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Abstract: The volatile composition of ten fibre hemp (Cannabis sativa L.) varieties was investigated during two successive growing seasons under temperate climatic conditions in Central Italy. The freshly plant inflorescences were hydrodistilled and the essential oils (EOs) were characterized by GC–MS. In addition, the composition of the aroma emitted spontaneously from the freshly plant inflorescences were analysed by SPME-GC–MS. The EO yields of eight dioecious (Carmagnola, C.S., Red Petiole, Pop 1, Pop 2, Pop 3, Pop 4, Pop 5) and two monoecious (Codimono and Felina 34) cultivars ranged from 0.11 to 0.25% (w/w) and showed a significant production of α-pinene (3–20%), β-pinene (1–8%), E-ocimene (1–10%), myrcene (8–45%) and terpinolene (0.12–22%). The monoterpene composition was useful to distinguish the monoecious cultivars from the dioecious ones. β-Caryophyllene (7–28%), α-humulene (3–12%), and caryophyllene oxide (2–6%) were the main sesquiterpenes. Tetrahydrocannabinol (THC) was present in traces in the EOs of only two dioecious cultivars cultivated in 2005. Cannabinol (CBN) was not detected in the essential oils, while the no-hallucinogenous cannabidiol (CBD) was found as typical volatile constituent in several analysed cultivars. These findings were also confirmed by the headspace GC–MS analysis carried out on the same samples. The analysed EOs obtained from fibre hemp varieties cultivated in Central Italy were characterized by an interesting and specific terpene composition with a legal and safe cannabinoid content. They were obtained from freshly plant inflorescences, which usually represent a waste material from C. sativa L. fibre varieties. The present study strengths the hypothesis to grow hemp as a multi-use crop through a complete utilization of the plant material using inflorescences to produce essential oils as natural flavour and fragrance additives. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • New insights regarding the mechanisms and processes involved in S. dolomitica drought adaptation are provided. • Moderate drought decreased growth, leaf water potential and stomatal conductance, while increased deyhdrin gene expression. • Severe drought decreased net photosynthesis and transpiration rate. • Drought increased sesquiterpene production by modulating gene expression of key enzymes of terpenoid biosynthesis. • Moderate drought can ameliorate secondary metabolites production and water-management practices in S. dolomitica. Abstract Sage is an important medicinal and aromatic plant. While Salvia officinalis and S. miltiorrhiza have been widely studied, little information regarding S. dolomitica exists, although it has recently attracted attention due to its anti-plasmodial and anti-inflammatory properties. This study investigated the performance and metabolic profile of this species in response to two drought treatments (moderate or severe) relative to well-watered control plants. Changes in growth and ecophysiological traits, as well as in bioactive and volatile compounds and essential oil production were determined. Given that terpenoids are the most representative class of secondary metabolites, the gene expression of key enzymes of terpenoid biosynthesis was also investigated. Moderate drought stimulated a decline in leaf water potential, growth and stomatal conductance, as well as an increase in deyhdrin expression. Serious stress symptoms occurred only in severe drought-stressed plants, where a decline in net photosynthesis and transpiration and an increase in endogenous abscisic acid was observed. Both drought stress conditions led to modulate the expression of some genes involved in biogenic volatile organic compound and essential oil biosynthesis and metabolic profile. In particular, drought induced an increase in sesquiterpene production, a class of terpenoids that is important in the food, cosmetics, and pharmaceutical industries. Thus, controlled drought, in addition to water savings during cultivation, can be applied to improve the production of secondary metabolites in S. dolomitica. [ABSTRACT FROM AUTHOR]

