Influence of Different Isolation Methods on Chemical Composition and Bioactivities of the Fruit Peel Oil of Citrus medica L. var. sarcodactylis (Noot.) Swingle.

Background: The chemical composition and bioactivities of essential oils (EOs) of fingered citron (Citrus medica L. var. sarcodactylis (Noot.) Swingle) are considerably sensitive and lapsible during high-temperature processing of traditional separating techniques. In the present research, vacuum distillation and ultrafiltration were utilized in order to process the concentrated juice from fingered citron, obtaining a high-quality essential oil. Methods: In order to compare the essential oils obtained by conventional means, the chemical compositions of the essential oils were analyzed using GC-MS, before antimicrobial and antioxidant screening assays were carried out. Results: Oil which had been subjected to vacuum distillation was shown to maintain most of the distinctiveness of the fingered citron, due to its high content of characteristic flavor components and low content of cyclic oxygenated monoterpenoids. Interestingly, the oil obtained by ultrafiltration showed notable in vitro antimicrobial activity. The DPPH· radical-scavenging assay method revealed that the antioxidant abilities were as follows, presented in descending order: vacuum distillation oil > hydrodistillation oil > ultrafiltration oil. Conclusions: The essential oil obtained by vacuum distillation could be combined with the juice produced from fingered citron to create one of the most promising techniques in the fine-processing of citron fruits.

The Chemotaxonomy of Common Sage (Salvia officinalis) Based on the Volatile Constituents.

Background: Common sage (Salvia officinalis) is a popular culinary and medicinal herb. A literature survey has revealed that sage oils can vary widely in their chemical compositions. The purpose of this study was to examine sage essential oil from different sources/origins and to define the possible chemotypes of sage oil. Methods: Three different samples of sage leaf essential oil have been obtained and analyzed by GC-MS and GC-FID. A hierarchical cluster analysis was carried out on 185 sage oil compositions reported in the literature as well as the three samples in this study. Results: The major components of the three sage oils were the oxygenated monoterpenoids α-thujone (17.2-27.4%), 1,8-cineole (11.9-26.9%), and camphor (12.8-21.4%). The cluster analysis revealed five major chemotypes of sage oil, with the most common being a α-thujone > camphor > 1,8-cineole chemotype, of which the three samples in this study belong. The other chemotypes are an α-humulene-rich chemotype, a ß-thujone-rich chemotype, a 1,8-cineole/camphor chemotype, and a sclareol/α-thujone chemotype. Conclusions: Most sage oils belonged to the "typical", α-thujone > camphor > 1,8-cineole, chemotype, but the essential oil compositions do vary widely and may have a profound effect on flavor and fragrance profiles as well as biological activities. There are currently no studies correlating sage oil composition with fragrance descriptions or with biological activities.

The Chemical Compositions of the Volatile Oils of Garlic (Allium sativum) and Wild Garlic (Allium vineale).

Garlic, Alliumsativum, is broadly used around the world for its numerous culinary and medicinal uses. Wild garlic, Allium vineale, has been used as a substitute for garlic, both in food as well as in herbal medicine. The present study investigated the chemical compositions of A. sativum and A. vineale essential oils. The essential oils from the bulbs of A. sativum, cultivated in Spain, were obtained by three different methods: laboratory hydrodistillation, industrial hydrodistillation, and industrial steam distillation. The essential oils of wild-growing A. vineale from north Alabama were obtained by hydrodistillation. The resulting essential oils were analyzed by gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Both A. sativum and A. vineale oils were dominated by allyl polysulfides. There were minor quantitative differences between the A. sativum oils owing to the distillation methods employed, as well as differences from previously reported garlic oils from other geographical locations. Allium vineale oil showed a qualitative similarity to Allium ursinum essential oil. The compositions of garlic and wild garlic are consistent with their use as flavoring agents in foods as well as their uses as herbal medicines. However, quantitative differences are likely to affect the flavor and bioactivity profiles of these Allium species.

Chemotypic Variation of Conocephalum salebrosum in the Southeastern Appalachian Range: A Search for Cryptic Plant Biodiversity Around the Tennessee River Valley.

The chemotaxonomy of the Conocephalum spp. complex, based on GC-MS analysis of the volatile compositions, has helped to reveal cryptic biodiversity and delineate actual distribution patterns of chemotypes. In the Appalachian Mountains, two samples from eastern central part of the range were previously shown to.be C. salebrosum. Additionally, it has recently come to light that stress can alter the volatile composition of C. conicun. This study address a previously unsampled region of the southeastern Appalachians, a region that is a biodiversity epicenter, to determine if more chemotypic diversity remains to be seen for the Conocephalun spp. complex. A common garden experiment was performed, but yielded more of a common stress experiment, and significantly altered the volatile compositions. Wild-collected controls and a meta-analysis of these data and those from previous works suggest that the common garden experiment caused stress and that the liverworts sampled belong to the C. salebrosin clade of of the Conocephalum spp. complex.

Biogeographic and phylogenetic effects on feeding resistance of generalist herbivores toward plant chemical defenses.

Many terrestrial and most marine herbivores have generalist diets, yet the role that evolutionary history plays in their foraging behaviors is poorly documented. On tropical hard-bottom reefs, generalist fishes and sea urchins readily consume seaweeds that produce lipophilic secondary metabolites. In contrast, herbivores on temperate reefs less commonly encounter seaweeds with analogous metabolites. This biogeographic pattern suggests that tropical herbivores should evolve greater feeding resistance to lipophilic defenses relative to temperate herbivores, but tests of this biogeographic pattern are rare. We offered lipophilic extracts from nine subtropical seaweeds at two concentrations to sea urchins (four subtropical and three cold-temperate populations) and quantified urchin feeding resistance. Patterns of feeding resistance toward lipophilic defenses were more similar within genera than across genera of urchins, indicating a substantial role for phylogenetic history in the feeding ecology of these generalist herbivores. The biogeographic origin of urchins also influenced feeding resistance, as subtropical species displayed greater feeding resistance than did temperate species. Similarly, a subtropical population of Arbacia punctulata had greater feeding resistance for Dictyota and Stypopodium extracts relative to temperate A. punctulata. We conclude that evolutionary history plays a more central role in the foraging ecology of generalist herbivores than is currently appreciated.