Synthetic analogs of natural flavolignans. IV. Synthesis of benzodioxocane analogs of silandrin and hydnocarpin

1,6-Benzodioxocane analogs of chalcones have been synthesized. From them have been obtained benzodioxocane analogs of silandrin and hydnocarpin. The PMR spectra of the substances synthesized are given and are discussed.Taras Shevchenko Kiev University, Ukraine. KIEN, Karakalpak Division, Academy of Sciences of the Republic of Uzbekistan, Nukus. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 490–493, July–August, 1994.     

Synthetic analogs of natural flavolignans. IV. Synthesis of benzodioxocane analogs of silandrin and hydnocarpin

1,6-Benzodioxocane analogs of chalcones have been synthesized. From them have been obtained benzodioxocane analogs of silandrin and hydnocarpin. The PMR spectra of the substances synthesized are given and are discussed. Taras Shevchenko Kiev University, Ukraine. KIEN, Karakalpak Division, Academy of Sciences of the Republic of Uzbekistan, Nukus. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 490–493, July–August, 1994.     

Synthetic analogs of natural flavolignans. II. A new synthesis of benzodioxepane analogs of silandrin and hydnocarpin

Benzodioxepane analogs of chalcones have been obtained from which analogs of natural flavolignans — silandrin and hydnocarpin — have been synthesized. The PMR spectra of the new substances are given and are discussed. KIEN, Karakalpak Division, Academy of Sciences of the Republic of Uzbekistan, Nukus. Taras Shevchenko Kiev University, Ukraine. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 480–483, July–August, 1994.     

Synthetic analogs of natural flavolignans. V. A new synthesis of 6-halogeno-1,3-benzodioxane analogs of silandrin and hydnocarpin

6-Halogeno-1,3-benzodioxane analogs of chalcones have been synthesized by various methods. Flavanone and flavone analogs of silandrin and hydnocarpin have been obtained from them. The structures of the new flavonoids have been shown by their PMR spectra.KIEN Karakalpak Division, Academy of Sciences of the Republic of Uzbekistan, Nukus. Taras Shevchenko Kiev University, Ukraine. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 494–498, July–August, 1994.     

Synthetic analogs of natural flavolignans. II. A new synthesis of benzodioxepane analogs of silandrin and hydnocarpin

Benzodioxepane analogs of chalcones have been obtained from which analogs of natural flavolignans — silandrin and hydnocarpin — have been synthesized. The PMR spectra of the new substances are given and are discussed.KIEN, Karakalpak Division, Academy of Sciences of the Republic of Uzbekistan, Nukus. Taras Shevchenko Kiev University, Ukraine. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 480–483, July–August, 1994.     

Chemistry of heteroanalogs of isoflavones 13. 1,3-Benzodioxan analogs of flavonoids

Some 1,3-benzodioxan analogs of chalcones and their epoxides have been obtained, and used to prepare pyrazolines and novel flavone and flavanone analogs of flavolignan (sylibin). The PMR spectra of novel compounds are shown and discussed, together with the results of preliminary biological tests.For Communication 12, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 879–887, July, 1992.     

Features of the reaction of heterocyclic analogs of chalcone with lanthanide shift reagents

The PMR spectra of heterocyclic analogs of 2-hydroxychalcone containing thiazole, benzofuran, triazole, imidazole, benzodioxane, or pyridine rings in the presence of lanthanide shift reagents are studied. It is found that the most effective reagent for modifying the spectra of these compounds is Yb(fod)3. The broadening of the spectra of 2-hydroxy chalcones in the presence of lanthanide shift reagents is explained by the dynamic effects of complex formation. An example is given of the determination of the conformation of molecules of 2-hydroxychalcone by the simultaneous use of lanthanide shift reagents and the homonuclear Overhauser effect.Taras Shevchenko Kiev University, Kiev 252017. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 457–463, April, 1994     

Chemistry of modified flavonoids

2,4-Dihydroxyphenoxyacetophenones were obtained by the reaction of resorcinol with phenoxyacetonitrile under the conditions of the Houben-Hoesch reaction. Their cyclization under the conditions of acid and alkaline catalysis gave new derivatives of 3-phenoxychromone.For Communication 18, see [1].Chemical Faculty, Taras Shevchenko Kiev University, Kiev 252033. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 598–603, May, 1997.     

Investigation of the structure of modified flavonoids by means of a lanthanide shift reagent and related1H NMR spectroscopic methods (review)

An approach to determination of the structure of the heterocyclic analogs and derivatives of flavone, isoflavone, chalcone, and aurone by measurement of their¹H NMR spectra in the presence of lanthanide shift reagents and in an aromatic solvent is described. The coordination of the lanthanide shift reagents with the substrate molecules is discussed, and a series of problems that can be solved most effectively by this method are identified. Examples of the solution of specific problems are given.Taras Shevchenko Kiev University, Kiev. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 723–737, June, 1996. Original article submitted January 15, 1996.     

