Search

Quinoline derivatives have been reported to possess a wide range of pharmaceutical activities. Our group previously synthesized a series of quinoline compounds, in which compound 91b1 showed a significant anticancer effect. The purpose of this study was to evaluate the anticancer activity of compound 91b1 in vitro and in vivo, and screen out its regulated target. A series of cancer cell lines and nontumor cell lines were treated with compound 91b1 by MTS cytotoxicity assay and cell-cycle assay. In vivo anticancer activity was evaluated by a xenografted model on nude mice. Target prediction of 91b1 was assessed by microarray assay and confirmed by pancancer analysis. Relative expression of the target gene Lumican was measured by qRT-PCR. 91b1 significantly reduced tumor size in the nude mice xenograft model. Lumican was downregulated after 91b1 treatment. Lumican was proven to increase tumorigenesis in vivo, as well as cancer cell migration, invasion, and proliferation in vitro. The results of this study suggest that the anticancer activity of compound 91b1 probably works through downregulating the gene Lumican., International Journal of Molecular Sciences, 23 (21), ISSN:1422-0067

Perception is defined by Merriam-Webster dictionary as (a) the process of attaining awareness of the elements of environment through physical sensation and (b) a physical sensation interpreted in the light of experience. In common terminology, the word “perception” comes from the Latin words perceptio, percipio, and means “receiving, collecting, action of taking possession, and apprehension with the mind or senses”.

Multidrug resistance (MDR) is one of conventional cancer chemotherapy&rsquo, s limitations. Our group previously synthesized a series of quinoline-based compounds in an attempt to identify novel anticancer agents. With a molecular docking analysis, the novel compound 160a was predicted to target p-glycoprotein, an MDR candidate. The purpose of this study is to evaluate 160a&rsquo, s MDR reversal effect and investigate the underlying mechanism at the molecular level. To investigate 160a&rsquo, s inhibitory effect, we used a series of parental cancer cell lines (A549, LCC6, KYSE150, and MCF-7), the corresponding doxorubicin-resistant cell lines, an MTS cytotoxicity assay, an intracellular doxorubicin accumulation test, and multidrug resistance assays. The Compusyn program confirmed, with a combination index (CI) value greater than 1, that 160a combined with doxorubicin exerts a synergistic effect. Intracellular doxorubicin accumulation and transported calcein acetoxymethyl (AM) (a substrate for p-glycoprotein) were both increased when cancer cells with MDR were treated with compound 160a. We also showed that compound 160a&rsquo, s MDR reversal effect can persist for at least 1 h. Taken together, these results suggest that the quinoline compound 160a possesses high potential to reverse MDR by inhibiting p-glycoprotein-mediated drug efflux in cancer cells with MDR.

Purpose 83b1 is a novel quinoline derivative that has been shown to inhibit cancer growth in human esophageal squamous cell carcinoma (ESCC). This study was conducted to comprehensively evaluate the cytotoxic effects of 83b1 on a series of ESCC cell lines and investigate the mechanisms by which 83b1 suppresses cancer growth based on molecular docking analysis. Materials and methods A series of ESCC and nontumor immortalized cell lines were exposed to 83b1 and cisplatin (CDDP) in a dose-dependent manner, and the cytotoxicity was examined by a MTS assay kit. Prediction of the molecular targets of 83b1 was conducted by molecular docking analysis. Expression of cyclooxygenase 2 (COX-2) mRNA and COX-2-derived prostaglandin E2 (PGE2) were measured by quantitative real-time polymerase chain reaction and enzymelinked immuno-sorbent assay, respectively. In vivo anti-tumor effect was determined using a nude mice xenografted model transplanted with an ESCC cell line, KYSE-450. Results 83b1 showed the significant anti-cancer effects on all ESCC cell lines compared to CDDP; however, 83b1 revealed much lower toxic effects on non-tumor cell lines than CDDP. The predicted molecular target of 83b1 is peroxisome proliferator-activated receptor delta (PPARδ), which is a widely known oncoprotein. Additionally the expression of COX-2 mRNA and COX-2-derived PGE2 were down-regulated by 83b1 in a dose-dependent manner in ESCC cell lines. Furthermore, 83b1 was shown to significantly reduce the tumor size in nude mice xenograft. Conclusion The results of this study suggest that the potential anti-cancer effects of 83b1 on human esophageal cancers occur through the possible oncotarget, PPARδ, and down-regulation of the cancer related genes and molecules.

