Environmental factors can influence secondary plant metabolism, inducing seasonal variation in chemical composition. Few works report how the seasons of Brazilian savanna (Cerrado), rainy and dry, impacts plant metabolism. We investigated the seasonal effect on the production of secondary metabolites in Duguetia furfuracea. Leaves of three individuals were collected monthly for one year and analyzed by ultra-fast liquid chromatography coupled to diode array detector and mass spectrometry (UFLC-DAD-MS), partial least squares-discriminant analysis (PLS-DA), hierarchical cluster analysis (HCA), volcano plot, and Pearson correlation. The main chemical classes found were benzyltetrahydroisoquinoline derivatives and flavonoids. Alkaloids are virtually perennial, with qualitative variation during the year, and flavonoids accumulate during the rainy season. Dew point temperature seemed to be the most representative weather indicator in the metabolite change. These results showed for the first time the effect of the Cerrado environment on the levels of flavonoids and alkaloids in Duguetia furfuracea. They could be useful for exploring this species since it is used in popular medicine and accumulates valuable secondary metabolites.

Abstract Condensed tannins have been used for many years in folk medicine to treat gastric problems. The mechanism of action that explains why tannins improve gastritis symptoms is based on their ability to chelate metals, antioxidant activity, and their complexation power with other molecules. Even though these uses are well-known, the requirements to become an herbal medicine are much more complex. Herein, we analyzed Stryphnodendron rotundifolium Mart., Fabaceae, extract using MALDI for tannin characterization and carried out a fluorescence-imaging study to prove the gastroprotective effects of tannins as coating agents. Through these methods we show that condensed tannins form a gastroprotective layer. Moreover, we revise and discuss other possible mechanisms of action for phenolic-rich plant extracts and their potential in the development of herbal medicines to treat ulcers and gastritis.

Abstract Echinodorus scaber Rataj and Echinodorus grandiflorus (Cham. & Schltdl.) Micheli, Alismataceae, are popularly used to relieve inflammatory complaints and as diuretic. A study on the antinociceptive effect and selected marker compounds in eleven extracts from different locations was undertaken and their antinociceptive effect was assessed. The fingerprints were compared by HPLC-DAD and the content of vitexin, isovitexin, isoorientin and vitexin-2-O-rhamnoside were determined. All samples presented antinociceptive activity reducing the writhes by 36.4-62.5% and 47.4-79.8% at 10 and 50 mg/kg, respectively; indomethacin (5 mg/kg) reduced writhes by 82.6-90.1%. The content of the flavonoids C-glycosides, however, presented a strong variation. Isovitexin and isoorientin were found in all the samples, with content ranging from traces to 14.70 µg/mg and 2.12-84.27 µg/mg extract, respectively, while vitexin-2-O-rhamnoside occurred in quantifiable amounts only in 3 out of 11 samples ranging from 5.43 to 33.13 µg/mg extract; vitexin was not detected at all or detected in trace amounts. According to the fingerprints, the samples could be arranged in four main groups. All eleven extracts showed antinociceptive activity. Isovitexin was the only flavonoid present in all samples and can be regarded, acting in synergy with the other compounds or not, as the responsible for the antinociceptive activity. Therefore, isovitexin is a good choice as chemical marker when the antinociceptive activity of E. scaber and E. grandiflorus is investigated.

Abstract We evaluated the antimicrobial activity of Aspilia latissima - an abundant plant from the Brazilian Pantanal region - against Candida albicans, Candida parapsilosis, Candida krusei, Candida tropicalis, Pseudomonas aeruginosa, Enterococcus faecalis, Escherichia coli and Staphylococcus aureus. The crude extracts and fractions showed activity in all tested microorganisms. The chloroform fraction of the leaves and roots showed the most antimicrobial activity against S. aureus, with an MIC of 500 μg/mL. This fraction was submitted to bioautographic assays to characterize the activity of the compounds. Two bands from the leaves (L-A and L-B) and three bands from the roots (R-C, R-D and R-E) were bioactive. Within the root-derived bands, the terpene derivatives stigmasterol, kaurenoic acid and kaura-9(11), 16-dien-18-oic acid were identified. Antibiotic activity of A. latissima is reported for the first time.

