Exploring the Volatile Composition and Antibacterial Activity of Edible Flower Hydrosols with Insights into Their Spontaneous Emissions and Essential Oil Chemistry.

In the circular economy framework, hydrosols, by-products of the essential oil industry, are gaining attention for their potential in waste reduction and resource reuse. This study analyzed hydrosols from six edible flowers, investigating their chemical composition (VOC-Hyd) and antibacterial properties alongside volatile organic compounds of fresh flowers (VOC-Fs) and essential oils (EOs). Antirrhinum majus exhibited ketones as major VOC-Fs (62.6%) and VOC-Hyd (41.4%), while apocarotenoids dominated its EOs (68.0%). Begonia cucullata showed alkanes (33.7%) and aldehydes (25.7%) as primary VOC-Fs, while alkanes were prevalent in both extracts (65.6% and 91.7% in VOC-Hyd and in EOs, respectively). Calandula officinalis had monoterpenoids in VOC-Fs and VOC-Hyd (89.3% and 49.7%, respectively), while its EOs were rich in sesquiterpenoids (59.7%). Dahlia hortensis displayed monoterpenoid richness in both VOC-Fs and extracts. Monocots species' VOC-Fs (Polianthes tuberosa, Tulbaghia cominsii) were esters-rich, replaced by monoterpenoids in VOC-Hyd. P. tuberosa EO maintained ester richness, while T. cominsii EOs contained a significant percentage of sulfur compounds (38.1%). Antibacterial assays indicated comparable minimum inhibitory concentration profiles across VOC-Hyd: B. calcullata and P. tuberosa against Staphylococcus aureus and Salmonella enterica ser. typhimurium, T. cominsii against Escherichia coli and S. enterica, A. majus and C. officinalis against S. aureus, and D. hortensis against S. enterica.

Phytochemical, Nutritional and Mineral Content of Four Edible Flowers.

The growing interest in functional foods is driven by the exploration of new foods with positive health effects. Pleasant sensory features are essential for consumer acceptance. In this work, we investigated the composition of the bioactive compounds, antioxidant activity, and aroma profiles of four edible flowers: Cucurbita moschata Duchesne, Dianthus chinensis L., Fuchsia regia (Vand. ex Vell.) Munz., and Viola cornuta L. For the first time, we quantified the water-soluble group of B vitamins. Significant variations in the content of soluble sugars, vitamins, and secondary metabolites were observed. V. cornuta showed the highest concentration of vitamin C and carotenoids, while C. moschata had the highest content of vitamin B and flavonoids. F. regia stood out for its exceptionally high content of total phenolics, while D. chinensis surpassed the other flowers in soluble sugar content. The aroma profile analysis revealed a diverse array of volatile organic compounds, with each species having its own unique composition. C. moschata was characterized by p-dimethoxybenzene and D. chinensis by non-terpene compounds; F. regia displayed high amounts of decanal and nonanal, while V. cornuta was rich in myrcene and α-farnesene. These findings provide valuable insights into the secondary metabolites and aroma profiles of these flowers, enhancing our understanding of their bioactive compounds and potential health benefits.

Production of bioactive and aroma volatile compounds of Lawsonia inermis L. cultivated under different growth conditions.

The present study aimed to investigate the influence of different growing conditions on the amount of leaf pigments (chlorophylls, carotenoids), bioactive metabolites, such as polyphenols, flavonoids, lawsone and volatile organic compounds (VOCs) of Lawsonia inermis L. (henna) plants. Young henna plants were cultivated for two months in a growth chamber (GC) and in open-air conditions during summer under the Mediterranean climate (OF), and leaves were analysed to evaluate their adaptive responses. The different growth conditions modified the carbon allocation priorities, increasing antioxidant metabolites (e.g. phenolic and flavonoid compounds) while decreasing lawsone in GC conditions. Quali-quantitative changes were observed for VOCs. This study revealed that GC conditions permit an alternative use of Lawsonia cultivation, because of the increase in the endogenous content of bioactive secondary metabolites with many potential biological activities.

Highly Efficient CRISPR/Cas9 Mediated Gene Editing in Ocimum basilicum 'FT Italiko' to Induce Resistance to Peronospora belbahrii.

