An investigation into membrane bound redox carriers involved in energy transduction mechanism in Brevibacterium linens DSM 20158 with unsequenced genome.

Brevibacterium linens (B. linens) DSM 20158 with an unsequenced genome can be used as a non-pathogenic model to study features it has in common with other unsequenced pathogens of the same genus on the basis of comparative proteome analysis. The most efficient way to kill a pathogen is to target its energy transduction mechanism. In the present study, we have identified the redox protein complexes involved in the electron transport chain of B. linens DSM 20158 from their clear homology with the shot-gun genome sequenced strain BL2 of B. linens by using the SDS-Polyacrylamide gel electrophoresis coupled with nano LC-MS/MS mass spectrometry. B. linens is found to have a branched electron transport chain (Respiratory chain), in which electrons can enter the respiratory chain either at NADH (Complex I) or at Complex II level or at the cytochrome level. Moreover, we are able to isolate, purify, and characterize the membrane bound Complex II (succinate dehydrogenase), Complex III (menaquinone cytochrome c reductase cytochrome c subunit, Complex IV (cytochrome c oxidase), and Complex V (ATP synthase) of B. linens strain DSM 20158.

Hepatoprotection by chemical constituents of the marine brown alga Spatoglossum variabile: a relation to free radical scavenging potential.

CONTEXT: In the course of searching hepatoprotective agents from natural sources, the protective effect of chemical constituents of the marine brown alga Spatoglossum variabile Figaro et DE Notar (Dictyoaceae) against CCl4-induced liver damage in Wistar rats was investigated. The compounds were first investigated for in vitro radical scavenging potential and were also tested for ß-glucuronidase inhibition to further explore the relationship between hepatoprotection and antiradical potential. METHODS: The compounds cinnamic acid esters 1 and 2 and aurone derivatives 3 and 4 were first investigated for in vitro radical scavenging potential against 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH), and superoxide anion radicals. In vivo hepatoprotective studies were performed in seven groups (n = 6) of Wistar rats. The test groups were pretreated with compounds (10 mg/kg body weight, po) orally for 30 min before the intraperitoneal administration of a dose of 20% CCl4 diluted with dietary cooking oil. Moreover, compounds were also tested for ß-glucuronidase inhibition to explore the relationship between hepatoprotection and radical scavenging potential. RESULTS: The test compounds 1-4 were found to exhibit antiradical activity against 1,1-diphenyl-2-picrylhydrazyl radicals with IC50 values ranging between 54 and 138 µM, whereas aurone derivatives 3 and 4 additionally exhibited superoxide anion scavenging effects with IC50 values of 95 and 87 µM, respectively. In addition, these compounds were found to be weak inhibitors of xanthine oxidase (IC50 ≥1000 µM). In animal model, pretreatment with compounds 2-4 significantly blocked the CCl4-induced increase in the levels of the serum biochemical markers. CONCLUSION: It appears that the hepatoprotection afforded by these compounds was mainly due to their radical scavenging activity that protected the cells from the free radicals generated by CCl4-induced hepatotoxicity.

Time-dependent AI-Modeling of the anticancer efficacy of synthesized gallic acid analogues.

BACKGROUND/AIM: Main objective of this study is mapping of the anticancer efficacy of synthesized gallic acid analogues using modeling and artificial intelligence (AI) over a large range of concentrations and exposure times to explore the underline mechanisms of drug action and draw careful inferences regarding drug response heterogeneity. METHODS: Two series of gallic acid derivatives i.e. esters and amides have been synthesized and characterized by FTIR, NMR and mass spectrometry. The compounds have been tested in vitro for their anticancer activity against wild type human ovarian cancer cell line A2780, prostate cancer cell line PC3 and normal human fibroblast cells 3T3. To completely characterize optimal anticancer activity, a comprehensive model using piecewise recursive Hill model is used to quantitatively assess the in vitro anticancer effect of the tested compounds as a function of concentration and exposure time for periods ranging from 24 to 72 h. A robust artificial intelligence approach i.e. the "Support Vector Machine (SVM) Learning Algorithm" is adopted to utilize the data obtained at different temporal values, to identify compounds that trail forecasting algorithm. RESULTS: All the synthesized analogues were found biocompatible. Significantly low EC50 values indicated that tested compounds have potent anticancer activity against A2780 cell line in comparison to PC3 cells where only few compounds generated same impact at almost 200 times high dose. On the basis of EC50 values, compounds 7 h, 7 m, 9c, 9b, 7c, 7b and 7 g were identified as the most active anticancer agent against A2780. Three major patterns of drug response heterogeneity were observed for different compounds in the form of multiple Hill graphs and shallow slopes. The anticancer efficiency of the compounds was verified using Machine learning SVM regression learner algorithm. For compounds 7a, 7b, 7e, 7 g, 7o, 7 r, 9b, 9e-9 g higher accuracy was found in predicted and experimentally obtained end point potency in terms of % viability. CONCLUSIONS: Pharmacodynamics modeling of anticancer potential of the synthesized compounds revealed that drug efficacy and response heterogeneity could be modulated by changing the exposure time to optimize therapeutic impact. Combining experimental results with AI based drug action forecasting, compounds 7b, 7 g, and 9b may be tested further as potent anticancer agent for in vivo studies. This approach may serve a useful tool for extrapolation of in vitro results for generating lead compounds in in vivo and preclinical studies.

Emodinol, beta-glucuronidase inhibiting triterpene from Paeonia emodi.

Emodinol, a new oleane type triterpene, has been isolated from the chloroform soluble fraction of Paeonia emodi. The structure 1beta, 3beta, 23-trihydroxyolean-12-en-28-oic acid 1 has been assigned on the basis of spectral studies including 2D NMR. It showed significant beta-glucuronidase inhibitory activity. In addition benzoic acid and 3-hydroxybenzoic acid have also been reported for the first time from this species.

Chemistry and biological significance of essential oils of Cymbopogon citratus from Pakistan.

Steam distilled oil of Cymbopogon citratus was analyzed by Gas Chromatographic-Mass Spectrometry (GC-MS) and citral was found as major constituent. The oil exhibited significant inhibition of beta-glucuronidase activity and also showed activities against some tested human, plant and animal pathogens. The minimum inhibitory concentrations could not be determined due to the lack of some chemicals.

Beta-N-cyanoethyl acyl hydrazide derivatives: a new class of beta-glucuronidase inhibitors.

Eight new beta-N-substituted acyl hydrazides along with their corresponding acyl derivatives were synthesized and screened for in vitro beta-glucuronidase inhibition and found to be active against the enzyme. All of these compounds were found to be noncompetitive inhibitors except for N'-(2-cyanoethyl)-4-hydroxy benzohydrazide (10), which was found to be an uncompetitive inhibitor. Structure-activity relationship studies indicated that the benzyloxy group present in compounds 12 and 13 is responsible for the beta-glucuronidase inhibition activity.