João Henrique G. Lago

Constituíntes fenólicos polares de Schinus terebinthifolius Raddi (Anacardiaceae)

The EtOH extract from the leaves of Schinus terebinthifolius showed anti-radicalar potential in the DPPH test. It was partitioned between n-BuOH:H2O (1:1) and these two phases were also evaluated for anti-radicalar activity. The active n-BuOH phase was partitioned between EtOAc:H2O (1:1) and the active EtOAc phase was submitted to chromatographic procedures to afford five active phenolic compounds: ethyl gallate, methyl gallate, quercitrin, myricetrin and myricetin. The structures of these compounds were established by NMR spectral data analysis.

Antimicrobial Activity of Oleanolic and Ursolic Acids: An Update

Triterpenoids are the most representative group of phytochemicals, as they comprise more than 20,000 recognized molecules. These compounds are biosynthesized in plants via squalene cyclization, a C30 hydrocarbon that is considered to be the precursor of all steroids. Due to their low hydrophilicity, triterpenes were considered to be inactive for a long period of time; however, evidence regarding their wide range of pharmacological activities is emerging, and elegant studies have highlighted these activities. Several triterpenic skeletons have been described, including some that have presented with pentacyclic features, such as oleanolic and ursolic acids. These compounds have displayed incontestable biological activity, such as antibacterial, antiviral, and antiprotozoal effects, which were not included in a single review until now. Thus, the present review investigates the potential use of these triterpenes against human pathogens, including their mechanisms of action, via in vivo studies, and the future perspectives about the use of compounds for human or even animal health are also discussed.

Composição química dos óleos essenciais das folhas de seis espécies do gênero Baccharis de "Campos de Altitude" da mata atlântica paulista

The essential oils from the leaves of six species of the Baccharis genus (B. dracunculifolia, B. microdonta, B. regnelli, B. schultzii, B. trimera, and B. uncinella), collected in the Campos de Altitude of the Atlantic Forest (SP), were extracted using hydrodistillation procedures and analyzed by GC and GC/MS. There was a predominance of sesquiterpenes in all studied oils as b-elemene in B. dracunculifolia and B. regnelli, a-humulene in B. trimera, g-gurjunene in B. schultzii, bicyclogermacrene in B. regnelli, d-cadinene in B. regnelli and B. uncinella, spathulenol in B. schultzii, caryophyllene oxide in B. microdonta and guaiol in B. uncinella. However, a high amount of monoterpenes was also observed in B. uncinella (a-pinene), B. regnelli (d-car-3-ene) and B. schultzii (limonene). The chemical compounds of the essential oils of B. schultzii, B. regnelli and B. microdonta are described for the first time in this work.

Microclimatic factors and phenology influences in the chemical composition of the essential oils from Pittosporum undulatum Vent. leaves

The essential oil from leaves of a Brazilian specimen of Pittosporum undulatum Vent. was analyzed by means of gas chromatography-mass spectrometry (GC-MS) and NMR analysis after chromatographic separation. The leaves of P. undulatum were collected during one year (January, March, May, July, September and November, 2004) and the obtained essential oils were analyzed. The oil is rich in hydrocarbon monoterpenes and sesquiterpenes, being (+)-limonene the main constituent. It was observed a significant variation on the relative amount of (+)-limonene in these collections, which could be associated to microclimatic parameters (temperature and pluviometric index) despite of phenology of the studied species.

Sesquiterpenos e hidrocarbonetos dos frutos de Xylopia emarginata (Annonaceae)

The hexane extract from Xylopia emarginata fruits was partitioned between hexane and MeOH/H2O. The hydro-alcoholic phase was submitted to chromatographic separation to afford four sesquiterpenes: caryophyllene oxide, spathulenol, 1b,6a-dihydroxy-4(15)-eudesmene and 4-hydroxy-1,15-peroxy-eudesmane. The hexane phase was fractioned in column chromatography to afford two hydrocarbons (nonadecane and 1-nonadecene) and one aliphatic ketone (hentriacontan-16-one). The structures of the isolated compounds were established by spectral data analysis, mainly NMR and MS.

