Essential Oils from Bolivia. XV. Herzogole, an Original Monoterpene Benzodioxole from an Essential Oil from Pentacalia herzogii (Cabrera) Cuatrec.

Over 15 years, with the support of a Canadian funding agency, the Universidad Mayor de San Simón, in Bolivia, undertook a large survey of aromatic plants of the South American country. More than a hundred species were studied under various aspects, including the production and characterization of essential oils. As part of this survey, the chemical composition of an essential oil sample obtained from Pentacalia herzogii (Asteraceae) growing wild in the High Valley region of the department of Cochabamba was determined by a combination of GC and GC-MS measurements. α-Pinene was the main constituent of this essential oil (34%), accompanied by limonene (22%) and germacrene D (7.5%) as well as an important fraction of methoxylated monoterpenoids. They were mainly isomers of thymol methyl ether, accounting for 13% of the chromatogram. A new quantitatively important compound (9%) was identified through NMR and chemical synthesis as 4-isopropyl-6-methylbenzo[d][1,3]dioxole, and designated herzogole, alongside the minor related compound 1-isopropyl-2,3-dimethoxy-5-methylbenzene. The monoterpene benzodioxole featured a distinctive green-phenolic aroma which could raise interest for fragrance use. Since these compounds were not known naturally, a biosynthetic mechanism of their formation was proposed and put in perspective to illustrate the metabolic originality of P. herzogii.

Limonene from Agastache mexicana essential oil produces antinociceptive effects, gastrointestinal protection and improves experimental ulcerative colitis.

ETHNOPHARMACOLOGY RELEVANCE: Agastache mexicana is a popular plant of great demand in folk medicine, essentially due to its calming properties and for alleviating arthritic, muscular and abdominal pain. Despite its spectrum for pain relief, pharmacological studies of its bioactive constituents have been barely investigated. AIM OF THE STUDY: To evaluate protective properties of the A. mexicana and bioactive compounds improving pathological gastrointestinal conditions in rodents. MATERIAL AND METHODS: Different doses of the essential oil of A. mexicana ssp. mexicana and ssp. xolocotziana (30-562.2 mg/kg, i.p.) and individual monoterpenes (3-300 mg/kg, i.p.) were evaluated in an abdominal pain model. The most active monoterpene limonene and sulfasalazine (reference drug, 100 mg/kg, p.o.) were also evaluated in the oxazolone-induced colitis model using an oral gavage, where some inflammatory cytokines were analyzed by enzyme-linked immunosorbent assays. Finally, colonic histological assessment and gastroprotection in the absolute ethanol-induced ulcer model were explored. RESULTS: Our results demonstrated that the essential oil of both subspecies produced a significant reduction in the abdominal writhes, where monoterpenes limonene and pulegone were partially responsible bioactive metabolites. Limonene showed the major antinociceptive efficacy in the writhing test. It also significantly decreased hyperalgesia, pathological biomarkers, and colonic inflammatory cytokines in the oxazolone-induced colitis model, as well as prevention in gastric damage. CONCLUSIONS: Present results provide scientific evidence to reinforce the use of A. mexicana in the traditional medicine for gastrointestinal conditions, mainly related to pain and inflammation, demonstrating the potential of monoterpenes as natural products in the therapeutics of gastrointestinal affections such as ulcer, colitis, and abdominal pain.

Minty aroma compounds in red wine: Development of a novel automated HS-SPME-arrow and gas chromatography-tandem mass spectrometry quantification method.

A novel automated method was developed for the quantitative determination of nine terpenoids that could contribute to the minty notes of red wine bouquet. The method couples headspace SPME-Arrow extraction with GC-MS/MS analysis. PDMS/DVB fiber was chosen for the extraction and an ionization energy of 30 eV permitted to optimize the analyte detection. The optimal sample preparation consists of a two-fold dilution of the wine sample with addition of 4 g of sodium chloride while the most suitable extraction conditions take place at 50 °C for 1 h. The method shows good linearity, intraday variations between 2 and 25%, interday variations between 7 and 23% and recoveries between 80 and 119%. The method exhibits the required low detection (between 3 and 60 ng/L) and quantification (between 6 ng/L and 200 ng/L) limits. These limits have permitted the quantification of the pool of minty terpenoids in fourteen red Bordeaux wines.

Comparative study of various processes used for removal of bitterness from kinnow pomace and kinnow pulp residue.

The current study was focused on new approaches for debittering of by-products like kinnow pomace and kinnow pulp residue by using various food grade mild chemical methods, such as alkali treatment, acid treatment, and solventogenesis. Whereas in the studied various chemical treatments, the solventogenesis method with acetone resulted in maximum extraction of naringin and limonene from kinnow pomace and pulp residue and showed high acceptability for food product development. The acetone treatment was further optimized by RSM for the maximum extraction of naringin and limonene. Under optimized conditions, the maximum amount of naringin and limonene extracted were found to be 8.955, 2.122 mg/g from kinnow pomace and 9.971, 3.838 mg/g from pulp residue, respectively. This process can not only result in the effective utilization of agro-industrial by-product but also provide a sustainable solution to the environmental pollution caused by kinnow juice industry.

Perilla frutescens Britton: A Comprehensive Study on Flavor/Taste and Chemical Properties During the Roasting Process.

