Chemical and Genotypic Variations in Aniba rosiodora from the Brazilian Amazon Forest.

Aniba rosiodora has been exploited since the end of the nineteenth century for its essential oil, a valuable ingredient in the perfumery industry. This species occurs mainly in Northern South America, and the morphological similarity among different Aniba species often leads to misidentification, which impacts the consistency of products obtained from these plants. Hence, we compared the profiles of volatile organic compounds (essential oils) and non-volatile organic compounds (methanolic extracts) of two populations of A. rosiodora from the RESEX and FLONA conservation units, which are separated by the Tapajós River in Western Pará State. The phytochemical profile indicated a substantial difference between the two populations: samples from RESEX present α-phellandrene (22.8%) and linalool (39.6%) in their essential oil composition, while samples from FLONA contain mainly linalool (83.7%). The comparison between phytochemical profiles and phylogenetic data indicates a clear difference, implying genetic distinction between these populations.

Anesthesia of tambaqui Colossoma macropomum (Characiformes: Serrasalmidae) with the essential oils of Aniba rosaeodora and Aniba parviflora and their major compound, linalool

The aim of this study was to determine the anesthetic efficacy of the essential oils (EOs) of Aniba rosaeodora (EOAR) and Aniba parviflora (EOAP) and one of their main compounds, linalool, in two forms: synthetic and extracted from EOAR (linalool-AR) in tambaqui (Colossoma macropomum). In the first experiment, the anesthetic induction and recovery of juveniles exposed to 25- 200 µL L-1 of EOAR or 50- 300 µL L-1 of EOAP or synthetic linalool or linalool-AR was evaluated. The second experiment observed the behavioral effects of long-term exposure (12h) of these EOs and linalools (5 and 10 µL L-1). Fish exposed to 50-200 µL L-1 of EOAR and 100-300 µL L-1 of EOAP and both linalools reached deep anesthesia between 1-10 min. Induction time for all anesthesia stages decreased with the increasing concentration of the anesthetics. Linalool-AR showed lengthier time for anesthesia induction in some stages and for recovery at 100 and 200 µL L-1 in comparison to synthetic linalool. Normal equilibrium and swimming behavior was observed in fish exposed to the EOs and linalools throughout the 12 h of exposure. In conclusion, both EOs and linalools can be used as anesthetics and sedatives in tambaqui.(AU)

O objetivo deste trabalho foi determinar a eficácia anestésica dos óleos essenciais (OEs) de Aniba rosaeodora (OEAR) Aniba parviflora (OEAP) e um de seus compostos majoritários, linalol, em duas formas: sintética e extraída a partir de OEAR (linalol-AR) em tambaqui (Colossoma macropomum). No primeiro experimento avaliou-se a indução anestésica e a recuperação de juvenis expostos a 25- 200 µL L-1 de EOAR ou 50- 300 µL L-1 de EOAP ou linalol sintético ou linalol-AR. No segundo experimento observaram-se os efeitos comportamentais de uma longa exposição (12h) a estes OEs e linalois (5 e 10 µL L-1). Os peixes expostos a 50-200 µL L-1 de EOAR e 100-300 µL L-1 de OEAP e ambos os linalois alcançaram anestesia profunda entre 1-10 min. Tempo de indução a todos os estágios de anestesia diminuiu com o aumento na concentração dos anestésicos. Linalol-AR levou um maior tempo para induzir anestesia e para recuperação com 100 e 200 µL L-1 em comparação ao composto sintético. Peixes expostos aos OES e linalois por 12 h apresentaram equilíbrio e comportamento natatório normais. Em conclusão, tanto os OEs como o linalol sintético ou natural de AR podem ser usados como anestésicos e sedativos em tambaqui.(AU)

Synthesis, antimalarial activity in vitro, and docking studies of novel neolignan derivatives.

The absence of effective vaccines against malaria and the difficulties associated with controlling mosquito vectors have left chemotherapy as the primary control measure against malaria. However, the emergence and spread of parasite resistance to conventional antimalarial drugs result in a worrisome scenario making the search for new drugs a priority. In the present study, the activities of nine neolignan derivatives were evaluated as follows: (i) against blood forms of chloroquine-resistant Plasmodium falciparum (clone W2), using the tritiated hypoxanthine incorporation and anti-HRPII assays; (ii) for cytotoxic activity against cultured human hepatoma cells (HepG2); and (iii) for intermolecular interaction with the P. falciparum cysteine protease of falcipain-2 (F2) by molecular docking. The neolignan derivatives 9 and 10 showed activity against the blood form of the chloroquine-resistant P. falciparum clone W2 and were not cytotoxic against cultured human hepatoma cells. A molecular docking study of these two neolignans with FP2 revealed several intermolecular interactions that should guide the design of future analogs.

