Absolute configurations of biantraquinones from Eremurus spectabilis BIEB.

This report covers extraction, isolation, and characterisation studies on Eremurus spectabilis BIEB (Liliaceae) species. Eremurus spectabilis BIEB was extracted with hexane, chloroform, ethyl acetate, and methanol, respectively. Using chromatographic methods, two known bianthraquinones (ES3, 7,10'-bichrysophanol and ES6, chrysalodin), three known anthraquinones (ES1, chrysophanol; ES2, chrysophanol-8-methyl ether; ES4, aloe emodin) and one known steroidal compound (ES5, daucosterol) were isolated from the chloroform extract. Structures of these isolated compounds were revealed by 1D and 2D NMR and HRMS spectroscopies. Absolute configurations of ES3 and ES6 were determined by single crystal X-Ray diffraction analysis.

New cytotoxic chalcone derivatives from Astragalus ponticus Pall.

Astragalus ponticus Pall. species was investigated for its antiproliferative effects on HeLa cells. Two new chalcones (B5 and B8) along with eight known compounds (B1, B2, B3, B6, B7, B10, B14 and B15) were isolated by following bioactivity guided isolation methods. In addition, from non-active fraction, three cycloartane glycosides (B11, B12 and B13) were isolated. Molecular structures of these isolated compounds were revealed by using spectroscopic methods like MS, 1D and 2D NMR and a single crystal X-ray diffraction analysis. New compounds B5 and B8 showed the highest antiproliferative activities against HeLa cells (IC50 values of 36.6 and 20.6 µM, respectively) while the rest showed high and low activities. Non-endemic species attract relatively low attention from the scientific community but this study demonstrates that valuable new compounds, which might be used as ingredients in medicinal preparations, can be obtained from these materials.

Phytochemical Study and Antioxidant Activities of the Water-Soluble Aerial Parts and Isolated Compounds of Thymus munbyanus subsp. ciliatus (Desf.) Greuter & Burdet

Objectives: The present study aimed to determine the phenolic compounds present in the water-soluble extracts of Thymus munbyanus subsp. ciliatus using high pressure liquid chromatography-time-of-flight mass spectrometry (MS). These phenolic compounds were further isolated and characterized for their antioxidant activities. Materials and Methods: The aerial parts of T. munbyanus subsp. ciliatus were air dried, powdered, and extracted using water:methanol three times. The concentrated hydromethanolic extract was further dissolved in H2O, filtered, and successively extracted using ethyl acetate, chloroform, and n-butanol. T. munbyanus extracts were further purified using column chromatography, and the purified extracts were subjected to in vitro antioxidant assays. Results: Two previously undescribed compounds, namely methyl 2,3,5,6-tetrahydroxybenzoate and 4-hydroxy-5-methoxy-2-oxo-2H-pyran-3-carboxylic acid, and 14 known compounds, including 3 flavonoids; namely 3',5,5',7-tetrahydroxyflavanone, luteolin, and isorhamnetin-3-O-ß-glucoside; a sterol glucoside named daucosterol; and 10 phenolic compounds, namely salicylic acid, ferulic acid, pluchoic acid, ethyl caffeate, methyl caffeate, protocatechuic acid, rosmarinic acid, p-coumaric acid, tyrosol, and protocatechuic aldehyde, were isolated from ethyl acetate and n-butanol extracts. The isolated compounds were characterized using 1D-2D-1H-13C nuclear magnetic resonance and MS methods. Conclusion: The compounds isolated from ethyl acetate and n-butanol extracts exhibited excellent antioxidant and 2,2-diphenyl-1-picrylhydrazyl scavenging activities. All these results highlighted the antioxidant potential of the isolated phenolic compounds and extracts, which could be further utilized for different pharmacological applications.

The cytotoxicity and antioxidant activity analysis of the isolated constituents and extracts from endemic Centaurea derderiifolia.

It is aimed to investigate the cytotoxic effects of the various extracts from the leaf and seed of Centaurea derderiifolia on the growth human cervical adenocarcinoma (HeLa) cells by xCELLigence method and to isolate the cytotoxic constituents. The results showed that subfractions 2 and 3 exhibited remarkable inhibitory effect against HeLa (IC50 < 10 µg/mL). The chloroform extract of leaf displayed the highest cytotoxic effect on HeLa cells (IC50 < 50 µg/mL) and was therefore subjected to a bioassay-guided multistep separation procedure. The pure compounds were elucidated by spectroscopic and mass-spectrometric analyses, including 1 D-, 2 D-NMR. In addition to cytotoxic effects of the isolated constituents, their antioxidant activities were also studied. On the other hand, subfraction 4 exhibited the highest DPPH radical scavenging activity (IC50 = 0.76 ± 0.03 mg/mL). ß-sitosterol-3-O-ß-d-glucopyranoside was isolated for the first time from this plant and three compounds from the bioactive subfractions were identified.

