Extraction of Camphor Tree Essential Oil by Steam Distillation and Supercritical CO2 Extraction

The essential oil extracted from Cinnamomum camphora leaves is a mixture of volatile compounds, mainly terpenes, and is widely used in medicine, perfume and chemical industries. In this study, the extraction processes of essential oil from Cinnamomum camphora leaves by steam distillation and supercritical CO₂ extraction were summarized and compared, and the camphor tree essential oil was detected by GC/MS. The extraction rate of essential oil extracted by steam distillation is less than 0.5%, while that of supercritical CO₂ extraction is 4.63% at 25 MPa, 45 °C and 2.5 h. GC/MS identified 21 and 42 compounds, respectively. The content of alcohols in the essential oil is more than 35%, and that of terpenoids is more than 80%. The steam extraction method can extract volatile substances with a low boiling point and more esters and epoxides; The supercritical method is suitable for extracting weak polar substances with a high alcohol content. Supercritical CO₂ extraction can selectively extract essential oil components and effectively prevent oxidation and the escape of heat sensitive substances.     

Volatiles Composition and Antimicrobial Activities of Areca Nut Extracts Obtained by Simultaneous Distillation–Extraction and Headspace Solid-Phase Microextraction

The volatile components of areca nuts were isolated by headspace solid-phase microextraction (HS-SPME, DVB/CAR/PDMS fiber extraction) and simultaneous hydrodistillation–extraction (SHDE) and analyzed by gas chromatography/mass spectrometry. Furthermore, all SHDE fractions were tested for antimicrobial activity using the disk diffusion method on nine Gram-negative and Gram-positive bacteria (Bacillus subtilis, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus canis, Streptococcus pyogenes, and Candida albicans). In total, 98 compounds (mainly alcohols, carbonyl compounds, fatty acids, esters, terpenes, terpenoids, and aliphatic hydrocarbons) were identified in SHDE fractions and by using SPME extraction Fatty acids were the main group of volatile constituents detected in all types of extracts. The microorganism most sensitive to the extract of the areca nut was Streptococcus canis. The results can provide essential information for the application of different treatments of areca nuts in the canning industry or as natural antibiotics.     

Comparative Study of the Petal Structure and Fragrance Components of the Nymphaea hybrid,a Precious Water Lily

Nymphaea hybrid, a precious water lily, is a widely-cultivated aquatic flower with high ornamental, economic, medicinal, and ecological value; it blooms recurrently and emits a strong fragrance. In the present study, in order to understand the volatile components of N. hybrid and its relationship with petals structure characteristics, the morphologies and anatomical structures of the flower petals of N. hybrid were investigated, and volatile compounds emitted from the petals were identified. Scanning and transmission electron microscopy were used to describe petal structures, and the volatile constituents were collected using headspace solid-phase microextraction (HS-SPME) fibers and analyzed using gas chromatography coupled with mass spectrometry (GC-MS). The results indicated that the density and degree of protrusion and the number of plastids and osmiophilic matrix granules in the petals play key roles in emitting the fragrance. There were distinct differences in the components and relative contents of volatile compounds among the different strains of N. hybrid. In total, 29, 34, 39, and 43 volatile compounds were detected in the cut flower petals of the blue-purple type (Nh-1), pink type (Nh-2), yellow type (Nh-3) and white type (Nh-4) of N. hybrid at the flowering stage, with total relative contents of 96.78%, 97.64%, 98.56%, and 96.15%, respectively. Analyses of these volatile components indicated that alkenes, alcohols, and alkanes were the three major types of volatile components in the flower petals of N. hybrid. The predominant volatile compounds were benzyl alcohol, pentadecane, trans-α-bergamotene, (E)-β-farnesene, and (6E,9E)-6,9-heptadecadiene, and some of these volatile compounds were terpenes, which varied among the different strains. Moreover, on the basis of hierarchical cluster analysis (HCA) and principal component analysis (PCA), the N. hybrid samples were divided into four groups: alcohols were the most important volatile compounds for Nh-4 samples; esters and aldehydes were the predominant volatiles in Nh-3 samples; and ketones and alkenes were important for Nh-2 samples. These compounds contribute to the unique flavors and aromas of the four strains of N. hybrid.     

