Characterization of the Essential oil of the Bat-Pollinated Passiflora mucronata

The genus Passiflora is an important source of food, therapeutic substances and for the horticultural economy. In the last decades, a detailed chemical composition of the essential oil of Passiflora species has been reported, but only for few species, mainly of agricultural interest, although little attention has been paid to chiropterophilous Passifloraceae, such as P. mucronata. The present study is focused on analyzing the essential oil composition of P. mucronata, a Brazilian bat-pollinated species. From GC/FID and GC/MS analyses of the volatile fraction from fresh flowers and leaves, hydrocarbons were quantified as 47.9% and 42.8% of the total volatiles of flowers and leaves, respectively, esters for 50.8% in flowers and 6.4% in leaves, and alcohols 38.2% and 0.3% of the total volatiles from leaves and flowers, respectively. Other classes of compounds, such as monoterpenes and aldehydes, together with phytol, were detected in higher concentration in leaves compared with flowers. The higher content of methyl and ethyl esters of long chain saturated and unsaturated fatty acids, i.e. ethyl linolenate (38.3%), methyl linolenate (7.0%) and ethyl palmitate (3.6%), were the most representative suggesting that esters might play a critical role for fertilization of P. mucronata acting as bat attractors

Composition of Volatile Fraction from Inflorescences and Leaves of Dendrobium moschatum (Orchidaceae)

The volatile fractions from fresh inflorescences and leaves of Dendrobium moschatum (Buchanan-Hamilton) Swartz (Orchidaceae) were isolated by steam distillation with a yield of 0.498% and 0.041% (weight/fresh weight basis), respectively. From GC/FID and GC/MS analyses, coumarin was identified to be the most abundant constituent and quantified as 48.8% and 47.8% of the total volatiles from inflorescences and leaves, respectively. Hydrocarbons, ketones, esters, acids and aldehydes were also detected. Long chain mono unsaturated hydrocarbons were quantified in higher amount in leaves and their structures were elucidated by GC/MS of their dimethyl disulfide derivatives. These compounds together with long chain ethyl esters and methyl ketones may represent a particular feature of this plant species and can play a critical role in the interaction with pollinator insect

Chemical composition of the essential oils from leaves and flowers of Passiflor sexocellata and Passiflora trifasciata

The chemical composition of the essential oils of Passiflora sexocellata and Passiflora trifasciata (Passifloraceae, subgenus Decaloba) were studied for the first time. Essential oils were obtained by steam distillation of fresh leaves and flowers. The chemical composition was assessed by using GC/FID and GC/MS. For P. sexocellata leaves, the optimized analytical procedure allowed the identification of 33 compounds (75% of the total oil composition) and 29 (74% of the total oil composition) in flowers. Regarding P. trifasciata, 35 compounds (76% of the total oil composition) were detected in leaves and 32 (71% of the total oil composition) in flowers. Terpenes and mono unsaturated hydrocarbons were quantified as major constituents of the volatile fraction in flowers (17.0 to 52.6%) and (13.7 to 20.0%). Organic acids were detected in both leaves and flowers with a percentage ranging from 3.3% to 32.0%. Aldehydes were also detected in leaves (12.6 to 41.4%) and in flowers (1.4 to 5.1%). The GC/MS analyzes allowed alcohols to be detected in leaves (20.6 to 42.9%) and in flowers (8.2 to 18.1%). These compounds represent the most important feature of the large Passiflora family. Moreover, a critical role in the coevolved mechanisms of pollinators' interaction has been investigated

Microwave-Assisted and Conventional Extractions of Volatile Compounds from Rosa x damascena Mill. Fresh Petals for Cosmetic Applications

