Essential Oils and Hexane Extracts from Leaves and Fruits of Cistus monspeliensis. Cytotoxic Activity of ent-13-epi-Manoyl Oxide and its Isomers

Abstract

Essential oils and hexane extracts from Cistus monspeliensis L. leaves and fruits were analysed by GC-MS. Manoyl oxide and its isomers, 3 beta-hydroxy-manoyl oxide, 3 beta-hydroxy-13-epi-manoyl oxide, as well as 3 beta-acetoxy-13-epi-manoyl oxide were detected for the first time in C. monspeliensis L. Ent-13-epimanoyl oxide was isolated from the hexane extract of leaves and its structure was determined using spectroscopic methods. In vitro cytotoxic activity of ent-13-epi-manoyl oxide and mixtures of manoyl oxide isomers at 10(-4) M concentrations ranged from 11.1 to 32.2% of the activity for a vinblastine control evaluated against nine leukemic cell lines. The results showed that the manoyl oxide isomer mixtures as well as ent-13-epi-manoyl oxide exhibited a slight growth inhibiting activity.

Detailed analysis of the essential oil from Cistus albidus L. by combination of GC/RI, GC/MS and 13C-NMR spectroscopy

“…For comparison purposes, the essential oils of the genus Cistus previously reported were characterized by a high content of monoterpene hydrocarbons [5][6][7][8][9]18], and/or sesquiterpenes (aromadendrane and cadinane) [6][7][8][9]16,19], and/or diterpenes (labdane and clerodane) [7,11,12,15,16]. Conversely, in the essential oil of C. albidus, monoterpene hydrocarbons are absent, sesquiterpenes are dominated by the bisabolane skeleton, and the labdane diterpenes are scarcely represented by the 13-epi-manoyl oxide 86 (0.5%).…”

“…The compositions of the essential oils of several species of the genus Cistus have been investigated: C. ladaniferus [4][5][6][7][8], C. monspelliensis [9][10][11], C. creticus [12][13][14][15], C. salviifolius [16], C. laurifolius [17], C. palhinae [18], and C. parviflorus [19]. A few studies are concerned with the phytochemistry of C. albidus.…”

Manoyl Oxide (13R), the Biosynthetic Precursor of Forskolin, Is Synthesized in Specialized Root Cork Cells in Coleus forskohlii

“…While the significance of (13R) manoyl oxide is attributed to its role as a forskolin precursor, manoyl oxide itself exhibits a number of important properties, such as antibacterial or antiinflammatory activities or as a potent anticancer agent (de las Heras and Hoult, 1994;Demetzos et al, 1994;Dimas et al, 1999;Angelopoulou et al, 2001). …”

Terpenoid constituents from leaves of Guarea kunthiana

“…15 The latter diterpene was then characterized as ent-13-epi-manoyl oxide, which was previously isolated from members of other plant families, e.g. Cistaceae and Flacourtiaceae 16 but, until now, not yet reported in the Meliaceae.…”

“…A previous chemical study of the aerial parts of a specimen of Guarea kunthiana found in Ecuador resulted in the isolation of the limonoid ecuadorin. 2 No limonoids were detected in the leaves of the specimen investigated in the present work which provided, on the other hand, one new, ent-kaur-16-en-2-one (3) and three known, ent-kaur-16-ene (1), ent-3β-and 3α-hydroxykaur-16-ene (2, 4) kaurenoids, three known ent-clerodane diterpenes, kolavelool (5), kolavenol (6) and kolavenal (7), the cembranoid (-)-nephthenol (8) and ent-13-epimanoyloxide (9) in addition to four known sesquiterpenes, spathulenol (10) alismol (11), alismoxide (12), and (-)-4β,10α-aromadendranediol (13), polyprenol-12 (14) and α-and δ-tocopherols (15,16). Kolavenal has now been reported for the first time from nature, while it was known earlier as a derivative by synthesis from kolavenol.…”