The inflorescences of Cannabis sativa L. represent a high-value by-product of industrial hemp cultivation, and their volatile fraction has recently attracted attention due to the applications of hemp-derived Essential Oil (EO) in several fields. Following a previous evaluation of the EOs profile in diverse hemp genotypes, the current study investigated how the phenological stage of inflorescences affects the EO chemical composition and hydrodistillation yield. Two hemp varieties with different flower behaviour, Codimono (monoecious) and Fibrante (dioecious), were cultivated in open field, and the flowering tops were collected at five developmental stages. The air-dried samples were hydrodistilled with a Clevenger apparatus, and the obtained EOs were analysed by Gas Chromatography coupled with Mass Spectrometry (GC-MS). All the samples showed terpenes and phytocannabinoids as major chemical classes. Among the former class, sesquiterpene hydrocarbons were the most abundant components in the EOs at all phenological stages, ranging from 34.1% to 67.6% and 33.8–73.8% in Codimono and Fibrante, respectively, while oxygenated sesquiterpenes were highest at the final stage (27.7% in Codimono and 24.0% in Fibrante). Phytocannabinoids, instead, were the second major chemical class, accounting for 29.3% in Codimono and 30.5% Fibrante. The EO yield increased with phenological development, reaching the highest rate at seed harvest time in both genotypes (0.018–0.265% w/w in Codimono and 0.026–0.265% w/w in Fibrante). [Display omitted] • Phytocannannabinoids are greatest at seed maturity in inflorescences and their EO. • Sesquiterpene hydrocarbons are the main chemical class of the hemp essential oil. • BBCH 69 and 87 are the optimal stages for the EO production. [ABSTRACT FROM AUTHOR]

The volatile fractions and essential oils from Rhus coriaria fruits collected in four locations in Sicily (Italy) were characterized by GC–FID and GC–MS analysis. Monoterpenes were identified as the main class of constituents in volatiles spontaneously emitted by sumac fruits collected in two of the four sites (42.1–59.9% in ‘CNS’ and ‘CIN’ respectively), while non terpenic compounds predominated in the other two (46.1–52.8% in ‘MR’ and ‘CG’, respectively). The EO composition were characterized by high amount of non terpenic compounds (from 27.5 to 55.1%), followed by sesquiterpenes and diterpenes. p -anisaldehyde was the main constituent both in volatiles emitted by ‘CG’ sample and in its essential oil (28.4 and 20.8%, respectively). The comparison between the EOs obtained from the Sicilian samples differed from the EO obtained from sumac fruits purchased on the Jordanian market, even though a similar composition were evidenced with Turkish samples reported in the literature. [ABSTRACT FROM AUTHOR]

The emergence of new multidrug-resistant (MDR) pathogens brought attention to the need for new antimicrobial compounds. One of the advances in addressing the global issue of antibiotic resistance is the discovery that microorganisms residing inside medicinal plants (i.e., the endophytes) may contribute to the production of metabolites of pharmaceutical interest. In this work, the composition of the essential oil (EO) and the cultivable bacterial communities isolated from three different species belonging to the genus Origanum , i.e., O. vulgare ssp. vulgare, O. vulgare ssp. hirtum and O. heracleoticum were analyzed, to check the possible nexus existing between them. The three species exhibited different EO aroma profiles, revealing two trans -sabinene hydrate chemotypes and a carvacrol chemotype. The composition of the bacterial endophytic cultivable microbiome isolated from flowers, leaves, and stems and the bacterial communities isolated from bulk soil were characterized at the genus, species, and/or strain level. The analyses revealed a high degree of biodiversity and a low number of strains shared between the three plant species and compartments of the same plant, suggesting the existence of one or more forces responsible for the distribution of the endophytes in the different microenvironments of the plant. Data obtained also suggested that the composition of the EO might be involved in the structuring of the microbial community and that bacteria might be able to colonize the plant since they are resistant to the antimicrobial activity exhibited by the EO itself and/or able to utilize some compounds as a carbon and energy source. Lastly, the composition of microbial communities might enhance or influence the EO composition. [Display omitted] • Three Origanum plants exhibited different essential oil aroma profiles. • Cultivable bacterial endophytes were isolated and molecularly characterized. • A very low number of bacterial strains was shared between plants. • Different plant compartments were inhabited by different endophytic communities. • Essential oil composition might be involved in the structuring of the microbiome. [ABSTRACT FROM AUTHOR]

