Aroma-active compounds ofPinus densi?ora (red pine) needles

New Essential Oils from Ecuadorian Gynoxys cuicochensis Cuatrec. and Gynoxys sancti-antonii Cuatrec. Chemical Compositions and Enantioselective Analyses

The present study belonged to an unfunded project, dealing on the systematic description of unprecedented essential oils (EOs), distilled from 12 species of genus Gynoxys Cuatrec. In this very case, the aim was the first chemical and enantiomeric analyses of two volatile fractions, obtained from the leaves of Gynoxys cuicochensis Cuatrec. and Gynoxys sancti-antonii Cuatrec. These EOs were analyzed by GC-MS (qualitatively) and GC-FID (quantitatively), detecting 89 and 60 components from G. cuicochensis and G. sancti-antonii, respectively. Major components for G. cuicochensis EO, on a nonpolar and polar stationary phase, were α-pinene (29.4-29.6%), p-vinylguaiacol (3.3-3.6%), and germacrene D (20.8-19.9%). In G. sancti-antonii EO, the main compounds were α-pinene (3.0-2.9%), β-pinene (12.9-12.1%), γ-curcumene (19.7-18.3%), germacrene D (9.0% on the polar phase), ar-curcumene (5.3% on the polar phase), δ-cadinene (4.1-4.6%), α-muurolol (3.3-2.4%), α-cadinol (3.0% on both columns), and an undetermined compound, of molecular weight 220. In addition to chemical composition, the enantioselective analysis of the main chiral compounds was carried out on two different chiral selectors. In G. cuicochensis EO, (1R,5R)-(+)-α-pinene, (S)-(+)-β-phellandrene, (R)-(-)-piperitone, and (S)-(-)-germacrene D were enantiomerically pure, whereas β-pinene, sabinene, α-phellandrene, limonene, linalool, and terpinen-4-ol were observed as scalemic mixtures. On the other hand, in G. sancti-antonii EO, the pure enantiomers were (1S,5S)-(-)-α-pinene, (1R,5R)-(+)-sabinene, (R)-(-)-β-phellandrene, (S)-(-)-limonene, (1S,2R,6R,7R,8R)-(+)-α-copaene, (R)-(-)-terpinen-4-ol, and (S)-(-)-germacrene D, whereas β-pinene, linalool, and α-terpineol were present as scalemic mixtures. The principal component analysis demonstrated that G. cuicochensis volatile fraction was quite similar to many of the other EOs of the same genus, whereas G. sancti-antonii produced the most dissimilar EO. Furthermore, the enantioselective analyses showed the usual variable enantiomeric distribution, with a greater presence of enantiomerically pure compounds in G. sancti-antonii EO.

Chemical and Enantioselective Analyses of an Unprecedented Essential Oil from Ecuadorian Aiouea montana: A Natural Source of S-Methyl-O-2-phenylethyl Carbonothioate

Fresh and dry leaves of Aiouea montana (Sw.) R. Rohde (Lauraceae) produced, in a quite high yield (0.88% and 1.60%, respectively), an unpleasantly smelling essential oil. The chemical composition was described in this study for the first time, detecting and quantifying 48 compounds. Major components of fresh and dry leaf essential oils were α-pinene (6.7-10.3%), β-pinene (2.8-3.8%), α-phellandrene (12.6-14.5%), α-copaene (3.1-15.7%), δ-cadinene (0.9-3.3%), and S-methyl-O-2-phenylethyl carbonothioate (58.5-33.3%). The dominant compound was already known in the literature by synthesis; however, it was unprecedented so far in nature. The carbonothioate was identified after purification and structure elucidation, by means of mass spectrometry, NMR spectroscopy, and FTIR spectrophotometry. The spectral results were identical to all data reported in the literature for the same molecule. Furthermore, the enantioselective analysis of the essential oil was conducted on a β-cyclodextrin-based stationary phase. Two chiral constituents, (+)-β-phellandrene and (1R,2S,6S,7S,8S)-(-)-α-copaene, were enantiomerically pure, whereas α-thujene, camphene, β-pinene, α-phellandrene, limonene, linalool, and germacrene D were scalemic mixtures. The different chemical and enantiomeric compositions suggested that enzymatic transformations could occur while drying.

