75187-56-3

Claisen condensation of substituted 2′-hydroxyacetophenones 1a-c with aromatic aldehydes affords respective substituted 2′-hydroxychalcones 2a-n which on base catalyzed cyclization in pyridine:methanol:water (1:1:1) give respective flavanones 3a-n. The oxidative rearrangement of flavanones with thallium(III) p-tosylate furnishes respective isoflavones 4a-n in overall 62-72% yields starting from 1. The present methodology has been successfully applied for the synthesis of naturally occurring isoflavones such as di-O-methyldaidzein 4a, cabruvin 4b, pseudobabtigenin methylether 4d, 5,7-dimethoxyisoflavone 4f, 5,7,4′-trimethoxyisoflavone 4g, derrustone 4i, 7,8,3′,4′- tetramethoxyisoflavone 41, purpuranin-A 4m and 7,8,3′,4′,5′- pentamethoxyisoflavone 4n and thus the first synthesis of 4n is reported.

The present invention provides novel antidipsotropic compounds. The invention further provides methods of inhibiting ALDH-2 using the compounds described herein. Methods for modulating alcohol consumption, alcohol dependence and/or alcohol abuse by administering the compounds of the invention to an individual are also provided. The present invention further provides a rationale for designing additional novel antidipsotropic compounds.

Daidzin, the active principle of an herbal remedy for 'alcohol addiction', has been shown to reduce alcohol consumption in all laboratory animals tested to date. Correlation studies using structural analogues of daidzin suggests that it acts by raising the monoamine oxidase (MAO)/mitochondrial aldehyde dehydrogenase (ALDH-2) activity ratio (J. Med. Chem. 2000, 43, 4169). Structure-activity relationship (SAR) studies on the 7-O-substituted analogues of daidzin have revealed structural features important for ALDH-2 and MAO inhibition (J. Med. Chem. 2001, 44, 3320). We here evaluated effects of substitutions at 2, 5, 6, 8, 3′ and 4′ positions of daidzin on its potencies for ALDH-2 and MAO inhibition. Results show that analogues with 4′-substituents that are small, polar and with hydrogen bonding capacities are most potent ALDH-2 inhibitors, whereas those that are non-polar and with electron withdrawing capacities are potent MAO inhibitors. Analogues with a 5-OH group are less potent ALDH-2 inhibitors but are more potent MAO inhibitors. All the 2-, 6-, 8- and 3′-substituted analogues tested so far do not inhibit ALDH-2 and/or have decreased potencies for MAO inhibition. This, together with the results obtained from previous studies, suggests that a potent antidipsotropic analogue would be a 4′,7-disubstituted isoflavone. The 4′-substituent should be small, polar, and with hydrogen bonding capacities such as, -OH and -NH2; whereas the 7-substituent should be a straight-chain alkyl with a terminal polar function such as -(CH 2)n-OH with 2≤n ≤6, -(CH2) n-COOH with 5≤n ≤10, or -(CH2)n-NH 2 with n ≥4.