Tumour growth is closely related to the development of new blood vessels to supply oxygen and nutrients to cancer cells. Without the neovascular formation, tumour volumes cannot increase and undergo metastasis. Antiangiogenesis is one of the most promising approaches for antitumour therapy. The exploration of new antiangiogenic agents would be helpful in antitumour therapy. Quinoline is an aromatic nitrogen compound characterized by a double-ring structure which exhibits a benzene ring fused to pyridine at two adjacent carbon atoms. The high stability of quinoline makes it preferable in a variety of therapeutic and pharmaceutical applications, including antitumour treatment. This work is to examine the potential antiangiogenic activity of the synthetic compound 2-Formyl-8-hydroxy-quinolinium chloride. We found that 2-Formyl-8-hydroxy-quinolinium chloride could inhibit the growth of human umbilical vein endothelial cells in vitro. Using the diethylnitrosamine-induced hepatocarcinogenesis model, 2-Formyl-8-hydroxy-quinolinium chloride showed strong antiangiogenic activity. Furthermore, 2-Formyl-8-hydroxy-quinolinium chloride could inhibit the growth of large Hep3B xenografted tumour from the nude mice. We assume that 2-Formyl-8-hydroxy-quinolinium chloride could be a potential antiangiogenic and antitumour agent and it is worthwhile to further study its underlying working mechanism.

Cisplatin (CDDP) is one of the front-line chemotherapeutic drugs used in the treatment of esophageal squamous cell carcinoma (ESCC). Occurrence of resistance to CDDP has become one of the main challenges in cancer therapy. In this study, the gene expression profile of CDDP-resistant ESCC cells was investigated and molecular approaches were explored in an attempt to reverse the CDDP resistance. A CDDP-resistant SLMT-1/CDDP1R cell line was established from SLMT-1 cells by subculturing in the medium containing an increasing concentration of CDDP (0.1&ndash, 1&mu, g/mL). Mitochondrial (MTS) cytotoxicity assay, cell proliferation assay and cell morphology were used to assess the acquisition of cisplatin-resistance. The most differentially expressed gene in SLMT-1/CDDP1R cells was identified by cDNA microarray analysis compared with the parental SLMT-1 cells and validated by quantitative real-time polymerase chain reaction (qPCR). Association between expression of the most differentially expressed target gene to cisplatin-resistance was verified by RNA interference. An attempt to reversecisplatin-resistance phenotypes was made by using the vector expressing the most downregulated target gene in the CDDP-resistant cells. A CDDP-resistant ESCC cell line, SLMT-1/CDDP1R, was established with 2.8-fold increase CDDP-resistance (MTS50 = 25.8 &mu, g/mL) compared with the parental SLMT-1 cells. cDNA microarray analysis revealed that IGFBP5 showed the highest level of downregulation in SLMT-1/CDDP1R cells compared with the parental SLMT-1 cells. Suppression of IGFBP5 mediated by IGFBP5-targeting siRNA in parental SLMT-1 cells confirmed that IGFBP5 suppression in ESCC cells would induce CDDP-resistance. More importantly, upregulation of IGFBP5 using IGFBP5 expression vector reduced cisplatin-resistance in SLMT-1/CDDP1R cells by 41%. Thus, our results demonstrated that IGFBP5 suppression is one of the mechanisms for the acquisition of cisplatin-resistance in ESCC cells. Cisplatin-resistance phenotype can be reversed by increasing the expression level of IGFBP5. The overall findings of this study thus offered a new direction for reversing the CDDP resistance in ESCC and possibly in other cancer types with further investigations in future.