A Comprehensive Investigation of Macro-Composition and Volatile Compounds in Spring-Picked and Autumn-Picked White Tea

The flavour of white tea can be influenced by the season in which the fresh leaves are picked. In this study, the sensory evaluation results indicated that spring-picked white tea (SPWT) was stronger than autumn-picked white tea (APWT) in terms of the taste of umami, smoothness, astringency, and thickness as well as the aromas of flower and fresh. To explore key factors of sensory differences, a combination of biochemical composition determination, widely targeted volatilomics (WTV) analysis, multivariate statistical analysis, and odour activity value (OAV) analysis was employed. The phytochemical analysis showed that the free amino acid, tea polyphenol, and caffeine contents of SPWTs were significantly higher than those of APWTs, which may explain the higher umami, smoothness, thickness, and astringency scores of SPWTs than those of APWTs. The sabinene, (2E, 4E)-2, 4-octadienal, (-)-cis-rose oxide, caramel furanone, trans-rose oxide, and rose oxide contents were significantly higher in SPWTs than in APWTs, which may result in stronger flowery, fresh, and sweet aromas in SPWTs than in APWTs. Among these, (2E,4E)-2,4-octadienal and (-)-cis-rose oxide can be identified as key volatiles. This study provides an objective and accurate basis for classifying SPWTs and APWTs at the metabolite level.

Chemical Composition and In Vitro Anti-Helicobacter pylori Activity of Campomanesia lineatifolia Ruiz & Pavón (Myrtaceae) Essential Oil

Helicobacter pylori is the most common cause of gastritis and peptic ulcers, and the number of resistant strains to multiple conventional antimicrobial agents has been increasing in different parts of the world. Several studies have shown that some essential oils (EO) have bioactive compounds, which can be attributed to antimicrobial activity. Therefore, EOs have been proposed as a natural alternative to antibiotics, or for use in combination with conventional treatment for H. pylori infection. Campomanesia lineatifolia is an edible species found in the Brazilian forests, and their leaves are traditionally used for the treatment of gastrointestinal disorders. Anti-inflammatory, gastroprotective, and antioxidant properties are attributed to C. lineatifolia leaf extracts; however, studies related to the chemical constituents of the essential oil and anti-H. pylori activity is not described. This work aims to identify the chemical composition of the EO from C. lineatifolia leaves and evaluate the anti-H. pylori activity. The EO was obtained by hydrodistillation from C. lineatifolia leaves and characterized by gas chromatography-mass spectrometry analyses. To assess the in vitro anti-H. pylori activity of the C. lineatifolia leaf's EO (6 μL/mL-25 μL/mL), we performed broth microdilution assays by using type cultures (ATCC 49503, NCTC 11638, both clarithromycin-sensitive) and clinical isolate strains (SSR359, clarithromycin-sensitive, and SSR366, clarithromycin-resistant). A total of eight new compounds were identified from the EO (3-hexen-1-ol (46.15%), α-cadinol (20.35%), 1,1-diethoxyethane (13.08%), 2,3-dicyano-7,7-dimethyl-5,6-benzonorbornadiene (10.78%), aromadendrene 2 (3.0%), [3-S-(3α, 3aα, 6α, 8aα)]-4,5,6,7,8,8a-hexahydro-3,7,7-trimethyl-8-methylene-3H-3a,6-methanoazulene (2.99%), α-bisabolol (0.94%), and β-curcumene (0.8%)), corresponding to 98.09% of the total oil composition. The EO inhibited the growth of all H. pylori strains tested (MIC 6 μL/mL). To our knowledge, the current study investigates the relation between the chemical composition and the anti-H. pylori activity of the C. lineatifolia EO for the first time. Our findings show the potential use of the C. lineatifolia leaf EO against sensitive and resistant clarithromycin H. pylori strains and suggest that this antimicrobial activity could be related to its ethnopharmacological use.

