Gynecological efficacy and chemical investigation of Vitex agnus-castus L. fruits growing in Egypt

Flavonoid glycosides, orientin and apigenin 3, 8-di-C-glycosides in addition to, iridoid compound, aucubin were isolated from the ethanolic extract of Vitex agnus-castus fruits. Their structures were identified on the basis of the spectroscopic data. The estrogenic activity of the ethanolic extract in two dose levels 0.6 and 1.2 g kg(-1) per body weight (b.w.) was studied by the vaginal smear, and uterine weight methods for normal and ovariectomized female rats. The extract induced significant increase in the uterine weight of ovariectomized rats at two dose levels comparable to that of control group. The percentages of the total average number of scores were increased significantly too. Significant increases in plasma progesterone and total estrogens levels were shown at the two dose levels when compared to that of control group. On the other side, the extract induced significant reduction in luteinizing and plasma prolactin hormones.     

Structure and vibrational dynamics of model compounds of the [FeFe]-hydrogenase enzyme system via ultrafast two-dimensional infrared spectroscopy

Ultrafast two-dimensional infrared (2D) spectroscopy has been applied to study the structure and vibrational dynamics of (mu-S(CH2)3S)Fe2(CO)6, a model compound of the active site of the [FeFe]-hydrogenase enzyme system. Comparison of 2D-IR spectra of (mu-S(CH2)3S)Fe2(CO)6 with density functional theory calculations has determined that the solution-phase structure of this molecule is similar to that observed in the crystalline phase and in good agreement with gas-phase simulations. In addition, vibrational coupling and rapid (<5 ps) solvent-mediated equilibration of energy between vibrationally excited states of the carbonyl ligands of the di-iron-based active site model are observed prior to slower (approximately 100 ps) relaxation to the ground state. These dynamics are shown to be solvent-dependent and form a basis for the future determination of the vibrational interactions between active site and protein.     

Methoxy-activated indole-7-carbohydrazides; synthesis,antioxidant, and anticancer properties

Indole has been known as a key heterocyclic motif in the development of new structures for both chemical and biological properties. In this current study, a new range of indole-7-carbohydrazides has been successfully synthesized starting from the readily available 3-phenyl and 2,3-diphenyl 4,6-dimethoxyindoles. The structures of the novel compounds were confirmed by utilizing ¹H NMR, ¹³C NMR, FT-IR, high-resolution mass spectrometry, and single crystal X- ray diffraction techniques. In addition, the indole-7-carbohydrazides showed promising antioxidant results in preliminary screens. Some of the new compounds generated from dimethoxy indoles were also screened for their anticancer activity against SH-SHY5Y (human neuroblastoma), AGS (human gastric adenocarcinoma), and MDA-MB-231 (human breast adenocarcinoma) cell lines. The results revealed that the compound 12 was the promising candidate, showing cytotoxic effects on both neuroblastoma, stomach, and breast cancer cells.     

Flow injection spectrophotometric determination of iron(III) using diphenylamine-4-sulfonic acid sodium salt

A highly sensitive and very simple spectrophotometric flow-injection analysis (FIA) method for the determination of iron(III) at low concentration levels is presented. The method is based on the measurement of absorbance intensity of the red complex at 410 nm formed by iron(III) and diphenylamine-4-sulfonic acid sodium salt (DPA-4-SA). It is a simple, highly sensitive, fast, and low cost alternative method using the color developing reagent DPA-4-SA in acetate buffer at pH 5.50 and the flow-rate of 1 mL min⁻¹ with the sample throughput of 60 h⁻¹. The method provided a linear determination range between 5 μg L⁻¹ and 200 μg L⁻¹ with the detection limit (3S) of 1 μg L⁻¹ of iron(III) using the injection volume of 20 μL. FIA variables influencing the system performance were optimized. The amount of iron(III) and total iron in river and seawater samples was successfully determined. Repeatability of the measurements was satisfactory at the relative standard deviation of 3.5 % for 5 determinations of 10 μg L⁻¹ iron(III). The accuracy of the method was evaluated using the standard addition method and checked by the analysis of the certified material Std Zn/Al/Cu 43 XZ3F.     

Efficient and selective synthesis of quinoline derivatives

The bromination reaction of 1,2,3,4-tetrahydroquinoline (7) was investigated by NBS and molecular bromine. One-pot synthesis is described for synthetically valuable 4,6,8-tribromoquinoline (3) and 6,8-dibromo-1,2,3,4-tetrahydroquinoline (6) on bromination of 1,2,3,4-tetrahydroquinoline (7) in efficient yields (75 and 90%, respectively). 6-Bromo- (4) and 6,8-dibromo-1,2,3,4-tetrahydroquinolines (6) were converted to 6-bromo- (1) and 6,8-dibromo quinolines (2), respectively, by aromatization with DDQ in 83 and 77% yields, respectively. Several novel trisubstituted quinoline derivatives were efficiently prepared via lithium-halogen exchange reactions of tribromide 3. Treatment of 4,6,8-tribromoquinoline with BuLi followed by quenching with electrophiles [Si(CH₃)₃Cl, S₂(CH₃)₂, I₂] regioselectively proceeded at C-4 and C-8 sites and afforded corresponding 4,8-disubstituted-6-bromoquinolines. Similarly, lithiation of tribromide 3 followed by addition of water to the intermediate produced 6-bromoquinoline in 65% yield. Copper-induced nucleophilic substitution of tribromide 3 with NaOMe afforded 4,6,8-trimethoxyquinoline (17) in 60% yield.     

Microwave assisted synthesis of novel annealed porphyrins

New pyrrole derivatives (isoindoles) have been readily prepared by the reaction of an α,β-unsaturated sulfone with ethyl isocyanoacetate in the presence of tert-BuOK in good yields. The isoindoles are converted into new porphyrins which undergo retro Diels-Alder reactions under microwave irradiation at 250 °C for 4 min to give novel annealed porphyrins in quantitative yields.     

A promising structural zinc enzyme model for CO2 fixation and calcification

A new ligand, namely, N-{tris([2-[(1-methylbenzimidazol-2-yl)ethyl]methyl]amino)-2-oxoethyl}iminodiacetic acid is synthesized and characterized and used to prepare a zinc complex as a promising model for the active site of the nacreous protein in mollusc shells. Preliminary investigation of CO₂ fixation and calcification is studied with regard to the influence of the pK_a value of the coordinated water molecule and the carboxylate groups.     

Microbial metabolism of biologically active secondary metabolites from Nerium oleander L

Ursolic acid (1) and kaempferol (3) are two major constituents of the Mediterranean plant Nerium oleander L. Microbial metabolism of (1) with Aspergillus flavus (ATCC 9170) resulted in the formation of 3-oxo-ursolic acid derivative, ursonic acid (2). On the other hand, Cunninghamella blakesleeana (ATCC 8688A) was able to convert (3) into kaempferol 3-O-beta-D-glucopyranoside (4) as well as the new natural product kaempferol 4'-sulfate (5). Incubation of kaempferol with Mucor ramannianus (ATCC 9628) led to the isolation of one metabolite identified as kaempferol 4'-O-alpha-L-rhamnopyranoside (6). Transformation of kaempferol to the new compound kaempferol 7-O-beta-D-4-O-methylglucopyranoside (7) and herbacetin 8-O-beta-D-glucopyranoside (8) was observed after fermentation with Beauveria bassiana (ATCC 13144). Cytotoxic as well as antioxidant activities of the isolated metabolites were determined.