ABSTRACT Linalool is the main compound of many essential oils and occurs in two isomeric forms: S-(+)- and R-(-)-linalool. This study aimed to determine if linalool isomers have different antimicrobial and anesthetic properties in fish. For this purpose, these compounds were previously isolated from Lippia alba (Mill.)N. E. Brown and Ocimum americanum L. essential oils. Antimicrobial effects were evaluated through the microdilution test against Aeromonas hydrophila, an important fish disease etiologic agent. Induction time until sedation, anesthesia and recovery time were determined in silver catfish (Rhamdia quelen) through bath exposure (60, 180, 300 or 500 μL L-1). The results showed different biological properties for the isomers being S-(+)-linalool the only active against A. hydrophila at 3.2 mg mL-1. The sedation was induced without differences between the compounds, however R-(-)-linalool promoted faster anesthesia. There were no differences regarding the recovery time of the animals exposed to the linalool isomers. Although both S-(+)- and R-(-)-linalool can be used for sedative purposes, their use in A. hydrophila infection is inadvisable due to the high effective concentration. Considering anesthesia as the main objective, the R-(-)-linalool demonstrated clear advantages at lower concentration.

Five sesquiterpenoid oxides, named nectandrene A, B, C, D, and E, were isolated from the essential oil of the leaves of Nectandra megapotamica. Their structures were elucidated by spectroscopic analysis, and the relative configurations were proposed by their nuclear Overhauser effect (NOESY) spectrum. Three of these isolated compounds displayed significant antimicrobial activity; the compound most active had minimal inhibitory concentration (MIC) values between 3.12 and 25.0 μg mL-1 against some tested bacteria, and antifungal activity with MIC values between 12.5 and 25.0 μg mL-1.

We herein described the preparation of a novel series of limonin derivatives (modification in A-ring), which was synthesized efficiently using methodology in solution as well as in heterogeneous medium (K-10). In addition, we obtained derivatives by inserting the 1,2,3-triazole nucleus via click reaction and also prepared derivatives from reactions with limonin-7-oxime. All compounds were submitted to investigation of the antimicrobial activity against a collection of microorganisms. The results of the antimicrobial activity, in general, demonstrated that a relevant number of synthetic derivatives presented higher activity than the natural product.

A atividade in vitro de queleritrina e lupeol, dois metabólitos isolados de Zanthoxylumrhoifolium, foram estudados contra o veneno da cobra Bungarus sindanus (Elapidae). O veneno, que é altamente tóxico para os seres humanos, é constituído principalmente pela enzima acetilcolinesterase (AChE). Ambos os compostos apresentaram atividade contra o veneno, e o alcalóide queleritrina apresentou maior atividade do que triterpeno lupeol.

The in vitro activity of chelerythrine and lupeol, two metabolites isolated from Zanthoxylum rhoifolium were studied against the venom of the snake Bungarus sindanus (Elapidae). The venom, which is highly toxic to humans, consists mainly by the enzyme acetylcholinesterase (AChE). Both compounds showed activity against the venom, and the alkaloid chelerythrine presented higher activity than did triterpene lupeol.

Os óleos essenciais de folhas de Poiretia latifolia Vogel nativas e cultivadas (amostras A e B, respectivamente) e de flores nativas (amostra C), foram obtidos por hidrodestilação e analisados por CG, CG/EM, e através de cromatografia gasosa em fase quiral (CGFQ). Vinte e quatro componentes foram identificados, representando 99,25, 99,26 e 99,23% dos óleos, respectivamente. Os maiores constituintes dos óleos foram os monoterpenos (S)-(-)-limoneno (16,05, 27,60, 15,60%, respectivamente), (1R, 4R)-trans-(+)-diidrocarvona (18,05, 0,66, 77,80%, respectivamente) e (R)-(-)-carvona (61,05, 64,20, 4,50%, respectivamente). Os óleos essenciais apresentaram uma atividade antimicrobiana moderada quando avaliados frente a bactérias e Gram-positivas, Gram-negativas e fungos

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.

Neste trabalho uma nova fase estacionária quiral,heptaquis (3-O-pentafluoropropionil-2,6-di-O-pentil)-β-ciclodextrina, foi sintetizada e avaliada frente uma grande variedade de compostos voláteis quirais. O novo derivado de ciclodextrina foi usado para a separação de componentes de óleos essenciais, como hidrocarbonetos, cetonas, aldeídos, álcoois de cadeia longa, compostos halogenados e compostos contendo nitrogênio e enxofre.

In this work, a new chiral stationary phase heptakis (3-O-pentafluoropropionyl-2,6-di-O-pentyl)-β-cyclodextrin was synthesized and evaluated with a wide variety of volatile chiral compounds. As a result, the new cyclodextrin derivative can be applied to the separation of chiral components of essential oils, as hydrocarbons, ketones, aldehydes, alcohols and of various classes of synthetic chiral compounds, as long chain alcohols, halocarbons, nitrogen and sulfur containing compounds.

