N-(Acyloxyalkoxycarbonyl) derivatives as potential prodrugs of amines. II. esterase-catalysed release of parent amines from model prodrugs

N-(Acetoxyethoxycarbonyl) derivatives of primary amines released a major fraction of the parent amine in the desired free form in plasma but a significant fraction of the undesired N-acetylated parent amine was also produced. The fraction of the parent amines released from the carbamate derivatives of the primary amines was greater in human plasma than in pH 7.4 buffer. In human plasma, the N-(acetoxyethoxycarbonyl) derivative of a secondary amine released the parent amine in a quantitative manner at a rate higher than that observed in pH 7.4 buffer. Experimental results suggested that the observed catalysis of the release of the parent amines from N-(acetoxyethoxycarbonyl) derivatives of primary and secondary amines was due to participation by plasma esterases. The data suggested that N-(acetoxyethoxycarbonyl) derivatives are well suited for use as prodrugs of secondary amines. Their utility as prodrugs of primary amines is more problematic and cannot be predicted prior to in-vivo studies for the individual compound.     

Averting transmission: A pivotal target to manage amoebiasis

Amoebiasis is a parasitic infectious disease caused by the enteric protozoan Entamoeba histolytica, a leading basis of deaths accounted to parasites, succeeding malaria and schistosomiasis. Conventional treatment methodologies used to deal with amoebiasis mainly rely on the administration of anti‐amoebic compounds and vaccines but are often linked with substantial side‐effects on the patient. Besides, cases of development of drug resistance in protozoans have been recorded, contributing further to the reduction in the efficiency of the treatment. Loopholes in the efficacious management of the disease call for the development of novel methodologies to manage amoebiasis. A way to achieve this is by targeting the essential metabolic processes of ‘encystation’ and ‘excystation’, and the associated biomolecules, thus interrupting the biphasic life cycle of the parasite. Technologies like the CRISPR‐Cas9 system can efficiently be exploited to discover novel and essential molecules that regulate the protozoan's metabolism, while efficiently manipulating and managing the known drug targets, leading to an effective halt and forestall to the enteric infection. This review presents a perspective on these essential metabolic processes and the associated molecules that can be targeted efficaciously to prevent the transmission of amoebiasis, thus managing the disease and proving to be a fruitful endeavour.     

Primary malignant pericardial mesothelioma presenting as effusive-constrictive pericarditis

Effusive-constrictive pericarditis is a clinical hemodynamic syndrome characterized by constriction of the heart by the visceral pericardium in the presence of a tense pericardial effusion. The hallmark of effusive-constrictive pericarditis is the persistence of elevated right atrial pressures and ventricular interdependence after relief of the elevated intrapericardial pressures. The present report discusses the unique case of a 46-year-old white female who presented with dyspnea on exertion and chest tightness in the setting of an effusive-constrictive pericarditis. The patient was subsequently diagnosed with primary malignant pericardial mesothelioma, an extremely rare neoplasm with a very poor prognosis.     

Synthesis and antibacterial activity of some new 1-heteroaryl-5-amino-4-phenyl-3-trifluoromethylpyrazoles

Treatment of 1,1,1-trifluoromethyl-3-cyano-3-phenylpropanone (1) with several heteroarylhydrazines (2a-e) in refluxing ethanol affords 1-heteroaryl-5-amino-4-phenyl-3-trifluoromethylpyrazoles (4) in a regioselective manner. The location of trifluoromethyl group at position-3 was established by a combined use of 13C and 19F NMR spectroscopy. The reaction proceeds through the intermediacy of the hydrazone which was isolated and characterized in one case (3e) by performing the reaction at room temperature. The compounds 3e and 4 were tested for their antibacterial property against six Gram-positive and three Gram-negative bacteria. Two compounds, namely 1-(benzothiazol-2'-yl)-5-amino-4-phenyl-3-trifluoromethylpyrazole (4a) and 1-(6'-methylbenzothiazol-2'-yl)-5-amino-4-phenyl-3-trifluoromethylpyrazole (4b) have displayed antibacterial activity comparable to the commercial antibiotics.