Search

beta,beta,beta',beta'-Tetrasubstituted, long-chain dioic acids of the general formula HOOC-C(XY)-C(R2)-Q-C-(R2)-C(XY)-COOH have been synthesized and evaluated as hypotriglyceridemic-hypocholesterolemic agents in rats and as antidiabetogenic agents in ob/ob diabetic mice. The free carboxyl function of analogues of the series was mandatory for their hypolipidemic-antidiabetogenic effect while nonhydrolyzable diesters were inactive. Other structure-activity relationships were determined as a function of the overall chain length (C12-C22), alpha,alpha'-substitutions (X, Y = H, F, Cl, Br, OH, CN), beta, beta'-substitutions (R = CH3, C6H5), and core substitutions [Q = (CH2)10, (CH2)4CH = CH(CH2)4, 1,4-C6H10[(CH2)3]2, 1,4-C6H4[(CH2)3]2, 1,4-C6H4(CH = CHCH2)2, CH2(OCH2CH2)3OCH2)]. The most effective hypolipidemic-antidiabetogenic members of the series were alpha,alpha'-nonsubstituted, beta,beta'-methyl-substituted analogues of 14-18-carbon chains having either a saturated aliphatic core or a 1,4-bis(propenyl)benzene core in the cis/trans configuration. The hypotriglyceridemic rather than the hypocholesterolemic capacity of members of the series was found to correlate with their respective capacities as liver peroxisomal proliferators in rats.

Azido-BSP (4-[2-(4-azido-benzenesulphonylamino)-ethyl]phen-oxyacetic acid) is a photolabile derivative of the competitive thromboxane A2 /prostaglandin H2 (TXA2/PGH2) receptor antagonist sulotroban (=BM 13.177). If protected from short wave light, azido-BSP reversibly inhibited the platelet shape change induced by the PGH2 analogue U 46619 but notthe shape change induced by ADP or PAF. Schild analysis revealed an apparent KD=0.2 μM with washed platelets. The irreversible inhibition requiredirradiation of the platelet suspensionwith UVlight (254 nm) for 5 minutes in the presenceof azido-BSP. After this treatment,the platelets were washed twice and used forplatelet function tests. Treatment with 0.5 μM of azido-BSP suppressed the U 46619(10 μM)-induced (3H)serotonin release and 1 μM of azido-BSP was necessary to block the U 46619(2 μM)-inducedaggregation.The platelet shape change induced by U 46619 (0.01μM) was only partially inhibited, even at very high concentrations (50μM) of the antagonist.This suggests that a small portion of the TXA2/PGH2 receptors could not be blocked bythe photoaffinity treatment with azido-BSP. After treatment with 1 μM azido-BSP, the shape change stimulated by ADP or PAF was not reduced. This indicates a high specificity of thephotoaffinity ligand for the TXA2/PGH2 receptor. It is concluded that UV irradiation of azido-BSP generates anitrene intermediate that covalently links to the majority of the TXA2/PGH2 receptors. Azido-BSP provides a specific tool for tagging and subsequent purification of the TXA2/PGH2 receptor of platelets.(Supported by the Deutsche Forschungsgemeinschaft, Grant Pa263).

The chemical synthesis of the antiallergic substance picumast dihydrochloride (3,4-dimethyl-7-[4-(4-chlorobenzyl)piperazine-1-yl]propoxycoumarin dihydrochloride) is described.