Márcia Ortiz Mayo Marques

Determination of the solubility of extracts from vegetable raw material in pressurized CO2: a pseudo-ternary mixture formed by cellulosic structure+solute+solvent

This paper discusses the application of the dynamic method to measure the solubility in pseudo-ternary systems formed by vegetable raw materials (cellulosic structure+solute) and CO2. For aromatic, medicinal, and spice plants, the soluble portion of the solid is formed of essential oils, oleoresins, pigments, and various substances from several other classes of organic compounds. The experimental data were measured in two independent laboratories, using three experimental set-ups, and three vegetable species: clove buds, eucalyptus, and ginger. The solubility for the system clove buds/CO2 varied from 0.220 to 0.277 kg-extract/kg-CO2 for the isotherm of 288.15 K. The ginger extract solubility varied from 2.01×10−3 to 7.20×10−3 kg-extract/kg-CO2 for pressures of 100–300 bar, and temperatures of 298.15–313.15 K. The eucalyptus solubility for the isobar of 66.7 bar varied from 3.95×10−3 to 4.07×10−3 kg-extract/kg-CO2.

Supercritical Fluid Extraction From Stevia Rebaudiana Bertoni Using Co2 And Co2 + Water: Extraction Kinetics And Identification Of Extracted Components

Stevia rebaudiana Bertoni contains glycosides, which are insoluble in carbon dioxide and soluble in mixtures of carbon dioxide and a polar solvent. The purpose of this work was to study the supercritical fluid extraction of these glycosides from stevia leaves using a two-step process: (i) CO2 extraction at 200 bar and 30 °C, and (ii) CO2+water extraction. The chemical compositions of the extracts were analyzed by GC-FID, GC-MS, TLC and HPLC. The overall extraction curves for the system stevia+CO2 had the typical shape and were successfully described by the Sovova’s model. Approximately 72% of the CO2-soluble compounds were recovered and the major compound was austroinulin. The system stevia+CO2+water behaved as expected at 10 and 16 °C and 120 and 250 bar but its behavior was unusual at 30 °C and 250 bar. The process removed approximately 50% of the original stevioside and about 72% of the rebaudioside A.

Effects of limonene and essential oil from Citrus aurantium on gastric mucosa: Role of prostaglandins and gastric mucus secretion

Essential oil from Citrus aurantium and the monoterpene limonene are widely used flavoring agents that are found in some common food items. This specie is also used medicinally throughout the world to treat gastritis and gastric disorders. Therefore, biological assays were performed in vivo on essential oil of C. aurantium (OEC) and its majority compound limonene (LIM) to evaluate their effect on gastric mucosa. The OEC (250 mg/kg, p.o.) and LIM (245 mg/kg, p.o.) provided effective (99%) gastroprotection against lesions induced by absolute ethanol and NSAID (non-steroidal anti-inflammatory drug) in rats. OEC and LIM do not interfere with gastric H(+) secretion, serum gastrin or glutathione (GSH) level in gastric mucosa. But the gastroprotective action of OEC and LIM occurs due to an increase in the gastric mucus production induced by conserving the basal PGE(2) levels after challenge by agents harmful to the gastric mucosa. Given that LIM and OEC are excellent flavoring agents and also present gastroprotective actions, they can be regarded as a promising target for the development of a new drug for the prevention of gastric damage.

Gastroprotective mechanisms of Citrus lemon (Rutaceae) essential oil and its majority compounds limonene and beta-pinene: Involvement of heat-shock protein-70, vasoactive intestinal peptide, glutathione, sulfhydryl compounds, nitric oxide and prostaglandin E-2