Plants Used in Traditional Medicine: Extracts and Secondary Metabolites Exhibiting Antileishmanial Activity

Plants and their extracts have been used traditionally against different pathologies, and in some poor regions they are the only therapeutic source for treatments. Moreover, the identification of specific active secondary metabolites can be account for amelioration of clinical status of suffering individual. A series of ethnopharmacological surveys conducted in Brazil recorded the traditional use of plants against different pathologies and interestingly, some of them presented antileishmanial activity in vitro and in vivo, possibly due to their immunostimulatory, healing and microbicidal properties. Of note, Leishmania parasites can alter patients immunological status, leading to the development of extensive skin and/or visceral alterations. Therefore, the extracts or secondary metabolites presented in plants that might be capable of improving the pathological conditions can be attractive candidates in the development of new chemotherapeuticals against leishmaniosis.

3α,4α-Epoxy-2-piperidone, a new minor derivative from leaves of Piper crassinervium Kunth (Piperaceae)

A new antifungal piperidone derivative 3α,4α-epoxy-2-piperidone, whose structure was determined by spectroscopic methods, was isolated from the MeOH extract from leaves of Piper crassinervium. This is the first occurrence of one amide in P. crassinervium.

3-Ishwarone and 3-Ishwarol, rare sesquiterpenes in essential oil from leaves of Peperomia oreophila Hensch.

The essential oil from Peperomia oreophila leaves (Piperaceae) was submitted to fractionation in silica gel column. This separation procedure yielded a fraction composed of a hydrocarbon sesquiterpene mixture which was identified as b-elemene, a-ylangene, a-guaiene and b-selinene. Besides, spathulenol and two sesquiterpenes with the rare ishwarane skeleton: 3-ishwarol and 3-ishwarone were also identified. 3-ishwarone was the major component of the crude oil (78% weight). Since the alcohol obtained was not sufficient to allow a complete structural determination, the original ketone was reduced to 3-ishwarol in order to give additional quantities. After the two sesquiterpenes purification, they were characterized by spectrometric techniques (1H-1H COSY, HMQC, HMBC and NOESY).

Antifungal derivatives from Piper mollicomum and P. lhotzkyanum (Piperaceae)

Bioguided fractionation of the extracts from leaves of Piper mollicomum and Piper lhotzkyanum against the fungi Cladosporium cladosporioides and C. sphaerospermum afforded seven bioactive compounds, four being chromenes: methyl 2,2-dimethyl-2H-chromene-6-carboxylate, methyl 8-hydroxy-2,2-dimethyl-2H-chromene-6-carboxylate, 2-methyl-2-[4-methyl-3-pentenyl]-2H-1-benzopyran-6-carboxylic acid, 2,2-dimethyl-2H-chromene-6-carboxylic acid, one a dihydrochalcone: 2,6-dihydroxy-4-methoxydihydrochalcone, and two flavanones: 7-methoxy-5,4-dihydroxy-flavanone and 7,4-dimethoxy-5-hydroxy-flavanone. The structures of the bioactive isolated derivatives were elucidated by interpretation of their NMR data [1H and 13C (BBD, DEPT 135o)], and mass spectral data as well as by comparison with data described in the literature.

Composition and Chemical Variation of the Essential Oil from Leaves Of Eugenia brasiliensis Lam. And Eugenia sp. (Myrtaceae)

Abstract The essential oils from leaves of Eugenia brasiliensis and Eugenia sp. collected bimonthly during one year (four times in the 15th day of January, March, May, July, September, and November 2004) were subjected to GC-FID and GC/MS analysis. The obtained data showed a significant variation in the proportions of the components, which could be associated to climatic parameters in each collection periods