Abstract Silver complexes containing 1,10-phenanthroline as a coordinated ligand have been of great interest due to their antibacterial and antifungal pharmacological properties. In this paper, we describe the synthesis of a new partial inclusion complex of bis(1,10-phenanthroline)silver(I) salicylate in β-cyclodextrin (β-CD) which was synthesized with a good yield. The compounds were characterized by FTIR, 1H, 13C NMR including 1H−1H COSY, TGA/DSC, elemental analysis (CHN), and X-ray powder diffraction. The results suggest the presence of non-covalent interactions such as hydrogen bonds, van der Waals forces, and hydrophobic interactions in the formation of the partial inclusion compound between β-CD and bis(1,10-phenanthroline)silver(I) salicylate [Ag(phen)2]salH. Additionally, an in silico prediction of 1,10-phenanthroline biological activities was carried out and the acquired data suggests several potential targets associated with the antimicrobial activity of this compound and its silver complex. Most predicted targets are related to antimicrobial virulence and resistance that are a serious threat to global public health. The inclusion compound showed a higher inhibiting growth of Candida albicans than the free complex [Ag(phen)2]salH indicating that the formation of the inclusion complex with β-CD increases the bioavailability of the antimicrobial active species [Ag(phen)2]+ of the new silver(I) compound.

ABSTRACT Myracrodruon urundeuva Allemão, Anacardiaceae, is a medicinal plant widely found in Brazil, especially in the northern region. In our previous study, the ethanolic extract from leaves of M. urundeuva showed antiviral activity against simian rotavirus SA-11. Here, the crude extract was subjected to fractionations in order to subsequently work with more concentrated and pure bioactive compounds, which were analyzed by TLC and HPLC methods to support a better understanding of their virucidal effect. The antiviral activity was evaluated using a rotavirus infection model in MA-104 cells treated with the maximum non-cytotoxic concentration of the crude extract and its fractions. Data were expressed as the percentage inhibition of viral replication calculated by the inhibition of cytopathic effect in the treated cells compared to untreated controls after 48 h of incubation. First, we conducted a fractionation, generating five fractions (F1–F5) which were submitted to antiviral assay. Then, the fraction that showed the highest virucidal effect (F3, PI = 75%) was subjected to a larger partition, yielding eighteen subfractions, which were submitted to new antiviral assays. Terpenes, flavonoids and tannins were the major secondary metabolites detected by TLC analysis in F3. SF1, a flavonoid-enriched fraction, showed the strongest in vitro activity against rotavirus (PI = 92%), preventing cytopathic effect. Chromatographic profiles were obtained by HPLC for the crude extract and SF1, the most potent subfraction. Overall, our data point to the potential anti-rotavirus activity of flavonoid-enriched fraction (SF1) of M. urundeuva leaves, corroborating the traditional use of this species to treat diarrhea and broadening our perspectives on in vivo assays in mice with SF1 isolated or associated with other fractions.

This paper describes 2D-QSAR and 3D-QSAR studies against Candida albicans and Cryptococcus neofarmans for a set of 20 bisbenzamidines. In the studies of 2D-QSAR with C. albicans it was obtained a correlation between log MIC-1 and lipolo component-Z (r² = 0.68; Q² = 0.51). In the case of C. neofarmans a correlation between log MIC-1 and lipolo component-Z and of Balaban index (r² = 0.85; Q² = 0.6) was obtained. 3D-QSAR studies using CoMFA showed that the steric fields contributed more to the predicted activities for Candida albicans (94.9%) and Cryptococcus neofarmans (97.9%).