Abstract Piper angustifolium Lam., Piperaceae, popularly known as "matito", "pimenta-de-macaco", "pimenta-longa" or "jagurandi" in Brazil, has been commonly used in the treatment of cutaneous leishmaniasis-associated lesions, but there are few studies on the activity against visceral leishmaniasis-associated species. This study demonstrates the first in vitro antileishmanial activity of the P. angustifolium essential oil, of which the phytochemical profile showed the presence of sesquiterpenes and monoterpenes. The main compounds were spathulenol (23.8%) and caryophyllene oxide (13.1%). P. angustifolium essential oil was highly active [the half maximum inhibitory concentration = 1.43 μg/ml] against intracellular amastigotes of Leishmania infantum, the etiological agent of visceral leishmaniasis in the New and Old World. Activity was obtained 24 h after addition of the oil (6.25–50 μg/ml), with a reduction of 100% in the infection index at concentrations of 25 and 50 μg/ml. P. angustifolium essential oil showed low cytotoxicity for mammalian fibroblasts and macrophages (the half maximum inhibitory concentration values of 31.67 and 48.22 μg/ml, respectively), and it was 33 and 22 times more toxic to amastigotes than to mammalian cells, as indicated by selectivity indexes. The results demonstrated that P. angustifolium essential oil is a promising alternative for the study of potential drugs for visceral leishmaniasis.

Este trabalho avaliou a atividade acaricida in vitro de extratos de 21 espécies de plantas do Pantanal de Mato Grosso do Sul. Na etapa I, foi realizado um teste de imersão larval utilizando três concentrações de extrato (5%, 20% e 40%). Na etapa II, utilizou-se apenas as plantas que apresentaram eficácia superior a 95%, na concentração de 40% na etapa I e que apresentasse quantidade suficiente para o teste de imersão de adulto. Aeschynomene denticulata, Angelonia hirta, Aspilia latissima, Caperonia castaneifolia, Centratherum punctatum, Crotalaria micans, Diodia kuntzei, Echinodorus paniculatus, Hyptis mutabilis, Lantana canescens, Melanthera latifolia, Ocotea diospyrifolia, Richardia grandiflora, Sebastiana hispida, Tocoyena formosa, Zanthoxylum rigidum e Sesbania virgata (extrato do fruto) apresentaram atividade acaricida sobre larvas de Rhipicephalus (Boophilus) microplus superior a 95% na concentração de 40% (w/v), enquanto Hippocratea volubilis e Randia armata apresentaram eficácia moderada e Croton glandulosus e Senna obtusifolia não apresentaram efeito acaricida. Os extratos brutos de M. latifolia, A. hirta, R. grandiflora e A. latissima foram avaliados sobre adultos e A. hirta apresentou eficácia próxima de 90%. Dezoito extratos apresentaram eficácia de até 95%, contra larvas, na concentração de 40%, sete extratos foram eficazes a 20% e apenas um (Sebastiana hispida) foi eficaz na concentração de 5%.

This research evaluated the in vitro acaricidal activity of extracts from 21 plant species from the Pantanal of Mato Grosso do Sul. During stage I, a larval immersion test was performed using three extract concentrations (5%, 20%, and 40%). During stage II, we used only plants that showed over 95% efficiency at the 40% concentration in stage I in an amount sufficient for the adult immersion test. Aeschynomene denticulata, Angelonia hirta, Aspilia latissima, Caperonia castaneifolia, Centratherum punctatum, Crotalaria micans, Diodia kuntzei, Echinodorus paniculatus, Hyptis mutabilis, Lantana canescens, Melanthera latifolia, Ocotea diospyrifolia, Richardia grandiflora, Sebastiana hispida, Tocoyena formosa, Zanthoxylum rigidum, and Sesbania virgata (fruit extract) showed acaricidal activity against the larval stage of Rhipicephalus (Boophilus) microplus higher than 95% at a 40% (w/v) concentration, while Hippocratea volubilis and Randia armata showed moderate efficacy and Croton glandulosus and Senna obtusifolia had no effect. The M. latifolia, A. hirta, R. grandiflora, and A. latissima raw extracts were evaluated for their activity against adults, and only A. hirta showed an efficacy close to 90%. Eighteen extracts had an efficacy of up to 95% against larvae at a 40% concentration, seven extracts were effective at 20%, and only one (Sebastiana hispida) was effective at a 5% concentration.