Ocimum basilicum (sweet basil) is an economically important aromatic herb; in Italy, approximately 1000 ha of "Genovese-type" basil are grown annually in greenhouses and open fields and are subjected to Downy Mildew (DM) disease, caused by Peronospora belbahrii, leading to huge crop losses. Mutation of the Susceptibility (S) gene DMR6 (Downy Mildew Resistant 6) has been proven to confer a broad-spectrum resistance to DM. In this work, an effective Genome Editing (GE) approach mediated by CRISPR/Cas9 in O. basilicum 'Italiko', the élite cultivar used to produce "Pesto Genovese D.O.P", was developed. A highly efficient genetic transformation method mediated by A. tumefaciens has been optimized from cotyledonary nodes, obtaining 82.2% of regenerated shoots, 84.6% of which resulted in Cas9+ plants. Eleven T0 lines presented different type of mutations in ObDMR6; 60% were indel frameshift mutations with knock-out of ObDMR6 of 'FT Italiko'. Analysis of six T1 transgene-free seedlings revealed that the mutations of T0 plants were inherited and segregated. Based on infection trials conducted on T0 plants, clone 22B showed a very low percentage of disease incidence after 14 days post infection. The aromatic profile of all in vitro edited plants was also reported; all of them showed oxygenated monoterpenes as the major fraction.

The colors of Tuscan bee pollen: phytochemical profile and antioxidant activity.

Bee pollen's nutritional and beneficial health properties depend on the botanical origin and storage conditions. Palynological analysis determines the botanical composition of the multiflora and colour fractions. This study aimed to characterize the phytochemical profile and antioxidant activity of Tuscan bee pollen stored at freezing temperature for 2 years to verify the preservation of nutraceutical properties of the multiflora and colour fractions. Polyphenols, flavonoids content, antioxidant activity and volatile compounds profiles were measured. Non-terpene derivatives (acids and aldehydes) represented the main class of volatile compounds in most analysed samples. Among the colour fractions, coral showed significant differences in the antioxidant compounds. In the multiflora were also determined the soluble sugar content (128.33 mg/g of fresh weight) and mineral content, with the prevalence of K, organic N and Ca. The results suggest that the freezing storage of bee pollen for a long period can be still used as food.

In Vitro Antimicrobial Activity of Thymus vulgaris, Origanum vulgare, Satureja montana and Their Mixture against Clinical Isolates Responsible for Canine Otitis Externa.

Otitis externa is a frequent inflammation among dogs, mainly caused by bacteria and yeasts that are often resistant to conventional drugs. The aim of the present study was to evaluate the in vitro antibacterial and antifungal activities of commercial essential oils (EOs) from Origanum vulgare, Satureja montana, and Thymus vulgaris, as well as a mixture of these three components, against 47 clinical bacterial strains (Staphylococcus sp., Streptococcus sp., Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Serratia marcescens) and 5 Malassezia pachydermatis strains, previously cultured from the ears of dogs affected by otitis externa. The tested Gram-positive bacteria were sensible to the analysed EOs with MICs ranging from 1.25% (v/v) to <0.0195% (v/v); Gram-negative isolates, mainly P. aeruginosa, were less sensitive with MICs from >10% (v/v) to 0.039% (v/v). M. pachydermatis isolates were sensitive to all EOs with MICs from 4.25% (v/v) to 2% (v/v). However, the mixture was active against all bacterial (except one P. aeruginosa strain) and fungal tested isolates. The three EOs and their mixture seem to be an interesting alternative for treating canine otitis externa when conventional antimicrobials are not active.

Echinacea purpurea against neuropathic pain: Alkamides versus polyphenols efficacy.

Chemotherapy-induced neuropathy represents the main dose-limiting toxicity of several anticancer drugs, such as oxaliplatin, leading to chronic pain and an impairment of the quality of life. Echinacea purpurea n-hexane extract (EP4 -RE ; rich in alkamides) and butanolic extract (EP4 -RBU ; rich in polyphenols) have been characterized and tested in an in vivo model of oxaliplatin-induced neuropathic pain, addressing the endocannabinoid system with alkamides and counteracting the redox imbalance with polyphenols. Thermal hypersensitivity was evaluated by the Cold Plate test. EP4 -RE showed a dose-dependent anti-hyperalgesic profile. The extract was more effective than its main constituent, dodeca-2 E,4 E,8Z,10 E/Z-tetraenoic acid isobutylamide (18 mg kg-1 , twofold to equimolar EP4 -RE 30 mg kg-1 ), suggesting a synergy with other extract constituents. Administration of cannabinoid type 2 (CB2) receptor-selective antagonist completely blocked the anti-allodynic effect of EP4 -RE , differently from the antagonism of CB1 receptors. EP4 -RBU (30 mg kg-1 ) exhibited anti-neuropathic properties too. The effect was mainly exerted by chicoric acid, which administered alone (123 µg kg-1 , equimolar to EP4 -RBU 30 mg kg-1 ) completely reverted oxaliplatin-induced allodynia. A synergy between different polyphenols in the extract had not been highlighted. Echinacea extracts have therapeutic potential in the treatment of neuropathic pain, through both alkamides CB2-selective activity and polyphenols protective properties.