Citrus lemon (CL) belongs to Rutaceae family and is popularly known in Brazil as limão siciliano. The phytochemical analysis of CL fruit bark essential oil showed two majority components, limonene (LIM) and β-pinene (PIN). This study aimed to evaluate the gastroprotective mechanism of action from CL, LIM and PIN in ethanol- and indomethacin-induced gastric ulcers and its in vitro anti-Helicobacter pylori activity. After ethanol-induced gastric ulcer, the ulcer area was measured and the stomachs were destined to histology (HE and PAS), immunohistochemistry for HSP-70 and VIP and glutathione (GSH) measurement. The involvement of nitric oxide (NO) and sulfhydryl (SH) compounds was determined. The ulcer area for indomethacin-induced gastric ulcers was measured. PGE₂ concentration was biochemically measured. The minimum inhibitory concentration (MIC) against H. pylori was determined in vitro. In ethanol model, CL and LIM demonstrated 100% of gastroprotection, while PIN did not exert effective gastroprotection (53.26%). In the indomethacin model, CL and LIM offered effective gastroprotection but PIN did not show gastroprotective effect. The gastric ulcer area of rats pretreated with NO-synthase inhibitor or SH-blocker was decreased in comparison to the control group. The MIC obtained for CL was 125 μg/mL, for LIM was 75 μg/mL and for PIN was 500 μg/mL. The gastroprotective effect of CL and LIM was involved with increasing in mucus secretion, HSP-70 and VIP, but not with GSH, NO or SH compounds. CL gastroprotective mechanism is involved with PGE₂. PIN did not present gastroprotective activity.

Phytochemical characterization of essential oil from Ocimum selloi

Ocimum selloi Benth, a native plant of Brazil, has medicinal uses as anti-diarrheic, antispasmodic and anti-inflammatory product. The yield of essential oils of the inflorescences, containing flowers and seeds, was 0.6%, and the yield of leaves, collected in two different seasons, was 0.25% (June 2000) and 0.20% (January 2001), respectively. The essential oils of the inflorescences and leaves presented as major constituents trans-anethol (41.34%, 45.42%, 58.59%) and methyl chavicol (27.10%, 24.14%, 29.96%).

Extraction of the soluble material from the shells of the bacuri fruit (Platonia insignis Mart) with pressurized CO2 and other solvents

The extraction of soluble material from bacuri shells has been studied. The effects of pressure, temperature, particle size, static period and flow time were investigated for extraction with liquid carbon dioxide (LCO2). The yield and the composition of the extracts obtained with LCO2 were compared with those for extracts obtained with other techniques, such as LCO2 plus ethanol (LCO2-EtOH), supercritical CO2 (SCO2), steam distillation (SD), cold ethanol (C-EtOH), and Soxhlet extraction with ethanol (EtOH-So). The LCO2 and LCO2-EtOH extractions were performed at pressures of 63–70 bar, and temperatures of 16–21°C. The constituents isolated from the bacuri shell extracts were predominantly free fatty acids: palmitic, oleic, linoleic, α-linolenic, and stearic acids. In addition to these fatty acids, the LCO2-EtOH extracts contained caprylic and myristic acids, alcohols (linalool and 3,7-dimethyl oct-1-en-3,7-diol), and the phenol ether eugenol. The SCO2 extraction was performed at 200 bar and 50°C. The SCO2 extract had a composition similar to the LCO2 extract, but the α-linolenic acid was not present, although hydrocarbons such as β-bisabolene, and alcohols such as 3,7-dimethyl-1-octen-3,7-diol, linalool, and α-terpineol were identified. In the extract obtained by SD, only hydrocarbons (methyl benzene and 2-methyl heptane), alcohols (linalool and α-terpineol), and oxides (cis-linalool oxide and trans-linalool oxide) were identified. In the C-EtOH and EtOH-So extracts only trimethyl citrate was identified.

Chemical Composition and Larvicidal Activity against Aedes aegypti Larvae of Essential Oils from Four Guarea Species

The essential oils of four Guarea species collected at Manaus (Amazonas, Brazil) were obtained by hydrodistillation and analyzed by GC-MS. Except for one diterpene detected, the compounds identified in the essential oils were hydrocarbons and oxygenated sesquiterpenes. The major sesquiterpenes were α-santalene (26.26%) and α-copaene (14.61%) from G. convergens branches; caryophyllene epoxide (40.91%) and humulene epoxide II (14.43%) from G. humaitensis branches; cis-caryophyllene (33.37%) and α-trans-bergamotene (11.88%) from G. scabra leaves; caryophyllene epoxide (36.54%) in leaves and spathulenol (14.34%) in branches from G. silvatica. The diterpene kaurene (15.61%) was found in G. silvatica leaves. Larvicidal activity assay of essential oils against third-instar Aedes aegypti larvae revealed that at higher concentrations (500 and 250 μg/mL), all the essential oils caused 100% mortality after 24 h of exposure. The most active essential oils were those of G. humaitensis branches (LC50 48.6 μg/mL), G. scabra leaves (LC50 98.6 μg/mL) and G. silvatica (LC50 117.9 μg/mL). The differences in the toxicity of essential oils of Guarea species on A. aegypti are due to qualitative and quantitative variations of the components, therefore the larvicidal effect may be due to higher amount of the sesquiterpenes with caryophyllane skeleton.