Candida albicans (C. albicans) is an opportunistic fungal pathogen, particularly observed in immunocompromised patients. C. albicans accounts for 50–70% of cases of invasive candidiasis in the majority of clinical settings. Terbinafine, an allylamine antifungal drug, has been used to treat fungal infections previously. It has fungistatic activity against C. albicans. Traditional Chinese medicines can be used as complementary medicines to conventional drugs to treat a variety of ailments and diseases. Berberine is a quaternary alkaloid isolated from the traditional Chinese herb, Coptidis Rhizoma, while berberrubine is isolated from the medicinal plant Berberis vulgaris, but is also readily derived from berberine by pyrolysis. The present study demonstrates the possible complementary use of berberine and berberrubine with terbinafine against C. albicans. The experimental findings assume that the potential application of these alkaloids together with reduced dosage of the standard drug would enhance the resulting antifungal potency.

Metals and metal complexes are promising antimicrobials due to their powerful inhibitory activity against microbes. However, the potential for metal toxicity to life remains unsolved. Mercury is a toxic element with no known positive biological functions, and its toxicity to humans is well known. With the known toxicity of Hg and its complexes, their usefulness for antimicrobial therapy should not be neglected. In this work, we investigated the antimicrobial activity of bis-(alkynyl)mercury(II) complexes with oligothiophene and bithiazole linking units against MRSA and C. albicans (pathogens commonly co-inhabit infected sites), and their cytotoxicity was tested on NIH 3T3 cells. Among the Hg(II) complexes, complex 2 showed potent microcidal activity against MRSA (MIC and MBC values = 0.2 μg mL−1) and C. albicans (MIC and MBC values = 0.4 μg mL−1). Complex 2 displayed a highly distinguished zone of clearance with comparably sharp zone edges on microbial agar plates. Time–kill kinetic studies showed that MRSA colonies were reduced by approximately 5 logs during the initial 3 h exposure to complex 2 at an 8× MIC level. The possible antimicrobial mechanism might be due to the intracellular ROS generation by complex 2 that caused the loss in MRSA viability. Complex 2 exhibited a higher IC50 value (0.8 μg mL−1) towards NIH 3T3 cells that was greater than its corresponding MIC values against tested microbes. Hg(II) complexes would be potent antimicrobials, but a challenge is to fully utilize their potential inhibitory effects on microbes while lowering their toxic levels on human health.

Water pollution by the discharge of dye residue has been polluting the planet for decades. Chitosan is one of the natural abundant biomasses that show excellent adsorption toward colorants. Nevertheless, sophisticated chemical modifications of chitosan are inevitable to enhance physical and chemical stabilities in practical applications. In the present study, simple freeze-drying has been adopted to chitosan (CHI) beads showing good stability at low levels of pH. The results show complete decolourisation of Reactive Blue 19 (RB19) within 2 hours at pH 3 and temperature of 37 ◦ C. The encapsulation of live bacterium Lactobacillus casei (L. casei) into chitosan beads for dyestuff removal is also evaluated. Kinetics studies show a faster initial rate of adsorption by L. casei-chitosan beads at pH 3 and temperature of 37 ◦ C. The adsorptions partially follow the intraparticle diffusion mechanism.

Many natural products that consist of quinoline core are found to be bioactive and the versatility of quinoline and its derivatives have attracted great attention in the field of drug development. As a result, in recent years, many green and sustainable synthetic approaches for the synthesis of structurally diverse quinolines have been developed. This review covers four main aspects, namely bioactive quinoline alkaloids, the biological activity and mechanism of action of quinoline-based compounds as well as various quinoline syntheses.

Quinoline core has been shown to possess a promising role in the development of anticancer agents. However, the correlation between its broad spectrum of bioactivity and the underlying mechanism of actions is poorly understood. The present study, with the use of bioinformatics approaches, reported a series of designed molecules which integrated quinoline core and sulfonyl moiety, with the objective of evaluating the substituent and linker effects on anticancer activities and associated mechanistic targets. We identified potent compounds (1h, 2h, 5 and 8) exhibiting significant anticancer effects towards liver cancer cells (Hep3B) with the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) relative values of cytotoxicity below 0.40, a value in the range of doxorubicin positive control with the value of 0.12. Bulky substituents and the presence of bromine atom, as well as the presence of sulfonamide linkage, are likely the favorable structural components for molecules exerting a strong anticancer effect. To the best of our knowledge, our findings obtained from chemical synthesis, in vitro cytotoxicity, bioinformatics-based molecular docking analysis (similarity ensemble approach, SEA),and electrophoretic mobility shift assay provided the first evidence in correlation to the anticancer activities of the selected compound 5 with the modulation on the binding of transcription factor NF-κB to its target DNA. Accordingly, compound 5 represented a lead structure for the development of quinoline-based NF-κB inhibitors and this work added novel information on the understanding of the mechanism of action for bioactive sulfonyl-containing quinoline compounds against hepatocellular carcinoma.