Resilience of Stevia rebaudiana (Bertoni) Bertoni in the Underwater Biospheres of Nemo's Garden®: Adaptation to New Cultivation Systems.

The Nemo's Garden® project is an alternative production system for areas with scarce cultivable land but significant presence of water; thus, it is an interesting intervention to address the climate crisis. This work aimed to evaluate the micromorphological, biochemical, and phytochemical characteristics of Stevia rebaudiana (Bertoni) Bertoni grown underwater compared to the terrestrial specimens. The micromorphological analyses, performed on the leaves using light microscopy, fluorescence microscopy, and scanning electron microscopy, evidenced a general uniformity of the trichome morphotype and distribution pattern. The histochemical investigation indicated the simultaneous presence of terpenes and polyphenols in the trichome secreted material from the underwater samples and a prevailing polyphenolic content in the terrestrial specimens; this was also confirmed by biochemical analyses (26.6 mg GAE/g DW). The characterization of non-volatile components, performed using HPLC-MS, showed similar chemical profiles in all the samples, which were characterized by phenolic compounds and steviol glycosides. The volatile compounds, evaluated using HS-SPME coupled with GC-MS, showed sesquiterpene hydrocarbons as the main class in all the analyzed samples (80.1-93.9%). However, the control plants were characterized by a higher content of monoterpene hydrocarbons (12.1%). The underwater biosphere environment did not alter S. rebaudiana micro-morphological characters, although slight qualitative changes were evidenced for the compounds produced as a response to the growth conditions.

Effects of Green Manures (in the Form of Monoculture and Intercropping), Biofertilizer and Organic Manure on the Productivity and Phytochemical Properties of Peppermint (Mentha piperita L.).

Nowadays, the application of sustainable and eco-friendly fertilizers plays an important role in improving the essential oil (EO) quantity and quality of medicinal and aromatic plants. Hence, the study aimed to investigate the effects of green manures, organic manures and biofertilizers on the nutrient content, dry matter yield, EO productivity and quality of peppermint. The treatments included green manures [barley monoculture (Bm), hairy vetch monoculture (HVm) and replacement intercropping of 75%HV + 25%B, 50%HV + 50%B and 25%HV + 75%B], arbuscular mycorrhizal fungi (AMF) and vermicompost (VC). A 50%HV + 50%B green manure appears to be the most effective treatment, since it provides the greatest amount of nutrients (N and K, 18.8 g kg-1, and 18.1 g kg-1, respectively), the tallest plants (61.5 cm), the most nodes per plant (17.5), the lateral branches (24.4), the highest leaf greenness index (45.5) and dry yield (266.7 g m-2) in peppermint. Moreover, this treatment evidenced the larger EO content (1.8%) and EO yield (4.84 g m-2). Regardless of the treatments, the chemical composition of peppermint EO was characterized by menthol (32.35-37.73%), menthone (16.96-20.64%) and 1,8-cineole (6.18-7.78%). The maximum content of menthol and 1,8-cineole was obtained by the application of 50%HV + 50%B. Additionally, the highest content of menthone was observed in AMF treatment. These results indicate that the application of 50%HV + 50%B green manures could be suggested as an environmentally friendly strategy for improving EO quantity and quality of peppermint.

Comparing Metabolomic and Essential Oil Fingerprints of Citrus australasica F. Muell (Finger Lime) Varieties and Their In Vitro Antioxidant Activity.

Comparative chemical analyses among peel and pulp essential oils (EOs) and methanolic extracts of four Citrus australasica varieties (Red, Collette, Pink Ice, and Yellow Sunshine), and the hybrid Faustrime, were performed using GC-MS and UHPLC-DAD-HR-Orbitrap/ESI-MS. Peel and pulp extracts were also analysed for their in vitro antioxidant activity on a Balb/3T3 clone A31 mouse embryo fibroblast cell line. The results of peel and pulp EOs were mainly characterised by monoterpenes and sesquiterpenes, respectively. All peels displayed a higher total phenol content (TPC) than pulps, and consequently a greater antioxidant activity. Collette peels and Pink Ice pulps showed the highest amount of identified flavonoids (e.g., luteolin, isosakuranetin, and poncirin derivatives). Collette and Red peels were rich in anthocyanins (delphinidin and petunidin glycosides), exhibiting the maximum protective activity against induced oxidative damage. In conclusion, finger lime fruits are good sources of health-promoting phytocomplexes, with the Red, Collette, and Pink Ice varieties being the most promising.

