Bioassay-guided isolation, identification of compounds from Origanum rotundifolium and investigation of their antiproliferative and antioxidant activities.

CONTEXT: Origanum (Lamiaceae) has been used in food and pharmaceutical industries. OBJECTIVE: Isolation and identification of bioactive compounds from Origanum rotundifolium Boiss. and investigation of their antiproliferative and antioxidant activities. MATERIALS AND METHODS: The aerial part of O. rotundifolium was dried and powdered (1.0 kg ±2.0 g) then extracted with hexane, ethyl acetate, methanol and water. Solvent (3 × 1 L) was used for each extraction for a week at room temperature. The aqueous extract was partitioned with ethyl acetate (3 × 1 L) to yield the water/EtOAc extract subjected to chromatography to isolate the active compounds. The structures of isolated compounds were elucidated by 1 D, 2 D NMR and LC-TOF/MS. RESULTS: Apigenin (1), ferulic acid (2), vitexin (3), caprolactam (4), rosmarinic acid (5), and globoidnan A (6) were isolated and identified. Globoidnan A (6), vitexin (3), and rosmarinic acid (5) revealed the excellent DPPH• scavenging effect with IC50 values of 22.4, 31.4, 47.2 µM, respectively. Vitexin (3) (IC50 3.6), globoidnan A (6) (IC50 4.6), apigenin (1) (IC50 8.9) and ferulic acid (2) exhibited more ABTS•+ activity than standard Trolox (IC50 13.8 µg/mL). Vitexin (3) revealed the most antiproliferative activity against HeLa, HT29, C6 and Vero cells lines with IC50 values of 35.6, 32.5, 41.6, 46.7 (µM), respectively. DISCUSSION AND CONCLUSION: Globoidnan A (6) has the most antioxidant effects on all assays. This has to do with the chemical structure of the compound bearing the acidic protons. Vitexin (3) could be a promising anticancer agent.

Bioactivity-guided isolation of flavonoids from Cynanchum acutum L. subsp. sibiricum (willd.) Rech. f. and investigation of their antiproliferative activity.

Cynanchum acutum L. subsp. sibiricum (Willd.) Rech. f. was extracted with hexane, acetone, methanol and water individually. A sample was heated in water then extracted with ethyl acetate. Among the extracts, the ethyl acetate extract exhibited the most antiproliferative activity, so isolation of bioactive compounds was carried out from this extract. A new compound, kaempferol-3-O-ß-xylopyranosyl-(1-2)-ß-rhamnopyranoside (1) along with five known compounds, quercetin-3-O-ß-xyloside (2), kaempferol-3-O-ß-glucoside (3), quercetin-3-O-ß-glucoside (4), kaempferol-3-O-ß-rhamnopyranoside (5), and kaempferol-3-O-ß-d-neohesperidoside (6) were isolated from ethyl acetate extract. The structures were elucidated by spectroscopic techniques, basically 1D NMR, 2D NMR and LC-TOF/MS. Antiproliferative effects of isolated compounds were determined by xCELLigence using the HeLa (human uterus carcinoma) cell lines. Compound 2 and compound 5 revealed the good antiproliferative activity against HeLa cell lines.

Bioactivity-Guided Isolation of Antiproliferative Sesquiterpene Lactones from Centaurea solstitialis L. ssp. solstitialis.

Centaurea solstitialis L. ssp. solstitialis (CSS) has been used as medicine for various diseases. In this work, root, stem and flower parts of the plant were separately extracted with methanol to execute bioassay-guided isolation. Antiproliferative activities of each extracts on C6 cells (Rat Brain tumor cells) and HeLa cells (human uterus carcinoma) were investigated in vitro. The methanol extract of stem exhibited the most antiproliferative activity therefore isolation of active compounds was carried out for stem of the plant. Methanol extract of stem was boiled at 97 °C for 2 hours in water and then hexane and ethyl acetate were extracted sequentially. Solstitialin A 1 and 15-dechloro-15-hydroxychlorojanerin 2 were isolated from ethyl acetate extract by column chromatography and identified by spectroscopic techniques. Solstitialin A 1 was isolated from CSS and 15-dechloro-15-hydroxychlorojanerin 2 was isolated from Saussurea lipschitz and Rhaponticum pulchrum previously. These two compounds exhibited very high antiproliferative activity on C6 and HeLa cells. IC50 and IC75 values of compound 1 were obtained as 10.78 and 53.65 against C6 cell and as 48.78 and 68.52 against HeLa, respectively. IC50 and IC75 values of compound 2 were determined as 432.43 and 109.79 against C6 cell.

Isolation and identification of chemical constituents from Origanum majorana and investigation of antiproliferative and antioxidant activities.

BACKGROUND: Origanum majorana L., belonging to the Lamiaceae family, has great potential and has been used as a folk medicine against asthma, indigestion, headache and rheumatism; in addition, the essential oils of this plant have been used widely in the food industry. Plant materials have been harvested from the Medicinal and Aromatic Plant Field of Gaziosmanpasa University. Air-dried plant materials were boiled in water, filtered, and the solvent part subsequently extracted with hexane and ethyl acetate. The chromatographic method was applied to the ethyl acetate extract to isolate bioactive secondary metabolites, the structures of which were elucidated by spectroscopic techniques: basically one-dimensional and two-dimensional nuclear magnetic resonance and quadrupole time-of-flight liquid chromatography. Antiproliferative and antioxidant activities of isolated secondary metabolites were determined. RESULTS: 5,6,3'-Trihydroxy-7,8,4'-trimethoxyflavone, hesperetin, hydroquinone, arbutin and rosmarinic acid were isolated from the water-soluble ethyl acetate extract of aerial parts of O. majorana. Antioxidant activities of isolated compounds and water-soluble ethyl acetate extract were investigated using assays of DPPH(•), ABTS(•+), reducing power and total phenolic content. Antiproliferative activities of the isolated compounds and plant extracts were investigated against C6 and HeLa cell lines using BrdU cell proliferation enzyme-linked immunosorbent assay and xCELLigence assay, respectively. Both hesperetin and hydroquinone were determined to have stronger antiproliferative activities against C6 and HeLa cells than the other isolated compounds and 5-fluorouracil. CONCLUSION: The results showed that the extract and isolated compounds exhibited significant antioxidant activities. Hence this plant has the potential to be a natural antioxidant in the food industry and an anticancer drug.