Análises comparativas entre os extratos hidrometanólico de Achyrocline alata (Kunth) DC. e A. satureioides (Lam.) DC., Asteraceae,foram desenvolvidas utilizando HPLC-DAD-MS. Ambas as plantas são utilizadas indistintamente para as mesmas indicações na medicina popular de Mato Grosso do Sul, Brasil, enquanto a A. alata ("jatei-ka-há) é predominante neste estado, a A. satureioides ("marcela") é predominante nos demais estados da Federação. Amostras das duas espécies coletadas em épocas diferentes, 1996 e 2002, apresentaram o mesmo perfil cromatográfico. O presente resultado pode justificar que A. alata possa ser utilizada como sucedânea de A. satureioides, pois apresentam similar composição de metabólitos secundários polares.

A comparative analysis between the hydromethanolic extracts of Achyrocline alata (Kunth) DC. and A. satureioides (Lam.) DC., Asteraceae, was performed by the use of HPLC-DAD-MS. Both plants were used without distinction and under the same indications in folk medicine in Mato Grosso do Sul, Brasil. While Achyrocline alata ("jatei-ka-ha") is used in folk medicine of the Brazilian state of Mato Grosso do Sul, A. satureioides is predominantly used in other states. Samples of both plants collected in different periods, 1996 and 2002, showed a very similar chemical profile. The results indicate that A alata could be used in phytotherapeutic preparations as substitue for A. satureioides, since they have similar chemical compositions of the polar extract.

Duguetia furfuracea, Annonaceae, uma invasora de pastagens, é também usada na medicina tradicional em diversos estados no Brasil. Devido à significante diferença de odor entre dois grupos de indivíduos desta planta em um remanescente de cerrado em Campo Grande, Mato Grosso do Sul, seis amostras foram selecionadas de acordo com a intensidade de odor em suas folhas: In-01, In-03 e In-05: odor pronunciado (Perfil A); In-02, In-04 e In-06: odor fraco ou ausência de odor (Perfil B). As folhas foram coletadas e submetidas a hidrodestilação para obtenção dos óleos essenciais, os quais foram analisados por CG/EM. Uma boa compatibilidade foi encontrada entre os resultados obtidos por CG/EM e a análise olfativa adotada para as amostras: espécimes odor pronunciado apresentaram uma alta porcentagem de monoterpenos e alguns sesquiterpenos: In-01 (β-felandreno, 42,2%; mirceno, 6,8%; α-felandreno, 4,6%); In-03 (terpin-4-ol, 21,6%; sabineno, 17,3%; p-cimeno, 5,6%); In-05 (sabineno, 25,1%; terpin-4-ol, 16,2%; p-cimeno, 8,3%). Apenas sesquiterpenos foram encontrados nos espécimes que apresentaram odor fraco ou ausência do mesmo (com constituinte majoritário biciclogermacreno: 21,4%, 24,0%, and 29,1%, respectivamente, para os In-02, In-04 e In-06).

Duguetia furfuracea, Annonaceae, a pasture weed, is also used in folk medicine in several Brazilian states. Because of the significant difference in odor between two groups of this plant in a remnant patch of savanna in Campo Grande county, Mato Grosso do Sul, six samples were selected according to the odor intensity in the leaves (In-01, In-03, and In-05: pronounced odor; In-02, In-04, and In-06: weak odor or its absence). The leaves were collected and subjected to steam distillation for extraction of essential oils, which were analyzed by GC-MS. A good agreement was found between CG/MS results and olfactory evaluation of the samples: specimens exhibiting leaf scent had a high percentage of monoterpenes and some sesquiterpenes, as follows: In-01 (β-phellandrene, 42.2%; myrcene, 6.8%; α-phellandrene, 4.6%); In-03 (terpin-4-ol, 21.6%; sabinene, 17.3%; p-cymene, 5.6%); In-05 (sabinene, 25.1%; terpin-4-ol, 16.2%; p-cymene, 8.3%). Only sesquiterpenes were found in the specimens having weakly scented or scentless leaves (main constituent bicyclogermacrene: 21.4%, 24.0%, and 29.1%, respectively, for In-02, In-04 and In-06).