Volatile composition of Brassica oleracea L. var. costata DC leaves using solid‐phase microextraction and gas chromatography/ion trap mass spectrometry

Volatile and semi‐volatile components of internal and external leaves of Brassica oleracea L. var. costata DC, grown under different fertilization regimens, were determined by headspace solid‐phase microextraction (HS‐SPME) combined with gas chromatography/ion trap mass spectrometry (GC/ITMS). Forty‐one volatiles and non‐volatile components were formally identified and thirty others were tentatively identified. Qualitative and quantitative differences were noticed between internal and external leaves. In general, internal leaves exhibited more aldehydes and sulfur volatile compounds than external ones, and less ketone, terpenes and norisoprenoid compounds. The fertilization regimens influenced considerably the volatile profile. Fertilizations with higher levels of sulfur produced Brassica leaves with more sulfur volatiles. In opposition, N and S fertilization led to leaves with lower levels of norisoprenoids and terpenes. Copyright © 2009 John Wiley & Sons, Ltd.     

Determination of eighty-one volatile organic compounds in dietary Rumexinduratus leaves by GC/IT-MS, using different extractive techniques

The volatile compounds of Rumexinduratus leaves were studied for the first time. In order to achieve the most complete volatile profile four different extractive techniques (hydrodistillation, solid-phase microextraction, Soxhlet system and direct solvent extraction) were applied. The different extracts were analysed by gas chromatography/ion trap-mass spectrometry (GC/IT-MS) which allowed the identification of 81 compounds, distributed by several chemical classes: esters, terpenes, aldehydes, acids, norisoprenoids, ketones, naphthalene derivatives, steroids derivatives and alcohols, among others. The different techniques lead to different compounds' extraction. Using hexane and dichloromethane, 9 and 4 compounds were extracted, respectively. Hydrodistillation, solid-phase microextraction and Soxhlet extraction allowed the extraction of 43, 24 and 29 compounds, respectively. Hydrodistillation was revealed to be the most effective technique, allowing the extraction of a higher number of compounds, both in the hydrolat (20 compounds) and essential oil (34 compounds), having 11 compounds in common.     

Comparative Analysis of the Floral Fragrance Compounds of Panax notoginseng Flowers under the Panax notoginseng-pinus Agroforestry System Using SPME-GC-MS

Panax notoginseng is a medicinal plant in China, the flowers of which have high medicinal value. To study the differences in the floral fragrance compounds of P. notoginseng flowers (bionic wild cultivation) from the forests of Yunnan Province, the floral fragrance compounds from four varieties of P. notoginseng flowers (four-forked seven leaves, three-forked seven leaves, four-forked five–seven leaves, and three-forked five–six leaves) were compared and analyzed via headspace solid phase microextraction combined with gas chromatography–mass spectrometry methods. A total of 53 floral fragrance compounds from the P. notoginseng flowers were divided into eight categories, mainly consisting of terpenes, alkynes, aromatic hydrocarbons, and alcohols. Moreover, high contents of 3-carene, germacrene D, (−)-α-gurjunene, valencene, (+)-γ-gurjunene, menogene, and aromandendrene were identified from the flowers of different P. notoginseng varieties. Interestingly, floral fragrance compounds such as 3-carene, valencene, aromandendrene, menogene, and (+)-γ-gurjunene were first reported in the flowers of P. notoginseng. Cluster analysis showed that P. notoginseng with four-forked and three-forked leaves clustered into two subgroups, respectively. In addition, principal component analysis showed that (+)-γ-gurjunene, (+)-calarene, copaene, 1,8,12-bisabolatriene, γ-elemene, (–)-aristolene, caryophyllene, 3-carenes, and 2,6-dimethyl-1,3,6-heptatriene can be used to distinguish the floral fragrance components of four P. notoginseng flower species. This study provides a theoretical basis for elucidating the floral fragrance compounds emitted from the flowers of different P. notoginseng varieties in an agroforestry system.     