O óleo essencial obtido a partir das cascas do caule de Croton urucurana Baillon (Euphorbiaceae) foi analisado por CG e CG-EM. 83 compostos foram identificados, sendo borneol (14,7%), acetato de bornila (5,2%), 1-isopropil-7-metil-4-metileno-1,3,4,5,6,8-hexaidro -2H-naftalen-4a-ol (14,7%), sesquicineol (10,5%) e epóxido de gama-gurjuneno (5,4%) os principais componentes. Para o óleo essencial bruto, foi determinada em 3,21 mg mL-1 a EC50 no ensaio de atividade antioxidante frente ao radical livre DPPH. A fração do óleo essencial bruto que apresentou atividade antioxidante foi purificada por CCD sobre sílica gel. Análises de CG e CG-EM revelaram que alfa-bisabolol (38,3%), alfa-eudesmol (9,3%) e guaiol (8,2%) são os principais componentes da fração antioxidante. A EC50 medida no teste frente ao DPPH foi de 1,05 mg mL-1 para a fração bioativa. Foi determinada a atividade antimicrobiana do óleo essencial bruto frente a sete bactérias Gram-positivas e Gram-negativas e três fungos. Os valores de CIM medidos variaram de 1,25 a 10,00 mg mL-1.

The essential oil obtained from the stem bark of Croton urucurana Baillon (Euphorbiaceae) was analysed by GC and GC-MS. 83 compounds were identified and borneol (14.7%), bornyl acetate (5.2%), 1-isopropyl-7-methyl-4-methylene-1,3,4,5,6,8-hexahydro-2H-naphthalen-4a-ol (14.7%), sesquicineole (10.5%) and gamma-gurjunene epoxide (5.4%) were the main components. The EC50 value of the crude essential oil in the DPPH free radical scavenging assay was 3.21 mg mL-1. The fraction of the crude essential oil that presented antioxidant activity was purified by prep-TLC on silica gel. GC and GC-MS analysis revealed that alpha-bisabolol (38.3%), alpha-eudesmol (9.3%) and guaiol (8.2%) were the main components of the antioxidant fraction. The EC50 value measured for the bioactive oil fraction in the DPPH assay was 1.05 mg mL-1. The antimicrobial activity of the crude essential oil was assayed against seven Gram-positive and Gram-negative bacteria and three yeasts. Measured MIC values ranged from 1.25 to 10.00 mg mL-1.

Uma série de cetonas e ésteres alfa,beta-insaturados b-amino ésteres, 4a-h e 6a-d, derivados de alfa-amino ácidos foi obtida a partir dos cloridratos dos alfa-amino ésteres 2a-d e dos compostos 1,3-dicarbonílicos 3a,b e 5 em presença de trietilamina. Estes compostos foram preparados empregando energia de microondas, sem uso de solvente, utilizando como suporte sólido K-10 ou KSF e também foram efetuadas reações na ausência de suporte sólido.

A series of beta-amino esters alpha,beta-unsaturated ketones and esters 4a-h and 6a-d derived from alpha-amino acids have been prepared starting from alpha-amino esters hydrochorides 2a-d with 1,3- dicarbonyl compounds 3a,b and 5 in presence of triethylamine. These compounds have been prepared under domestic microwave oven, under solvent free condition with and without solid support (K-10 or KSF).

Os óleos essenciais obtidos das partes aéreas de Aloysia sellowii, coletadas em duas diferentes localidades (A e B) do sul do Brasil, foram analisadas por CG, CG-EM, e através de cromatografia gasosa com fases quirais (CGC). Dos quarenta e oito componentes identificados, representando cerca de 93 e 91% dos óleos das regiões A e B, respectivamente, 1,8-cineol, beta-pineno, sabineno e beta-(Z)-santalol foram os principais componentes. Um "screening" preliminar das duas amostras de óleos de A. sellowii mostrou atividade frente a Artemia salina (LC50 = 2,85 µg mL-1), além de exibirem atividade antimicrobiana frente a bactérias Gram-positivas e Gram-negativas e frente a leveduras (MIC 1,7-16 mg mL-1).

The essential oils obtained from aerial parts of Aloysia sellowii from two different collection locations Southern Brazil (A and B), were analyzed by GC, GC/MS, and chiral phase gas chromatography (CPGC). It was identified 48 compounds representing ca 93% and 91% of the oils of samples A and B, respectively. Besides them 1,8-Cineole, beta-pinene, sabinene, and beta-(Z)-santalol were the major components. In a preliminary biological screening the samples of essential oils of A. sellowii displayed strong activity in the brine shrimp lethality assay (LC50 = 2.85 µg mL-1) as well as antimicrobial activity against Gram-positive and Gram-negative microorganisms and two yeasts (MIC 1.7-16 mg mL-1).