A new naphthoquinone, (-)-3-[2-(acetyloxy)propyl]-2-hydroxy-8-methoxy-1,4-naphthoquinone (1) was isolated from the bulb of Eleutherine americana MERR. et HEYNE (Iridaceae) together with two known compounds, eleutherinol (6) and 1,5-dihydroxy-3-methylanthraquinone (7) which were found in this species for the first time. The other known compounds, (-)-isoeleutherin (2), (+)-eleutherin (3), (-)-ho...

incorporation of this acid in vitamin K 2 23 and vitamin K t 4 in bacteria and higher plants. Degradation of labeled vitamin K 2 after feeding shikimic acid (-U-1 4C) has shown that the intact ring of this acid is incorporated into the benzenoid moiety of this naphthoquinone 2 ' 3 . fn contrast, the degradation studies on lawsone 1 indicated that the ring atoms of shikimic acid (-U-1 4C) are tr...

The reaction of 3-aminopyrazole (1) with 1,2-naphthoquinone-4-sulfonic acid sodium salt (2) was studied in different aqueous media. The novel pyrazolylnaphthoquinones synthesized were physical and spectroscopically characterized, including 2D NMR spectroscopy (HETCOR). The possible reaction mechanism is proposed. Introduction Quinones and naphthoquinones are widely distributed in nature and pla...

The genus Diospyros is one of the most important sources of bioactive compounds, exclusively 1,4-naphthoquinones. The following information is an attempt to cover the developments in the biology and phytochemistry of 1,4-naphthoquinones isolated from this genus, as well as the studies done and the suggested mechanisms regarding their activities. During the past 60 years, many of these agents ha...

Self-organizing molecular field analysis (SOMFA), a simple three-dimensional quantitative structure activity relationship (3D-QSAR) based cheminformatics method was used in present case to study the correlation between the molecular properties and the PTP 1B inhibitory activities of a series of 1,2-naphthoquinone that acts as selective PTP 1B inhibitors. The statistical results, cross-validated...

Aim. To develop and validate a spectrophotometric technique for quantitative determination of glibenclamide in tablets by reaction with 2,3-dichloro-1,4-naphthoquinone. Materials methods. In the study, substance pharmacopoeial purity was used, – “Maninil” 5 mg “Glibenclamid-Zdorovye” mg, 2,3-dichloro-1,4-naphthoquinone “CFA” qualification chosen as reagent, solvent dimethylformamide (DMF) “CFA”...