Elucidation of Analytical–Compositional Fingerprinting of Three Different Species of Chili Pepper by Using Headspace Solid-Phase Microextraction Coupled with Gas Chromatography–Mass Spectrometry Analysis,and Sensory Profile Evaluation

The aim of the present study was to determine the volatile compounds of three different species of chili peppers, using solid-phase microextraction (SPME) methods in combination with gas chromatography–mass spectrometry (GC-MS). The detection of marker aroma compounds could be used as a parameter to differentiate between species of chili peppers for their detection and traceability in chili pepper food. The sensorial contribution was also investigated to identify the predominant notes in each species and to evaluate how they can influence the overall aroma. Three different pepper species belonging to the Capsicum genus were analyzed: Chinense, Annuum, and Baccatum. A total of 269 volatile compounds were identified in these species of chili peppers. The Capsicum annum species were characterized by a high number of acids and ketones, while the Capsicum chinense and Capsicum baccatum were characterized by esters and aldehydes, respectively. The volatile profile of extra virgin olive oils (EVOOs) flavored with chili peppers was also investigated, and principal component analysis (PCA) and hierarchical cluster analysis (HCA) of the volatile profiles were demonstrated to be a powerful analytical strategy for building a model that highlights the potential of a volatile characterization approach for use in evaluating food traceability and authenticity.     

A comparative study of phytochemical metabolites and antioxidant properties of Rhodiola

Rhodiola crenulata (RC) and Rhodiola fastigiata (RF) are representative species of Rhodiola with well-accepted health benefits; the roots are the medicinal part. However, prior to this study, the differences in phytochemicals between these two species and different parts of the same species remained unclear. Using LC-ESI-MS/MS, HS-SPME-GC–MS, chemical and sensory analyses, volatile compounds and non-volatile compounds, and antioxidant activities of the roots of Rhodiola crenulata and Rhodiola fastigiata and four parts (roots, leaves, flowers, and above-ground stems) of RC were investigated. The volatile compounds and non-volatile compounds of RC roots exhibited upregulation overall compared to those of RF roots, and the odorousness, phenolic content, and antioxidant activity were more pronounced in the RC roots. The phenolic content and antioxidant activity of roots and leaves, alongside the odorousness of roots and flowers, were more significant among the four parts of RC, and the RC roots and RC flowers exhibited similar odorousness. Comparison of non-volatile differential metabolites between RC roots and RC leaves showed upregulations of saccharides and phospholipids, and minor upregulations of flavonoids and phenylpropanoids in the roots; in addition, amino acids, organic acids, and vitamins were upregulated in the leaves. These results revealed the following: 1) RC roots are superior to RF roots regarding volatile compounds and non-volatile compounds, and antioxidant activity; 2) it is more favorable to select RC roots for exploiting volatile compounds compared with RC flowers in consideration of the biomass available; 3) in terms of non-volatile compounds, and antioxidant ability, RC leaves are also of great value in addition to RC roots, though these two parts show distinct characteristics.     