Rosa x damascena Mill. essential oil is mainly used in the cosmetics and perfumery industry, but it also finds application in the food industry as a flavoring agent. The chemical composition of essential oils is affected by environment, soil, harvesting technique, storage condition, and extraction methods. Nowadays, the study and design of greener, more efficient, and sustainable extractive procedures is the main and strategic focus in the chemical research and development of botanical derivatives, especially as regards fragrances and essential oils. Several technologies are available, and the best method to use depends on the desired chemicals, but conventional extractive processes are often laborious and time-consuming, involve large amounts of solvents, and may cause the partial loss of volatiles, affecting the quality of the final product. In the last decade, microwave irradiation has been successfully applied to classical techniques, often improving the general extractive efficiency and extract quality. In the present paper, as a preliminary analytical screening approach, two microwave-mediated techniques, Solvent-Free Microwave Extraction (SFME) and Microwave Hydrodiffusion and Gravity (MHG), and two conventional procedures, Hydrodistillation (HD) and Steam Distillation (SD), were applied and compared for the extraction of volatile compounds from R. x damascena fresh petals to highlight differences and advantages of the selected procedure and of the obtained extracts useful in a cosmetic context as fragrances or active ingredients. The chemical composition of the extracts was investigated by GC-MS and GC-FID. Sixty-one components, distributed in the four techniques, were identified. SD and HD are dominated by oxygenated terpenes (59.01% and 50.06%, respectively), while MHG and SFME extracts are dominated by alcohols (61.67% and 46.81%, respectively). A relevant variability in the composition of the extracts relating to the extraction techniques used was observed. To point out the correlation between the process and composition of the obtained natural products, principal component analysis (PCA) of the data extracted from GC-FID was used. Taking into account a cosmetic application, SFME shows several advantages when compared with the other procedures. The extract (obtained in a significantly higher amount) contains a meaningful lower level of potential fragrance allergenic compounds and quite a double amount of benzyl alcohol and 2-phenyl ethanol that can also enhance the preservative action in personal care products

Volatile Organic Compounds (VOCs) Diversity in the Orchid Himantoglossum robertianum (Loisel.) P. Delforge from Sardinia (Italy)

Volatile Organic Compounds (VOCs) are produced by plants to address a variety of physiological and ecological tasks (among others, stress resistance, and pollinator attraction). Genetics is a key factor in determining plants’ VOCs content and emission, nevertheless, environment strongly influences VOCs profiles in plants. Orchids are a widespread group of plants that colonize diverse environments and rely on complex and refined pollination mechanisms to reproduce. Orchids VOCs are rarely studied and discussed in relation to growing conditions. In the present study, we compare the volatile profiles of inflorescences of Himantoglossum robertianum (Loisel.) P. Delforge sampled in six ecologically diverse populations on Sardinia Island (Italy). The essential oils obtained by steam distillation were characterized by GC‐FID and GC‐MS analysis. A total of 79 compounds were detected, belonging to the chemical classes of saturated hydrocarbons, esters, alcohols, ketones, unsaturated hydrocarbons, sesquiterpenes, oxygenated terpenes, terpenes, acids, and aldehydes. Multivariate statistics separated H. robertianum populations based on their chemical profiles. Differences were positively linked to the distance separating populations and reflected climatological features of the sampling sites. Interestingly, our results differed from those available in the literature, pointing out the high variability of VOCs profiles in this food‐deceptive orchid

Chemical Composition of Essential Oil from Flowers of Five Fragrant Dendrobium (Orchidaceae)

A detailed chemical composition of Dendrobium essential oil has been only reported for a few main species. This article is the first to evaluate the essential oil composition, obtained by steam distillation, of five Indian Dendrobium species: Dendrobium chrysotoxum Lindl., Dendrobium harveyanum Rchb.f., and Dendrobium wardianum R.Warner (section Dendrobium), Dendrobium amabile (Lour.) O’Brien, and Dendrobium chrysanthum Wall. ex Lindl. (section Densiflora). We investigate fresh flower essential oil obtained by steam distillation, by GC/FID and GC/MS. Several compounds are identified, with a peculiar distribution in the species: Saturated hydrocarbons (range 2.19–80.20%), organic acids (range 0.45–46.80%), esters (range 1.03–49.33%), and alcohols (range 0.12–22.81%). Organic acids are detected in higher concentrations in D. chrysantum, D. wardianum, and D. harveyanum (46.80%, 26.89%, and 7.84%, respectively). This class is represented by palmitic acid (13.52%, 5.76, and 7.52%) linoleic acid (D. wardianum 17.54%), and (Z)-11-hexadecenoic acid (D. chrysantum 29.22%). Esters are detected especially in species from section Dendrobium, with ethyl linolenate, methyl linoleate, ethyl oleate, and ethyl palmitate as the most abundant compounds. Alcohols are present in higher concentrations in D. chrysantum (2.4-di-tert-butylphenol, 22.81%), D. chrysotoxum (1-octanol, and 2-phenylethanol, 2.80% and 2.36%), and D. wardianum (2-phenylethanol, 4.65%). Coumarin (95.59%) is the dominant compound in D. amabile (section Densiflora) and detected in lower concentrations (range 0.19–0.54%) in other samples. These volatile compounds may represent a particular feature of these plant species, playing a critical role in interacting with pollinators