Phytochemical Characterization of Citrus-Based Products Supporting Their Antioxidant Effect and Sensory Quality.

The increasing attention on the impact of food on human and environmental health has led to a greater awareness about nutrition, food processing, and food waste. In this perspective, the present work deals with the investigation of the chemical non-volatile and volatile profiles of two Citrus-based products, produced through a conscious process, using Citrus peels as natural gelling agents. Moreover, the total polyphenol content (TPC) and the antioxidant properties were evaluated, as well as their sensorial properties. Chemical and antioxidant results were compared with those of Citrus fresh fruits (C. reticulata, C. sinensis, and C. limon). Concerning the non-volatile fingerprint, the two samples showed a very similar composition, characterized by flavanones (naringenin, hesperetin, and eriodyctiol O-glycosides), flavones (diosmetin and apigenin C-glucosides), and limonoids (limonin, nomilinic acid, and its glucoside). The amount of both flavonoids and limonoids was higher in the Lemon product than in the Mixed Citrus one, as well as the TPC and the antioxidant activity. The aroma composition of the two samples was characterized by monoterpene hydrocarbons as the main chemical class, mainly represented by limonene. The sensorial analysis, finally, evidenced a good quality of both the products. These results showed that the most representative components of Citrus fruits persist even after the transformation process, and the aroma and sensorial properties endow an added value to Citrus preparations.

Exploitation of Marginal Hilly Land in Tuscany through the Cultivation of Lavandula angustifolia Mill.: Characterization of Its Essential Oil and Antibacterial Activity.

Lavandula angustifolia Mill., known as one of the best essential oil-bearing plants, is an aromatic plant that is well cultivated in many Mediterranean regions due to its adaptability to variations in climatic and edaphic conditions. Therefore, its essential oil (EO) composition and its antimicrobial activity change as a consequence of abiotic and biotic factors. The chemical composition of L. angustifolia EO collected during four consecutive years of growth was one of the aims of this work. The volatile profile evidenced the prevalence of linalool and linalool acetate even though they switched their positions according to age. Plants in their first year were characterized by a high amount of sesquiterpene compounds (22.1% of the identified fraction). This percentage decreased during plant growth, not representing more than 5.3% in the fourth year. It is interesting to note that both the third- and fourth-year plants showed a content of monoterpenes that exceeded 90% of the total identified constituents. The EO extracted from the oldest plants evidenced higher activity on the studied strains, with more sensitivity on the Gram-positive ones. Tuscan lavender EO, especially that obtained from the four-year-old plants, is of great interest for its potential industrial applications and constitutes an example for the valorization of marginal Tuscan land and good-quality production.

Halophyte Artemisia caerulescens L.: Metabolites from In Vitro Shoots and Wild Plants.

Halophyte plants are potential resources to deal with the increasing soil salinity determined by climatic change. In this context, the present study aimed to investigate the germplasm conservation of Artemisia caerulescens collected in the San Rossore Estate (Pisa, Italy) through in vitro culture, biochemical properties, and the phytochemical composition of the volatile fraction of both in vitro shoots and different organs of wild plants (leaves, young and ripe inflorescences). The best medium tested for the shoot proliferation was MS, with the addition of 1 µM BA. Total polyphenol content and antioxidant activity were noticeable in both the inflorescences, while leaves and in vitro shoots showed lower amounts. Concerning the phytochemical investigation, the headspaces (HSs) and the essential oils (EOs) were characterized by oxygenated monoterpenes as the main chemical class of compounds in all samples, and with α- and ß-thujone as the major constituents. However, the EOs were characterized by noticeable percentages of phenylpropanoids (23.6-28.8%), with brevifolin as the unique compound, which was not detected in the spontaneous volatile emissions of the same parts of the wild plant. Good amounts of EOs were obtained from different organs of the wild plant, comprising between 0.17% and 0.41% of the young and ripe inflorescences, respectively.

Valorization of a Waste Product of Edible Flowers: Volatile Characterization of Leaves.