Cedrus deodara (Roxb. ex D.Don) G.Don: A review of traditional use, phytochemical composition and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Cedrus deodara (Roxb. ex D.Don) G.Don (Family: Pinaceae) is a medicinal tree traditionally important and well mentioned in traditional system of medicine of India, Pakistan, China, Korea etc. for its use in the management of skin diseases, microbial infections, joint disorders, asthma, kidney stones, ulcer, brain disorders and immunological disorders.

AIM AND OBJECTIVES

This review provides an insight into the information available regarding traditional uses, ethnobotany, phytochemistry and, pharmacological profiling of C. deodara crude extract, its isolated compounds and, fractions, to explore its potential for the development of novel therapeutic agents.

MATERIAL AND METHODS

Various databases including Scopus, Google Scholar, Science Direct, ACS, Wiley, Web of Science, Springer Link and, PubMed were used to collect all the appropriate information available in previously published literature related to this plant. Besides, other official electronic sources viz. Encyclopedia Britannica and Northern Regional Center, Botanical Survey of India, theplantlist.org. and relevant book chapters and books were also explored.

RESULTS

C. deodara is a popular medicinally active tree, traditionally used in the form of decoction, syrup, oil, powder, and extract alone or in combination with other herbs for the management of different ailments viz. asthma, ulcers, bone fractures, sprains rheumatism, boils, leprosy, etc. Phytochemical studies reported 105 chemical constituents from different parts of the plant, most of them belong to a class of terpenoids and flavonoids. Crude extracts, essential oils, fractions, and isolated compounds of C. deodara exhibited some important pharmacological activities including anticancer, antimicrobial, antifungal, analgesic, anti-inflammatory, neuroprotective, antidiabetic, antiurolithiatic, antiarthritic and, antiasthmatic.

CONCLUSION

Present article delivers in-depth information on botany, ethnopharmacology, phytochemistry, pharmacology, and toxicology. C. deodara has been in practice among indigenous people of India, Pakistan, Nepal, Korea, China, Nigeria and Russia and 28 different ethnicities for the management of approximately 40 diseases. Bioactive compounds particularly cedrin, himachalol, himachalene and atlantone are recognized as key constituents for observed pharmacological activities of C. deodara. However, further in-depth studies involving bio-guided fractionation, isolation, identification using advanced techniques to afford some new therapeutically active phytoconstituents in the management of different diseases. Preliminary pharmacological investigations on different extracts and fractions of C. deodara partially validated its traditional claims in different ailments such as skin diseases, asthma, neurological disorders, arthritis, microbial infections, gastric disturbances, and inflammation. However, immediate attempts are required to establish its mechanism of action, efficacy, dosage range, and safety in combating different pathological states.

Reactive oxygen species mediated-antifungal activity of cinnamon bark (Cinnamomum verum) and lemongrass (Cymbopogon citratus) essential oils and their constituents against two phytopathogenic fungi

To find new and safe type of control agents against phytopathogenic fungi, the fumigant antifungal activity of 10 plant essential oils and constituents identified in cinnamon bark (Cinnamomum verum) and lemongrass (Cymbopogon citratus) essential oils was investigated against two phytopathogenic fungi, Raffaelea quercus-mongolicae and Rhizoctonia solani. Among plant essential oils, cinnamon bark and lemongrass essential oils showed 100% inhibition of R. quercus-mongolicae and R. solani at 5 mg/paper disc, respectively. Among test constituents, salicylaldehyde, eugenol, and hydrocinnamaldehyde showed 100% inhibition of growth of R. quercus-mongolicae at 2.5 mg/paper disc. Neral, geraniol, geranial, trans-cinnamaldehyde, methyl cinnamate, isoeugenol, and methyl eugenol exhibited >80% inhibition of growth of R. quercus-mongolicae at 2.5 mg/paper disc. Neral, geranial, trans-cinnamaldehyde, hydrocinnamaldehyde, and salicylaldehyde showed 100% inhibition of growth of R. solani at 2.5 mg/paper disc. A fumigant antifungal bioassay of artificial blends of the constituents identified in cinnamon bark and lemongrass essential oils indicated that trans-cinnamaldehyde and geranial were major contributors to the fumigant antifungal activity of the artificial blend. Confocal laser scanning microscopy images of fungi treated with cinnamon bark and lemongrass essential oils, trans-cinnamaldehyde, neral, and geranial revealed the reactive oxygen species (ROS) generation and cell membrane disruption.

