Maria Claudia M. Young

Chemical Composition and Antimicrobial Properties of Piper ovatum Vahl

The chemical composition of the essential oil obtained from the leaves of Piper ovatum Vahl by hydrodistillation was analyzed by GC–MS. The main constituents found were δ-amorphene (16.5 %), cis-muurola-4(14),5-diene (14.29 %) and γ-muurolene (13.26%). The crude extracts and isolated compounds were screened for their antimicrobial activity. Hydroalcoholic extracts of different parts of Piper ovatum Vahl, essential oil and amides isolated from leaves were tested against Gram-positive and Gram-negative bacteria and Candida species. All extracts and amides were active against Bacillus subtilis and Candida tropicalis, including clinical strains. Essential oil was active against C. tropicalis. These amides showed an inhibitory effect on the adherence of C. tropicalis ATCC 28707 on cover glasses at 10 µg/mL, but did not show morphological alterations at the tested concentrations. Amides were identified as piperovatine and piperlonguminine, and showed MIC values of 15.6 and 31.2 µg/mL to B. subtilis and 3.9 µg/mL to C. tropicalis, and low toxic effects to Vero cells and macrophages.

Biciclogermacreno, resveratrol e atividade antifúngica em extratos de folhas de Cissus verticillata (L.) Nicolson & Jarvis (Vitaceae)

Cissus verticillata L. (Vitaceae) is popularly employed as hypoglicemic and it shows fungitoxic activity. This work aims at identification of fungitoxic compounds on extracts of leaves. The ethanol extract was partitioned using solvents of different polarities (hexane, chloroform, ethyl acetate and butanol) and its fungitoxic activity was analysed upon Cladosporium sphaerospermum. The chloroform and ethyl acetate extracts showed activity and they were fractionated by column chromatography and preparative TLC, respectively. Three terpenoids were isolated from the chloroform extract, one of them identified by GLC-MS analysis as sesquiterpene bicyclogermacrene. The active compound of the ethyl acetate extract was identified by HPLC analyses as stilbene resveratrol.

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.

Anti-inflammatory activity of essential oil from leaves of Myrciaria tenella and Calycorectes sellowianus.

The GC-MS analysis revealed that the leaf essential oils of Myrciaria tenella (DC.) Berg and Calycorectes sellowianus O. Berg (Myrtaceae) were composed of 34 and 37 compounds, respectively. The main constituents of M. tenella oil were β-caryophyllene (25.1%), and spathulenol (9.7%), while for C. sellowianus were guaiol (13.1%) and β-caryophyllene (8.6%). The anti-inflammatory effect of both essential oils was investigated in vitro and in vivo. Both oils reduced significantly (p < 0.005) the treated neutrophils chemotaxis with 93% and 91% inhibition for M. tenella and C. sellowianus, respectively. However, in the systemic treatment with the essential oils (50u2009mg/kg p.o.) only the M. tenella oil was able to significantly reduce the carrageenan-induced paw edema with a similar effect to that observed for indomethacin (10u2009mg/kg), the positive control.

Chemical Composition and Antifungal Activity of Essential Oil from Brazilian Propolis

Abstract The essential oil from Brazilian propolis was isolated by hydrodistillation in a yield of 0.04 %. Twenty-five compounds were identified by GC-MS and calculation of their Kovats indexes. The most abundant essential oil components were α-pinene (18.3 %), β-pinene (6.5 %), germacrene D (6.4 %) and δ-cadinene (7.0 %).Additionally, the antifungal potential of crude oil was evaluated using a bioautographic assay. The minimal amount required to inhibit the growth of fungi Cladosporium cladosporioides and C. sphaerospermum assay was determined as 5.0 μg, in comparison to positive control nystatin (1.0μg) and miconazole (1.0 μg).

Chemical composition and acetylcholinesterase inhibitory activity of essential oils of Myrceugenia myrcioides(Cambess.) O. Berg and Eugenia riedelianaO. Berg, Myrtaceae

The chemical composition of volatile oils from two Myrtaceae species, Myrceugenia myrcioidesand Eugenia riedeliana, both native from the Brazilian Atlantic Rain Forest, was analyzed by GC-MS. Acetylcholinesterase inhibitory activity was colorimetrically evaluated for these oils. For M. myrcioides, monoterpene hydrocarbons represented the major class in the volatile oil, with α-pinene as the most abundant component and a weak inhibitory activity was observed, whilst for E. riedeliana sesquiterpenes were found in higher amounts, being valerianol the major compound, and this oil presented a strong acetylcholinesterase inhibition.

