Tagetnoic acid,a new lipoxygenase inhibitor peroxy fatty acid from Tagetes minuta growing in Saudi Arabia

Abstract

A new peroxy fatty acid, tagetnoic acid (5) [4-((3S,6S)-6-((3E,8E)-octadeca-3,8-dien-1-yl)-3,6-dihydro-1,2-dioxin-3-yl)butanoic acid] and four known metabolites: ecliptal (5-formyl-α-terthiophene) (1), 5-(4-hydroxybut-1-ynyl)-2,2′-bithiophene (2), 22,23-dihydrospinasterone (3), and stigmasterol (4) were separated from the n-hexane fraction of the aerial parts of Tagetes minuta L. (Asteraceae). Their chemical structures were verified using IR, UV, 2D and 1D NMR, and HRMS. Compounds 3–5 displayed potent lipoxygenase inhibitory potential with IC₅₀s 2.26, 1.83, and 1.17?μM, respectively compared to indomethacin (IC₅₀ 0.89?μM). Moreover, molecular docking study revealed that the potent activity of 5 is due to H-bonding and hydrophobic interaction. The results of this study suggested that Tagetes minuta dietary consumption would be useful for the individuals at risk of acute and chronic inflammatory disorders.     

Occurrence and prevention of photodissolution at the phase junction of magnetite and titanium dioxide

A stable magnetic photocatalyst was prepared by coating a magnetic core with a layer of photoactive titanium dioxide. A direct deposition of titanium dioxide onto the surface of magnetic iron oxide particles proved ineffective in producing a stable magnetic photocatalyst, with high levels of photodissolution being observed with these samples. This observed photodissolution is believed to be due to the dissolution of the iron oxide phase, induced by the photoactive the titanium dioxide layer due to electronic interactions at the phase junction in these magnetic photocatalysts. The introduction of an intermediate passive SiO₂ layer between the titanium dioxide phase and the iron oxide phase inhibited the direct electrical contact and hence prevented the photodissolution of the iron oxide phase. The magnetic photocatalyst is for use in slurry-type reactors from which the catalyst can be easily recovered by the application of an external magnetic field.     

2-Phenyl-4-quinolinone Alkaloids from Casimiroa edulis Llave et Lex (Rutaceae)

Summary.  Three new 4-quinolinone alkaloids (5,6-dimethoxy-2-(3-methoxyphenyl)-1H-quinolin-4-one, 5,6-dimethoxy-2-(3,4-dimethoxyphenyl)-1H-quinolin-4-one, 5,6-dimethoxy-2-(2,5,6-trimethoxyphenyl)-1H-quinolin-4-one) were isolated from the leaves of Casimiroa edulis Llave et Lex (Rutaceae) cultivated in Egypt. Their structures were determined by UV/Vis, IR, ¹H and ¹³C NMR, and EI mass spectroscopy. The alkaloids were also detected in the kernels of the seeds. Received May 28, 2001. Accepted (revised) July 24, 2001     

Synthesis of 5-azaindolizine derivatives by the palladium-catalyzed intermolecular formal [3+2] cycloaddition of alkylidenecyclopropanes with 1,2-diazines

The palladium-catalyzed formal [3+2] cycloaddition reaction of alkylidenecyclopropanes with 1,2-diazines proceeded smoothly to give the corresponding 5-azaindolizine derivatives in good to allowable yields. For example, in the presence of 5 mol % of Pd(PPh(3))(4), the reaction of 1-propylhexylidenecyclopropane with phthalazine or with pyridazine proceeded at 120 degrees C without solvent, and the corresponding 2-(1-butylpentyl)pyrrolo[2,1-a]phthalazine or 6-(1-butylpentyl)pyrrolo[1,2-b]pyridazine was obtained in 61% or 49% yield, respectively.     

QSAR Modeling,Molecular Docking and Cytotoxic Evaluation for Novel Oxidovanadium(IV) Complexes as Colon Anticancer Agents

Four new drug-based oxidovanadium (IV) complexes were synthesized and characterized by various spectral techniques, including molar conductance, magnetic measurements, and thermogravimetric analysis. Moreover, optimal structures geometry for all syntheses was obtained by the Gaussian09 program via the DFT/B3LYP method and showed that all of the metal complexes adopted a square-pyramidal structure. The essential parameters, electrophilicity (ω) value and expression for the maximum charge that an electrophile molecule may accept (ΔN_max) showed the practical biological potency of [VO(CTZ)₂] 2H₂O. The complexes were also evaluated for their propensity to bind to DNA through UV–vis absorption titration. The result revealed a high binding ability of the [VO(CTZ)₂] 2H₂O complex with K_b = 1.40 × 10⁶ M⁻¹. Furthermore, molecular docking was carried out to study the behavior of the VO (II) complexes towards colon cancer cell (3IG7) protein. A quantitative structure–activity relationship (QSAR) study was also implemented for the newly synthesized compounds. The results of validation indicate that the generated QSAR model possessed a high predictive power (R² = 0.97). Within the investigated series, the [VO(CTZ)₂] 2H₂O complex showed the greatest potential the most selective compound comparing to the stander chemotherapy drug.     

基于氨基酸的Cu(Ⅱ)-色氨酸MOF催化剂上环氧化物与CO2环加成反应

由天然的/生物单元(氨基酸)构成的金属有机框架材料(MOFs)具有自然属性和丰富的酸/碱位和官能团,因而可用于CO2化学中.本文报道了氨基酸系含铜MOF(CuTrp,Trp = L-色氨酸)的催化效率.以甲醇为溶剂,在室温采用直接混合法合成了CuTrp催化剂,该方法具有很高的能量效率.采用X射线衍射、红外光谱、热重分析、电感耦合等离子体发射光谱法、扫描电镜和BET分析等手段对该催化剂进行了表征.采用环氧化物与CO2环加成制备环状碳酸酯反应评价了CuTrp催化剂活性.结果表明,在无溶剂条件下,CuTrp 催化剂可与四丁基溴化铵助催化剂发生协同作用.通过条件实验确定了优化的反应条件,并基于该实验结果和前期的密度泛函理论计算结果提出了反应机理.另外,CuTrp 催化剂在水中也表现出令人满意的稳定性,可重复使用三次以上而活性无明显下降.     

A C2-symmetric, living alpha-diimine Ni(II) catalyst: regioblock copolymers from propylene

An isomerically pure, C2-symmetric Ni(II) complex was synthesized and found to be living for propylene polymerization. The regioselectivity of the catalyst varied greatly with reaction temperature, with regioregular, highly isotactic polypropylene (PP) produced at low temperatures, and regioirregular PP produced at high temperatures. Regioblock PP was formed by changing the reaction temperature during the polymerization.     

Fokker-Planck equation for a periodic potential

The Fokker-Planck equation in one dimension has been solved for a system in a periodic potential and linearly perturbed by a time- and space- varying external electric field. The solution is not exact, but we believe it is less approximate than any attempted previously on this problem. We have calculated the frequency and wave-vector dependent mobility and discussed its behaviour in some limiting cases.The application of our model to various physical situations is discussed.     

Study of a soliton in a medium

The solution of the sine-Gordon equation for a medium is studied in a simplified “quasi-linear” approximation. Several aspects of this approximation are explored and compared with other approximate solutions for the sine-Gordon soliton.