Volume 70, Issue 3-4

Satureja rechingeri is a rare endemic and endangered species found in Iran. Its propagation, variations in essential oil and phenolic content, as well as antioxidant and antimicrobial activities at different phenological stages are reported in this study. The chemical composition of essential oils obtained by hydro-distillation from the aerial parts were determined by GC and GC-MS. A total of 47 compounds were identified in the essential oils of S. rechingeri at different phenological stages. The major components of all oils were carvacrol (83.6%–90.4%), p -cymene (0.8%–2.9%) and γ-terpinene (0.6%–2.4%). The total phenolic content and the antioxidant activity of methanolic extracts were determined with the Folin-Ciocalteau reagent and by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and ferric reducing antioxidant power (FRAP) assay, respectively. Total phenols varied from 35.5 to 37.5 mg gallic acid equivalents/g dry weight (dw), and IC 50 values in the radical scavenging assay ranged from 46.2 to 50.2 mg/mL, while those in the FRAP assay were between 49.6 and 52.5 μM quercetin equivalents/g dw. By the disc diffusion method and by determination of the minimum inhibitory concentrations (MIC), the essentials oils of the various phenological stages were found to have high activities against four medically important pathogens.

The mineral coating of Dyerophytum indicum Kuntze (Plumbaginaceae) was analyzed by isotope ratio mass spectrometry, X-ray diffraction, thermogravimetric and differential thermal analysis, and scanning electron microscopy/energy-dispersive X-ray spectroscopy methods. Its composition was found to be similar to those of the carbonate mixtures isolated from rotting cacti and speleothems. The coating consisted of three major phases (monohydrocalcite, nesquehonite, and calcite), a minor phase of hydromagnesite, and traces of silica and sylvite. This is the first time that the occurrence of monohydrocalcite, nesquehonite, and hydromagnesite in a living higher plant has been reported. A possible mechanism of the formation of the coating is also discussed.

A series of novel arylmethylamine derivatives of honokiol ( 5a - m ) was prepared. Their insecticidal activity was tested against the pre-third-instar larvae of the oriental armyworm ( Mythimna separata Walker), a typical lepidopteran pest. Compounds 5a , 5b , 5e , 5h , and 5k exhibited insecticidal activity equal to, or higher than, that of the positive control toosendanin.

Among secondary metabolites, alkylresorcinols are considered particularly important for the antimicrobial defense system in cereal grains. Dry rye caryopses and young seedlings contain detectable quantities of resorcinolic lipids. Overall, 11 distinct alkylresorcinol homologues were identified, which showed variable profiles during rye germination and early seedling development, especially with reference to the production of very long homologues and to side chain saturation. Additionally, changes in the alkylresorcinol composition during rye seedling growth are presented for the first time.

Chemical investigation of an unknown marine sponge, which was collected in the Gulf of Aqaba (Jordan), afforded a new brominated alkaloid 3-amino-1-(2-amino-4-bromophenyl)propan-1-one ( 1 ), as well as 7-bromoquinolin-4(1 H )-one ( 2 ) which had previously only been reported as a synthetic compound. In addition, caulerpin ( 6 ), previously only known to be produced by algae, was likewise isolated. Furthermore, three known alkaloids including ( Z )-5-(4-hydroxybenzylidene)-hydantoin, ( Z )-6-bromo-3′-deimino-2′,4′-bis(demethyl)-3′-oxoaplysinopsin, and 6-bromoindole-3-carbaldehyde ( 3–5 ), were also obtained. All compounds were unambiguously elucidated based on extensive 1D and 2D NMR spectroscopy, LCMS, as well as by comparison with the literature and tested for their cytotoxic activity toward the mouse lymphoma cell line L5178Y.