A series of 8-benzyloxy-substituted quinoline ethers (2a–n) compounds were synthesized. All synthesized compounds were screened in vitro for their preliminary antimicrobial activities against two Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli), two Gram-positive bacteria (Staphylococcus aureus and Staphylococcus epidermidis), and a fungal species (Aspergillus niger). Among all synthesized compounds, compound 2e showed a significant growth inhibitory activity with MIC value 3.125 μg/mL which was comparable to 8-hydroxyquinoline (2.5 μg/mL) and terbinafine (1.25 μg/mL) against A. niger.

This study reports the synthesis and characterization of quinoline derivatives. The synthesized quinoline compounds were applied to the dyeing treatment of acrylic fabrics. The color fastness to washing and light of quinoline compound-dyed fabrics was examined. Human skin HaCaT cell line was also used for the skin cytotoxicity evaluation of the quinoline compound-dyed acrylic fabrics.

Gelatin/Collagen-based matrix and reservoir nanoparticles require crosslinkers to stabilize the formed nanosuspensions, considering that physical instability is the main challenge of nanoparticulate systems. The use of crosslinkers improves the physical integrity of nanoformulations under the-host environment. Aldehyde-based fixatives, such as formaldehyde and glutaraldehyde, have been widely applied to the crosslinking process of polymeric nanoparticles. However, their potential toxicity towards human beings has been demonstrated in many previous studies. In order to tackle this problem, D-glucose was used during nanoparticle formation to stabilize the gelatin/collagen-based matrix wall and reservoir wall for the deliveries of Calendula officinalis powder and oil, respectively. In addition, therapeutic selectivity between malignant and normal cells could be observed. The C. officinalis powder loaded nanoparticles significantly strengthened the anti-cancer effect towards human breast adenocarcinoma MCF7 cells and human hepatoma SKHep1 cells when compared with the free powder. On the contrary, the nanoparticles did not show significant cytotoxicity towards normal esophageal epithelial NE3 cells and human skin keratinocyte HaCaT cells. On the basis of these evidences, D-glucose modified gelatin/collagen matrix nanoparticles containing C. officinalis powder might be proposed as a safer alternative vehicle for anti-cancer treatments.

Fenton oxidative wastewater treatment of CI Reactive Black 5 and CI Reactive Blue 19 effluent was performed after a simulated laboratory-scale dyeing process, and the cytotoxicity of the treated effluent was evaluated using human skin cell lines. Among the components for Fenton oxidation, the human skin cell results showed that iron(II)sulfate at 150 mm did not show any significant cytotoxic effect, while other components, such as Glauber's salt solution (20 g l−1; 14%), CI Reactive Black 5 (30 mg l−1; 24%), caustic soda (5 g l−1; 30%), CI Reactive Blue 19 (30 mg l−1; 32%), hydrogen peroxide (0.01 m) and soda ash (5 g l−1) showed cytotoxic potential; the reagent sodium sulfite (30 mm; 48%) exhibited the strongest cytotoxicity level. Fast decolorisation (>95%) was achieved within 10 min for CI Reactive Black 5, while for CI Reactive Blue 19 it took longer (1.5 h) to achieve the same decolorisation. Studies showed that decolorisation for both dyes followed second-order kinetics. In spite of the remarkable efficacy of the Fenton oxidation process in removing colour within a short period of time, the resulting treated wastewater (within a reaction time of 1.5 h) also showed cytotoxicity towards the human HaCaT skin keratinocyte cell line. This observation can be explained by the strong oxidant and intermediate species produced during the advanced oxidation process, and a treatment step using sodium sulfite and a prolonged residence time can help to reduce the cytotoxicity.

