Guaianolides and a seco-Eudesmane from the Resinous Exudates of Cushion Bush (Leucophyta brownii) and Evaluation of Their Cytostatic and Anti-inflammatory Activity

Abstract

A detailed phytochemical investigation of a dichloromethane extract of the resinous exudates of the cushion bush plant (Leucophyta brownii) resulted in the isolation of the new 8,12-guaianolides leucophytalins A (5) and B (6), the new 1,10-seco-eudesmane leucophytalin C (10), six rare 8,12-guaianolides (1-4, 7, and 8), and the xanthanolide tomentosin (9). The structures of all isolated compounds were elucidated on the basis of spectroscopic and spectrometric analyses. The structures of compounds isolated in crystalline form, including leucophytalins A and C, were further confirmed by X-ray crystallography. The crude extract exhibited moderate cytostatic activity against a breast cancer (MCF-7) and human colon cancer (HT-29) cell line with IC₅₀ values of 9.3 and 18 μg/mL, respectively, and anti-inflammatory activity against the macrophage-like cell line RAW 264.7 with IC₅₀ values of 3.9 and 6.1 μg/mL for thromboxane B2 and prostaglandin E2 production, respectively. The isolated compounds were evaluated for their cytostatic activity against MCF-7 and HT-29 cells (1, 3-10) and their anti-inflammatory activity against RAW 264.7 cells (1-10). All isolated compounds are most likely derived from (+)-germacrene A, and a biosynthetic pathway is proposed for these sesquiterpenoids.

Tomentosin Induces Telomere Shortening and Caspase‐Dependant Apoptosis in Cervical Cancer Cells

“…Tomentosin IC 50 were 25.68 ± 1.86 μM and 23.69 ± 0.79μM in SiHa and HeLa cells, respectively, after 24h treatment. A recent study showed that the xanthanolide tomentosin isolated from Leucophyta brownii extract, exhibited moderate cytostatic activity against a breast cancer (MCF‐7) and human colon cancer (HT‐29) cell line with IC 50 values of 26.6 and 56.5 µM/mL, respectively [Hyldgaard et al, ]. While, Li et al [] reported that tomentosin isolated from the whole plant of Carpesium faberi did not exert antiproliferative effects against MCF‐7 cells, with IC 50 >50 μg/mL [Li et al, ].…”

Allergenic sesquiterpene lactones from cushion bush (Leucophyta brownii Cass.): new and old sensitizers in a shrub‐turned‐a‐pot plant

“…Readings were performed on day (D) 3 according to ICDRG criteria . The sesquiterpene lactones used for patch testing were all isolated from a dichloromethane extract of cushion bush in a purity of >98% (determined by NMR spectroscopy and high‐performance liquid chromatography coupled with a diode array detector), as previously described . The study was approved by the local ethics committee (project ID: S‐20150064).…”

“…Recently, Hyldgaard et al published a detailed chemical investigation of the resinous exudate of cushion bush, and they detected two new 8,12‐guaianolides, named leucophytalin A and B, one new 1,10‐seco‐eudesmane, named leucophytalin C, six known but rare 8,12‐guaianolides, and the xanthanolide tomentosin . Furthermore, nuclear magnetic resonance (NMR) and X‐ray crystallographic analysis of calocephalin revealed an epoxide group at C‐1,2 and an acetoxy group at C‐4 (Fig.…”

New anti-inflammatory guaianes from the Atlantic hydrotherm-derived fungus Graphostroma sp. MCCC 3A00421

“…Guaianes are sesquiterpenoids bearing a bicyclo[5.3.0]-decane skeleton with enormously structural diversities, including nor-guaianes 1 , guaiane alkaloids 2 , 3 , guaiane dimers 4 , 5 , etc . They possessed a variety of intriguingly biological activities, such as antioxidant 2 , antimalarial 6 , 7 , antinociceptive 7 , anti-emetic 8 , antitumor 9 – 11 , anti-inflammatory 12 , 13 , and antibacteria 14 , 15 . Guaianes occur mainly in terrestrial plants 16 .…”