Classification of Amazonian rosewood essential oil by Raman spectroscopy and PLS-DA with reliability estimation.

The Amazon tree Aniba rosaeodora Ducke (rosewood) provides an essential oil valuable for the perfume industry, but after decades of predatory extraction it is at risk of extinction. The extraction of the essential oil from wood implies the cutting of the tree, and then the study of oil extracted from the leaves is important as a sustainable alternative. The goal of this study was to test the applicability of Raman spectroscopy and Partial Least Square Discriminant Analysis (PLS-DA) as means to classify the essential oil extracted from different parties (wood, leaves and branches) of the Brazilian tree A. rosaeodora. For the development of classification models, the Raman spectra were split into two sets: training and test. The value of the limit that separates the classes was calculated based on the distribution of samples of training. This value was calculated in a manner that the classes are divided with a lower probability of incorrect classification for future estimates. The best model presented sensitivity and specificity of 100%, predictive accuracy and efficiency of 100%. These results give an overall vision of the behavior of the model, but do not give information about individual samples; in this case, the confidence interval for each sample of classification was also calculated using the resampling bootstrap technique. The methodology developed have the potential to be an alternative for standard procedures used for oil analysis and it can be employed as screening method, since it is fast, non-destructive and robust.

Antimycobacterial activity of 2-phenoxy-1-phenylethanone, a synthetic analogue of neolignan, entrapped in polymeric microparticles.

Conventional treatment of tuberculosis (TB) demands a long course therapy (6 months), known to originate multiple drug resistant strains (MDR-TB), which emphasizes the urgent need for new antituberculous drugs. The purpose of this study was to investigate a novel treatment for TB meant to improve patient compliance by reducing drug dosage frequency. Polymeric microparticles containing the synthetic analogue of neolignan, 1-phenyl-2-phenoxiethanone (LS-2), were obtained by a method of emulsification and solvent evaporation and chemically characterized. Only representative LS-2-loaded microparticles were considered for further studies involving experimental murine TB induced by Mycobacterium tuberculosis H37Rv ATCC 27294. The LS-2-loaded microparticles were spherical in shape, had a smooth wall and showed an encapsulation efficiency of 93% in addition to displaying sustained release. Chemotherapeutic potential of LS-2 entrapped in microparticles was comparable to control groups. These findings are encouraging and indicate that LS-2-loaded microparticles are a potential alternative to conventional chemotherapy of TB.

Isolation of chavibetol from essential oil of Pimenta pseudocaryophyllus leaf by high-speed counter-current chromatography.

Counter-current chromatography (CCC) was used to isolate chavibetol from the essential oil of leaves of Pimenta pseudocaryophyllus (Gomes) Landrum. Chavibetol was obtained in high purity (98%) and mass recovery (94.4%). Methyleugenol was also isolated. The CCC biphasic solvent system used was composed of hexane:n-butanol:methanol:water (12:4:4:3, v/v/v/v).

Structure-activity relationship of antileishmanials neolignan analogues.

Twenty-two synthetic analogues of neolignans comprising beta-ketoethers and beta-ketosulfides were obtained from condensation reactions among beta-bromoketones and phenols or thiophenols, respectively, in basic solutions, and assayed in vitro for activity against intracellular Leishmania amazonensis and Leishmania donovani amastigotes, the causative agents of cutaneous and visceral leishmaniasis. The highest selective activity was found for compounds with sulfur bridges, whereas beta-ketosulphoxides and beta-ketosulphones had significantly less growth inhibitory activity. Compounds 2-[(4-chlorophenyl)thio]propan-1-one and 1-(3,4-dimethoxy)-2-[(4-methylphenyl)thio]propan-1-one were the most potent, inhibiting the growth parasite species by over 90% at microgram/mL, but only compound 1-(3,4-dimethoxy)-2-[(4-methylphenyl)thio]propan-1-one was selectively toxic to the parasites.

Cytotoxic withanolides from Acnistus arborescens.

Three cytotoxic withanolides, two with new structures, were isolated from the leaves of Acnistus arborescens and their structures determined by a combination of 1D and 2D NMR, mass spectral, and molecular modeling studies. Dereplication analysis of the ethyl ether extract was useful for evaluating the components showing significant cytotoxic activity.