naphthoquinones and indole

Mycobacterium tuberculosis (Mtb) causes one of the most grievous pandemic infectious diseases, tuberculosis (TB), with long-term morbidity and high mortality. The emergence of drug-resistant Mtb strains, and the co-infection with human immunodeficiency virus, challenges the current WHO-TB stewardship programs. The first-line anti-TB drugs, isoniazid (INH) and rifampicin (RIF), have become extensively obsolete in TB control from chromosomal mutations during the last decades. However, based on clinical trial statistics, the production of well-tolerated anti-TB drug(s) is miserably low. Alternately, semi-synthesis or structural modifications of first-line obsolete antitubercular drugs remain as the versatile approach for getting some potential medicines. The use of any suitable phytochemicals with INH in a hybrid formulation could be an ideal approach for the development of potent anti-TB drug(s). The primary objective of this review was to highlight and analyze available INH-phytochemical hybrid research works. The utilization of phytochemicals through chemical conjugation is a new trend toward the development of safer/non-toxic anti-TB drugs.

Topics: Antitubercular Agents; Benzaldehydes; Drug Development; Glycosides; Humans; Indoles; Isoniazid; Molecular Structure; Mycobacterium tuberculosis; Naphthoquinones; Phytochemicals; Steroids; Structure-Activity Relationship; Terpenes; Tuberculosis; Tuberculosis, Multidrug-Resistant

Topics: Antineoplastic Agents; Apoptosis; Carcinoma, Hepatocellular; DNA Damage; Furans; Hep G2 Cells; Humans; Indoles; Naphthoquinones; Neovascularization, Pathologic; Phosphorous Acids

The photoreduction of 1,4-benzoquinone, 1,4-naphthoquinone, 9,10-anthraquinone (AQ) and several methylated or halogenated derivatives in argon-saturated acetonitrile-water mixtures by indole, N-acetyltryptophan and N-acetyltyrosine was studied by time-resolved UV-vis spectroscopy using 20 ns UV laser pulses. The quinone triplet state is quenched by the aromatic amino acids and the rate constants are (1-5)x10(9)M(-1)s(-1). The semiquinone radical anion Q.(-) is the major observable transient after electron transfer from amino acids to the quinone triplet state. Termination of Q.(-) and amino acid derived radicals takes place in the mus-ms range. The effects of structure and other specific properties of quinones and amino acids are discussed. The radicals are subjects of intercept with oxygen, whereby hydrogen peroxide is eventually formed. The quantum yield of oxygen uptake Phi(-O2) as a measure of formation of hydrogen peroxide increases with increasing amino acid concentration, approaching Phi(-O2) for AQ in air-saturated solution.

Topics: Amino Acids, Aromatic; Anthraquinones; Benzoquinones; Electron Transport; Free Radicals; Halogens; Hydrogen Peroxide; Indoles; Kinetics; Methylation; Naphthoquinones; Oxidation-Reduction; Oxygen; Quinones; Spectrum Analysis; Tryptophan; Tyrosine; Ultraviolet Rays

[reaction: see text] Thermal decomposition of phenyliodonium ylide of 2-hydroxy-1,4-naphthoquinone (lawsone) in the presence of indole derivatives affords 3-acylated indoles existing in their enol forms, through a ring contraction and alpha,alpha'-dioxoketene formation reaction. The same reactants afford 3-(3-indolyl)-2-hydroxy-1,4-naphthoquinones in a copper-catalyzed reaction. Enamines, among other C-nucleophiles tested, give analogous results.

Topics: Indoles; Molecular Structure; Naphthoquinones; Onium Compounds