Versatility in the biological behavior of two aminobenzoate oxidovanadium (V, IV) compounds. Inhibition or simulation of enzymes.

K. JORI; A.M. DE COSTA FERRIRA; P.A.M. WILLIAMS; J. PARENTE; A. ARNDT; S.R. BORTOLIN ULINANA; E.G. FERRER; L.G. NASO; C.A. FRANCA; B. PANNIA ESPÓSITO

Montevideo

Simposio; 11th International Vanadium Symposium, Montevideo, Uruguay; 2018

Universidad de la República

The pharmacological potential of vanadium compounds is of great interest to researchers in treatments of various diseases (diabetes, cancer, tropical endemic diseases, etc.) [1,2]. On the basis of the potential biological/pharmacological applications, in this work we have synthesized and physico-chemically characterized, two new complexes containing vanadium (IV) and (V) with 4-aminobenzoic acid as the ligand (L). The experimental results obtained (elemental analysis, FTIR, diffuse reflectance and UV-vis spectroscopy, EPR and 1HNMR) as well as the theoretical calculations (DFT) performed allowed us to determine the following stoichiometries [VO(O2)LH2O].H2O (1) and cis-[VOL2H2O] (2). The inhibitory effects on acid phosphatases (AcP) and alkaline phosphatases (ALP) were determined. The complexes demonstrated specific activities: (2) better inhibitor of AcP (IC50 = 250 μM), (1) higher inhibition on ALP (IC50 = 500 μM). The pro-oxidant, antioxidant and anti-leishmaniasis activities were also studied. Only (1) catalyzes the oxidation of dihydrorhodamine (DHR) but none of them manifests activity against L. amazonensis promastigotes. Both complexes catalyzed the dismutation of superoxide (IC50(1) = 114.0 μM, kMcF = 1.6 x105 M-1.s-1, IC50(2) = 155.0 μM, kMcF = 1.1x105 M-1.s-1), showing a moderate effect and also mimicked peroxidase activity (phenol red, (1) Vmax = 8.34 x 10-5 min-1, Km = 3.29 x 10-4 M, kcat = 3.48 min-1, kcat/Km=10577.5 M- .min-1; (2) Vmax = 3.44 x 10-5 M.min-1, Km=1.35x10-4 M, kcat =1.43 min-1, kcat/Km = 10592.6 M-1.min-1). Interaction with albumin will also be discussed.Both complexes resulted with potential pharmacological activities in some of the aspects studied.