Secondary metabolites isolated from Piper chimonantifolium and their antifungal activity

In this study, the CH2Cl2 extract from leaves of Piper chimonantifolium was subjected to several chromatographic separation procedures to afford one chromene (gaudichaudianic acid) as a major compound as well as two flavonoids (dihydrooroxylin and pinocembrin) and three steroids (sitosterol, sitosteryl palmitate and stigmasterol). The structures of all determined compounds were characterised by spectrometric analysis, mainly mass spectrometry and NMR, as well as their optical properties. This article describes the first phytochemical study of the leaves of P. chimonantifolium and an evaluation of the antifungal activity of its major compounds.

Chemical composition and antimicrobial activities of the essential oil of Hypericum cordatum (Vell. Conc.) N. Robson (Hypericaceae).

Abstract The volatile constituents of the fresh materials of Hypericum cordatum were isolated by hydrodistillation and analyzed by GC and GC/MS. The leaves produced 0.04% of a yellowish essential oil and the flowers did not. The main components of the oil were myrcene (40.18%), α-pinene (16.40%), and limonene (12%). The antibacterial activities of the oil against Saccharomyces aureus and Escherichia coli and the anti-fungal activities of the oil against the fungi Cladosporium cladosporioides and C. sphaerospermum were evaluated. The oil showed an antibacterial activity against the bacteria S. aureus and anti-fungal activity against the two fungi.

Chemical Composition, Antimicrobial and Antioxidant Activities of Essential Oils from Two Avicennia schaueriana Stapf & Leechm. Ex Moldenke (Acanthaceae) Populations

Background: Avicennia schaueriana Stapf & Leechm. ex Moldenke (Acanthaceae) is a native species from the Brazilian mangroves presenting ecological and economic significance. This study compared the composition and the biological activities from the essential oils obtained from two A. schaueriana populations collected at Jureia-Itatins and Ilha do Cardoso. Methods: Essential oils were obtained by conventional means, and their compositions were analyzed by GC-MS. Screening assays for antimicrobial activity were carried out by the microdilution method and the antioxidant potential was assessed by the DPPH scavenging method. Results: The GC-MS analysis indicated that the Jureia oil (1) was composed mostly of the fatty acids palmitic (46.5%) and myristic (11.6%) acids, while the main components for the Ilha do Cardoso oil (2) were eugenol (19.7%), eugenol acetate (12.9%) and palmitic acid (15.1%). The oils showed an IC50 of 0.9 ± 0.011 mg/mL for 1 and 1.13 ± 0.028 mg/mL for 2 in the DPPH assay. The antimicrobial assay indicated MIC > 217 µg/mL for all tested microorganisms. Conclusions: The different essential oil composition may indicate the presence of chemotypes for A. schaueriana. The antioxidant activity of the oils was weak if compared with flavonoids. Despite the high MIC values, these oils presented some antibacterial potential against Pseudomonas aeruginosa.

Chemical characterization of the volatile compounds of the flowers of Bidens segetum Martius ex Colla (Asteraceae)

The volatile compounds present in the volatile oils and aroma from fresh flowers of Bidens segetum Martius ex Colla were characterized. The samples were collected from naturally occurring populations of the Brazilian Cerrado and from plants cultivated at the Instituto de Botânica de São Paulo (Atlantic rainforest) from its seeds. The essential oils were obtained by hydrodistillation in a Clevenger apparatus, while the aroma was extracted by headspace solid-phase microextraction (HS-SPME) and both were analyzed by gas chromatography (GC) and GC–mass spectrometry (GC–MS). β-Phellandrene (18–45%) and germacrene D (6–32%) were always present in the oils and aroma; however, their percentages varied. Besides these, E-β-ocimene (11.6%), myrcene (11.2%), α-pinene (7.3%), sabinene (6.7%), bicyclogermacrene (5.7%) and δ-cadinene (3.2%) appeared as major constituents of the volatile components from B. segetum flowers.