(1) Background: The leaves of some plants are reported for their culinary uses, while in edible flowers, they are one of the discarded products in the supply chain. We investigated the volatile profile (VP) and the essential oil (EO) compositions of leaves from 12 Lamiaceae species, of which nine belong to the Mentheae tribe and three to the Ocimeae tribe. (2) Methods: Phytochemical analyses were performed using a GC-MS instrument. (3) Results: More than 53% of the Ocimeae tribe VP was represented by sesquiterpene hydrocarbons (SH), followed by phenylpropanoids, except for O. × citriodorum, where oxygenated monoterpenes (OM) were the second main class. OM prevailed in six species of the Mentheae tribe except for Agastache 'Arcado Pink', Salvia discolor, and S. microphylla, where SH dominated. The EO composition of Ocimeae tribe showed a similar behavior to that of VP concerning the predominant classes. O. basilicum 'Blue Spice' (Ob-BS) was an exception, since it showed oxygenated sesquiterpenes (OS: 29.6%) as a second principal class. Sesquiterpene compounds were also present in a high amount in two species of the Salviinae subtribe (S. microphylla and S. discolor) and two of the Nepetinae subtribe (Nepeta × faasenii and A. 'Arcado Pink'). The remaining species of the Mentheae tribe were characterized by OM. (4) Conclusions: Many of the main compounds found were reported for their importance in human health and thus are important as ingredients in several new industrial products.

Essential oil composition of Salvia rosmarinus Spenn. wild samples collected from six sites and different seasonal periods in Elba Island (Tuscan Archipelago, Italy).

The hydrodistilled essential oils from eighteen samples of Salvia rosmarinus Spenn. collected in six localities of Elba Island (Tuscany, Italy) during three different seasonal periods were analyzed by GC-MS for the first time. Fifty-five components were identified, representing 96.8-99.6% of the total chemical composition. All the tested essential oils were characterized by a high content of monoterpenes (oxygenated 49.2-80.3%; hydrocarbons 18.7-48.3%). Among them, 1,8-cineole (26.4-49.1%), α-pinene (4.5-34.8%), camphor (1.1-18.8%) and borneol (1.7-16.2%) were the main constituents. The high amount of 1,8-cineole/α-pinene/camphor/borneol may suggest the presence of an intermediate rosemary chemotype. Statistical analysis was also performed on the essential oil (EO) composition evidenced an expected difference depending on the collection seasons, to the geographical areas and soil composition. A comparison with the essential oil composition from S. rosmarinus collected in all the other islands of Tuscan Archipelago (Italy) was also reported, together with a Multivariate Statistical Analysis.

Volatiloma analyses of four South African Helichrysum spp. grown in Italy.

The volatiloma of four Helichrysum species (H. anomalum, H reflexum, H. retortum and H. rugulosum) was analysed here for the first time by GC-MS for a chemotaxonomic contribution to this genus. Sesquiterpene hydrocarbons (SHs) prevailed in the aroma profile (VOCs) of H. reflexum, H. rugulosum and H. anomalum (74.7%, 93.6% and 41.6%, respectively), even though the main compounds were different (ß-caryophyllene, α-humulene and α-copaene, respectively). The VOCs of H. retortum showed a high percentage of aliphatic hydrocarbons (NTs, 77.7%) mainly represented by octyl ether. The essential oil composition of each of H. rugulosum and H. retortum followed the same trend as VOCs related to the main class (SHs and NTs, respectively). In H. reflexum EO, the SHs were replaced by oxygenated sesquiterpenes (OS, 49.0%) with caryophyllene oxide as the main compound, while in H. anomalum the SHs were swapped in NTs (37.3%).

In vitro antimicrobial activity of selected essential oils against bacteria and yeasts isolated from the genital tract of mares.

The aim of the present study, the first to test clinical equine isolates, was to evaluate the antimicrobial activity of commercial essential oils (EOs) obtained from Origanum vulgare, Thymus vulgaris, Cinnamomum zeylanicum, Cymbopogon citratus, Aloysia triphylla and Syzygium aromaticum against Streptococcus spp., Staphylococcus spp., Candida albicans and Rhodotorula spp. previously isolated from uteri of mares with reproductive disorders. T. vulgaris showed the best antibacterial activity against all the selected agents, with MICs ranging from 0.07 mg/mL for S. equi subsp. zooepidemicus to 0.29 mg/mL versus Streptococcus sp. and Staphylococcus spp. isolates and versus C. albicans and Rhodotorula spp., with MICs of 0.46 mg/mL and 1.86 mg/mL, respectively. O. vulgare, S. aromaticum, C. zeylanicum EOs showed good antibacterial activity with MICs ranging from 0.07 mg/mL to 0.29 mg/mL, 0.16 mg/mL to 0.32 mg/mL, 0.07 mg/mL to 0.63 mg/mL, respectively; A. triphylla was the most active EO against Rhodotorula spp. (0.43 mg/mL).

