No abstract

The new triterpene friedelan-1,3,21-trione, the known compounds friedelan-3-one, 3β-friedelinol, 3,4-seco-friedelan-3-oic acid, 28-hydroxyfriedelan-3-one, friedelan-3-oxo-28-al, friedelan-3,21-dione, 30-hydroxyfriedelan-3-one, a mixture of 30-hydroxyfriedelan-3-one/21α-hydroxyfriedelan-3-one, 21β-hydroxyfriedelan-3-one, gutta-percha, squalene, and a mixture of palmitic/stearic/oleic acids were isolated from the hexane extracts of leaves and branches of T. micrantha. Their chemical structures were established by Fourier transform infrared spectroscopy (FTIR), gas chromatography (GC), 1D/2D nuclear magnetic resonance (NMR) and comparison with the literature data. All compounds were described for T. micrantha and the genus Tontelea for the first time. The branch and leaf extracts displayed anti-Zika virus activity at the lowest tested concentration of 15.6 µg mL-1 , mainly virucidal effect, and presented no cytotoxicity to Vero cells. Furthermore, the ethyl acetate and methanolic leaf extracts demonstrated the best activities at the concentration of 31.2 and 15.6 µg mL-1 at the viral adsorption and penetration stages, respectively. These results showed that these extracts may be promising candidates for the Zika virus treatment.

A new pentacyclic triterpene, 3β,11β-dihydroxyfriedelane was isolated from leaves of Maytenus robusta Reissek (Celastraceae) together with other four known compounds: 3-oxofriedelane (friedelin), 3β-hydroxyfriedelane, 3-oxo-29-hydroxyfriedelane and 3-oxo-11β-hydroxyfriedelane. The structure and chemical conformation of the new friedelane triterpene were established by 1 H and 13 C NMR, including the 2D experiments, HSQC, HMBC, COSY and NOESY.

Structural Determination of 3β,11β-Dihydroxyfriedelane (I) from Maytenus robusta (Celastraceae) by 1D and 2D NMR -[isolation and structure elucidation]. -(SOUSA, G. F.; FERREIRA, F. L.; DUARTE*, L. P.; SILVA, G. D. F.; MESSIAS, M. C. T. B.; VIEIRA FILHO, S. A.; J. Chem. Res. 36 (2012) 4, 203-205, http://dx.doi.org/10.3184/174751912x13318236224684 ; Dep. Quim., Univ. Fed. Minas Gerais, 30161 Belo Horizonte, Minas Gerais, Brazil; Eng.) -M. Bohle 37-190

The use of antimicrobials represents one of the most successful ways of chemotherapy in the medical clinic. These drugs were responsible for the control of several infectious diseases, which have been considered as the main cause of mortality and morbidity throughout the history of the humanity. [1] However, infectious diseases remain a major challenge to human health. Currently, it is estimated that about 1 billion people are diagnosed with mycoses annually, and more than 1.5 million die from complications of invasive fungal diseases. [2] Furthermore, infectious diarrhea and pneumonia account for 40% of child deaths worldwide, especially in underdeveloped regions. [3] Over the past 40 years, only two classes of antibiotics effective against Gram-negative bacteria have been approved for clinical use (e.g., oxazolidinones and cyclic lipopeptides) and the development of new antimicrobials in the future seems unpromising. [3] Currently, there is a scarce therapeutic arsenal for the treatment of fungal infections and the development of new antifungal drugs conflicts with the difficulty of finding compounds which are specific for fungal cells. [4] Similar situation happens with the development of new antivirals. Since viruses are obligate intracellular parasites, finding a drug that has an action against the virus but does not interfere with the basal functions of the cells is pointed out as the main challenge. [5] In this regard, considering the 15 largest companies in the pharmaceutical industry, only 5 of their drugs in the clinical or preclinical research phase are anti-infective agents. [3] The alarming increase in the microorganism's resistance to the currently available antimicrobials, caused mainly by the long-term exposure to subinhibitory concentrations of these