This study investigated changes of volatile compounds, sniffing test-assisted sensory properties, taste associated-constituent and free amino acid compositions, taste description by electronic-tongue, and chemical characteristics in Perilla frutescens Britton var. acuta Kudo after roasting at 150 °C for 0⁻8 min. A total of 142 volatile compounds were identified, among which methyl benzoate and limonene were predominant, regardless of roasting time, and these were also detected as the major compounds in the sniffing test by GC-olfactometry. For constituent amino acids analyzed by the acid hydrolysis method using hydrochloric acid (HCl), the concentration of glutamic acid, aspartic acid, and leucine showed an increase pattern with increased roasting time, which results in umami taste, sour taste, and bitter taste, respectively. For free amino acids, valine and hydroxylysine eliciting bitter and bitter and sweet tastes, respectively, also tend to increase by roasting. The pattern of amino acid concentration by roasting was readily matched to the taste description by electronic-tongue but that of sweetness and sourness by electronic-tongue did not coincide with the amino acid composition. For the chemical properties, total phenolic content, antioxidative capacity, and browning intensity tend to increase with roasting but decreased by 8 min. The results of this study provide fundamental information on perilla in both the food industry and cooking environment for the sake of increasing the utilization of perilla as a food source and ingredient.

Chiral high-performance liquid and supercritical fluid chromatographic enantioseparations of limonene-based bicyclic aminoalcohols and aminodiols on polysaccharide-based chiral stationary phases.

Enantioseparation of limonene-based bicyclic 1,3-aminoalcohols and 1,3,5- and 1,3,6-aminodiols was performed by normal-phase high-performance liquid chromatographic and supercritical fluid chromatographic (SFC) methods on polysaccharide-based chiral stationary phases. The effects of the composition of the mobile phase, the column temperature and the structures of the analytes and chiral selectors on retention and selectivity were investigated by normal-phase LC and SFC technique. Thermodynamic parameters derived from selectivity-temperature-dependence studies were found to be dependent on the chromatographic method applied, the nature of the chiral selector and the structural details of the analytes. Enantiorecognition in most cases was enthalpically driven but an unusual temperature behavior was also observed: decreased retention times were accompanied by improved separation factors with increasing temperature, i.e. some entropically driven separations were also observed. The elution sequence was determined in all cases. The separation of the stereoisomers was optimized in both chromatographic modalities.

Effect of exposure to light emitted diode (LED) lights on essential oil composition of sweet mint plants.

Sweet mint plants (Mentha spicata) were separately exposed to blue, red and green light emitted diodes (LED) lights and natural sunlight as a control. Leaves were analyzed periodically for their essential oil composition using head space GCMS analysis. Control experiments showed that the main essential oil components were carvone (80%), limonene (17%) and other minor terpenes (3%). Exposed plants to green and red lights showed that their headspace essential oils were similar to that of the control plants. However, blue LED lights caused complete disappearance of carvone and limonene, which were never recovered. Disappearance of carvone and limonene were associated with the appearance of new chemicals at concentrations of 65 and 21% that were identified as carvone oxide and eucalyptol, respectively.

Stability of lime essential oil microparticles produced with protein-carbohydrate blends.

The objective of this work was to analyze the influence of maltodextrin equivalent dextrose on the lime essential oil reconstitution, storage, release and protection properties. Four treatments were evaluated: whey protein concentrate (WPC), and blends of maltodextrin with dextrose equivalents of 5 (WM5), 10 (WM10) and 20 (WM20). The reconstitution and storage properties of the microparticles (solubility, wettability and density), water kinetics adsorption, sorption isotherms, thermogravimetric properties, controlled release and degradation kinetics of encapsulated lime essential oil were studied to measure the quality of the encapsulated materials. The results of the study indicated that the DE degree influences the characteristics of reconstitution, storage, controlled release and degradation characteristics of encapsulated bioactive compounds. The increase in dextrose equivalent improves microparticle solubility, wettability and density, mainly due to the size of the maltodextrin molecules. The adsorption kinetics and sorption isotherm curves confirmed the increase in the hygroscopicity of maltodextrins with higher degrees of polymerization. The size of the maltodextrin chains influenced the release and protection of the encapsulated lime essential oil. Finally, the maltodextrin polymerization degree can be considered a parameter that will influence the physicochemical properties of microencapsulated food.

Insecticide activity of Baccharis dracunculifolia essential oil against Cochliomyia macellaria (Diptera: Calliphoridae).

The ethnobotanical uses of Brazilian plants for different injuries and diseases conjoined with local rich biodiversity represent an important resource for research and development. This study aimed to characterise BDEO and its in vitro activity on the third instar larvae (L3) of Cochliomyia macellaria. Groups of 20 L3 were placed on filter paper impregnated with increasing concentrations of 5-30% (v/v), equivalent to 0.79-4.77 µL/cm2, solubilised in ethanol or acetone. The major constituents of BDEO were ß-pinene (9.94%), D-limonene (9.59%), ß-nerolidol (7.93%), caryophyllene (7.69%), spathulenol (6.69), α-muurolene (6.74%) and α-pinene (5.31%). Lethal concentrations of 50% for BDEO on C. macellaria (LC50) after 24 and 48 h of exposure were 2.63 and 2.47 µL/cm2 for ethanol and 9.58 and 8.11 µL/cm2 for acetone, respectively. Furthermore, larvae cuticle abnormalities and adult deformity were observed. Our data confirm the effectiveness of BDEO as an ecofriendly product against blowflies.