HS–SPME–GC–MS and Electronic Nose Reveal Differences in the Volatile Profiles of Hedychium Flowers

Floral fragrance is one of the most important characteristics of ornamental plants and plays a pivotal role in plant lifespan such as pollinator attraction, pest repelling, and protection against abiotic and biotic stresses. However, the precise determination of floral fragrance is limited. In the present study, the floral volatile compounds of six Hedychium accessions exhibiting from faint to highly fragrant were comparatively analyzed via gas chromatography–mass spectrometry (GC–MS) and Electronic nose (E-nose). A total of 42 volatile compounds were identified through GC–MS analysis, including monoterpenoids (18 compounds), sesquiterpenoids (12), benzenoids/phenylpropanoids (8), fatty acid derivatives (2), and others (2). In Hedychium coronarium ‘ZS’, H. forrestii ‘Gaoling’, H. ‘Jin’, H. ‘Caixia’, and H. ‘Zhaoxia’, monoterpenoids were abundant, while sesquiterpenoids were found in large quantities in H. coccineum ‘KMH’. Hierarchical clustering analysis (HCA) divided the 42 volatile compounds into four different groups (I, II, III, IV), and Spearman correlation analysis showed these compounds to have different degrees of correlation. The E-nose was able to group the different accessions in the principal component analysis (PCA) corresponding to scent intensity. Furthermore, the pattern-recognition findings confirmed that the E-nose data validated the GC–MS results. The partial least squares (PLS) analysis between floral volatile compounds and sensors suggested that specific sensors were highly sensitive to terpenoids. In short, the E-nose is proficient in discriminating Hedychium accessions of different volatile profiles in both quantitative and qualitative aspects, offering an accurate and rapid reference technique for future applications.     

Impact of Altitudinal Variation on the Phytochemical Profile,Anthelmintic and Antimicrobial Activity of Two Pinus Species

Active components from natural sources are the current focus in most pharmacological research to provide new therapeutic agents for clinical use. Essential oils from the Pinus species have been traditionally used in medicine. This study aimed to investigate the chemical profile of two Pinus species, Pinus halepensis L. and Pinus pinea Mill, from different altitudes in Libya and study the effect of environmental conditions on the biological activities of essential oils. A clevenger apparatus was used to prepare the essential oils by hydrodistillation. Analyses were done using GC/MS. Anthelmintic and antimicrobial activities were tested against the earthworm Allolobophora caliginosa, gram-positive bacteria, gram-negative bacteria, and fungi. Different chemical profiles were observed among all tested essential oils, and terpenes were the most dominant class. All studied essential oils from the Pinus species exhibited a remarkable anthelmintic activity compared to the standard piperazine citrate drug. Pinus halepensis from both altitudes showed broad-spectrum antimicrobial activity against all tested microorganisms, while Pinus pinea was effective against only Escherichia coli. From these findings, one can conclude that there are variations between studied species. The essential oil compositions are affected by environmental factors, which consequently affect the anthelmintic and antimicrobial activity.     

Synthesis of new terpene derivatives via ruthenium catalysis: rearrangement of silylated enynes derived from terpenoids

Enyne rearrangement of silylated modified terpenoids has been used as the key step for the synthesis of new terpenes and terpenoids. The catalytic system generated in situ from [RuCl₂(p-cymene]₂, 1,3-bis(mesityl)imidazolinium chloride and cesium carbonate is able to perform the transformation of silylated 1,7-enynes into cyclic siloxanes. Selective cleavage of the silicon-carbon and silicon-oxygen bonds by simple reactions has been performed to afford new terpenes and terpenoids by formal addition of a C5 unit.     

Deeper Insight into the Volatile Profile of Rosa willmottiae with Headspace Solid-Phase Microextraction and GC–MS Analysis

