ABSTRACT Medicinal plants play an important role in human health care. It is estimated that about 25–30% of all drugs are evaluated as therapeutic agents derived from natural products. Research in the pharmaceutical industry has demonstrated that for complex diseases, natural products still represent a valuable source for the production of new chemical compounds, since they possess privileged structures. Among Brazilian biodiversity, "catuaba" is popularly used as a tonic to treat fatigue, stress, impotence, memory deficits, and digestive disorders. Studies show antibacterial, trypanocidal, antioxidant, antiarrhythmic, antidepressant, improvement of memory, anti-inflammatory and antinociceptive activities, as well as phytocosmetic activity in cellulite treatment and in anti-ageing. The Brazilian plants known and used as catuaba are represented by more than twenty different species; however, the plant most commonly found in Brazil as "catuaba" is the species Trichilia catigua A. Juss., Meliaceae. Thus, the aim of this paper is to present a review of T. catigua, with emphasis on biological activities, chemical and analytical development and formulations in order to provide a broader and deeper insight, seeking a herbal medicine and/or phytocosmetic as well as future prospects for commercial exploitation and directions for future studies.

The flowers of Tagetes patula L., Asteraceae, commonly known as French marigold, are used in folk medicine as an antiseptic, diuretic, blood purifier and insect repellent. This study was conducted to optimize the extraction process through the biomonitoring of flavonoids, using a statistical mixture simplex-centroid design, to evaluate the effect of the solvents water, ethanol and acetone, as well as mixtures of these solvents, assessed by the total flavonoid content. The extracts were tested for dry residue, radical scavenging activity, chromatographic profile, and larvicidal activity. The acetone extract had the highest total flavonoid content, 25.13 ± 1.02% (4.07%); and the best radical scavenging activity, with IC50of 15.74 μg/ml ± 1.09 (6.92%), but with lower dry residue, 6.62 ± 1.33% (20.10%). The water extracts showed higher levels of dry residue, but lower total flavonoid content and radical scavenging activity than the acetone extract. The positive correlation between the total flavonoid content and radical scavenging activity of the extracts showed that flavonoids contribute significantly to the antioxidant capacity. The statistical mixture design allowed us to optimize the extraction of flavonoids from flowers of T. patula, with acetone as the best extraction solvent. Preliminary studies on the biological activity of the optimized extracts demonstrated a larvicidal effect of the acetone extract on Aedes aegyptimosquitoes.

A statistical mixture-design technique was used to study the effects of different solvents and their mixtures on the yield, total polyphenol content, and antioxidant capacity of the crude extracts from the bark of Schinus terebinthifolius Raddi (Anacardiaceae). The experimental results and their response-surface models showed that ternary mixtures with equal portions of all the three solvents (water, ethanol and acetone) were better than the binary mixtures in generating crude extracts with the highest yield (22.04 ± 0.48%), total polyphenol content (29.39 ± 0.39%), and antioxidant capacity (6.38 ± 0.21). An analytical method was developed and validated for the determination of total polyphenols in the extracts. Optimal conditions for the various parameters in this analytical method, namely, the time for the chromophoric reaction to stabilize, wavelength of the absorption maxima to be monitored, the reference standard and the concentration of sodium carbonate were determined to be 5 min, 780 nm, pyrogallol, and 14.06% w v-1, respectively. UV-Vis spectrophotometric monitoring of the reaction under these conditions proved the method to be linear, specific, precise, accurate, reproducible, robust, and easy to perform.

The use of thin-layer chromatography (TLC) is a commonplace practice and can be of significant help to different laboratories with quality control, especially those that work with plant extracts and phytotherapeutics. This study evaluated ten species of plants (Schinus terebinthifolius; Arctium lappa; Trichilia catigua; Camellia sinensis; Mikania glomerata; Croton echioides; Achyrocline satureioides; Heteropterys aphrodisiaca; Plantago major; Arctostaphylos uva-ursi) that are commonly sold by compounding pharmacies, using TLC with reference substances and pharmacopoeic physical and chemical tests (loss on drying, level of extractives, and total ash content). The results showed that the ten species showed losses on drying consonant with the literature. The level of extractives for two species and total ash for five species were also consonant with the literature, and those of the other species were established in this study. The semipurified extracts of the ten species were assayed by TLC, and the analysis with the use of reference substances proved to be effective, in addition to being practical, simple, versatile, and economically viable.