Transcriptome analysis of the curry tree (Bergera koenigii L., Rutaceae) during leaf development

The curry tree (Bergera koenigii L.) is a widely cultivated plant used in South Asian cooking. Next-generation sequencing was used to generate the transcriptome of the curry leaf to detect changes in gene expression during leaf development, such as those genes involved in the production of oils which lend the leaf its characteristic taste, aroma, and medicinal properties. Using abundance estimation (RSEM) and differential expression analysis, genes that were significantly differentially expressed were identified. The transcriptome was annotated with BLASTx using the non-redundant (nr) protein database, and Gene Ontology (GO) terms were assigned based on the top BLAST hit using Blast2GO. Lastly, functional enrichment of the assigned GO terms was analyzed for genes that were significantly differentially expressed. Of the most enriched GO categories, pathways involved in cell wall, membrane, and lignin synthesis were found to be most upregulated in immature leaf tissue, possibly due to the growth and expansion of the leaf tissue. Terpene synthases, which synthesize monoterpenes and sesquiterpenes, which comprise much of the curry essential oil, were found to be significantly upregulated in mature leaf tissue, suggesting that oil production increases later in leaf development. Enzymes involved in pigment production were also significantly upregulated in mature leaves. The findings were based on computational estimates of gene expression from RNA-seq data, and further study is warranted to validate these results using targeted techniques, such as quantitative PCR.

Resolving the smell of wood - identification of odour-active compounds in Scots pine (Pinus sylvestris L.)

Being one of the most common trees in forests, Pinus sylvestris L. is a frequently used raw material for wood products. Its specific odour is, however, mostly unresolved to date. Accordingly, we investigated Scots pine wood samples grown in Germany for their main odorant composition. We employed dedicated odorant analysis techniques such as gas chromatography-olfactometry (GC-O) and aroma extract dilution analysis (AEDA) and successfully detected 44 odour-active compounds; of these, 39 substances were successfully identified by gas chromatography-mass spectrometry/olfactometry (GC-MS/O) and two-dimensional gas chromatography-mass spectrometry/olfactometry (2D-GC-MS/O). Among the main odorants found were (E,E)-nona-2,4-dienal, vanillin, phenylacetic acid, 3-phenylpropanoic acid, δ-octalactone and α-pinene, all of them having been detected with high flavour dilution factors during GC-O analyses. The majority of the identified odorants were fatty acid degradation products, plus some terpenoic substances and odorous substances resulting from the degradation of lignin. Although some of the detected substances have previously been reported as constituents of wood, 11 substances are reported here for the first time as odour-active compounds in wood, amongst them heptanoic acid, γ-octalactone, δ-nonalactone and (E,Z,Z)-trideca-2,4,7-trienal.

Identification of olfactory receptor neurons in Uraba lugens (Lepidoptera: Nolidae) and its implications for host range

Phytophagous insects detect volatile compounds produced by host and non-host plants, using species-specific sets of olfactory receptor neurons (ORNs). To investigate the relationship between the range of host plants and the profile of ORNs, single sensillum recordings were carried out to identify ORNs and corresponding active compounds in female Uraba lugens (Lepidoptera: Nolidae), an oligophagous eucalypt feeder. Based on the response profiles to 39 plant volatile compounds, 13 classes of sensilla containing 40 classes of ORNs were identified in female U. lugens. More than 95% (163 out of 171) of these sensilla contained 16 classes of ORNs with narrow response spectra, and 62.6% (107 out of 171) 18 classes of ORNs with broad response spectra. Among the specialized ORNs, seven classes of ORNs exhibited high specificity to 1,8-cineole, (±)-citronellal, myrcene, (±)-linalool and (E)-β-caryophyllene, major volatiles produced by eucalypts, while nine other classes of ORNs showed highly specialized responses to green leaf volatiles, germacrene D, (E)-β-farnesene and geranyl acetate that are not produced by most eucalypts. We hypothesize that female U. lugens can recognize their host plants by detecting key host volatile compounds, using a set of ORNs tuned to host volatiles, and discriminate them from non-host plants using another set of ORNs specialized for non-host volatiles. The ORNs with broad response spectra may enhance the discrimination between host and non-host plants by adding moderately selective sensitivity. Based on our finding, it is suggested that phytophagous insects use the combinational input from both host-specific and non-host specific ORNs for locating their host plants, and the electrophysiological characterization of ORN profiles would be useful in predicting the range of host plants in phytophagous insects.

