Ledol

Abstract: The chemical composition of the essential oil of the leaves of Cistus creticus subsp. eriocephalus (Viv.) Greuter & Burdet, (Cistaceae), was investigated by GC/MS. Thirty-nine components were identified, representing 73.9% (based on % total peak area by GC) of the oil composition. The main components of the oil were alpha-cadinene (6.5%), delta-cadinene (5.6%), viridiflorol (5.4%), bulnesol (6.3%), ledol (3.8%), alpha-copaene (3.8%), beta-selinene (3.4%), cubenene (3.3%), manoyl oxide (9.9%) and 13-epi-manoyl oxide (3.4%). Antibacterial studies were carried out in vitro against Gram-positive and Gram-negative organisms.

Abstract: The essential oil of Cistus ladaniferus L., obtained from plants of Spanish origin grown in Corsica, was investigated by 13C-NMR spectroscopy (identification of components) and GC (quantification). First, a bulk sample was analysed and 45 constituents were identified. The main components were α-pinene (39%), viridiflorol (11.8%), ledol (3.3%) and bornyl acetate (3.1%). The occurrence of cyclosativene, γ-cadinene, (E)-β-farnesene and β-eudesmol in the essential oil of Cistus ladaniferus is reported here for the first time. Then, in order to study the chemical variability of individual oils, we examined 20 samples. α-Pinene (11.1–47.4%) was the most abundant component in 18 of the 20 samples, followed by trans-pinocarveol (4.4–10.9%) and viridiflorol (4.7–10.7%). Two samples exhibited a different chemical composition, not as yet described, characterized by the predominance of viridiflorol (20–22.6%), ledol (6.4–6.7%) and trans-pinocarveol (5.4–8.6%). © 1997 John Wiley & Sons, Ltd.

Abstract: The seasonal variations in the chemical composition of the essential oil of wild and cultivated Baccharis trimera populations indicated the presence of three clusters of oils regarding population and phenophase. The first included flowering, wild, and cultivated samples from a period of March-May, with high percentages of globulol and spathulenol. In cluster II, with wild samples collected from June-February, the major constituents were germacrene D and (E)-caryophyllene, while cluster III included cultivated samples from June-February containing a high content of ledol. The canonical correlation analysis revealed that (E)-caryophyllene, Mn, Al saturation, and precipitation were quite strongly related to wild samples (cluster II), whereas ledol and guaiol were related to chemical balance in soils (P, K, S, Cu, Zn, and base saturation) of cultivated samples (cluster III). Both essential oils have predominantly hydrocarbon compositions, although for a couple of months the oxygenated sesquiterpene content is over 40% for both samples. The observed chemovariation might be environmentally determined.

Abstract: Eryngium campestre and E. amethystinum are thorny herbs belonging to the Apiaceae family and spontaneously growing in stony pastures and dry meadows, preferentially on calcareous substrates. In the Mediterranean countries, these plants have been used as a food or traditional remedies to treat various ailments. In the present work, we have analysed the chemical composition of the essential oils distilled from the aerial parts by GC-FID and GC-MS, and evaluated their cytotoxic effects on a panel of human cancer cells, namely A375 (human malignant melanoma), MDA-MB 231 cells (human breast adenocarcinoma) and HCT116 cells (human colon carcinoma), by the MTT assay. Furthermore, the Eryngium essential oils were evaluated for antioxidant and acetylcholinesterase (AChE) activities. The two essential oils were rich in sesquiterpene hydrocarbons, with germacrene D as the major compound, accompanied by allo-aromadendrene, β-elemene, spathulenol and ledol. They resulted highly cytotoxic on the tumor cells, with IC50 values (1.65-5.32 and 1.57-2.99 μg/ml for E. amethystinum and E. campestre, respectively) comparable or close to those of the anticancer drug cisplatin. The E. amethystinum essential oil exhibited a moderate antioxidant activity whereas that of E. campestre a weak AChE inhibition. This article is protected by copyright. All rights reserved.