Caesalpinia peltophoroides is a domesticated tree found in Brazil. It was necessary to develop an analytical method to determine the content of total polyphenols (TP) in this herbal drug. The pre-analytical method was standardized for analysis time, wavelength, and the best standard to use. The optimum conditions were: pyrogallol, 760 nm, and 30 min respectively. Under these conditions, validation by UV/Vis spectrophotometry proved to be reliable for TP of the crude extract and semipurified fractions from C. peltophoroides. Standardization is required for every herbal drug, and this method proved to be linear, precise, accurate, reproducible, robust, and easy to perform.

Das cascas de Guazuma ulmifolia Lam. (Sterculiaceae) foram isolados e identificados nove compostos: ent-catequina, epicatequina, ent-galocatequina, epigalocatequina, epiafzelequina-(4β→8)-epicatequina, epicatequina-(4β→8)-catequina (procianidina B1), epicatequina-(4β→8)-epicatequina (procianidina B2), epicatequina-(4β→8)-epigalocatequina, e a nova substância 4'-O-metil-epiafzelequina. Suas estruturas foram elucidadas com base nos dados espectrais e da literatura. A "impressão digital" de um extrato semipurificado por cromatografia líquida de alta eficiência foi realizada em coluna C18, com uma mistura de acetonitrila (0,05% de ácido trifluoroacético):água (0,05% de ácido trifluoroacético) (v/v) com vazão de 0,8 mL min-1. O volume injetado da amostra foi de 100 µL e o comprimento de onda 210 nm.

From the bark of Guazuma ulmifolia Lam. (Sterculiaceae), nine compounds were isolated and identified: ent-catechin, epicatechin, ent-gallocatechin, epigallocatechin, epiafzelechin-(4β→8)-epicatechin, epicatechin-(4β→8)-catechin (procyanidin B1), epicatechin-(4β→8)-epicatechin (procyanidin B2), epicatechin-(4β→8)-epigallocatechin, and the new compound 4'-O-methyl-epiafzelechin. Their structures were elucidated on the basis of spectral and literature data. HPLC fingerprint analysis of the semipurified extract was performed on a C18 column, with a mixture of acetonitrile (0.05% trifluoroacetic acid):water (0.05% trifluoroacetic acid) (v/v) with a flow rate of 0.8 mL min-1. The sample injection volume was 100 µL and the wavelength was 210 nm.

Atividade antioxidante de extrato, frações, subfrações e substâncias isoladas das cascas de Stryphnodendron obovatum Benth. foi avaliada através da redução do radical 1,1-difenil-2-picrilhidrazila (método DDPH·) em cromatografia em camada delgada. O extrato bruto (CE, acetona:água), as frações acetato de etila (EtOAc) e aquosa (FW), as subfrações (F1-F12) e as substâncias isoladas I, II e III apresentaram a capacidade de reduzir o radical DDPH·. A atividade antifúngica foi determinada pela concentração inibitória mínima (CIM) e concentração fungicida mínima (CFM) frente às amostras de leveduras Candida albicans, Candida parapsilosis, Candida krusei e Candida tropicalis. O extrato bruto (CE), as frações (EtOAC e FW), e os compostos isolados I, II e III, como também as subfrações cromatográficas (F1-F12) foram inativos frente a todas as leveduras testadas. Por outro lado, as subfrações cromatográficas F13-15 e F20 apresentaram atividade antifúngica moderada. Já as subfrações F16-19 e F21-22 mostraram boa atividade antifúngica frente às cepas de C. albicans e C. parapsilosis. As substâncias I, II, e III, isoladas da fração EtOAc por cromatografia e recromatografia em coluna de Sephadex® LH-20, foram identificadas como sendo os monômeros de flavan-3-ol, epigalocatequina e galocatequina, e um dímero, epigalocatequina-(4<FONT FACE=Symbol>b®</FONT>8)-galocatequina, respectivamente.

The antioxidant activity of stem-bark extracts from Stryphnodendron obovatum Benth., including fractions and isolated compounds, was evaluated by DPPH in thin-layer chromatography. All the fractions and isolated compounds showed antioxidant activity. Antifungal activity was determined by the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) against the yeasts Candida albicans, Candida parapsilosis, Candida krusei and Candida tropicalis. All extracts (CE, EtOAc and FW), subfractions (F1-F12) and the compounds I, II and III were inactive against the yeasts. Against C. parapsilosis and C. albicans, fractions F13-15 and F20 showed moderate antifungal activity, and fractions F16-19 and F21-22 showed good activity. Chemical isolation of the ethyl-acetate fraction resulted in the identification of three compounds: epigallocatechin, gallocatechin and epigallocatechin-(4<FONT FACE=Symbol>b®</FONT>8)-gallocatechin.