(R)-(-)-carvone and (1R, 4R)-trans-(+)-dihydrocarvone from poiretia latifolia vogel

The essential oils of Poiretia latifolia Vogel, native and cultivated leaves (Samples A and B, respectively) and native flowers (sample C), were obtained by hydrodistillation and analyzed by GC, GC/MS and chiral phase gas chromatography (CPGC). Twenty-four compounds were identified, representing 99.25, 99.26 and 99.23% of the oils, respectively. The major constituents of the oils were the monoterpenes (S)-(-)-limonene (16.05, 27.60, 15.60%, respectively), (1R, 4R)-trans-(+)-dihydrocarvone (18.05, 0.66 and 77.80%, respectively) and (R)-(-)-carvone (61.05, 64.20 and 4.50%, respectively). The essential oils were evaluated against some strains of Gram (+) and Gram (-) bacteria, and yeast, but displayed only modest antimicrobial activity

Absolute configuration of clemateol

The present study reports the determination of absolute stereochemistry of clemateol, an irregular monoterpene containing an epoxy group, which was isolated as the main component from the essential oil of Calea clematidea (Asteraceae). Its absolute stereochemistry was unambiguously established on the basis of detailed nuclear magnetic resonance (NMR) spectroscopic evidence (3JH-H analysis, derivatization as Mosher's esters and nuclear Overhauser effect (NOESY) spectrum) and also by resonance scattering effects in the single crystal X-ray diffraction (XRD) resolution of its (R)-mandelic acid ester derivative.Fil: Pedroso, Marcelo. Universidade Federal de Santa Maria; BrasilFil: Gehn, Adriana Z.. Universidade Federal de Santa Maria; BrasilFil: Stivanin, Mateus L.. Universidade Federal de Santa Maria; BrasilFil: Larghi, Enrique Leandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Burrow, Robert A.. Universidade Federal de Santa Maria; BrasilFil: Resende, Jackson A. L. C.. Universidade Federal Fluminense; BrasilFil: Da Silva, Ubiratan F.. Universidade Federal de Santa Maria; BrasilFil: Mostardeiro, Marco A.. Universidade Federal de Santa Maria; BrasilFil: Dalcol, Ionara I.. Universidade Federal de Santa Maria; BrasilFil: Morel, Ademir F.. Universidade Federal de Santa Maria; Brasi

Seasonal variation, chemical composition and antimicrobial activity of essential oil of achyrocline satureoides (Lam.) D.C.

Seasonal variation of the oil composition and biological activities from aerial parts of Achyrocline satureoides were investigated. Essential oils were analysed by gas crhromatography-mass spectrometry (GC-MS) after hydrodestillation. Results exhibited maximum amounts of hydrodistilled essential oils in spring (0.10 %; m/m). The compounds α-pinene (28.5-41.7 %) and (E)-caryophyllene (29.8-38.5 %) were the most abundant component in all seasons. Antimicrobial activity measurement of minimum inhibitory concentration (MIC) varied significantly (p < 0.05). It was more significant in autumn (37.9 μg/mL) and winter (38.4 μg/mL) than other seasons against bacterial strains Staphylococcus epidermidis ATCC11228. MIC against bacterial strains Bacillus cereus ATCC11778 was 37.9 μg/mL (autumn) and 76.8 μg/mL (winter) and 37.9 μg/mL (autumn) and 76.8 μg/mL (winter) against bacterial strains Klebsiella pneumoniae ATCC13883. The results showed that yield, chemical composition and antimicrobial activity of essential oil of Achyrocline satureoides (Lam) D.C changed according to the plant collection period.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Plant litter dynamics in the forest-stream interface: Precipitation is a major control across tropical biomes

Riparian plant litter is a major energy source for forested streams across the world and its decomposition has repercussions on nutrient cycling, food webs and ecosystem functioning. However, we know little about plant litter dynamics in tropical streams, even though the tropics occupy 40% of the Earth's land surface. Here we investigated spatial and temporal (along a year cycle) patterns of litter inputs and storage in multiple streams of three tropical biomes in Brazil (Atlantic forest, Amazon forest and Cerrado savanna), predicting major differences among biomes in relation to temperature and precipitation regimes. Precipitation explained most of litter inputs and storage, which were generally higher in more humid biomes (litterfall: 384, 422 and 308 g m-2 y-1, storage: 55, 113 and 38 g m-2, on average in Atlantic forest, Amazon and Cerrado, respectively). Temporal dynamics varied across biomes in relation to precipitation and temperature, with uniform litter inputs but seasonal storage in Atlantic forest streams, seasonal inputs in Amazon and Cerrado streams, and aseasonal storage in Amazon streams. Our findings suggest that litter dynamics vary greatly within the tropics, but point to the major role of precipitation, which contrasts with the main influence of temperature in temperate areas. © 2017 The Author(s)

Chemical composition and antimicrobial activity of the essential oil from Aeolanthus suaveolens Mart. ex Spreng

The essential oils from leaves (sample A) and flowers (sample B) of Aeolanthus suaveolens Mart. ex Spreng were obtained by hydrodistillation and analyzed by GC, GC-MS, and chiral phase gas chromatography (CPGC). Six compounds have been identified from the essential oils, representing ca 94.3 and 93% of the oils corresponding to samples A and B, respectively. The major constituents of samples A and B essential oils were respectively, linalool (34.2%/34.9%), (-)-massoialactone (25.9%/17.0%) and (E)-beta-farnesene (25.4%/29.1%). The enantiomeric distribution of the monoterpene linalool was established by analysis on heptakis- (6-O-methyl-2,3-di-O-pentyl)-beta-cyclodextrin capillary column. The antimicrobial activity of the essential oil from leaves and isolated compounds was also evaluated