Larvicidal activity of Mentha x villosa Hudson essential oil, rotundifolone and derivatives.

The aim of this study was to evaluate the larvicidal activity of Mentha x villosa essential oil (MVEO) and its major constituent, rotundifolone, against larvae of Aedes aegypti. Additionally, a set of 15 analogues of the rotundifolone were evaluated to identify the molecular characteristics which contribute to the larvicidal effect. The results from the present study showed that the MVEO exhibited outstanding toxic effects against Ae. aegypti larvae (LC50=45.0ppm). Rotundifolone exhibited reasonable larvicidal activity (LC50=62.5ppm). With respect to comparative study of rotundifolone and its analogues, all tested compounds were less potent than rotundifolone, except (-)-limonene. In general, replacement of C-C double bonds by epoxides groups decreases the larvicidal potency. The presence of α,β-unsaturated carbonyls contributes to the larvicidal toxicity. The addition of hydroxyl groups in the chemical structure resulted in less potent compounds. Furthermore, the enantioselectivity seems to play an important role for the larvicidal toxicity.

Composição química e modulação da resistência bacteriana a drogas do óleo essencial das folhas de Rollinia leptopetala R. E. Fries

The essential oil from the leaves of Rollinia leptopetala was obtained by hydrodistillation in Clevengers apparatus and its chemical composition was analyzed by GC-MS. With this technique could be identified 22 constituents in a complex mixture of monoterpenes (54.5%) and sesquiterpenes (45.5%). The main component found in the leaves was the bicyclogermacrene (22.47%). The essential oil was assayed against a strain of Staphylococcus aureus possessing efflux mechanism of resistance to norfloxacin. Although the essential oil did not display relevant antibacterial activity in vitro, it modulated the activity of the norfloxacin, i.e. in combination with the antibiotic it was observed a fourfold reduction in the minimum inhibitory concentration for norfloxacin, indicating inhibition of efflux pump.

PERFORMANCE OF GINGER GRASS (Lippia alba) FOR TRAITS RELATED TO THE PRODUCTION OF ESSENTIAL OIL

Lippia alba (Verbenaceae) is a shrub whose essential oil has important biological, pharmacological, and aromatizing properties. To reach the sustained cultivation of new species with economic potential, the present study aimed to evaluate L. alba performance for fresh leaf matter (FM), leaf dry matter (DM), virus symptoms (VS - Cucumber mosaic virus, CMV), oil yield (OY), and oil chemical composition (OC), and to evaluate DM stability and adaptability. Ten genotypes of four chemical groups (chemotypes) were evaluated in six experiments designed as randomized blocks with two plants per plot, over the whole State of Sao Paulo, Brazil. A 2.0 x 0.4 x 1.6 m spacing was used in Monte Alegre do Sul and Pindorama, while a 1.0 x 0.4 x 0.6 m spacing was used in Campinas, where four experiments were established under different irrigation and fertilization conditions. The genotype effect was significant (p < 0.05) for all traits evaluated, with high leaf productivity of IAC-16 (citral chemotype), best OY means in the linalool and limonene/carvone chemotypes, and susceptibility of the latter chemotype to CMV. The genotype performance oscillations in the six environments were significant for FM and DM, and despite their significance for phytochemical traits (OY and OC), they were of low magnitude. No qualitative variation was detected for OC. The IAC-2 (linalool) and IAC-13 (limonene/carvone) genotypes showed high stability and wide adaptability, and are recommended to establish initial cultivations of this species. This research also indicated genetic sources to start Lippia alba genetic breeding programs.