The genus Helichrysum Miller is a source of many bioactive metabolites commonly used in traditional medicine. In particular, Helichrysum petiolare Hilliard & B.L. Burtt shows activities as antiseptic, anti-inflammatory and in the control of anxiety disorder. Biosynthesis and accumulation of secondary metabolites is a defense mechanism of plants and it is strictly influenced by the surrounding environmental conditions. In this study, drought was imposed on H. petiolare (HEL008 clone CREA-Sanremo collection) to understand the effect of water stress on the dynamics of plant biomass and secondary metabolites production, and the morphological and physiological mechanisms involved in plant responses. H. petiolare was cultivated for 34 days under three water regimes: 100% of container capacity (CC, control), 50% CC (moderate water stress), and 0% CC (severe water stress). Plant growth traits, leaf water potential, gas exchange parameters, phenol, flavonoid, and anthocyanin content, and antioxidant activity changes were determined twice a week, while the volatile organic compounds (VOCs) and essential oils (Eos) at the end of the trial. Severe water stress dramatically reduced aerial and root dry weight, chlorophyll and carotenoid content, leaf water potential, water use efficiency (WUE, A / E ), transpiration rate ( E ), stomatal conductance ( gs ), net photosynthetic rate ( A ) and antioxidant activity. Moderate water stress induced only slight changes and led to an increase of WUE at the end of the experiment. The total amount of VOCs and Eos was not affected by water stress while their quality changed. Moderate water stress increased the main constituents of both VOCs, i.e. the monoterpene hydrocarbons, and Eos, i.e., the oxygenated sesquiterpenes. In conclusion, this H. petiolare cultivation under the applied moderate drought condition could lead to a double benefit i.e., water-saving irrigation practice and high quality metabolite production. [ABSTRACT FROM AUTHOR]

The main constituents of essential oil (EO) of Origanum syriacum L. collected from cultivated and growing wild in Sinai, Egypt were identified and determined by GC–MS. The antimicrobial activity of these essential oils against Gram positive and Gram negative bacterial strains was studied. The antimycotic activity of these EOs was also evaluated against eight fungal strains isolated from different sources. Forty-six compounds were identified in the EO of both samples, dominated by carvacrol in cultivated type. Thymol, γ-terpinene, linalool and 4-terpineol were the most represented constituents in O. syriacum plants collected from wild populations. Both EOs showed antibacterial activity with varying magnitudes, while EO from cultivated O. syriacum showed high antibacterial activity against Staphylococcus aureus with an inhibition zone of 32 ± 4.0 mm. Both EOs showed good antifungal activity against all fungal strains. O. syriacum EO from cultivated plants showed the lowest MIC 0.25 mg/L with Aspergillus fumigates clinical strain isolated either with Aspergillus flavus. [ABSTRACT FROM AUTHOR]

Six weld genotypes (Reseda luteola L.) were evaluated for their agronomic characteristics in a 4-year field study carried out under rainfed condition in Central Italy in order to point out productive potential and the best harvest time to maximise yield of dye. Good agronomic performances were observed with an overall dry yield of about 40 g per plant and an estimated dry yield per hectare of 2.8 tons. Differences were found among the six accessions and some of them withstanded well to drought conditions experienced in drier growing seasons. The harvest of plants during flowering or during beginning of fruit ripening did not affect overall dry yield (40 and 45 g per plant at flowering and fruit maturity, respectively). The luteolin amount (expressed in mg g−1 dry weight) was affected by climatic conditions as experienced in two different growing seasons (1993 and 1994) and by the plant phenological stages at harvest being luteolin most abundant in the dryest year and in plants harvested during flowering. Genetic variability existed for the luteolin content in leaves plus reproductive structures (inflorescences and fruits) that varied from 13.6 to 28.7 mg g−1 dry weight in the six accessions tested in 1994. The dry powder from leaves and reproductive structures was used in the dyeing of cotton, wool and silk yarns. Good and bright yellow colours were observed using a ratio 30:100 (weight/weight) of weld on the textile materials. Separated weld organs showed different dyeing capacities being the leaves, inflorescences and fruits the most effective ones. Weld showed a progressive decrease in resistance to fading going from cotton, to the other kind of yarns. Finally, all dyed specimens exhibited good resistance to light and wash fastness making the use of weld a viable alternative to synthetic yellow dyes. [Copyright &y& Elsevier]