Approaches of aroma extraction dilution analysis (AEDA) for headspace solid phase microextraction and gas chromatography-olfactometry (HS-SPME-GC-O): Altering sample amount, diluting the sample or adjusting split ratio?

Aroma extract dilution analysis (AEDA) is widely used for the screening of aroma-active compounds in gas chromatography-olfactometry (GC-O). In this study, three aroma dilution methods, (I) using different test sample volumes, (II) diluting samples, and (III) adjusting the GC injector split ratio, were compared for the analysis of volatiles by using HS-SPME-AEDA. Results showed that adjusting the GC injector split ratio (III) was the most desirable approach, based on the linearity relationships between Ln (normalised peak area) and Ln (normalised flavour dilution factors). Thereafter this dilution method was applied in the analysis of aroma-active compounds in Japanese soy sauce and 36 key odorants were found in this study. The most intense aroma-active components in Japanese soy sauce were: ethyl 2-methylpropanoate, ethyl 2-methylbutanoate, ethyl 3-methylbutanoate, ethyl 4-methylpentanoate, 3-(methylthio)propanal, 1-octen-3-ol, 2-methoxyphenol, 4-ethyl-2-methoxyphenol, 2-methoxy-4-vinylphenol, 2-phenylethanol, and 4-hydroxy-5-ethyl-2-methyl-3(2H)-furanone.

The compositions of volatiles and aroma-active compounds in dried omija fruits (Schisandra chinensis Baillon) according to the cultivation areas

Differences in the compositions of volatiles from dried omija fruits (Schisandra chinensis Baillon) cultivated in different areas (Mungyeong, Jangsu, Jechon, and Hoengseong) in South Korea were determined by applying principal component analysis to gas chromatography-mass spectrometry data sets. Quantitative assessments revealed that terpene hydrocarbons, such as germacrene D, β-selinene, α-ylangene, β-elemene, α-selinene, and (E)-β-farnesene, were the main volatiles in all omija fruit samples. On the other hand, (E)-β-ocimene, calarene, (E)-β-farnesene, β-selinene, nonanal, 2-methylbutanoic acid, benzoic acid, 2,3-butanediol, and phenethyl alcohol were the major volatile components that contributed to the discrimination between omija fruit samples from the four cultivation areas. In addition, aroma-active compounds in four dried omija fruits were investigated and compared by gas chromatography-olfactometry using aroma extract dilution analysis. (E)-β-Ocimene (floral and herbaceous), α-pinene (pine-like and woody), hexanal (cut grass-like), 5-methylfurfural (burnt sugar-like and sweet), and α-terpinene (minty, green, and fresh) were important aroma-active compounds in all omija samples. Interestingly, the flavor dilution factors of most aroma-active compounds were lower for omija sample cultivated in Hoengseong than for those cultivated in Mungyeong, Jangsu, and Jechon.

Influence of blanching and grinding process with hot water on beany and non-beany flavor in soymilk

