Mari-mari (Cassia leiandra Benth.) is an Amazonian native fruit that is highly appreciated in the northern region of Brazil, but there are few studies regarding its chemical composition and/or biological properties. A phytochemical study was conducted on the extracts of the pulp, peel and seeds; and their antioxidant, cytotoxic and antimicrobial potential were also determined. Methanol and acetone extracts from different fruit parts were subjected to total phenolic, 2,2-diphenyl-1 picrylhydrazyl (DPPH) radical scavenging and FeIII reducing capacity (FRAP) assays. From the peel extracts, the engeletin and astilbin could also be isolated and characterized based on nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry. A quantification using ultra-fast liquid chromatography of acetone dry crude extracts (DCE) of the peel showed that engeletin was the main compound (532.77 mg g-1 DCE). Astilbin content was also determined (131.53 mg g-1 DCE). The antibacterial and antiproliferative activities were evaluated and the methanol extract of the peel showed higher growth inhibition activity against all tested bacteria. Engeletin showed a relevant antimicrobial effect against Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli. Acetone and methanol peel extracts exhibited a relevant inhibitory effect on the proliferation of breast carcinoma cells (MCF-7), with no toxicity to the normal cell line (NIH/3T3).

Phytochemical investigation of Endopleura uchi led to the isolation of a gallic acid derivate, known as bergenin (2) and friedelin (1), a pentacyclic triterpene. The present work also reports the bergenin quantification in different Endopleura uchi bark, twig and leaves extracts. Our findings showed the highest bergenin concentration in bark methanol extracts (4.75%) and the lowest concentration in twig aqueous extracts (1.89%). Phenolics quantification by Folin-Ciocalteu, revealed phenolic compounds level values from 16.69 to 43.02 mg GAE g-1 dry extract. The ferric reducing antioxidant activity ranged from 230.43 to 567.89 mmol Fe+2 g-1 dry extract. DPPH IC50 free radicals showed to range from 12.04 to 24.20 μg mL-1. Leaves’ chloroform fraction exhibited the highest nitric oxide inhibiting activity bearing IC50= 3.2 μg mL-1. Results show this species to hold significant bergenin concentrations as well as phenolic and anti-inflammatory compounds in all extracts suggesting it bear therapeutic potential.

Endopleura uchi (Huber) Cuatrec. is an Amazonian medicinal plant with restricted distribution to the North Region of Brazil. Its bark is commonly used as natural medicines for the treatment of many diseases. Although widely investigated from the phytochemical viewpoint, the knowledge regarding the phenolic content remains unexplored. In order to access the phenolic composition of E. uchi bark, an integrative approach based on simplex-centroid design, direct infusion electrospray ionization mass spectrometry (ESI-MS) and chemometric analysis was adopted. In addition, the extracts were evaluated to total phenolic content and antioxidant activity. The multivariate analysis pointed to the ethanol-based extracts as the most representative for phenolic compounds, with 3,5-di-O-galloylquinic acid (2), gallic acid (4), 5-galloylquinic acid (5) and gallocatechin gallate (6) tentatively identified by MS analysis, all described for the first time in E. uchi. Besides, pure ethanol extract presented highest total phenolic content (TPC = 133.61 ± 0.3 mg GAE 100 g-1) and antioxidant activity (half maximal inhibitory concentration, IC50 = 9.32 ± 0.15). The integrative approach proposed to this work provided an effective way to assess the phenolic compounds of E. uchi bark, therefore, improving the knowledge regarding phenolic content in this Amazonian medicinal plant.

Simaba guianensis subesp. ecaudata (Simaroubaceae) is a tree found in the Brazilian Amazon. This work describes for the first time the fractionation of stems of this species that resulted in the isolation of the cytotoxic triterpene piscidinol A, the alkaloid 9-methoxycanthin-6-one, caryophyllene oxide, also isolated for the first time from this species and a new alkaloid (6-methoxy-(9H-β-carbolin-1-il)-(Z)-2-propenoic acid). Quantification of 9-methoxycanthin-6-one in different extracts and fractions of stems of S. guianensis by high performance liquid chromatography was also performed. The concentration of 9-methoxycanthin-6-one in methanolic and aqueous extracts were inferior to the known cytotoxic concentration of this compound.

