Biological and catalytic evaluation of Ru(II)‐p‐cymene complexes of Schiff base ligands: Impact of ligand appended moiety on photo‐induced DNA and protein cleavage,cytotoxicity and C‐H activation

Two organometallic Ru(II)‐p‐cymene complexes of the type [Ru(η⁶‐p‐cymene)(L)Cl]PF₆ 1 and 2 , where L is N,N‐bis(4‐isopropylbenzylidene)ethane‐1,2‐diamine (bien, L1 ) or N,N‐bis (pyren‐2‐ylmethylene)ethane‐1,2‐diamine (bpen, L2 ) have been prepared and characterized well. Because of appended pyrenyl groups in coordinated bpen ligand, the complex 2 exhibits higher DNA and protein binding than complex 1 in which isopropylbenzyl groups are incorporated. Interestingly, the luminescent characteristic complex 2 is unique in displaying DNA cleavage after light activation by UVA light at 365 nm through oxygen dependent mechanism. AFM analysis attests the photo‐induced DNA fragmentation ability of complex 2 . Also, the complex 2 cleaves the protein after light exposure in a non‐specific manner suggesting that it can act as a protein photo cleaving agent. In contrast to the trend of DNA and protein interaction of complexes, the complex 1 exhibits cytotoxic activity against human breast carcinoma ( MCF‐7 ) and liver carcinoma ( HepG2 ) with potency higher than that of complex 2 due to enhanced hydrophobicity of isopropyl groups present in p‐cymene and bien ligands. Indeed, complex 2 is inactive against MCF‐7 and HepG2 cancer cell lines even up to 200 μM concentration. The AO/EB staining assay reveals that the complex 1 is able to induce late apoptotic mode of cell death in breast cancer cells, which is further confirmed by inter‐nucleosomal DNA cleavage. Furthermore, the complexes 1 and 2 are evaluated for their catalytic activities and found to be working well for the β‐carboline directed C–H arylation to afford the desired products in good yield (40–47%).     

Simultaneous determination of ascaridole,p‐cymene and α‐terpinene in rat plasma after oral administration of Chenopodium ambrosioides L. by GC‐MS

A sensitive and reliable GC‐MS method was developed and validated for the simultaneous determination of ascaridole, p‐cymene and α‐terpinene in rat plasma using naphthalene as internal standard. The plasma samples were extracted with ethyl acetate. Chromatographic separation was carried out on a HP‐5MS capillary analytical column (30 m × 0.25 mm, 0.25 µm) and detection was performed on a quadrupole mass spectrometer detector operated under selected ion monitoring mode. The method showed excellent linearity over the investigated concentration range (r > 0.99) with the limit of quantitation down to 50, 10 and 5 ng/mL for ascaridole, p‐cymene and α‐terpinene, respectively. The intra‐day and inter‐day precisions (RSD) were <11.3%, and the accuracy was between 90.7 and 113.8%. The method was successfully applied to investigate the pharmacokinetics of Chenopodium ambrosioides L. following oral administration to rats. Copyright © 2015 John Wiley & Sons, Ltd.     

Transalkylation of toluene with diisopropylbenzene over rey zeolite

Production of cymenes and cumene through transalkylation of toluene with diisopropylbenzene has been studied over REY zeolite. Variation of different reaction parameters and their effects on the conversion of DIPB and selectivity to cymenes and cumene are described. Concentration of cymenes are more than cumene due to successive and simultaneous reactions.     

无有机模板快速合成ECR-1沸石

成功地在无有机模板剂的条件下快速合成了硅铝沸石分子筛ECR-1,其合成温度为120 oC,反应时间为4天,这与传统的无有机模板合成需要14天的反应时间相比,其生长周期大大缩短,该现象归属于它们的晶体生长机理的区别. 进一步,通过红外光谱、氮气吸附、扫描电镜、ICP及核磁等表征手段对产品的物理化学性能进行了系统表征,同时以异丙苯裂化作探针反应考察了产品的催化裂化性能.     

Unusual coordination mode of aroyl/acyl thiourea ligands and their π‐arene ruthenium (II) piano‐stool complexes: Synthesis,molecular geometry,theoretical studies and biological applications

Two mononuclear ruthenium complexes ( 1 and 2 ) with aroyl/acylthiourea as an ancillary ligand of type, [(η⁶‐p‐cymene)RuCl(L‐N,S)], where [ L1  = 2,4‐dichloro‐N‐(o‐tolylcarbamothioyl)benzamide] and L2  = N‐(phenylcarbamothioyl)cyclohexanecarboxamide] were synthesized and well characterized. The single crystal X‐ray diffraction studies revealed the coordination mode and the geometry of the complexes. The two complexes adopted general piano‐stool (three‐legged) geometry with a novel coordination mode of aroyl/acylthiourea through amide N (anionic) and thiocarbonyl S (neutral). This type of monobasic bidentate coordination of the aroyl/acylthiourea ligand was witnessed the first time around the metal ion. The coordination of the complexes was well explained through geometric parameters and frontier molecular orbital parameter values computed at the B3LYP/SDD level. The synthesized complexes were also screened for their antibacterial, antifungal, antioxidant and in vitro antiproliferative activities. Complexes exhibited good antimicrobial agents against various pathogens. The antioxidant activity of the complex 2 has shown most potent activity with IC₅₀ value of 48.55 ± 1.7 μM compared to the reference drug. In addition, the in vitro antiproliferative activity of the complex 2 showed excellent activity against HepG‐2 cell line with the IC₅₀ value of 24.30 ± 1.20 μM which is close to Doxorubicin standard drug.     

Transfer hydrogenation of ketones catalysed by half‐sandwich (η6‐p‐cymene) ruthenium(II) complexes incorporating benzoylhydrazone ligands

Neutral half‐sandwich η⁶‐p ‐cymene ruthenium(II) complexes of general formula [Ru(η⁶‐p ‐cymene)Cl(L)] (HL = monobasic O, N bidendate benzoylhydrazone ligand) have been synthesized from the reaction of [Ru(η⁶‐p ‐cymene)(μ‐Cl)Cl]₂ with acetophenone benzoylhydrazone ligands. All the complexes have been characterized using analytical and spectroscopic (Fourier transform infrared, UV–visible, ¹H NMR, ¹³C NMR) techniques. The molecular structures of three of the complexes have been determined using single‐crystal X‐ray diffraction, indicating a pseudo‐octahedral geometry around the ruthenium(II) ion. All the ruthenium(II) arene complexes were explored as catalysts for transfer hydrogenation of a wide range of aromatic, cyclic and aliphatic ketones with 2‐propanol using 0.1 mol% catalyst loading, and conversions of up to 100% were obtained. Further, the influence of other variables on the transfer hydrogenation reaction, such as base, temperature, catalyst loading and substrate scope, was also investigated.     

异松油烯空气氧化产物的GC-MS分析

用气相色谱-质谱联用技术对异松油烯的空气氧化产物进行了分析,确定其主要产物为p-伞花醇、p,α-二甲基苯乙烯、对伞花烃、双戊烯等,并通过改变温度、溶剂等对氧化产物中各成分的含量变化进行了研究.