stigmasterol and cyasterone

A simple, specific, and sensitive liquid chromatography-mass spectrometry (LC-MS) method for determination of cyasterone in rat plasma was developed in our laboratory. Cucurbitacin B was used as an internal standard (IS). After protein precipitation with twofold volume of acetonitrile, the analyte and IS were separated on a Luna C18 column (100 × 4.6 mm, i.d., 3.0 µm; Phenomenex) by isocratic elution with acetonitrile-water (80:20, v/v) as the mobile phase at a flow rate of 0.4 mL/min. An electrospray ionization source was applied and operated in the positive ion mode; selected ion monitoring scan mode was used for quantification, and the target ions m/z 543.3 for cyasterone and m/z 581.3 for IS were chosen. Good linearity was observed in the concentration range of 0.40-400 ng/mL for cyasterone in rat plasma. Intra-day and inter-day precision were both <7.4%. This method was proved to be suitable for pharmacokinetic studies after oral (5.0 mg/kg) or intravenous (0.5 mg/kg) administration of cyasterone in rats. Copyright © 2015 John Wiley & Sons, Ltd.

Topics: Animals; Biological Availability; Calibration; Chromatography, Liquid; Limit of Detection; Pilot Projects; Rats; Spectrometry, Mass, Electrospray Ionization; Stigmasterol

Topics: Animals; Antineoplastic Agents; Apoptosis; Caspase 9; Cell Proliferation; Dose-Response Relationship, Drug; ErbB Receptors; Female; HCT116 Cells; HEK293 Cells; Human Umbilical Vein Endothelial Cells; Humans; Mice, Inbred BALB C; Mice, Nude; Neoplasms; p38 Mitogen-Activated Protein Kinases; Proto-Oncogene Proteins c-akt; Signal Transduction; Stigmasterol; Time Factors; Tumor Burden; Xenograft Model Antitumor Assays

A C29 phytoecdysteroid named amarasterone A (1) has been isolated from Cyathula capitata (Amaranthaceae), Leuzea carthamoides (Asteraceae), and Microsorum scolopendria (Polypodiaceae). We recently isolated amarasterone A from C. officinalis. Amarasterone A has been postulated as a biosynthetic intermediate of cyasterone in Cyathula sp. The stereochemistry at the C-24 and C-25 positions of these amarasterone A samples was investigated by comparing the NMR spectroscopic data with those of stereodefined model compounds, (24R,25S)-, (24R,25R)-, (24S,25S)-, and (24S,25R)-isomers of (20R,22R)-3β-methoxystigmast-5-ene-20,22,26-triol (2a-d), which were synthesized in the present study. Amarasterone A isolated from Cyathula officinalis was determined to be the (24R,25S)-isomer (1a), while amarasterone A from L. carthamoides was found to be the (24R,25R)-isomer (1b). Amarasterone A from M. scolopendria was found to be a mixture of 1a and 1b. The biosynthesis of cyasterone in Cyathula sp. is discussed on the basis of the identical C-24 configuration of sitosterol and amarasterone A.

Topics: Magnetic Resonance Spectroscopy; Stereoisomerism; Stigmasterol

Ecdysteroids are steroid hormones that control moulting and govern several changes during metamorphoses in arthropods. The discovery of the same molecules (phytoecdysteroids) in several plant species displayed a wide array of rather beneficial agricultural impact. Many representatives of the genus Ajuga plants contain phytoecdysteroids with a 5β-7-ene-6-one system exhibiting physiological activities in insects.. By means of chromatographic (silica gel column, TLC) and LC-MS, two major ecdysteroids (20-hydroxyecdysone and cyasterone) have been isolated and identified from Israeli carpet bugle Ajuga iva (L.) Schreber (Lamiales: Lamiaceae) plants. Ajuga iva extract fractionated on the silica gel column yielded two fractions that showed high activity against the sweetpotato whitefly Bemisis tabaci and the persea mite Oligonychus perseae. A dose of 5 mg AI L(-1) of the purely identified A. iva ecdysterone significantly reduced fecundity, fertility and survival of these pests, while commercial 20-hydroxyecdysone at the same dose had lesser effects.. The results demonstrate considerable efficacy of natural phytoecdysteroids against major agricultural pests, and suggests that these materials should be considered for potential development of friendly control agents.

