Celochalcoside, a new quinochalcone C-glycoside from Celosia trigyna.

A new quinochalcone C-glycoside featuring a unique quinonoid moiety, named celochalcoside (1), was isolated from the n-butanol extract of the aerial parts of Celosia trigyna L. The structure was determined by extensive spectroscopic analysis as well as mass spectrometric data. Compound 1 showed moderate cytotoxic activities against breast cancer cell lines (MCF-7), colon cancer cell lines (HT-29) and hepatocellular carcinoma cell lines (HepG2) with IC50 values of 23.16, 37.05 and 18.35 µg/ml, respectively.

Salvastearolide, a new acyl-glyceride, and other constituents from the seeds of Salvadora persica

Abstract The chemical investigation of the n-hexane fraction of Salvadora persica L., Salvadoraceae, seeds afforded a new stearic acid ester, salvastearolide, together with five other phytosteroids identified as stigmasterol, β-sitosterol, Δ7-campesterol, Δ7-avenasterol and campesterol. Their structures were established on the basis of extensive spectroscopic methods including 1D and 2D NMR experiments and HRESI mass spectrometry. In addition, salvastearolide and the isolated fractions were tested for their cytotoxicity against human cancer cell lines MCF-7, MDA-MB-231 and HT-29. The n-hexane fraction exhibited significant anti-proliferative effect against human breast cancer cell line MCF-7 (IC50 50 µg/ml), while salvastearolide possessed a weak cytotoxic effect against MCF-7 cells with IC50 103.98 µg/ml.

Sesquiterpenes from the Saudi Red Sea: Litophyton arboreum with their cytotoxic and antimicrobial activities.

A new pseudoguaiane-type sesquiterpene named litopharbol (1) was isolated from the methanolic extract of the Red Sea soft coral Litophyton arboreum, along with known sesquiterpenoids alismol (2), alismorientol B (3), teuhetenone A (4), and calamusin I (5); steroid, 24-methyl-cholesta-5,24(28)-diene-3ß-ol (6), alkyl glyceryl ether, chimyl alcohol (7); sphingolipid, erythro-N-dodecanoyl-docosasphinga-(4E,8E)-dienine (8); and nitrogenous bases, thymine (9) and thymidine (10). The structures were determined on the basis of nuclear magnetic resonance (NMR) spectroscopic (1D and 2D NMR data including heteronuclear single quantum coherence spectroscopy, heteronuclear multiple-bond correlation spectroscopy, and nuclear Overhauser effect spectroscopy) and mass spectrometric analyses. Compounds 1-5 were explored for antimicrobial activity and cancer cell line sensitivity tests. Compound 1 exhibited antibacterial activity against Bacillus cereus with a minimum inhibition concentration of 1.8 µg/mL, whereas compound 3 showed significant potent cytotoxic effect against MCF-7 (breast cancer cells) with IC50 4.32 µM.

Induction of caspase-8 and death receptors by a new dammarane skeleton from the dried fruits of Forsythia koreana.

A new naturally occurring compound based on the dammarane skeleton, i.e. cabralealactone 3-acetate-24-methyl ether, was isolated from the aqueous methanolic extract of Forsythia koreana fruits, along with eight known compounds: cabralealactone 3-acetate, ursolic acid, arctigenin, arctiin, phillyrin, rutin, caffeic acid, and rosmarinic acid. The identification of the isolated compounds was based on their spectral analysis including: HREI-MS, 1D and 2D NMR spectroscopy. The selected compounds and the aqueous methanolic extract were evaluated for their cytotoxic activity against human solid tumour cell lines. Cabralealactone 3-acetate-24-methyl ether and ursolic acid were found to be active against human breast cancer cells (MCF-7). The cytotoxicity was associated with the activation of caspase-8, the induction of the death receptors DR4 and DR5, as well as DNA fragmentation, and was thus due to apoptosis rather than necrosis.

Polyphenolic compounds in the fruits of Egyptian medicinal plants (Terminalia bellerica, Terminalia chebula and Terminalia horrida): characterization, quantitation and determination of antioxidant capacities.

Thirty-four polyphenolic substances in methanol extracts of the fruits of Terminalia bellerica, Terminalia chebula and Terminalia horrida, three plants used in Egyptian folk medicine, were initially identified by HPLC-ESI-MS and quantitated by analytical HPLC after column chromatography on Sephadex LH-20. After purification by semi-preparative HPLC the compounds were identified by their mass and fragmentation patterns using ESI-MS-MS. For several compounds detailed 1H/13C NMR analysis at 600 MHz was performed. Two polyphenolics, namely 4-O-(4''-O-galloyl-alpha-L-rhamnopyranosyl)ellagic acid and 4-O-(3'',4''-di-O-galloyl-alpha-L-rhamnopyranosyl)ellagic acid were identified by NMR. Antioxidant capacities of the raw fruit extracts and the major isolated substances were determined using the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), oxygen radical absorbance capacity (ORAC) and ferric reducing ability of plasma (FRAP) in vitro assays and indicated that chebulic ellagitannins have high activity which may correlate with high potential as cancer chemopreventive agents. Therefore, further studies (metabolism, bioavailability and toxicity) of the polyphenolics in Terminalia species using preclinical models and in vivo human intervention trials are warranted.

A new pyranone derivative from the leaves of Livistona australis.

A new pyranone derivative, 3-hydroxy-2-(4-hydroxyphenyl)-6-methyl-4H-pyran-4-one (1), was isolated from the leaves of Livistona australis. The structure was determined by NMR spectral analysis.