A total of 8 beany odor-active compounds and 4 non-beany aroma-active compounds of traditional soymilk were identified through dynamic headspace dilution analysis (DHDA) and gas chromatography-olfactometry-mass spectrometry (GC-O-MS). To eliminate the beany flavors, soymilk was processed with hot water blanching and grinding for 2, 4, 6, 8, and 10 min with a temperature between 80 and 100 °C. A total of 5 beany odor-active compounds and 3 non-beany aroma-active compounds of this soymilk were analyzed by headspace solid phase microextraction (HS-SPME). As a result, lipoxygenase (LOX) activity gradually decreased by hot water treatment with time, and with the decrease of Lox activity, the 5 beany odor-active compounds and 3 non-beany aroma-active compounds were significantly decreased. However, the reduction in non-beany flavor compounds was smaller than for beany odor compounds. Therefore, a balance between beany and non-beany flavors can be reached in soymilk. When the soaked soybeans were blanched and ground with hot water for 2 to 6 min, the LOX activity was between 38% and 57% of the beginning activity. For these processing times, the non-beany compounds could be largely maintained. The ratio of the total peak area of the 3 non-beany aroma compounds and 5 beany flavor compounds was between 0.07 and 0.12, and the sensory scores of the aromas were higher than that of the off-flavors. Practical Application: Beany flavors in soymilk could be reduced with hot water blanching and grinding at temperature above 80 °C. However, the treatment of hot water blanching affected the non-beany aromas of soymilk. A suitable blanching and grinding time is necessary to achieve a balance of soymilk flavors.

Glomerular activity patterns evoked by natural odor objects in the rat olfactory bulb are related to patterns evoked by major odorant components

To determine how responses evoked by natural odorant mixtures compare to responses evoked by individual odorant chemicals, we mapped 2-deoxyglucose uptake during exposures to vapors arising from a variety of odor objects that may be important to rodents in the wild. We studied 21 distinct natural odor stimuli ranging from possible food sources such as fruits, vegetables, and meats to environmental odor objects such as grass, herbs, and tree leaves. The natural odor objects evoked robust and surprisingly focal patterns of 2-deoxyglucose uptake involving clusters of neighboring glomeruli, thereby resembling patterns evoked by pure chemicals. Overall, the patterns were significantly related to patterns evoked by monomolecular odorant components that had been studied previously. Object patterns also were significantly related to the molecular features present in the mixture components. Despite these overall relationships, there were individual examples of object patterns that were simpler than might have been predicted given the multiplicity of components present in the vapors. In these cases, the object patterns lacked certain responses evoked by their major odorant mixture components. These data suggest the possibility of mixture response interactions and provide a foundation for understanding the neural coding of natural odor stimuli.

Seasonal variations of monoterpene emissions from Pinus densiflora in East Asia

The emission rates and compositions of monoterpene from Pinus densiflora were investigated in the Gumsung (GM) and Worak (WM) mountains. The standard emission rates (ERs: ERs is the monoterpene emission rate at standard temperature, 30 degrees C) from P. densiflora ranged from 0.817 to 1.704 (microgC/gdw-h). The ERs and beta-values of total monoterpene were measured at the two study sites (GM and WM). In the spring and summer, the ERs were the highest, while relatively low values (<0.058microgC/gdw-h) were measured in the autumn and winter. In GM and WM sites the beta-value obtained for the different seasons ranged from 0.047 to 0.179, with an average of 0.09. The major monoterpene compounds from P. densiflora were alpha-pinene, myrcene, beta-phellandrene, d-limonene and alpha-terpinene. The fractional compositions of individual monoterpene compounds were significantly different between the two test sites in the summer and winter. The ERs of the older group (31-40 years) were higher than those in the younger group (21-30 years). However, the monoterpene compositions were similar between the two age groups.

Determination of optimum conditions for the analysis of volatile components in pine needles by double-shot pyrolysis–gas chromatography–mass spectrometry

The optimum conditions for the analysis of the volatile organic components of pine needles from Pinus densiflora using double-shot pyrolysis-gas chromatography-mass spectrometry (DSP-GC-MS) were investigated with respect to thermal desorption temperature and duration of heating. A total of 41 compounds were identified using thermal desorption temperatures of 150 degrees C, 200 degrees C, 250 degrees C and 300 degrees C. Thermal decomposition products, which include acetol, acetic acid, furfurals and phenols, were observed only at thermal desorption temperatures exceeding 250 degrees C: they were not observed in the extract from a simultaneous distillation extraction (SDE) method. Heating times of 1 s, 6 s, 30 s, 150 s and 300 s were investigated at the thermal desorption temperature of 200 degrees C, whence it was found that thermal decomposition products were produced only at heating times over 30 s. The optimum pyrolyzer conditions for the analysis of pine needles using DSP-GC-MS is 200 degrees C for 6 s. Under these conditions, this method gives comparable results to the SDE method.