Francisco José Tôrres de Aquino

Seasonal Variation of the Chemical Composition and Antimicrobial and Cytotoxic Activities of the Essential Oils from Inga laurina (Sw.) Willd.

The seasonal chemical composition of essential oils from Inga laurina was determined by GC/MS. In the stem bark’s essential oil extracted during the dry season, the presence of terpenoids (30.05%) stood out, and phytol (9.76%) was the major compound identified. For the stem bark oil obtained during the rainy season, in addition to terpenoids (26.63%), a large amount of fatty acids (46.84%) were identified, in particular palmitic acid (25.40%). Regarding the leaves’ essential oil obtained in the dry season, esters (42.35%) were the main components. The main ester present was (Z)-hex-3-enyl benzoate (10.15%) and the major compound of this oil was (Z)-hex-3-en-1-ol (14.23%). Terpenoids (33.84%), long-chain alkanes (27.04%) and fatty acids (21.72%) were the main components of the essential oil from leaves in the rainy season. Phytol (33.21%), nonacosane (21.95%) and palmitic acid (15.20%) were the major compounds identified. The antimicrobial activity against aerobic and anaerobic oral bacteria was evaluated by the microdilution broth method and cytotoxic activity was carried out with Vero cells. The essential oils from the rainy season showed a better inhibition of the bacterial growth with Minimal Inhibitory Concentrations (MIC) values of 25 or 50 µg·mL−1 for aerobic bacteria, and high selectivity against bacteria was observed. The large amount of fatty acids in rainy season oils may be related to the better inhibitory effects observed.

Chemical Composition, Cytotoxic and Antimicrobial Activity of Essential Oils from Cassia bakeriana Craib. against Aerobic and Anaerobic Oral Pathogens

The chemical composition of the essential oils from leaves, bark and wood of Cassia bakeriana Craib. was determined by gas chromatography (GC) and gas chromatography–mass spectrometry (GC-MS). Alcohols, aldehydes and fatty acids were the major components in leaf and bark oil, while wood essential oil was rich in fatty acids. Terpenes such as linalool, (E)-nerolidol and phytol were present in low concentrations. The antimicrobial activity against aerobic and anaerobic oral bacteria was evaluated using the microdilution method, as was the cell viability test carried out with Vero cells. The oils from leaves and bark showed high antimicrobial activity, with minimum inhibitory concentrations between 62.5 and 125 µg·mL−1 for most of the tested bacteria, including Streptococcusmutans, the main etiological agent of dental caries. Leaves oil displayed the lowest cytotoxic effect (EC50 of 153 µg·mL−1), while wood oil exhibited the highest toxicity to Vero cells. C. bakeriana oils are thus a source of biologically active compounds against aerobic and anaerobic oral microorganisms. This study is the first report on the chemical composition, antimicrobial activity and cytotoxicity of C.bakeriana.

Chemical Constituents and Evaluation of Antimicrobial and Cytotoxic Activities of Kielmeyera coriacea Mart. & Zucc. Essential Oils

Many essential oils (EOs) of different plant species possess interesting antimicrobial effects on buccal microorganisms and cytotoxic properties. EOs of Kielmeyera coriacea Mart. & Zucc. were analyzed by gas chromatography coupled to mass spectrometry (GC-MS). The EO from leaves is rich in sesquiterpenes hydrocarbons and oxygenated sesquiterpenes. The three major compounds identified were germacrene-D (24.2%), (E)-caryophyllene (15.5%), and bicyclogermacrene (11.6%). The inner bark EO is composed mainly of sesquiterpenes hydrocarbons and the major components are alpha-copaene (14.9%) and alpha-(E)-bergamotene (13.0%). The outer bark EO is composed mainly of oxygenated sesquiterpenes and long-chain alkanes, and the major components are alpha-eudesmol (4.2%) and nonacosane (5.8%). The wood EO is mainly composed of long-chain alkanes and fatty acids, and the major components are nonacosane (9.7%) and palmitic acid (16.2%). The inner bark EO showed the strongest antimicrobial activity against the anaerobic bacteria Prevotella nigrescens (minimum inhibitory concentration-MIC of 50 µg mL−1). The outer bark and wood EOs showed MICs of 100 µg mL−1 for all aerobic microorganisms tested. The EOs presented low toxicity to Vero cells. These results suggest that K. coriacea, a Brazilian plant, provide initial evidence of a new and alternative source of substances with medicinal interest.

Volatile Compounds Obtained by the Hydrodistillation of Sugarcane Vinasse, a Residue from Ethanol Production

Sugarcane vinasse is the main by-product from ethanol production industries. Generated in large quantities, it is composed by water, inorganic and organic compounds and is extensively used as fertiliser in agriculture, promoting improvements in soil quality and crop yield. However, it has high pollution potential, as the high concentration of organic matter can lead to contamination of the soil and water, in addition to the risk of leaching of the mineral components. In the current study, the volatile components of vinasse were obtained by hydrodistillation using a Clevenger apparatus, then analysed by gas chromatography-mass spectrometry (GC-MS). A waxy material was obtained, and the GC-MS analysis indicated that vinasse is rich in fatty acids, alcohols and esters. The major components were phenylethyl alcohol (22.28%), myristic acid (17.45%), palmitic acid (15.81%), ethyl palmitate (8.99%) and hexadecanol (6.06%).

Chemical Composition, Antimicrobial and Antiprotozoal Activity of Essential Oils From Vernonia brasiliana (Less) Druce (Asteraceae)

Abstract Vernonia brasiliana (L) Druce is a plant from the Asteraceae family. The essential oils obtained by hydro distillation from flowers and roots of V. brasiliana were analyzed by GC and GC-MS for the first time. The major components found in the flowers were (E)-hex-2-enal (4.04 %), hexan-1-ol (4.23 %), (Z)-hex-2-en-1-ol (6.32 %), palmitic acid (8.30 %), and hexacosane (4.91 %). The roots presented as major components modheph-2-ene (8.69% ), α-isocomene (15.41 %), α-gurjunene (9.61 %), β-isocomene (10.26 %) and trans-caryophyllene (10.42 %), α-humulene (5.36 %), and palmitic acid (5.25 %). Leaves essential oil presented as major components trans-caryophyllene (8.73 %), bicyclogermacrene (5.78 %), germacrene-D (10.19 %), and caryophyllene oxide (4.51 %). The antimicrobial activity of the essential oil from leaves, flower and roots of V. brasiliana was evaluated against the microorganisms Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922), using the broth micro dilution method, and the assays have showed no positive results. However, the three essential oils showed antiprotozoal activity against Trypanosoma cruzi and Leishmania amazonensis, and did not display cytotoxicity against Vero (ATCC CCL 81) and RAW 264.7 (ATCC TIB 71) cell lines. Up to date, no studies have been carried out on the antitrypanosomal, antileishmanial and cytotoxic activities of the essential oils from leaves, flowers and roots of this plant.

Antifungal and cytotoxicity activities of Banisteriopsis argyrophylla leaves

This work aimed to evaluate the antifungal and cytotoxic activity of the EtOH extract and fractions of Banisteriopsis argyrophylla leaves, and to perform the identification of these bioactive metabolites.