SYNTHESIS OF 1,3,4-OXADIAZOLES AS SELECTIVE T-TYPE CALCIUM CHANNEL INHIBITORS.

Neuropathic pain, epilepsy, insomnia, and tremor disorder may arrive from an increase of intracellular Ca2+ concentration through a dysfunction of T-type Ca2+ channels. Thus, T-type calcium channels could be a target in drug discovery for the treatments of neuropathic pain and epilepsy. From rational drug design approach, a group of 2,5-disubstituted 1,3,4-oxadiazole molecules was synthesized and their selective T-type channel inhibitions were evaluated. The synthetic strategy consists of a short sequence of three reactions: (i) condensation of thiosemicarbazide with acid chlorides; (ii) ring closing by 1,3-dibromo-5,5- dimethylhydantoin; and (iii) coupling with various acid chlorides. 5-Chloro-N-(5- phenyl-1,3,4-oxadiazol-2-yl)thiophene-2-carboxamide (11) was found to selectively inhibit T-type Ca2+ channel over Na+ and K+ channels in mouse dorsal root ganglion neurons and/or human embryonic kidney (HEK)-293 cells and to suppress seizure-induced death in mouse model. Consequently, compound 11 is a useful probe for investigation of physiologic and pathophysiologic roles of the T-channel, and provides a basis to develop a novel therapeutic to treat chronic neuropathic and inflammatory pains.

Chemical synthesis of tetracyclic terpenes and evaluation of antagonistic activity on endothelin-A receptors and voltage-gated calcium channels.

A class of tetracyclic terpenes was synthesized and evaluated for antagonistic activity of endothelin-1 (ET-1) induced vasoconstriction and inhibitory activity of voltage-activated Ca(2+) channels. Three repeated Robinson annulation reactions were utilized to construct the tetracyclic molecules. A stereoselective reductive Robinson annulation was discovered for the formation of optically pure tricyclic terpenes. Stereoselective addition of cyanide to the hindered α-face of tetracyclic enone (-)-18 was found and subsequent transformation into the aldehyde function was affected by the formation of bicyclic hemiiminal (-)-4. Six selected synthetic tetracyclic terpenes show inhibitory activities in ET-1 induced vasoconstriction in the gerbil spiral modiolar artery with putative affinity constants ranging between 93 and 319 nM. Moreover, one compound, (-)-3, was evaluated further and found to inhibit voltage-activated Ca(2+) currents but not to affect Na(+) or K(+) currents in dorsal root ganglion cells under similar concentrations. These observations imply a dual mechanism of action. In conclusion, tetracyclic terpenes represent a new class of hit molecules for the discovery of new drugs for the treatment of pulmonary hypertension and vascular related diseases.

Determination of Antiproliferative Activities of Volatile Contents and HPLC Profiles of Dicranum scoparium (Dicranaceae, Bryophyta).

The aim of this study was to examine the anticancer activities and phytochemical profiles of Dicranum scoparium against HeLa cell lines. The bio-guided fractionation studies of dichloromethane extract have high antiproliferative activities. Fractions 7, 9, 19, 20 are rich source of unsaturated fatty acids, and- in the case of Fr-19 may improve the antiproliferative activities as well as increase the unsaturated fatty acid content. The effect of proliferative activities in hexane extract can be attributed to the saturated fatty acid composition of D. scoparium. The Fr-9 exhibited strong antiproliferative activity at concentrations of 100 and 50 µg mL(-1) compared to 5-FU. The fractions of 7, 9, 19 and 20 from dichloromethane extracts exhibited antiproliferative activities at a concentration of 100 µg mL(-1). The HPLC-TOF/MS studies gave nine compounds from the most active fraction of dichloromethane at concentrations of 250 and 100 µg mL(-1). The lower activities were obtained from the fractions including steroid derivatives.

Phytochemical screening, anticancer and antioxidant activities of Origanum vulgare L. ssp. viride (Boiss.) Hayek, a plant of traditional usage.

BACKGROUND: A detailed phytochemical analysis of Origanum vulgare L. ssp. viride (Boiss.) Hayek was carried out and the antioxidant activities of five different crude extracts were determined. The antiproliferative activities of the extracts were determined using the xCELLigence system (Real Time Cell Analyzer). RESULTS: Differences between the essential oil and volatile organic compound profiles of the plant were shown. The main component of the essential oil was caryophyllene oxide, while the main volatile organic compounds were sabinene and eucalyptol as determined by HS-GC/MS. Phenolic contents of the extracts were determined qualitatively and quantitatively by HPLC/TOF-MS. Ten phenolic compounds were found in the extracts from O. vulgare and Origanum acutidens: rosmarinic acid (in highest abundance), chicoric acid, caffeic acid, p-coumaric acid, gallic acid, quercetin, apigenin-7-glucoside, kaempferol, naringenin and 4-hydroxybenzaldehyde. CONCLUSION: This study provides first results on the antiproliferative and antioxidant properties and detailed phytochemical screening of O. vulgare ssp. viride (Boiss.) Hayek.