Search

Quorum sensing (QS) is a cell-to-cell communication process that controls bacterial collective behaviors. The QS network regulates and coordinates bacterial virulence factor expression, antibiotic resistance and biofilm formation. Therefore, inhibition of the QS system is an effective strategy to suppress the bacterial virulence. Herein, we identify a phosphate ester derivative of chrysin as a potent QS inhibitor of the human pathogen Pseudomonas aeruginosa (P. aeruginosa) using a designed luciferase reporter assay. In vitro biochemical analysis shows that the chrysin derivative binds to the bacterial QS regulator LasR and abrogates its DNA-binding capability. In particular, the derivative exhibits higher anti-virulence activity compared to the parent molecule. All the results reveal the potential application of flavone derivative as an anti-virulence compound to combat the infectious diseases caused by P. aeruginosa. [ABSTRACT FROM AUTHOR]

Background: Cisplatin has been extensively used in therapeutics for its broad-spectrum anticancer activity and frequently used for the treatment of solid tumors. However, it presents several side-effects and several cancers develop resistance. Combination therapy of cisplatin with poly (ADP-ribose) polymerase 1 (PARP1) inhibitors has been effective in increasing its efficacy at lower doses. Methods and results: In this work, we have shown that the nitro-flavone derivative, 2-(4-Nitrophenyl)-4H-chromen-4-one (4NCO), can improve the sensitivity of cancer cells to cisplatin through inhibition of PARP1. The effect of 4NCO on cisplatin toxicity was studied through combination therapy in both exponential and density inhibited A375 melanoma cells. Combination index (CI) was determined from isobologram analysis. The mechanism of cell killing was assessed by lactate dehydrogenase (LDH) assay. Temporal nicotinamide adenine dinucleotide (NAD+) assay was done to show the inhibition of PARP1. We also performed in silico molecular modeling studies to know the binding mode of 4NCO to a modeled PARP1-DNA complex containing cisplatin-crosslinked adduct. The results from both in silico and in cellulo studies confirmed that PARP1 inhibition by 4NCO was most effective in sensitizing A375 melanoma cells to cisplatin. Isobologram analysis revealed that 4NCO reduced cell viability both in exponential and density inhibited A375 cells synergistically. The combination led to cell death through apoptosis. Conclusion: The synthetic nitro-flavone derivative 4NCO effectively inhibited the important nuclear DNA repair enzyme PARP1 and therefore, could complement the DNA-damaging anticancer drug cisplatin in A375 cells and thus, could act as a potential adjuvant to cisplatin in melanoma therapy. [ABSTRACT FROM AUTHOR]

Background: Flavonoid-rich extract of the plant is long known for its anti-diabetic activities in traditional medicine. S002-853, a new flavone derivative synthesized by Central Drug Research Institute (CDRI) has been used for the present study. Objectives: The present study aimed at development of an assay method for quality control (QC) and stability studies of a new anti-diabetic and anti-dyslipidemic agent CDRI compound S002-853. Materials and Methods: A validated high-performance liquid chromatography analysis method for S002-853 was developed for in process QC and stability studies. The separation was achieved on a RP-C18 (25 cm x 0.4 cm, 5 μm, Phenomenex) at 240 nm with flow rate of 1.0 ml/min. This method was applied successfully in establishing forced degradation and drug-excipient testing protocols as per International Conference on Harmonization guidelines. Results: The result of estimation and stress testing studies indicated a high degree of selectivity of this method. S002-853 was most stable at pH 7 and under photolytic conditions. The temperature degradation pattern of S002-853 was found tofollow the zero order degradation. Conclusion: The method described is easy and simple hence can be easily reproduced. This method can be very useful for bulk manufacture QC, and drug development process. [ABSTRACT FROM AUTHOR]

Two new complexes having general formula VOL· nHO [( 1) L: 5-hydroxyflavone, n = 1; ( 2) L: chrysin, n = 4] were synthesized and characterized. Based on IR and electronic data we concluded that studied flavones act as bidentate ligands in complexes with metallic ion coordinated in a square-pyramidal stereochemistry. The thermal analysis (TG, DTA) elucidated the composition and also the number and nature of the water molecules. The thermal behavior also indicated strong interactions between oxovanadium (IV) and these oxygen donor ligands. [ABSTRACT FROM AUTHOR]

Examines the potent glucosylation activity of the hairy roots of medicinal morning glory, Pharbitis nil, against umbelliferone and aesculetin. Provision of a potential plant culture system for the production of useful secondary metabolites and research into the secondary metabolism and biotransformation of substrates; Capability of hairy roots against some phenolic compounds; Conversion of incubated coumarin and flavone derivatives by the hairy roots.