Abstract The ethanol crude extract from cashew (Anacardium occidentale L. Anacardiaceae) displayed significant antiplasmodial activity (IC50 0.577 µg/ml). Liquid chromatography-high resolution Mass spectrometry analysis was performed to identify the main compounds existing in the ethanol extract. The occurrence of anacardic acids, cardols, and 2-methylcardols derivatives was confirmed in the extract. The IC50 obtained, when the main isolated compounds were evaluated in Plasmodium falciparum D6 strain, ranged from 5.39 µM to >100 µM. Tested here for the first time, the data showed that cardol triene 1 (IC50 = 5.69 µM) and 2-methylcardol triene 4 (IC50 = 5.39 µM) demonstrated good antimalarial activity. In conclusion, Anacardium occidentale nuts presented relevant biological potential, and further studies should be considered.

Abstract Recent publications have highlighted the numerous biological activities attributed to the lignan (-)-cubebin (1), Piper cubeba L. f., Piperaceae, and ongoing studies have focused on its structural optimization, in order to obtain derivatives with greater pharmacological potential. The aim of this study was the obtainment of (1), its semisynthetic derivatives and evaluation of antibacterial activity. The extract of the seeds of P. cubeba was chromatographed, subjected to recrystallization and was analyzed by HPLC and spectrometric techniques. It was used for the synthesis of: (-)-O-methylcubebin (2), (-)-O-benzylcubebin (3), (-)-O-acetylcubebin (4), (-)-O-(N, N-dimethylamino-ethyl)-cubebin (5), (-)-hinokinin (6) and (-)-6.6'-dinitrohinokinin (7). The evaluation of the antibacterial activity has been done by broth microdilution technique for determination of the minimum inhibitory concentration and the minimum bactericidal concentration against Porphyromonas gingivalis, Prevotella nigrescens, Actinomyces naeslundii, Bacteroides fragilis and Fusobacterium nucleatum. It was possible to make an analysis regarding the relationship between structure and antimicrobial activity of derivatives against microorganisms that cause endodontic infections. The most promising were minimum inhibitory concentration =50 µg/ml against P. gingivalis by (2) and (3), and minimum inhibitory concentration =100 µg/ml against B. fragilis by (6). Cytotoxicity assays demonstrated that (1) and its derivatives do not display toxicity.

In this paper we screened the dichloromethane extract from the aerial parts of Salvia officinalis L., Lamiaceae, against a representative panel of microorganisms that cause caries, conducted a bioassay-guided fractionation to establish themselves the most active metabolite (manool) and determined the Salvia officinalis fraction with the manool highest concentration to be used to activate an ingredient in oral care products such as toothpastes and mouthwashes. Both manool and S. officinalis extract showed very promising minimal inhibitory concentration values (between 6.24 and 31.36 µg.ml-1) and time kill curves against the primary causative agents of dental caries (Streptococcus mutans) revealed that, at twice its minimal bactericidal concentration (12.48 µg.ml-1), manool required 6 h to completely kill the bacteria. Salvia officinalis extract at twice its minimal bactericidal concentration (31.36 µg.ml-1) needed 12 h. The results achieved with Salvia officinalis extract motivated us to develop and validate an analytical RP-HPLC method to detect and determine manool in this extract. The validation parameters were satisfactorily met and evaluated allows us to consider the developed method suitable for use in different labs. In conclusion, our results evidenced that the manool-rich S. officinalis extract can be considered an analytically validated alternative to develop novel and effective antimicrobial agents against the main bacteria responsible for dental caries.

O presente trabalho descreve o isolamento do novo triterpeno 3beta-O-tiglyl-24-metilcicloartanol e uma mistura contendo os ácidos ursólico e oleanólico de Almeidea coerulea. Além dos triterpenos foram isolados cinco alcalóides da mesma planta: 7-O-acetilhaplofilidina, dutadrupina, isodutadrupina, 7-metoxi-8-(3,3-dimetilalil)-dictamina e arborinina. De A. rubra foram isolados os seguintes alcalóides: arborinina, metilarborinina, evolitrina, esquimianina, cocusagina e folinina. As estruturas das substâncias isoladas foram estabelecidas com base em dados espectroscópicos. Os alcalóides 7-metoxi-8-(3,3-dimetilalil)-dictamina e 7-O-acetilhaplofilidina estão sendo descritos pela primeira vez na literatura.

A new triterpene 3-beta-tiglyl-24-methylcycloartanol jointly with a mixture containing 3beta-hydroxy-urs-12-ene-28-oic and 3beta-hydroxy-olean-12-ene-28-oic acids were isolated from Almeidea coerulea. In addition to the triterpenes five alkaloids were also isolated from the same plant: 7-O-acetylhaplophyllidine, dutadrupine, isodutadrupine, 7-methoxy-8-(3,3-dimethylallyl)-dictamnine and arborinine. From A. rubra, the alkaloids arborinine, methylarborinine, evolitrine, skimmianine, kokusagine and folinine were isolated. Their structures were established based on their spectral data. The alkaloids 7-methoxy-8-(dimethylallyl)-dictamnine and 7-O-acetylhaplophyllidine are described for the first time as natural products.