A simple and sensitive spectrophotometric method has been developed for the assay of lercanidipine hydrochloride (LER) in bulk and in formulations. The method is based on the formation of coloured species between the drug and 1,2-naphthaquinone-4-sulphonic acid sodium salt (NQS) by means of nucleophilic substitution reaction. Absorbance was measured at λ(max) = 460 nm. The method was analyzed s...

This study investigated the potential anticaries properties of synthetic 1,4-naphthoquinone derivatives. Synthetic derivatives (2-4) were designed and synthesized by employing lawsone methyl ether (LME, 1), a plant-derived 1,4-naphthoquinone, as lead compound. The compounds characterized infrared spectroscopy, 1H-nuclear magnetic 13C- nuclear high-resolution mass spectrometry. Minimum inhibitor...

1. Three peptides containing alpha-aminoadipic acid and cysteine have been obtained in small amounts from the mycelium of a Cephalosporium sp. 2. The peptides were precipitated as cuprous mercaptides together with glutathione and resolved from the latter and from each other by preparative paper electrophoresis and chromatography either in the sulphonic acid form or as S-sulphonyl derivatives. F...

Condensation of phthalimidoacetone (1) with DMFDMA (N,N-Dimethylformamide dimethyl acetal) has afforded enaminone 2. Refluxing 2 with equimolecular amounts of benzaldehyde and urea in acetic acid afforded a mixture of tetrahydropyrimidine 5 and the dihydropyridine 6. Compound 2 undergoes self-condensation on heating in acetic acid or under microwave irradiation in presence of acidic zeolite to ...

Abstract Chromophores, colored substances of rather high stability that reduce brightness, are present in all kinds cellulosic products, such as pulp, fibers, aged material, and even very low concentrations highly bleached pulps. Thus, they the prime targets industrial pulp bleaching. In this study, three key chromophores 2,5-dihydroxy-1,4-benzoquinone (DHBQ, 1 ), 5,8-dihydroxy-1,4-naphthoquino...

Aluminium phthalocyanines substituted to different degrees with hydrophilic sulphonic acid and hydrophobic phthalimidomethyl groups were investigated in vivo as new agents for the photodynamic therapy of malignant tumours. Parameters studied included the photodynamic action on EMT-6 mammary tumours in BALB/c mice, the therapeutic window and the potential for direct cell killing, assayed via an ...

Tigloylshikonin, a new shikonin derivative esterified with tiglic acid ((E)-2-methylbut-2-enoic acid), was isolated as a minor pigment from a food colorant "Shikon color," a commercial root extract from Lithospermum erythrorhizon SIEBOLD et ZUCCARINI. The structure of tigloylshikonin was elucidated using (1)H, (13)C, the difference nuclear Overhauser effect (NOE), and 2D NMR techniques. Its ste...

Hydroxybenzylidene hydrazines exhibit a wide spectrum of biological activities. Here, we report synthesis and free radical scavenging activity of nine new N-(hydroxybenzylidene)-N'-[2,6-dinitro-4-(trifluoromethyl)]phenylhydrazines. The chemical structures of these compounds were confirmed by 1H-NMR, 13C-NMR, 19F-NMR, IR spectroscopy, LC-MS, and elemental analysis. The prepared compounds were te...