Stilbene compounds

Some low-molecular dyes also have been investigated in inactive polymer matrices. For stilbene compounds in polystyrene, peak wavelengths in the green spectral region are obtained, with net optical gain coefficients of g = 15-20 cm-1 [187],... 

Isolation of spiro-indan and dihydro CS102 stilbene compounds from a Panamanian variant grown in Mississippi,... 

El Sohly, H. N. and C. E. Turner. Constituents of Cannabis sativa L. XXll. Isolation of spiro-indan and dihydro-stilbene compounds from a Panamanian variant grown in Mississippi, United States of America. Bull Nar 1982 34(2) 51-56. 

An interesting observation is that the differences between the nitro and sulfonyl electron accepting properties have less of an impact on the nonlinearity for the more highly conjugated stilbene compounds than they do in the case of the aniline systems. A similar effect also can also be seen in substituted polyenes. The calculated results for /3Z of A-(CH=CH2)n-NH2 (A = N02, S02CH3) are shown in Figure 2 as a... 

Compounds 1-4 were characterized by conventional spectroscopic techniques. For the stilbene compounds 1-3, the trans conformation of the double bond was confirmed by XH NMR analysis. For example, in the XH NMR spectrum of 1, the olefinic protons were detected as a doublet of doublets with resonances at 7.23 and 7.01 ppm, with a trans coupling constant of 16.3 Hz. In addition, the 13C NMR spectra of the stilbene compounds indicated the presence of a single isomer that was consistent with the desired structures. The UV/visible spectra in tetrahydrofuran solution showed a X value for 1-3 at 378 nm (e 2.6 x 10 ) and for 4 at 490 nm (e 3. ax 101 ). 

We decided to explore the possibility of performing electric field poling of a NLO-active compound at room temperature and solidifying the material by in-situ photopolymerization. In essence, instead of cooling the sample below Tg, we proposed to raise the Tg of the material above the poling temperature. This paper reports on systems in which the active NLO species is present either as a dopant in a photocrosslinkable host matrix or as the matrix itself. We also describe the preparation and use of several new donor-acceptor stilbene compounds similar to 1. 

Stilbene compounds 4 were prepared according to Figure 2. N V-Dialkyl anilines 2 were synthesized by direct alkylation of aniline. 

Adrian M, Jeandet P, Veneau J, Weston LA, Bessis R. 1997. Biological activity of resveratrol, a stilbenic compound from grapevines, against Botrytis cinerea, the causal agent for gray mold. J Chem Ecol 23 1689-1702. 

Versari A, Parpinello GP, Tronielli GB, Ferrarini R, Giulivo C. 2001 Stilbene compounds and stilbene synthase expression during ripening, wilting and UV treatment in grape cv. Corvina. J Agric Food Chem 49 5531-5536. 

Community. The administration of hormone growth promoters was prohibited because of fears about health effects from residues, although there is a need to standardise conditions of trade in animal products from countries outside the EU where these compounds are still licensed for use. The use of one particular group of synthetic anabolic agents with oestrogenic activity, the stilbene compounds,... 

Structures of type 15 to 20 can also be considered aza analogues of ( )-stilbene compounds 17 and 18 are an unusual type of push-pull ( )-stilbene that should show a spectrum of properties ranging between those of ( )-stilbenes and betaines. The 19 types of compounds selected, 10-28, and their precursors, 29-47, outlined in Scheme 3 and Table I, have been ordered by (a) the nature of the interannular linkage (-Q-) (b) the nature of the two atoms linking the 7r-deficient nucleus and the interannular group (C—N bond type and C—C bond type) (c) the substitution pattern between the 7r-deficient nucleus and the interannular group. 

Azobenzene and stilbene compounds have been examined as molecular... 

Bavaresco, L. and Fregoni, C. (2001) Physiological role and molecular aspects of grapevine stilbenic compounds, in Molecular biology biotechnology of the grapevine, A.K. Roubelakis-Angelakis (Ed), Kluwer Academic Publishers. 

CAS 56-53-1. A nonsteroid, synthetic estrogen, always in the trans form. It is the most active of the commonly used stilbene compounds. 

Durbeej, B., and Leif A. Eriksson. 2005. Photodegradation of substituted stilbene compounds What colors aging paper yellow J. Phys. Client. A, 109(25) 5677-5682. 

Photochemical [2+2] cycloaddition of alkenes in the crystalline state is synthetically very useful because it usually produces only one stereoisomer predicted ftom the crystal structure. On the other hand, this stereospeciflcity of the reaction can be a disadvantage because of inaccessibility to other stereoisomers. In order to circumvent such a problem, we explored compelled orientational control of the photodimerization of particular compounds like ranj-cinnamic acids and anthracenecarboxylic acids [74-78]. During our study, photochemistry of fluoro- and chloro-substituted ranj-stilbene-4-carboxylic acids and their methyl esters and alkaline and alkaline earth salts in the crystalline phase was likewise studied in order to synthesize specific stereoisomers selectively (Scheme 41) [79]. Most of these stilbene compounds dimerized to give exclusively or mainly syn head-to-head cyclobutane dimers. Some were photochemicaUy inert. 

Jayasuriya et al. [11] and Jayatilak et al. [60] isolated several stilbene compounds from the methanol fraction of Polygonum cuspidatum roots. The isolated compounds included /rans-resveratrol (15), /rans-piceid (16), /nm -resveratrol-04-p-glucoside (17), cw-resveratrol (18), cw-piceid (19) and c/s-resveratrol-04-p-glucoside (20). Yan et al. also isolated 2,3,4 -5-tetrahydroxystilbene-2-O-P-D-glucoside (21) from P. panjutinii species [37]. 

Protein tyrosine kinases are enzymes that catalyze the transfer of phosphate from adenosine triphosphate (ATP) to the hydroxyl group of the amino acid tyrosine on many essential proteins. These proteins play an essential role in cell signalling, regulation of cell growth and transformation of the cells [10]. The identification of specific inhibitors of protein tyrosine kinase may uncover potential anticancer agents [10]. Jayatilak et al. [60] investigated the kinase inhibitor activity of stilbene compounds, 15-20, that were extracted from the polar methanol fraction of Polygonum cuspidatum roots. The compounds were evaluated in protein... 

Inamori et al. [78] investigated the effects of two stilbene compounds on the growth of several fungi and bacteria. The compound 3,4-0-isopyrilidene-3,3, 4,5 -tetrahydroxystilbene (44) was chemically derived from 3,3, 4,5 -tetrahydroxystilbene (45). 

Bavaresco L, Fregoni C, Cantu E, Trevisan M. Stilbene compounds from the grapevine to wine. Drugs Exp Clin Res 1999 25 57-63. 

Figure 1.1 The most important synthetic routes to stilbene compounds. (Reproduced with permission from Ref. [24].)...

Due to their miscellaneous photophysical and photochemical properties, stilbene compounds can be used for many applications in materials science. Data on the photochemistry of stilbenoid compounds and their role in materials science were reviewed [1-3]. In this chapter, we briefly discuss materials for lasers, nonlinear optical systems, photoconductive materials, and imaging and switching techniques. 

There are hydrocarbon substituents other than the simple alkyl fragments just discussed. Alkene and alkyne groups may be attached to a benzene ring. In 15, an ethenyl group is attached that is known as ethenylbenzne, but the common name is styrene. Compound 16 is -l,2-diphenylethene, but it is commonly called trans-stilbene. Compound 17 is simply known as 1,2-diphenyl-ethyne (or diphenyl acetylene, although it has the common name of tolane). 

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