Suzana C. Santos

Antifungal activity of volatile constituents of Eugenia dysenterica leaf oil

The essential oil from the hydrodistillation of Eugenia dysenterica leaves consisted mainly of beta-caryophyllene and alpha-humulene as the major sesquiterpene, while limonene and alpha-thujene were the major monoterpene hydrocarbons. The main oxygenated mono and sesquiterpene constituents were alpha-terpineol and beta-caryophyllene oxide, respectively. The oil was investigated against eight strains of Candida albicans, 35 strains of Cryptococcus neoformans var. neoformans, and two C. neoformans var. gattii isolated from HIV-infected individuals with candidosis or cryptococcal meningitis using the agar dilution method. Based on the minimal inhibitory concentration (MIC) values, the most significant results were obtained against Cryptococcus strains. It was observed that 22 strains were inhibited at a concentration of 250 microg/ml, whereas four exhibited potent inhibition with MIC values below 125 microg/ml against 10(6) UFC/ml organisms. We found MICs > or = 3.12 microg/ml for 91.6, 50 and 30% of all Cryptococcus strains in relation of amphotericin B, fluconazole and itraconazole, respectively.

Tannin composition of barbatimão species

A comparative study of tannin composition of three species known as barbatimão (Stryphnodendron adstringens, Stryphnodendron polyphyllum and Dimorphandra mollis) was developed by TLC, hydrolysis followed by PC, and colorimetry. Principal component analysis of the data obtained showed strong differentiation between the genus Dimorphandra and Stryphnodendron. Additionally, barks from the two Stryphnodendron sp. also presented considerable differences in the tannin structure.

Chemical variability in the essential oil of Hyptis suaveolens

The essential oils of Hyptis suaveolens plants collected from 11 localities of the Brazilian Cerrado region were investigated by GC-MS. Sabinene, limonene, biclyclogermacrene, beta-phellandrene and 1,8-cineole were the principal constituents. The results were submitted to principal component and chemometric cluster analysis which allowed three groups of essential oils to be distinguished with respect to the content of p-mentha-2,4(8)-diene, limonene/beta-phellandrene/gamma-terpinene and germacrene D/bicyclogermacrene. In patterns of geographic variation in essential oil composition indicated that the sesquiterpenes are mainly produced in the samples grown at lower latitudes.

Molluscicidal activity against Biomphalaria glabrata of Brazilian Cerrado medicinal plants

Alcoholic extracts of six Brazilian Cerrado medicinal plants were evaluated for their molluscicidal activity against Biomphalaria glabrata, intermediate host of schistosomiasis. Stryphnodendron polyphyllum bark extract, rich in condensed tannins, was the most promising as molluscicide.

Essential oil chemotypes in Hyptis suaveolens from Brazilian Cerrado

The composition of nine samples of essential oil of individual plants in fruiting stage of Hyptis suaveolens from Brazilian Cerrado was investigated by GC–MS. Spathulenol, 1,8-cineole and (E)-caryophyllene were the principal constituents. The results were submitted to Principal Component and Chemometric Cluster Analysis which allowed three groups of essential oils to be distinguished with respect to the content of 1,8-cineole/sabinene, β-bourbonene and α -bulnesene. Latitude seems to be the most important environmental factor influencing the oil contents. Pattern of geographic-variation in essential oil composition indicated that sesquiterpenes are mainly produced in the samples grown at lower latitudes and altitudes.  2002 Elsevier Science Ltd. All rights reserved.

Atividade tripanocida in vivo de Stryphnodendron adstringens (barbatimão verdadeiro) e Caryocar brasiliensis (pequi)

Crude extracts from barks of Stryphnodendron adstringens and Caryocar brasiliensis, native species of Cerrado, have been screened at 400 ppm for antiparasitic activity against Trypanosoma cruzi. Mice were inoculated with 1x104 parasites, after 24 h they were treated with one day dose extracts during ten days. The trypanosomicidal activity was evaluated each 48 h until animals death. The extracts of S. adstringens and C. brasiliensis decreased significantly the number of parasites in the blood.

Seasonal variability of essential oils of Eugenia uniflora leaves

Seasonal influence on the chemical composition of essential oils of Eugenia uniflora leaves with red-orange fruit colour biotype has indicated the presence of two oil clusters in the two seasons of the Brazilian Cerrado. Cluster I included samples collected during dry months (April-September) which were characterized by the highest percentages of spathulenol (10%) and caryophyllene oxide (4.1%). In cluster II, whose samples were collected during wet months (October-March), the major constituent was selina-1,3,7(11)-trien-8-one epoxide (29%). The canonical correlation indicated that spathulenol and caryophyllene oxide revealed a strong relationship with the phenolics and nutrient balance (S, Ca, Fe) in leaves, whereas selina-1,3,7(11)-trien-8-one epoxide was related to K, Cu, Mn, and precipitation during the months of the wet season. Oxygenated sesquiterpenes were predominant in all the sampling months and the oil chemovariation observed might be environmentally determined by a clear seasonal influence.

Seasonal variation in the content of tannins in barks of barbatimão species

A composicao de taninos em cascas de especies de barbatimao, Stryphnodendron adstringens (Mart.) Cov. and S. polyphyllum (Mart.), foi analisada mensalmente durante um ano. Os resultados foram correlacionados com as condicoes climaticas do periodo de coleta (precipitacao, umidade e temperatura media) atraves de metodos quimiometricos. Analise de componentes principais dos dados mostrou uma tendencia de maior producao de taninos na estacao quente e chuvosa, sugerindo que os fatores ambientais podem afetar os teores de taninos nestas especies.

Atividade antifúngica de Caryocar brasiliensis (Caryocaraceae) sobre Cryptococcus neoformans

The widespread occurrence of cryptococcosis mainly in immunocompromised patients and the side effects of available drugs which are effective against this mycosis have led investigators to search for new antimycotic agents. Caryocar brasiliensis derived compounds were investigated against Cryptococcus neoformans using the agar dilution method. Based on MIC values, the best results were obtained with a concentration of < 250 g/mL of cuticular waxes of the Caryocar brasiliensis leaf collected during the dry period (170.8mm of precipitation) which inhibited the growth of 91.3% (21/23) Cryptococcus neoformans isolates.

Seasonal variability in the essential oils of wild and cultivated Baccharis trimera

The seasonal variations in the chemical composition of the essential oil of wild and cultivated Baccharis trimera populations indicated the presence of three clusters of oils regarding population and phenophase. The first included flowering, wild, and cultivated samples from a period of March-May, with high percentages of globulol and spathulenol. In cluster II, with wild samples collected from June-February, the major constituents were germacrene D and (E)-caryophyllene, while cluster III included cultivated samples from June-February containing a high content of ledol. The canonical correlation analysis revealed that (E)-caryophyllene, Mn, Al saturation, and precipitation were quite strongly related to wild samples (cluster II), whereas ledol and guaiol were related to chemical balance in soils (P, K, S, Cu, Zn, and base saturation) of cultivated samples (cluster III). Both essential oils have predominantly hydrocarbon compositions, although for a couple of months the oxygenated sesquiterpene content is over 40% for both samples. The observed chemovariation might be environmentally determined.