Areej Mohammad Al-Taweel

Novel quinolines and pyrimido[4,5-b]quinolines bearing biologically active sulfonamide moiety as a new class of antitumor agents

Some novel quinolines and pyrimido[4,5-b]quinolines have been synthesized. The structures of which were confirmed by elemental analyses and spectral data. All the target compounds were subjected to in-vitro antitumor activity against Ehrlich Ascites Carcinoma (EAC) cells. Compounds 24, 19 and 12 showed higher activity with IC(50) values (5.5, 6.9, 7 microg/ml) when compared with Doxorubicin as a reference drug (IC(50) value 38 microg/ml).

Synthesis and biological evaluation of 2-amino-7,7-dimethyl 4-substituted-5-oxo-1-(3,4,5-trimethoxy)-1,4,5,6,7,8-hexahydro-quinoline-3-carbonitrile derivatives as potential cytotoxic agents

A large number of antimitotic drugs, derived from natural sources or chemically synthesized, have been identified and shown to interfere with the tubulin system. Inhibition of tubulin polymerization is among the important targets useful in the cancer therapy. The present work reports the synthesis of some novel quinoline derivatives bearing a trimethoxyphenyl moiety. The trimethoxybenzene moiety has been reported to be crucial to obtain relevant cytotoxic and antitubulin responses. All the newly synthesized compounds were evaluated for their in vitro anticancer activity. Several compounds showed interesting cytotoxic activities compared to the used reference drug.

Discovering some novel tetrahydroquinoline derivatives bearing the biologically active sulfonamide moiety as a new class of antitumor agents.

The present article describes the synthesis of some novel 4-(2-amino-3-cyano-4-(substituted-aryl)-5-oxo-5,6,7,8-tetrahydroquinolin-1(4H)-yl)benzenesulfonamide (23-41) starting with 4-(3-oxo-cyclohex-1-enylamino)benzenesulfonamide (3). All the newly synthesized compounds were evaluated for their in vitro antitumor activity. Compounds 32, 25, 41, 35, 33, and 37 with IC50 values (2.5, 3, 5, 10, 12, and 12.5 microg/mL) are more potent and efficacious than Doxorubicin (CAS-23214-92-8) as reference drug with (IC50 value=37.5 microg/mL). Also, compounds 28, 30, 31, and 34 (with IC50 values=25 microg/mL) are nearly as active as Doxorubicin.

Antioxidant and urease inhibitory C-glycosylflavonoids from Celtis africana.

Two new C-glycosylflavonoids celtisides A (1) and B (2) have been isolated from n-butanol-soluble fraction of Celtis africana, along with five known C-glycosylflavonoids vitexin (3), orientin (4), isoswertiajaponin (5), isoswertisin (6), and 2″-O-rhamnosyl vitexin (7) reported for the first time from this species. Their structures were assigned from 1D and 2D NMR spectra. These compounds were investigated for biological activities and showed significant antioxidant and urease inhibitory activities.

Determination of Luteolin and Apigenin in Herbs by Capillary Electrophoresis with Diode Array Detection

Capillary electrophoresis with a diode array detector was employed for the determination of luteolin and apigenin in plant extracts. The experimental factors affecting the elution of the analytes were carefully optimized. The final analysis was achieved utilizing a fused silica capillary (58 cm effective length, 75 μm ID) and a background electrolyte solution consisting of borax buffer (20 mM, pH 10.0) and methanol (90: 10, v/v) with a 23 kV driving voltage and detection at 210 nm. The method was fully validated as per the guidelines of the International Conference on Harmonization for Analytical Procedures. The relationship between peak area and concentration was linear between 3 and 800 μg/mL for both compounds with detection limits of 1.05 for luteolin and 0.53 μg/mL for apigenin. The method was employed for the determination of the analytes in extracts of thyme and parsley. Both compounds were resolved from interfering peaks that were present in the extracts. Recovery studies were performed by fortifying the extracts with standards and demonstrated good accuracy with recovery values between 97.29 and 104.88% for luteolin and 96.89 and 105.18% for apigenin. Thyme and parsley were shown to contain high concentrations of luteolin and apigenin.

New flavonol glycosides from the leaves of Caragana brachyantha

Two new flavonol glycosides, brachysides C and D, together with three known flavonol glycosides, were isolated from the leaves of Caragana brachyantha. The structures of brachysides C and D were elucidated on the basis of detailed spectroscopic analysis as quercetin 5-O-[α-l-rhamnopyranosyl-(1 → 6)-β-d-glucopyranoside]-7-O-[α-l-rhamnopyranoside] and quercetin 5-O-[α-l-rhamnopyranosyl-(1 → 6)-β-d-glucopyranoside]-7-O-[α-l-rhamnopyranoside]-4′-O-[α-l-rhamnopyranoside], respectively. The presence of flavonol tetra- and triglycosides bearing a sugar moiety at position 5 was the first report from this genus Caragana.