As the distribution center of Rosa in the world, China has abundant wild germplasm resources, which can contribute to the breeding of modern roses. To explore the potential value of wild roses distributed in the Sichuan–Tibet region, solid phase microextraction (SPME) and gas chromatography–mass spectrometry (GC–MS) were used to determine the volatile organic compounds (VOCs) in Rosa willmottiae flowers at three flowering stages (bud stage, initial flowering stage, full flowering stage). Meanwhile, we compared the VOCs of R. willmottiae with different phenotypes (double flowers and single flowers). A total of 74 volatile compounds were identified. The results show that the essential substances belong to alcohols and terpenoids. The main volatile organic compounds are 2-phenyl ethanol (20.49%), benzyl alcohol (10.69%), β-maaliene (8.66%), geranyl acetate (8.47%), and (+)-α-long pinene (6.127%). Different flowering stages had great influence on the volatile profile, from the bud stage to full flowering stage; the content of terpenoids released decreased by 6.17%, whereas alcohols and esters increased by 8.58% and 11.56%, respectively. The chemical diversity and the content of the main components with a different phenotype were not significantly different. Our result will provide a theoretical basis for the development and utilization of Rosa willmottiae in Sichuan and Tibet.     

The Effect of Salvia hispanica and Nigella sativa Seed on the Volatile Profile and Sensory Parameters Related to Volatile Compounds of Dry Fermented Sausage

The aim of the study was to evaluate the effects of Salvia hispanica and Nigella sativa seed addition on the volatile compounds and sensory characteristics (with particular emphasis on odor and flavor) of traditionally produced dry fermented sausages with reduced nitrites. Five different sausage formulations were prepared: control sample; samples with 1% and 2% addition of chia seed; samples with 1% and 2% addition of black cumin seed. The sausages were subjected to analysis including proximate chemical composition, volatile compound determination, and sensory analysis. The sausages with chia seed in the amounts of 1% and 2% as well as the sample with 1% addition of black cumin seed were characterized by positive sensory features, and their overall quality was rated above 7 c.u. on a 10-point scale, similar to the control sausage. Sausage samples with the addition of cumin seed were characterized by the highest herbal odor and flavor. The addition of Salvia hispanica and Nigella sativa seed significantly affected the amount of volatile compounds in fermented sausages. Sausages with black cumin presented the greatest amount of total volatile compounds, mainly contributed by terpenes.     

Within-Plant Variation in Rosmarinus officinalis L. Terpenes and Phenols and Their Antimicrobial Activity against the Rosemary Phytopathogens Alternaria alternata and Pseudomonas viridiflava

This study investigated within-plant variability of the main bioactive compounds in rosemary (Rosmarinus officinalis L.). Volatile terpenes, including the enantiomeric distribution of monoterpenes, and phenols were analyzed in young and mature foliar, cortical and xylem tissues. In addition, antimicrobial activity of rosmarinic acid and selected terpenes was evaluated against two rosemary pathogens, Alternaria alternata and Pseudomonas viridiflava. Data showed that total concentration and relative contents of terpenes changed in relation to tissue source and age. Their highest total concentration was observed in the young leaves, followed by mature leaves, cortical and xylem tissues. Rosmarinic acid and carnosic acid contents did not show significant differences between leaf tissues of different ages, while young and mature samples showed variations in the content of four flavonoids. These results are useful for a more targeted harvesting of rosemary plants, in order to produce high-quality essential oils and phenolic extracts. Microbial tests showed that several terpenes and rosmarinic acid significantly inhibited the growth of typical rosemary pathogens. Overall, results on antimicrobial activity suggest the potential application of these natural compounds as biochemical markers in breeding programs aimed to select new chemotypes less susceptible to pathogen attacks, and as eco-friendly chemical alternatives to synthetic pesticides.     

Genome-Wide Analysis of the UGT Gene Family and Identification of Flavonoids in Broussonetia papyrifera