Topics: Ajuga; Animals; Chemical Fractionation; Ecdysteroids; Female; Fertility; Hemiptera; Insect Control; Mites; Plant Growth Regulators; Stigmasterol

Chemical investigation of ecdysteroidal constituents of the roots and stems of Cyathula officinalis led to the isolation of two cyasterone stereoisomers, 2 and 3, together with the known cyasterone 1. The structures of compounds 2 and 3 were determined to be 28-epi-cyasterone and 25-epi-28-epi-cyasterone, respectively, by means of spectroscopic analysis. X-Ray structures of 1 and 2 confirmed the 24S,25S,28R configuration for 1 and 24S,25S,28S for 2.

Topics: Amaranthaceae; Crystallography, X-Ray; Models, Molecular; Molecular Conformation; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Plant Roots; Spectrophotometry, Ultraviolet; Stereoisomerism; Stigmasterol

Two new compounds, 28-epi-cyasterone and eriophytonoide, along with 11 known compounds, cyasterone, ajuforrestins A and B, 20-hydroxyecdysone, polypodin B, ajugalactone, 8-O-acetylharpagid, apigenin, N-[2hydroxy-(nonadecanoyl-tricosanoyl)]-4-hydroxy-trans-8-sphingenine, beta-sitosterol, and daucosterol, were isolated from the aqueous ethanolic extract of the whole herb of Eriophyton wallchii Benth. The structures of 28-epi-cyasterone and eriophytonoide were elucidated as (22R,24S,25S,28S)-5beta-stigmast-7-en-26-oic acid, 2beta,3beta,14,20,22,28-hexa hydroxy-6-oxo-gamma-lactone, and 1-O-beta-d-glucopyranosyl-(2S,3S,4R,8E)-2-[(2R)-2-hydroxyhexadecanoylamino]-1,3,4-octadecanetriol-8-ene, respectively, on the basis of spectral and chemical evidence.

Topics: Ceramides; Drugs, Chinese Herbal; Ecdysone; Ethanol; Phytosterols; Plants, Medicinal; Stigmasterol

Hairy roots of Ajuga reptans var. atropurpurea produce clerosterol, 22-dehydroclerosterol, and cholesterol as sterol constituents, and 20-hydroxyecdysone, cyasterone, isocyasterone, and 29-norcyasterone as ecdysteroid constituents. To better understand the biosynthesis of these steroidal compounds, we carried out feeding studies of variously 2H- and 13C-labeled sterol substrates with Ajuga hairy roots. In this article, we review our studies in this field. Feeding of labeled desmosterols, 24-methylenecholesterol, and 13C2-acetate established the mechanism of the biosynthesis of the two C29-sterols and a newly accumulated codisterol, including the metabolic correlation of C-26 and C-27 methyl groups. In Ajuga hairy roots, 3alpha-, 4alpha-, and 4beta-hydrogens of cholesterol were all retained at their original positions after conversion into 20-hydroxyecdysone, in contrast to the observations in a fern and an insect. Furthermore, the origin of 5beta-H of 20-hydroxyecdysone was found to be C-6 hydrogen of cholesterol exclusively, which is inconsistent with the results in the fern and the insect. These data strongly support the intermediacy of 7-dehydrocholesterol 5alpha,6alpha-epoxide. Moreover, 7-dehydrocholesterol, 3beta-hydroxy-5beta-cholest-7-en-6-one (5beta-ketol), and 3beta,14alpha-dihydroxy-5beta-cholest-7-en-6-one (5beta-ketodiol) were converted into 20-hydroxyecdysone. Thus, the pathway cholesterol-->7-dehydrocholesterol-->7-dehydrocholesterol 5alpha,6alpha-epoxide-->5beta-ketol-->5beta-k etodiol is proposed for the early stages of 20-hydroxyecdysone biosynthesis. 3beta-Hydroxy-5beta-cholestan-6-one was also incorporated into 20-hydroxyecdysone, suggesting that the introduction of a 7-ene function is not necessarily next to cholesterol. C-25 Hydroxylation during 20-hydroxyecdysone biosynthesis was found to proceed with ca. 70% retention and 30% inversion. Finally, clerosterol was shown to be a precursor of cyasterone and isocyasterone.

Topics: Carbon Isotopes; Deuterium; Ecdysteroids; Models, Chemical; Plant Roots; Plants, Medicinal; Stereoisomerism; Steroids; Sterols; Stigmasterol

Topics: Animals; Cholestenes; Ecdysterone; Female; Phytosterols; Stigmasterol; Ticks