Endopleura uchi (Huber) Cuatrec. é uma planta medicinal da Amazônia utilizada no tratamento de inflamações e doenças do aparelho reprodutor feminino. A bergenina pura foi isolada do extrato metanólico das cascas de E. uchi, inicialmente por um processo de partição líquido-líquido, seguido de cromatografia em coluna de permeação em gel Sephadex LH-20 e finalmente de adsorção utilizando sílica gel 60. A elucidação estrutural foi determinada pela análise dos espectros de RMN. A atividade anti-inflamatória in vitro foi determinada pela medida da concentração inibitória (CI) da bergenina frente a três importantes enzimas: COX-1, COX-2 (ciclooxigenases) e fosfolipase A2 (PLA2). Essas enzimas foram selecionadas, porque são importantes alvos terapêuticos no processo de descobrimento de novas drogas anti-inflamatórias associadas com a biossíntese das prostaglandinas. A CI50 da bergenina para a fosfolipase A2 foi de 156,6 µmol L-1. Comparada ao padrão de tioeteramida PC, bergenina foi considerada pouco ativa. A bergenina também não foi capaz de inibir COX-1 (CI50 = 107,2 µmol L-1). Entretanto, bergenina foi capaz de inibir seletivamente COX-2 (CI50 = 1,2 µmol L-1). Considerando o uso de E. uchi na medicina tradicional, a quantidade de bergenina no extrato aquoso preparado da forma popular foi quantificado por CLAE em fase reversa como sendo 3% nas cascas. Esses resultados indicam uma alta concentração de bergenina nos chás e nas cascas. A atividade inibitória seletiva para COX-2 também é importante, uma vez que inibidores seletivos de COX-2 têm sido clinicamente validados como drogas anti-inflamatórias por sua eficácia e por não apresentar efeitos gastrintestinais colaterais.

Endopleura uchi (Huber) Cuatrec. is an Amazon species traditionally used for the treatment of inflammations and female disorders. Pure bergenin was isolated from the methanolic extract of bark of E. uchi, firstly by using liquid-liquid partition chromatography followed by column chromatography over Sephadex LH-20 and then silica gel 60 flash chromatography. The structure of bergenin was identified on the basis of its NMR spectra. The in vitro anti-inflammatory activity was determined by the measurement of the inhibitory concentration (IC) of bergenin against three key enzymes: COX-1, COX-2 (cyclooxygenases) and phospholipase A2 (PLA2). These enzymes were selected because they are important targets for the discovery of new anti-inflammatory drugs associated with the biosynthesis of prostaglandins. The IC50 of bergenin for phopholipase A2 was determined as 156.6 µmol L-1 and bergenin was not considered active as compared to the positive control, tioetheramide PC. Bergenin did not inhibit COX-1 as well (IC50 = 107.2 µmol L-1). However, bergenin selectively inhibited COX-2 (IC50 = 1.2 µmol L-1). Because of the use of E. uchi in traditional medicine, bergenin was quantified in teas prepared as prescribed in traditional medicine by RP-HPLC as being 3% in the bark of E. uchi. The inhibitory activity towards COX-2 is important, since selective inhibitors of COX-2 have been clinically validated as anti-inflammatory therapeutics due to their enhanced gastrointestinal safety.

Simaba polyphylla is a small tree found in the Amazon region, known by the common names "marupazinho" or "serve para tudo". It is used in traditional medicine for the treatment of fevers. This work describes the phytochemical study of the hexane extract and chloroform fraction obtained by partitioning the methanol extract of stems, which led to isolation and identification of the triterpenes niloticin, dyhidroniloticin, taraxerone and of the cytotoxic alkaloid 9-methoxy-canthin-6-one. These compounds are described for the first time in S. polyphylla.