Cytotoxic sesquiterpene lactones from Centaurothamnus maximus and Vicoa pentanema

Abstract

The aerial parts of Centaurothamnus maximus yielded three cytotoxic guaianolides, chlorojanerin (1), cynaropicrin (2) and janerin (3). The structure elucidation of 1-3 was based on (1)H and (13)C NMR data, mainly 2D-NMR (1)H-(1)H COSY and (1)H-(13)C HETCOR experiments. Compounds 1-3 showed in vitro cytotoxic activity against human cancer cell lines of malignant melanoma (SK-MEL), epidermoid (KB), ductal (BT-549) and ovarian (SK-OV-3) carcinomas with IC(50) values of 2-6 microgram/mL. In addition, 12 sesquiterpene lactones (4-15), isolated previously from the aerial parts of Vicoa pentanema, were evaluated for cytotoxic and antimicrobial activities. 2alpha- Acetoxy-3beta-hydroxyalantolactone (10) and 8beta-hydroxyparthenolide (14) were found to be the main cytotoxic agents (IC(50) values of 2-6 microgram/mL against SK-MEL, BT-549 and SK-OV-3), while lactones 4, 5, 11 and 15 selectively inhibited the growth of human malignant melanoma (IC(50) value of 3.6-7.3 microgram/mL). Cell aggregation and cell adhesion assays, using HL-60 and HeLa cell lines, evaluated the effect of cytotoxic constituents 1-3, 10 and 14 on immune response and inflammation.

Sesquiterpenoids in subtribe Centaureinae (Cass.) Dumort (tribe Cardueae, Asteraceae): Distribution, 13C NMR spectral data and biological properties

“…They were also tested against human cancer cell lines of malignant melanoma (SK-MEL), epidermoid (KB), ductal (BT-549) and ovarian (SK-OV-3) carcinomas for cynaropicrin (162), janerin (208) and chlorojanerin (219), showing in vitro cytotoxic activity with IC 50 values of 2-6 lg/mL (Muhammad et al, 2003).…”

A novel acyclic diterpenic alcohol isolated from antioxidant active ethanol extract of leaves of <i>Centaurothamnus maximus</i> grown in Saudi Arabia

“…On the basis of mass and 13 C NMR spectra the molecular ion peak of CM1 was determined at m/z 344 consistent with the molecular formula of a tetrahydroxy diterpene, C 20 + indicated the existence of hydroxyl groups at C 9 , C 7 and C 5 carbons. The 1H NMR spectrum of CM1 exhibited the presence of a one-proton doublet at δ 6.22 (J= 6.0 Hz) and a one-proton multiplet at δ 5.72 assigned to cis-oriented vinylic H-13 and H-12 protons, respectively.…”

“…Sesquiterpene lactones are also prominent constituents in Asteraceae family (Ling, 1992;Iwashina et al, 1995;Tzakao et al, 1995 andAkkal et al, 1997). The aerial parts of C. maximus reportedly contain three sesquiterpene lactones namely guainolides chlorojanerin, cynaropicrin and janerin which are active against human cancer cell lines of malignant melanoma (SK-MEL), epidermoid (KB), ductal (BT-549) and ovarian (SK-OV-3) carcinomas with IC50 values of 2-6 μg/mL (Muhammad et al, 2003).…”

New Eudesmane Derivatives and Other Sesquiterpenes from the Epigeal Parts of Dittrichia graveolens

“…1) These lactones have been reported to possess a diversity of conspicuous biological activities, such as cytotoxic, antitumorigenic, and highly bactericidal and fungicidal properties. 13,[17][18][19][20][21][22][23] Many of these compounds or plants containing them are a cause of allergic contact dermatitis in humans. 18) On the other hand, some of these lactones have been reported to possess a wide spectrum of pharmacological activities, such as hypotensive, hyperglycemic (high doses) and hypoglycemic (lower doses), 24) anthelminthic, 21) diuretic, 25) antiinflammatory, and antipyretic.…”

“…The results of the antimicrobial activity of D. graveolens extracts and chromatographic fractions are recorded in Table 3. The observed antimicrobial activity could be attributed to the presence of sesquiterpene lactones [17][18][19][20][21][22] and sesquiterpene acids. 23) 1540…”