ATP-Diphosphohydrolases in Parasites: Localization, Functions and Recent Developments in Drug Discovery.

ATP-diphosphohydrolases (EC 3.6.1.5), also known as ATPDases, NTPases, NTPDases, EATPases or apyrases, are enzymes that hydrolyze a variety of nucleoside tri- and diphosphates to their respective nucleosides, being their activities dependent on the presence of divalent cations, such as calcium and magnesium. Recently, ATP-diphosphohydrolases were identified on the surface of several parasites, such as Trypanosoma sp, Leishmania sp and Schistosoma sp. In parasites, the activity of ATPdiphosphohydrolases has been associated with the purine recuperation and/or as a protective mechanism against the host organism under conditions that involve ATP or ADP, such as immune responses and platelet activation. These proteins have been suggested as possible targets for the development of new antiparasitic drugs. In this review, we will comprehensively address the main aspects of the location and function of ATP-diphosphohydrolase in parasites. Also, we performed a detailed research in scientific database of recent developments in new natural and synthetic inhibitors of the ATPdiphosphohydrolases in parasites.

Development and validation of a UHPLC-ESI-MS/MS method for the quantification of artepillin C in Brazilian green propolis

Objectives: The aim of this study was the development and validation of a fast method to quantify artepillin C in green propolis using ultra high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UHPLC-ESI-MS/MS). Methods: High purity (97.8%) artepillin C was isolated from green propolis using chromatography techniques. Quantification was performed using a C18 (2.1 x 100 mm; 1.7 µm) column, gradient of water and methanol (with 0.01% formic acid) as mobile phase, at a flow rate of 0.4 mL/min and 45 ºC in temperature. A mass spectrometer operated in selected reaction monitoring mode to monitor the deprotonated molecular ion of artepillin C (m/z 299) > fragment ion (m/z 200.12). Several parameters such as specificity, linearity, limit of detection (LOD), limit of quantitation (LOQ), precision, accuracy, and robustness were determined. Results: The method was linear in the 50 ­ 400 µg/mL range (r2 = 0.9906), showing LOD = 10.79 µg/mL and LOQ = 32.70 µg/mL with satisfactory intra-day and inter-day precision with relative standard deviation (RSD %) of 1.9% and 3.4%, respectively. The accuracy showed recovery of 93-104%, the method was robust and artepillin C was quantified in green propolis at 6.51%. Conclusions: The proposed method showed advantages in comparison with other methods, such as short analysis time and high selectivity for artepillin C.