Synthesis and reactions of thiophene analogs of chalcones

A new method of synthesizing thiophene analogs of chalcones, based on condensing aryl-β-chlorovinyl ketones with thiophene in the presence of stannic chloride, is extended. Hitherto undescribed thiophene analogs of chalcones are obtained in good yields. Addition of 2-nitropropane, nitromethane, and morpholine to the active double bond of thiophene analogs of chalcones gives γ-nitroketones and morpholine derivatives of ketones containing the benzene ring and thiophene. Oxidation with alkaline hydrogen peroxide gives an α-ketooxide of the thiophene analog of chalcone.     

Synthesis of thiophene analogs of 1, 3, 5-triphenylpyrazoline derivatives

Nineteen ²-pyrazolines hitherto undescribed in the literature are prepared by reacting thiophene and selenophene analogs of chalcones with phenylhydrazine or p-nitrophenylhydrazine. It is shown that thiophene and selenophene chalcones can be more easily cyclized than their furan analogs. The 2, 4, 6-trimethoxy group when present in the 1-(thienyl-2)-3-arylpropenone-1 molecule causes steric hindrance in the corresponding pyrazoline.     

Synthesis and complete assignment of NMR data of 20 chalcones

Chalcones, intermediates in flavonoid biosynthesis, can exhibit antibacterial, antiproliferative, and anti-inflammatory properties. Chalcones contain two benzene rings and both hydroxylated and methoxylated analogs are frequently produced by hydroxylases and O-methyltransferases in plant biosynthetic pathways. Assignments of NMR peaks in the spectra of hydroxylated and/or methoxylated chalcones can help in identifying novel chalcone derivatives isolated from natural sources by referencing these data against NMR spectra obtained from known chalcones. We report here the syntheses of 20 chalcones and complete assignments of (1)H and (13)C NMR spectra.     

Determination of LogP for Biologically Active Chalcones and Cyclic Chalcone Analogs by RPTLC

JPC – Journal of Planar Chromatography – Modern TLC - LogP values of 41 biologically active chalcones (Figure 1, 1) and their cyclic analogs, E-2-(X-benzylidene)-1-indanones (Figure 1,...     

Chemistry of isoflavone heteroanalogs.

Benzodioxane analogs of chalcones were isomerized to the corresponding flavanones and isoflavones. The PMR and IR spectra of these compounds were discussed.For Communication 11, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 319–323, March, 1989.     

Synthesis and reactions of thiophene analogs of chalcones

A new method of synthesizing thiophene analogs of chalcones, based on condensing aryl--chlorovinyl ketones with thiophene in the presence of stannic chloride, is extended. Hitherto undescribed thiophene analogs of chalcones are obtained in good yields. Addition of 2-nitropropane, nitromethane, and morpholine to the active double bond of thiophene analogs of chalcones gives -nitroketones and morpholine derivatives of ketones containing the benzene ring and thiophene. Oxidation with alkaline hydrogen peroxide gives an -ketooxide of the thiophene analog of chalcone.     

Synthetic analogs of natural flavolignans. V. A new synthesis of 6-halogeno-1,3-benzodioxane analogs of silandrin and hydnocarpin

6-Halogeno-1,3-benzodioxane analogs of chalcones have been synthesized by various methods. Flavanone and flavone analogs of silandrin and hydnocarpin have been obtained from them. The structures of the new flavonoids have been shown by their PMR spectra.     

Allergy-preventive flavonoids from Xanthorrhoea hastilis

Allergy-preventive activity was demonstrated for an extract of resins from Xanthorrhoea hastilis R. BR. in a search for allergy-preventive substances from natural sources. By bioassay-directed fractionation of this plant extract, a new flavanone, 3',5'-dihydroxy-7,4'-dimethoxyflavanone (1), and two new chalcones, 3,5,2'-trihydroxy-4,4'-dimethoxychalcone (2) and 5,2'-dihydroxy-3,4,4'-trimethoxychalcone (3), were isolated together with five known compounds, 5'-hydroxy-7,3',4'-trimethoxyflavanone (4), 3'-hydroxy-7,4'-dimethoxyflavanone (5), liquiritigenin 7-methyl ether (6), 4,2'-dihydroxy-4'-methoxychalcone (7) and sakuranetin (8). The structures of 1, 2 and 3 were elucidated by spectroscopic methods. All of these compounds showed allergy-preventive effects.     

Synthetic analogs of natural flavolignans VII. Synthesis of 1,3-benzodioxane analogs of dehydrosilybin

Structural analogs of dehydrosilbyn have been obtained from 1,3-benzodioxane derivatives of chalcones. Their structures have been confirmed by their PMR spectra.     

Chemistry of isoflavone heteroanalogs. 11. Benzodioxane analogs of chalcone,flavone, and isoflavone

Benzodioxane analogs of chalcones and their epoxides have been prepared. Different types of analogs of natural flavonolignan — silibin — have been synthesized from these compounds. The PMR spectra of the new compounds and the results of the preliminary biological testings are reported and discussed.For article 10, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 192–198, February, 1986.     

Anthocyanins and other flavonoids

More than 450 new flavonoid structures, reported from January 2001 until December 2003, are reviewed.They comprise anthocyanidins, flavones, flavonols, chalcones, dihydrochalcones, aurones, flavanones and dihydroflavonols, both as aglycones and as glycosides. The biological activity of some of the compounds is briefly discussed. There are 289 cited references.