Facile Synthesis of Benzimidazoles via Oxidative Cyclization of Acyclic Monoterpene Aldehyde with Diamines: Studies on Antimicrobial and in Vivo Evaluation of Zebrafish

Citral ( 1a ), a bioactive component of Cymbopogon citratus (lemongrass) could be isolated and semi-synthetic analogs synthesized with improved therapeutic properties. Herein we first report describes citral ( 1a ) as a primary material for the synthesis of benzimidazole derivatives between various o-phenylenediamines ( 2a – l ) in the presence of Diisopropylethylamine (DIPEA) as a commercially available environmentally benign base, ethanol as a green solvent and the yield of all benzimidazole derivatives ( 3a – l ) was between 68–76 %; The semi-synthetically prepared benzimidazole derivatives ( 3a – l ) were assessed for their anti-bacterial and anti-fungal properties. The benzimidazole compounds ( 3a – b , and 3g – j ) exhibit good anti-microbial activity. In addition, in silico study was carried out to determine the specific binding affinity of the diamine halogen substituted benzimidazole derivatives to the specific target proteins. In silico analysis revealed a high correlation between docking results and experimental results. Finally, benzimidazole demonstrated significant antibacterial and antifungal activity. Zebrafish embryos were subjected to In vivo toxicological test found that all of the benzimidazole compounds ( 3a – l ) were non-toxic and had low embryotoxicity after 96 h, with an LC₅₀ of 36.425 μg, which could facilitate the design of novel antimicrobial agents using a cost-effective method.     

Antifertility effect of Andrographis paniculata (Nees) in male albino rat

Dry leaf powder of A. paniculata, when fed orally to male albino rats, at a dose level of 20 mg powder per day for 60 days, resulted in cessation of spermatogenesis, degenerative changes in the seminiferous tubules, regression of Leydig cells and regressive and/or degenerative changes in the epididymis, seminal vesicle, ventral prostate and coagulating gland. There was reduction in the weight and fluid content of the accessory glands. The treatment also resulted in accumulation of glycogen and cholesterol in the testis, and increased activities of lactate dehydrogenase in testis and alkaline phosphatase in testis and ventral prostate. The results suggest antispermatogenic and/or antiandrogenic effect of the plant.     

MODEL DEVELOPMENT AND PROCESS OPTIMIZATION FOR SOLVENT EXTRACTION OF POLYPHENOLS FROM RED GRAPES USING BOX–BEHNKEN DESIGN

The objective of the present study is to find out the optimum extraction conditions for extraction of polyphenols from red grapes using Box–Behnken design. Red grapes polyphenols were extracted using acid–ethanol solvent at various extraction temperature (40–60°C), extraction time (20–100 min) and different solid–liquid ratio (1:5–1:15 g:ml). The effect (main and interactive) of extraction conditions on total anthocyanin, phenolic and flavonoid content were studied using Box–Behnken design (three factors at three levels). The results showed that the contribution of the quadratic model was significant for all the responses. Second-order mathematical regression models were developed and were found to fit well with observed data. Derringer's desirability function methodology was performed to find out the optimal conditions based on both individual and combinations of all responses (extraction temperature: 57°C, time: 61 min, and solid–liquid ratio: 1:8.7 g:ml) were established. At this optimal condition, the anthocyanin yield, total phenolic and flavonoid content were 73.92 mg/100 g, 221.4 mg GAE/100 g, and 79.08 mg CE/100 g, respectively. A desirability value of 0.902 was achieved at this point.     

A delayed rectifier current is modulated by the circadian pacemaker in Bulla

Basal retinal neurons of the marine mollusc Bulla gouldiana continue to express a circadian modulation of their membrane conductance for at least two cycles in cell culture. Voltage-dependent currents of these pacemaker cells were recorded using the whole-cell perforated patch-clamp technique to characterize outward currents and investigate their putative circadian modulation. Three components of the outward potassium current were identified. A transient outward current (IA) was activated after depolarization from holding potentials greater than -30 mV, inactivated with a time constant of 50 ms, and partially blocked by 4-aminopyridine (1-5 mM). A Ca(2+)-dependent potassium current (IK(Ca)) was activated by depolarization to potentials more positive than -10 mV and was blocked by removing Ca2+ from the bath or by applying the Ca2+ channel blockers Cd2+ (0.1-0.2 mM) and Ni2+ (1-5 mM). A sustained Ca(2+)-independent current component including the delayed rectifier current (IK) was recorded at potentials positive to -20 mV in the absence of extracellular Na+ and Ca2+ and was partially blocked by tetraethylammonium chloride (TEA, 30mM). Whole-cell currents recorded before and after the projected dawn and normalized to the cell capacitance revealed a circadian modulation of the delayed rectifier current (IK). However, the IA and IK(Ca) currents were not affected by the circadian pacemaker.     

Importance of uracil DNA glycosylase in Pseudomonas aeruginosa and Mycobacterium smegmatis,G+C-rich bacteria,in mutation prevention,tolerance to acidified nitrite,and endurance in mouse macrophages

Uracil DNA glycosylase (Ung (or UDG)) initiates the excision repair of an unusual base, uracil, in DNA. Ung is a highly conserved protein found in all organisms. Paradoxically, loss of this evolutionarily conserved enzyme has not been seen to result in severe growth phenotypes in the cellular life forms. In this study, we chose G+C-rich genome containing bacteria (Pseudomonas aeruginosa and Mycobacterium smegmatis) as model organisms to investigate the biological significance of ung. Ung deficiency was created either by expression of a highly specific inhibitor protein, Ugi, and/or by targeted disruption of the ung gene. We show that abrogation of Ung activity in P. aeruginosa and M. smegmatis confers upon them an increased mutator phenotype and sensitivity to reactive nitrogen intermediates generated by acidified nitrite. Also, in a mouse macrophage infection model, P. aeruginosa (Ung-) shows a significant decrease in its survival. Infections of the macrophages with M. smegmatis show an initial increase in the bacterial counts that remain for up to 48 h before a decline. Interestingly, abrogation of Ung activity in M. smegmatis results in nearly a total abolition of their multiplication and a much-decreased residency in macrophages stimulated with interferon gamma. These observations suggest Ung as a useful target to control growth of G+C-rich bacteria.     

Differentiation to the CCR2+ inflammatory phenotype in vivo is a constitutive, time-limited property of blood monocytes and is independent of local inflammatory mediators

It is proposed that CCR2+ monocytes are specifically recruited to inflammatory sites, whereas CCR2- monocytes are recruited to normal tissue to become resident macrophages. Whether these subsets represent separate lineages, how differential trafficking is regulated and whether monocytes undergo further differentiation is uncertain. Using a mouse model of autoimmune uveoretinitis we examined monocyte trafficking to the inflamed retina in vivo. We show that bone marrow-derived CD11b+ F4/80- monocytes require 24 to 48 h within the circulation and lymphoid system before acquiring the CCR2+ phenotype and trafficking to the inflamed retina is enabled. This phenotype, and the capacity to traffic were lost by 72 h. Monocyte CCR2 expression followed a similar time course in normal mice indicating that differentiation to an inflammatory phenotype is a constitutive, time-limited property, independent of local inflammatory mediators. Phenotypic analysis of adoptively transferred cells indicated that circulating inflammatory monocytes also differentiate into CD11c+ and B220+ dendritic cells and F4/80+ tissue macrophages in vivo. Our data supports the hypothesis of continuous extravasation and progressive differentiation over time of inflammatory monocytes in the circulation rather than replication within the actively inflamed tissue, and supports the concept of myeloid dendritic cell differentiation from trafficking monocytes under physiological conditions in vivo.