Azaphenanthrene alkaloids with antitumoral activity from Anaxagorea dolichocarpa Sprague & Sandwith (Annonaceae).

Phytochemical investigation of Anaxagorea dolichocarpa Sprague & Sandwith led to isolation of three azaphenanthrene alkaloids: eupolauramine, sampangine and imbiline 1. Their chemical structures were established on the basis of spectroscopic data from IR, HR-ESI-MS, NMR (including 2D experiments) and comparison with the literature. Sampangine and imbiline 1 are being described in the Anaxagorea genus for the first time. Eupolauramine and sampangine show concentration-dependent antitumoral activity in leukemic cells K562 with IC(50) of 18.97 and 10.95 µg/mL, respectively.

Ecdysteroids from Vitex species: distribution and compilation of their 13C-NMR spectral data.

Iridoids and ecdysteroids are found in some genera of the family Verbenaceae. In such cases, they are used as chemotaxonomic markers for the difficult task of taxonomic identification by using morphological characteristics of plants belonging to this family. The present work describes the distribution of ecdysteroids in plants from the genus Vitex from a review of previous work on seventeen Vitex species. In addition, (13)C-NMR data of the main ecdysteroids found in this genus are described. This study attempted to summarize previous research on ecdysteroids distribution in Vitex species with the addition of (13)C-NMR analysis to further refine the characterization of these compounds in the Verbenaceae family.

Nb-benzoyltryptamine derivatives with relaxant activity in guinea-pig ileum.

A series of derivatives analogous to Nb-benzoyltryptamine were synthesized by the Schotten-Bauman procedure. The products obtained were: Nb-4-methoxy-benzoyltryptamine, Nb-2,4-dimethoxy-benzoyltryptamine, Nb-3,4-dimethoxy-benzoyltryptamine, Nb-3,4-methylenedioxy-benzoyltryptamine and Nb-3,4,5-trimethoxy-benzoyltryptamine. They were characterized through the usual spectrometric methods (UV, IR, 1H and 13C NMR) and showed non-selective relaxant activity in guinea-pig ileum pre-contracted with acetylcholine, histamine and KCl.

Cytotoxic pyranonaphthoquinones from Melloa quadrival vis (Bignoniaceae).

Three new pyranonaphthoquinones: 5-hydroxy-6-methoxy-alpha-lapachone, 5,6-dihydroxy-a-lapachone and 4',5-dihydroxy-6-methoxy-alpha-lapachone, and two known compounds: lapachol and 5,5'-dihydroxy-3',4',7-trimethoxyflavanone, were isolated from the stem bark of Melloa quadrivalvis. Their structures were established by spectrometric data, mainly 1D- and 2D-NMR and mass spectra. The methylazoetetrazolium (MTT) method using viable cells of the strain Hep2 and the strain NCIH-292 demonstrated cytotoxic activity. The CI50 was also calculated. The chloroform extract and 5-hydroxy-6-methoxy-alpha-lapachone inhibited cell growth.

Two new alkaloids from Hornschuchia obliqua.

The stem and roots of Hornschuchia obliqua provided two new alkaloids, 4,5-didehydroguadiscine and demethoxyguadiscine. Four known alkaloids, roemerine, guadiscine, liriodenine and cleistopholine were also isolated. The structures of the novel compounds were elucidated by spectroscopic analysis, including 2D NMR and MS.

ent-Trachylobane diterpenoids from Xylopia langsdorffiana.

Two new diterpenes of the ent-trachylobane type were isolated from the stems of Xylopia langsdorffiana, ent-7alpha-acetoxytrachyloban-18-oic acid (1) and ent-7alpha-hydroxytrachyloban-18-oic acid (2). The structures of these isolates were deduced by spectroscopic data interpretation. X-ray crystallography of 1 was used to confirm its structure. The cytotoxic activity of 1 against V79 fibroblasts and rat hepatocytes was investigated.

Flavanones from aerial parts of Cordia globosa (Jacq.) Kunth, Boraginaceae / Flavanonas isoladas das partes aéreas de Cordia globosa (Jacq.) Kunth (Boraginaceae)

The phytochemical analysis of aerial parts of Cordia globosa, collected in the Municipality of Picuí, State of Paraíba, Brazil, resulted in the isolation and structural identification of narigenin-4',7-dimethyl ether (0.025 g) and eriodictyol (0.015 g). These compounds are the first flavanones aglycones isolated from the genus Cordia.

A análise fitoquímica das partes aéreas de Cordia globosa, coletadas no município de Picuí, PB, Brasil, resultou no isolamento e identificação estrutural da 7,4'-dimetilnarigenina (0,025 g) e eriodictiol (0,015 g). Estas duas flavanonas são as primeiras agliconas, desta classe, isoladas no gênero Cordia.