Broussonetia papyrifera is a multifunctional deciduous tree that is both a food and a source of traditional Chinese medicine for both humans and animals. Further analysis of the UGT gene family is of great significance to the utilization of B. papyrifera. The substrates of plant UGT genes include highly diverse and complex chemicals, such as flavonoids and terpenes. In order to deepen our understanding of this family, a comprehensive analysis was performed. Phylogenetic analysis showed that 155 BpUGTs were divided into 15 subgroups. A conserved motif analysis showed that BpUGT proteins in the same subgroups possessed similar motif structures. Tandem duplication was the primary driving force for the expansion of the BpUGT gene family. The global promoter analysis indicated that they were associated with complex hormone regulatory networks and the stress response, as well as the synthesis of secondary metabolites. The expression pattern analysis showed that the expression level of BpUGTs in leaves and roots was higher than that in fruits and stems. Next, we determined the composition and content of flavonoids, the main products of the BpUGT reaction. A total of 19 compounds were isolated and analyzed by UPLC-ESI-MS/MS in 3 species of Broussonetia including B. kazinoki, B. papyrifera, and B. kazinoki × B. papyrifera, and the number of compounds was different in these 3 species. The total flavonoid content and antioxidant capacities of the three species were analyzed respectively. All assays exhibited the same trend: the hybrid paper mulberry showed a higher total flavonoid content, a higher total phenol content and higher antioxidant activity than the other two species. Overall, our study provides valuable information for understanding the function of BpUGTs in the biosynthesis of flavonoids.     

Bauhinia forficata Link Infusions: Chemical and Bioactivity of Volatile and Non-Volatile Fractions

This study aimed to evaluate Bauhinia forficata infusions prepared using samples available in Rio de Janeiro, Brazil. As such, infusions at 5% (w/v) of different brands and batches commercialized in the city (CS1, CS2, CS3, and CS4) and samples of plant material botanically identified (BS) were evaluated to determine their total phenolic and flavonoid contents (TPC and TFC), antioxidant capacity (ABTS^•+, DPPH^•, and FRAP assays), phytochemical profile, volatile compounds, and inhibitory effects against the α-amylase enzyme. The results showed that infusions prepared using BS samples had lower TPC, TFC and antioxidant potential than the commercial samples (p < 0.05). The batch averages presented high standard deviations mainly for the commercial samples, corroborating sample heterogeneity. Sample volatile fractions were mainly composed of terpenes (40 compounds identified). In the non-volatile fraction, 20 compounds were identified, with emphasis on the CS3 sample, which comprised most of the compounds, mainly flavonoid derivatives. PCA analysis demonstrated more chemical diversity in non-volatile than volatile compounds. The samples also inhibited the α-amylase enzyme (IC₅₀ value: 0.235–0.801 mg RE/mL). Despite the differences observed in this work, B. forficata is recognized as a source of bioactive compounds that can increase the intake of antioxidant compounds by the population.     

Chemotaxonomic and morphological classification of six Indigofera species in Jazan region,KSA

The chemical constituent pattern and morphological traits of six species of Indigofera; I. argentea, I. articulata, I. colutea, I. oblongifolia, I. hochstetteri and I. sessiliflora were surveyed and compared. The chemical characters revealed one series for all species using total estimation of secondary metabolites; alkaloids, flavonoids, saponins, tannins, terpenoids and phenolic compounds by using TLC and HPLC analysis. 26 main morphological studies were distinguished as macro and micro- characters. The studied species showed different active phytochemical constituents and high number of morphological characters. Similarity matrix and cluster analysis were constructed based on all traits. The results illustrated that there were some related and distant species by using the tree display graph besides I. hochstetteri is regarded as the transitional species among the studied species. The study confirmed that more studies should be carried out to investigate about unknown phenolic compounds.     

Using thermodesorption-GC/cryocondensation-FT-IR for the measurement of biogenic VOC emissions

For the investigation of terpene emissions from plants a thermodesorption-GC/cryocondensation-FT-IR system was used to complement GC/MS measurements. FT-IR spectra allow to obtain structural information on functional groups, especially if they contain oxygen. Measurements of the release of volatile organic compounds from pine trees (Pinus sylvestris L.) and lavender show the potential of GC/FT-IR to detect and quantify terpenes down to the pg-level. One major advantage of the system is the cryocondensation step on a ZnSe-slide, which allows to scan the substances repeatedly with higher scan number and/or resolution to improve the signal-to-noise ratio.