Prosocial Effects of Nonpsychotropic Cannabis sativa in Mice.

Introduction:Cannabis sativa L. (C. sativa) is used since ancient times to produce fabrics, baskets, and cords. Later, different ethnic groups used to burn the leaves and flowers of psychotropic cultivars with high Δ9-tetrahydrocannabinol (D9-THC) levels, during the religious or propitiatory rites to alter the state of consciousness. To date, it is not known whether also nonpsychotropic cultivars of C. sativa were used during these rites, and whether these varieties could have an effect on human behavior. This study aimed to evaluate the behavioral effects of an extract of nonpsychotropic C. sativa (NP-CS) in mice. Materials and Methods: An extract of a nonpsychotropic cultivar of C. sativa dissolved in medium-chain triglyceride oil was used and the different phytochemical components were evaluated. The relative composition in terms of phytocannabinoid content was assessed by reverse phase high-performance liquid chromatography coupled to UV detection (RP-HPLC-UV), and the volatile components were analyzed by gas chromatography-mass spectrometry (GC-MS). In addition, the behavioral effect of NP-CS was assessed on a wild-type mouse model. The animals were treated for 14 days (oral gavage) and motility, anxiety, and social effects were assessed. Results: RP-HPLC-UV analysis demonstrated that D9-THC was present in lower concentration with respect to other cannabinoids, like cannabidiol. Furthermore, the GC-MS analysis revealed the presence of several terpenoids. Concerning in vivo studies, chronic treatment with NP-CS did not alter body weight, motility, and anxiety and increased social interaction. Conclusions: This study highlighted the prosocial effects of NP-CS.

Screening of the essential oil effects on human H1N1 influenza virus infection: an in vitro study in MDCK cells.

Nineteen essential oils (EOs) obtained from different plants have been evaluated for their potential in vitro anti-H1N1 influenza virus efficacy. Both multivariate analyses and bivariate correlation were performed to better understand how the composition influences the activity. The results evidenced that for the laboratory distilled EOs both rosemary hybrids (S. x lavandulaceus and S. x mendizabalii) showed a good antiviral activity with low cytotoxic effect. Concerning the commercial ones: Eucalyptus globulus and Juniperus communis EOs exhibited virtuous effects on influenza virus. These results were confirmed by the multivariate analyses and only eucalyptol showed a positive correlation with cell viability. On the contrary, o-cymene and terpinolene correlated to the inhibitory effect. Rosemary hybrids, E. globulus and J. communis could be considered as promising candidate to develop new alternative anti-H1N1 natural agent.

Volatolomics of Three South African Helichrysum Species Grown in Pot under Protected Environment.

Helichrysum decorum DC, Helichrysum lepidissimum S. Moore, and Helichrysum umbraculigerum are three species traditionally used in the South African medicine. The present work deals with the investigation of the spontaneous emission and the essential oils obtained from these plants cultivated in open field under uniform conditions. Fractions of the volatile organic compounds of the three species were rich in monoterpene hydrocarbons, representing more than 70% of the total composition. Pinene isomers were the most representative compounds: ß-pinene in H. decorum (53.0%), and α-pinene in H. lepidissimum (67.9%) and H. umbraculigerum (54.8%). These latter two species evidenced an important amount of sesquiterpene hydrocarbons (SH) especially represented by γ-curcumene (H. lepidissimum) and α- and ß-selinene (H. umbraculigerum). On the contrary, in the EOs, sesquiterpenes compounds prevailed, representing more than 64% of the identified fraction to reach more than 82 and 87% in H. umbraculigerum and H. lepidissimum, respectively. Although the chemical classes and their relative abundances were comparable among the three species, the individual compounds of EOs showed large differences. In fact, caryophyllene oxide (26.7%) and γ-curcumene (17.4%) were the main constituents in H. decorum, and H. lepidissimum respectively, while neo-intermedeol (11.2%) and viridiflorol (10.6%) characterized H. umbraculigerum.