Secondary metabolites isolated from Richardia brasiliensis Gomes (Rubiaceae) / Metabólitos secundários isolados de Richardia brasiliensis Gomes (Rubiaceae)

A família Rubiaceae compreende cerca de 637 gêneros e aproximadamente 10700 espécies, ocorrendo essencialmente nas regiões tropicais do Brasil. Richardia brasiliensis Gomes, popularmente conhecida por "poaia branca", é uma planta nativa da região sul do Brasil, utilizada na medicina popular como anti-emética e no tratamento de diabetes. Este trabalho reporta o isolamento e identificação estrutural de um flavonóide glicosilado, um triterpeno, uma cumarina e dois derivados de ácido benzóico, objetivando contribuir para quimiotaxonomia do gênero Richardia. Através deste estudo foi possível isolar e identificar os metabólitos isorametina-3-O-rutinosídeo, ácido oleanólico, a cumarina escopoletina e os ácidos p-hidroxi-benzóico e m-metoxi-p-hidroxi-benzóico, todos isolados pela primeira vez no gênero, exceto o último, apresentando, portanto, relevante importância quimiotaxonômica para o mesmo. As estruturas foram identificadas com o uso de técnicas espectroscópicas de IV, RMN ¹H e 13C uni e bidimensionais e comparação com dados da literatura.

The family Rubiaceae comprises around 637 genera and approximately 10,700 species, occurring essentially in tropical regions of Brazil. Richardia brasiliensis Gomes, known popularly as "poaia branca", is native to Brazil south region, used in folk medicine as anti-emetic and in the treatment of diabetes. This work reports the isolation and structural identification of a flavonoid glycoside, a triterpene, a coumarin and two benzoic acid derivatives, aiming at contributing to the chemotaxonomy of the genus Richardia, through a phytochemical study of Richardia brasiliensis. By means of this study the metabolites isorhamnetin-3-O-rutinoside, oleanolic acid, the coumarin scopoletin and p-hydroxy-benzoic and m-methoxy-p-hydroxy-benzoic acids were isolated and identified. All of them, but the latter, were isolated for the first time in the genus, thereby presenting relevant chemotaxonomic importance to it. The structures were identified using spectroscopic techniques such as IR, one and two-dimensional ¹H and 13C NMR besides comparison with literature data.

Estudo fitoquímico das partes aéreas de Aristolochia birostris Ducht. (Aristolochiaceae) / Phytochemical study of the aerial parts of Aristolochia birostris Ducht. (Aristolochiaceae)

A família Aristolochiaceae apresenta entre seus constituintes terpenóides, alcalóides e lignóides. Papo-de-peru, jarrinha, mil-homens e capivara são nomes populares da espécie Aristolochia birostris, a qual é utilizada na medicina popular como antiofídica, sudorífica, anticatarral e abortiva. Um estudo fitoquímico anterior com as partes aéreas desta espécie reportou o isolamento de quatro terpenóides, um lignóide e uma antraquinona. Dando continuidade a esse estudo, este trabalho relata a identificação de 4 lignóides, sendo dois do tipo ariloxiarilpropânico (4-metilenodioxi-5,3',5' -trimetoxi-1'-alil-8.O.4'-neolignana e 3,4,5,3',5'-pentametoxi-1'-alil-8.O.4'-neolignana), um do tipo tetraidrofurano (grandisina) e uma lignana dibenzilbutirolactônica [(-)-hinoquinina], além de vanilina. As estruturas foram estabelecidas através de métodos espectroscópicos de infravermelho e ressonância magnética nuclear uni e bidimensionais. Os lignóides foram avaliados quanto a atividade antimicrobiana frente a algumas cepas de bactérias, fungos e leveduras, entretanto foram inativos.

The family Aristolochiaceae presents among its chemical constituents terpenoids, alkaloids and lignoids. Aristolochia birostris is a species of this family popularly known as "papo-de-peru", "jarrinha", "mil-homens" and "capivara", and it is used in the folk medicine to treat snake bites, as a sudorific, expectorant and abortive. A previous phytochemical study of the aerial parts of this plant reported the isolation of four terpenoids, lignoids and antraquinone. Continuing this study it is now reported the isolation of four lignoids, two of the type aryloxyarylpropane (4-methylenedioxy-5,3',5'-trimethoxy-1'-alyl-8.O.4' -neolignan and 3,4,5,3',5'-pentamethoxy-1'-alyl-8.O.4'-neolignan), one tetrahydrofuran (grandisin) and a dibenzylbutyrolactone lignans [(-)-hinokinin], and also vanillin. The chemical structures of the isolated compounds were established based on spectral data, mainly IR and NMR including 1D and 2D experiments. The lignoids were evaluated for their activity against some bacteria (Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus faecalis and Escherichia coli), fungi (Aspergilus flavus and Microsporum canis) and yeast (Candida albicans, Candida tropicalis and Criptococcus neoformans), but they were inactive.