A series of novel 5-(4-methylpiperazin-1-yl)-2-phenyl-1 H -benzimidazoles ( 5 – 14 ) were synthesized and evaluated for their in vitro antiproliferative activities against the human leukemia cell line HL-60. Compounds 5 – 7 and 10 – 12 exhibited potent antiproliferative activities against this cell line. The quantitative analysis of apoptosis by flow cytometry demonstrated that the percentages of apoptotic HL-60 cells treated with compounds 5 and 10 – 12 were significantly higher than in the control.

This study revealed a differential cytotoxic activity of the petroleum ether extract (IC 50 =5 μg/mL) of the resinous exudates of Commiphora molmol against two mouse cell lines KA31T and NIH3T3 (untransformed and transformed mouse fibroblasts, respectively). Four new compounds ( 1 – 4 ) and five known compounds ( 5 – 9 ) were isolated from the petroleum ether extract. The identity of these new compounds was determined as γ-elemane lactone ( 1 ), 5-αH,8-βH-eudesma-1,3,7(11)-trien-8,12-olide ( 2 ), 2-hydroxy-11,12-dihydrofuranodiene ( 3 ), and 2-hydroxyfuranodiene ( 4 ). 1 and 2 displayed the highest cytotoxic activity against NIH3T3 cells. 7 and 9 exhibited moderate cytotoxic activity against KA31T cells. Compounds 3 – 6 showed weak cytotoxic activities against both cell lines. These results may explain the high efficacy of the petroleum ether fraction in several myrrh-derived pharmaceutical preparations.

A novel C 25 sterol peroxide, phomasterol A ( 1 ), together with two known compounds ( 2 – 3 ), was isolated from the endophytic fungus Phoma sp. EA-122. The structure of phomasterol A ( 1 ) was elucidated by MS, 1D, and 2D NMR data analyses. Phomasterol A ( 1 ) was evaluated for its inhibitory activities against protein-tyrosine phosphatases MEG2 and PTP1Bc, showing moderate activities with identical IC 50 values of 25 μM.

Liquid fermentations of the fungus Stereum rameale (N° 2511) yielded extracts with antibacterial activity. The antibacterial activity reached its peak after 216 h of stirring. Bioassay-guided fractionation methods were employed for the isolation of the bioactive metabolites. Three known compounds were identified: MS-3 ( 1 ), vibralactone ( 2 ) and vibralactone B ( 3 ). The three compounds showed antibacterial activity as a function of their concentration. Minimal bactericidal concentrations (MBC) of compound 1 against Gram-positive bacteria were as follows: Bacillus cereus (50 μg/mL), Bacillus subtilis (10 μg/mL) and Staphylococcus aureus (100 μg/mL). Compounds 2 and 3 were active only against Gram-negative bacteria. The MBC of compound 2 against Escherichia coli was 200 μg/mL. Compound 3 inhibited significantly the growth of E. coli and Pseudomonas aeruginosa , with MBC values of 50 and 100 μg/mL, respectively.

5-Lipoxygenase (5-LOX) plays a key role in the pathway of leukotriene biosynthesis. To predict the inhibitory activity of flavonoid inhibitors against 5-LOX from Spatholobus suberectus Dunn, Autodock 4.2 and comparative molecular field analysis (CoMFA) were employed. For the positive inhibitors (n=7), the value of the coefficient of determination ( R 2 ) between the binding free energy, calculated using Autodock 4.2, and the experimental pIC 50 is 0.838. In the training set (n=21) of inhibitors against 5-LOX, the R 2 of non-cross-validated partial least squares analysis between the actual and predicted pIC 50 values, using the no-validation with the optimum number of components set to 6, is 0.997 (p=0.000). For the model generated by CoMFA, the contribution of electrostatic and steric factors are 0.522 and 0.478, respectively. Among the flavonoids of S. suberectus , liquiritigenin, catechin, butin, 3′,4′,7-trihydroxyflavone, plathymenin, and gallocatechin are the more potent inhibitors of 5-LOX based on the calculated binding free energy and the predicted pIC 50 value.