in sensitive and resistant leukemia cells. When tested in sensitive cell lines, HL60 and HUT78, 3'-hydroxypterostilbene was 50-97 times more potent than trans-resveratrol in inducing apoptosis, while pterostilbene appeared barely active. However, both compounds, but not tr…