José Carlos Seraphin

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.

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.

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.

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.

Environmental influence on phenols and essential oils of Myrciaria cauliflora leaves.

Foliar contents of total phenols and tannins and the essential oil composition of Myrciaria cauliflora populations cultivated in six sampling sites have shown the presence of four clusters related to soil types and foliar nutrients. Cluster I included samples which originated from sandy loam soil (S1) with the highest and lowest percentages of γ-eudesmol (11.55%) and germacrene D (20.48%), respectively, as well as high total phenol (136.68 mg g-1) and tannin (60.72 mg g-1) contents. Cluster II, rich in elemol (4.61%), included all the samples cultivated from clay sand loam soils (S2, S3, and S6), whereas clay soils S4 (cluster III) and S5 (cluster IV) had the highest amounts of germacrene D (III: 27.20%; IV: 26.83%) and the lowest levels of elemol (2.12-2.55%), total phenols (79.69 and 111.77 mg g-1), and tannins (34.04 and 44.51 mg g-1). The canonical redundancy analysis revealed the relationship between chemical balances in the soil and leaf nutrients in different clusters. Chemovariations may be environmentally determined.

Influence of fruit biotypes on the chemical composition and antifungal activity of the essential oils of eugenia uniflora leaves

A analise multivariada da composicao quimica dos oleos essenciais das folhas de Eugenia uniflora com diferentes cores de fruto indicou a presenca de tres grupos de oleos em relacao ao biotipo do fruto das amostras. O primeiro grupo incluiu amostras de frutos amarelos, vermelhos escuros e roxos contendo altas percentagens de germacreno B (11,1-30,7%), germacrona (9,8-54%) e atractilona (0-19,9%). No grupo II, com amostras de frutos vermelhos claro, os constituintes majoritarios foram o curzereno (42,0-43,2%), germacreno D (8,7-9,0%) e germacreno A (5,9-8,9%), enquanto que o grupo III incluiu amostras com frutos vermelho-alaranjado, caracterizadas por um alto conteudo de selina-1,3,7(11)-trien-8-ona (40,3-55,4%) e epoxido de selina-1,3,7(11)-trien8-ona (12,7-24,4%). Os oleos essenciais foram investigados frente ao fungo Paracoccidioides brasiliensis pela tecnica de macrodiluicao em caldo. O resultado mais significativo foi obtido com o oleo do grupo II, com a forma leveduriforme de P. brasiliensis sendo inibida completamente na concentracao de 62,5 mg mL -1 . The multivariate chemical analysis of essential oils of Eugenia uniflora leaves with different fruit colours indicated the presence of three oil clusters regarding sample biotypes. The first cluster included yellowish, dark red and purple fruits with high percentages of germacrene B (11.1-30.7%), germacrone (9.8-54%) and atractylone (0-19.9%). In cluster II, with bright red fruit samples, the major constituents were curzerene (42.0-43.2%), germacrene D (8.7-9.0%) and germacrene A (5.9-8.9%), whereas cluster III included red-orange fruit samples containing high contents of selina-1,3,7(11)-trien-8-one (40.3-55.4%) and selina-1,3,7(11)-trien-8-one epoxide (12.7-24.4%). The clustered oils were investigated against the systemic fungus Paracoccidioides brasiliensis via the broth macrodilution method. The oil from cluster II revealed the most significant result. The yeast form of P. brasiliensis was completely inhibited at a concentration of 62.5 mg mL -1

Coeficiente de heterogeneidade do solo e tamanho de parcela

The aim of this research was to present ways to estimate the coefficient of soil heterogeneity from the intraclass correlation coefficient for different structure of experimental designs. The coefficient of soil heterogeneity estimates obtained by this method were compared with those obtained by the generalized least square method. Practically, there was no difference between the estimates obtained from both methods, and thus it is recommended to use the estimate obtained from the coefficient of intraclass correlation due to its simplicity and practicability. Several plot sizes were obtained from the coefficient of soil heterogeneity estimates, for different combinations of variation coefficient, replicate number, expected difference between treatments and significance level.

Toxicity of neem oil to Bemisia tabaci biotype B nymphs reared on dry bean.

O objetivo deste trabalho foi determinar o estagio ninfal de Bemisia tabaci biotipo B mais suscetivel ao oleo de nim (Azadirachta indica A. Juss.) aplicado em feijoeiro (Phaseolus vulgaris L.), em casa telada. Foram avaliados o tempo letal (TL) e concentracao letal (CL) do oleo comercial de sementes de nim Dalneem. Para CL, concentracoes de 0, 0,1, 0,25, 0,5, 1 e 2% do produto foram pulverizadas diretamente sobre as ninfas em cada instar. Para TL, o produto foi avaliado a 0, 0,5 e 1% de oleo de nim em cada instar. Ninfas vivas e mortas foram contadas cinco dias apos a pulverizacao para CL e diariamente para TL durante seis dias. Para o quarto instar, a CL50 foi de 0,56% de oleo de nim. Considerando todos os instares, CL50 e CL95 foram estimadas em 0,32 e 2,78% de oleo de nim, respectivamente. Os TL50 para 1% de nim foram estimados em 2,46, 4,45, 3,02 e 6,98 dias para o primeiro, segundo, terceiro e quarto instares, respectivamente. Os TL50 estimados para 0,5 e 1% de oleo de nim foram de cinco e quatro dias, respectivamente, considerando todos os instares. No sexto dia, foi observada mortalidade superior a 80% para o primeiro, segundo e terceiro instares a 1% de oleo de nim. Os tres primeiros instares foram mais suscetiveis ao oleo de nim que o quarto instar.