3-O-trans-Caffeoylisomyricadiol: A New Triterpenoid from Tamarix nilotica Growing in Saudi Arabia

A detailed chemical study of the aerial parts of Tamarix nilotica (Tamaricaceae) from Saudi Arabia led to the isolation of a new pentacyclic triterpenoid, 3-O-trans-caffeoylisomyricadiol, in addition to nine known compounds. The structures of all isolated compounds were unambiguously elucidated by 1D, 2D NMR, and mass spectrometry. In the radical scavenging (DPPH) assay, 3-O-trans-caffeoylisomyricadiol exhibited potent antioxidant activity with an IC50 value of 3.56 μM, while that for quercetin (standard antioxidant) was 5.72 μM

Bioactivity and chemical characterization of Acalypha fruticosa Forssk. growing in Saudi Arabia

Acalypha is an important genus of the Euphorbiaceae family. The genus is represented by five species in Saudi Arabia. Acalypha fruticosa Forssk. Fl. Aeg is traditionally used as a cure for stomachache, dyspepsia, rheumatism, dermatitis, and swellings of the body. The present study endeavors to provide a phytochemical and biological evaluation of the plant, with the aim of relating activity to constituting secondary metabolites in the plant. Column chromatographic separation of the methanol extract led to the isolation of four compounds namely 2-methyl-5,7-dihydroxychromone 5-O-β-d-glucopyranoside 1, acalyphin 2, apigenin 3 and kaempferol 3-O-rutinoside 4. The plant extracts and the isolated compounds were subjected to biological assays to screen peroxisome proliferator-activated receptor alpha (PPARα) and PPARγ agonistic, anti-inflammatory and cytotoxic activities. Results proved for the first time, the PPARγ activator effect of acalyphin, as well as its promising anti-inflammatory activity, in addition to the dual PPAR activator effect of the chromone glucoside. The plant extracts and isolated compounds were non-cytotoxic to the tested cell lines. Thus A. fruticosa could be a valuable source of important therapeutics that may hold clinical prospect.

Anticancer activity of flavane gallates isolated from Plicosepalus curviflorus.

Background: Previous investigation of the methanol extract of Plicosepalus curviflorus leaves led to the isolation of two new flavane gallates (1, 2), together with other compounds including quercetin (3). The stems of P. curviflorus are used traditionally for the treatment of cancer in Yemen. Objective: The aim of this study was to evaluate the anticancer activity of the plant methanol extract as well as isolated compounds (1-3). Materials and Methods: The human cancer cell lines used were; MCF-7, HepG-2, HCT-116, Hep-2, HeLa and normal, Vero cell line using the Crystal Violet Staining method (CVS). Results: Quercetin (3) possessed the highest anticancer effect against all five cell lines (IC50 ranging from 3.6 to 16.2 μg/ml). It was followed by 2S, 3R-3, 3′, 4′, 5, 7-pentahydroxyflavane-5-O-gallate (1), with IC50 ranging from 11.6 to 38.8 μg/ml. The weakest anticancer activity was given by 2S, 3R-3,3′,4′,5,5′,7-hexahydroxyflavane-3′,5-di-O-gallate (2) with IC50 ranging from 39.8 to above 50 μg/ml, compared to vinblastine sulphate as reference drug. Colon, liver and breast cell lines seemed to be more sensitive to the tested compounds than the cervical and laryngeal cell lines. Concerning the cytotoxic effect on Vero cell line, the pentahydroxyflavane-5-O-gallate (1) showed the highest IC50 ( 138.2 μg/ml), while quercetin exhibited the lowest IC50 to Vero cells (30.5 μg/ml), compared to vinblastine sulphate as reference drug (IC50: 39.7 μg/ml). Conclusion: The results suggest the possible use of compounds 1 and 3 as anticancer drugs especially against colon and liver cancers.

Cytotoxic glucosphingolipid from Celtis Africana.

Background: Literature survey proved the use of the powdered sun-dried bark and roots of Celtis africana for the treatment of cancer in South Africa. Objective: The aim of this study was to do further isolation work on the ethyl acetate fraction and to investigate the cytotoxic activities of the various fractions and isolated compound. Materials and Methods: Cytotoxicity of petroleum ether, chloroform, ethyl acetate, n-butanol fractions and compound 1 were tested on mouse lymphoma cell line L5178Y using the microculture tetrazolium assay. Results: One new glucosphingolipid 1 was isolated from the aerial parts of C. africana. The structure of the new compound was determined by extensive analysis by one-dimensional and two-dimensional nuclear magnetic resonance spectroscopy and mass spectrometry. The ethyl acetate fraction and compound 1 showed strong cytotoxic activity with an EC50 value of 8.3 μg/mL and 7.8 μg/mL, respectively, compared with Kahalalide F positive control (6.3 μg/mL). Conclusion: This is the first report of the occurrence of a cytotoxic glucosphingolipid in family Ulmaceae.