In this study, a novel green microencapsulation system was used to develop Phyllanthus urinaria (PU) extract containing microcapsules. Agar was used with gelatin as the wall matrix materials of microcapsules to prevent the use of toxic crosslinker formaldehyde. Microencapsulated PU extract was developed to improve the potential antifungal activities of PU water extracts. The active components and surface morphology of PU extract containing microcapsules were analyzed by liquid chromatography/mass spectrometry and scanning electron microscopy, respectively. The in vitro release study demonstrated that approximately 80% of drug was released after 120 h. PU loaded microcapsules were shown to have a stronger anti-Aspergillus niger activity than the free drug.

Purpose 83b1 is a novel quinoline derivative that has been shown to inhibit cancer growth in human esophageal squamous cell carcinoma (ESCC). This study was conducted to comprehensively evaluate the cytotoxic effects of 83b1 on a series of ESCC cell lines and investigate the mechanisms by which 83b1 suppresses cancer growth based on molecular docking analysis. Materials and Methods A series of ESCC and nontumor immortalized cell lines were exposed to 83b1 and cisplatin (CDDP) in a dose-dependent manner, and the cytotoxicity was examined by a MTS assay kit. Prediction of the molecular targets of 83b1 was conducted by molecular docking analysis. Expression of cyclooxygenase 2 (COX-2) mRNA and COX-2–derived prostaglandin E2 (PGE2) were measured by quantitative real-time polymerase chain reaction and enzymelinked immuno-sorbent assay, respectively. In vivo anti-tumor effect was determined using a nude mice xenografted model transplanted with an ESCC cell line, KYSE-450. Results 83b1 showed the significant anti-cancer effects on all ESCC cell lines compared to CDDP; however, 83b1 revealed much lower toxic effects on non-tumor cell lines than CDDP. The predicted molecular target of 83b1 is peroxisome proliferator-activated receptor delta (PPARδ), which is a widely known oncoprotein. Additionally the expression of COX-2 mRNA and COX-2–derived PGE2 were down-regulated by 83b1 in a dose-dependent manner in ESCC cell lines. Furthermore, 83b1 was shown to significantly reduce the tumor size in nude mice xenograft. Conclusion The results of this study suggest that the potential anti-cancer effects of 83b1 on human esophageal cancers occur through the possible oncotarget, PPARδ, and down-regulation of the cancer related genes and molecules.

Many natural products that consist of quinoline core are found to be bioactive and the versatility of quinoline and its derivatives have attracted great attention in the field of drug development. As a result, in recent years, many green and sustainable synthetic approaches for the synthesis of structurally diverse quinolines have been developed. This review covers four main aspects, namely bioactive quinoline alkaloids, the biological activity and mechanism of action of quinoline-based compounds as well as various quinoline syntheses.

Nitrogen heterocyclic fluorescent compounds and their possible dyeing pathway on acrylic fabrics was investigated. Their chemical spectral properties, including fluorescence and ultraviolet–visibility, were evaluated in this work. The colour fastness properties of these dyes attributable to light reflection and washing were examined. The CIE L*, a* and b* values after the dyeing process were studied and the colour fastness properties were also determined. Two quinoline derivatives showed stronger fluorescence properties and were also demonstrated to be non-cytotoxic towards human HaCaT skin keratinocytes at a reasonable dose. These results led to speculation that these two compounds could be further used as dyes in various textile applications.

Chitosan based microcapsule which encapsulated with phyllanthin was developed by simple coacervation. The composition and surface morphology of phyllanthin containing microcapsules were analyzed by Fourier Transform Infrared spectroscopy and Scanning Electron Microscopy, respectively. The release of phyllanthin from the microcapsules was found to be more than 60% after 120 h. In vitro biological assays demonstrated that these phyllanthin containing microcapsules showed a stronger anti-oxidation potential on both human fibroblasts and keratinocytes as well as a better growth inhibitory activity towards Staphylococcus aureus.

A new chiral ligand 6,6′-dimethoxy-2,2′-diaminobiphenyl was successfully prepared from 3-nitrophenol via iodination, Ullmann coupling, and reduction. The resolving reagent (2R, 3R)- or (2S,3S)-2,3-di (phenylaminocarbonyl)tartaric acid was prepared from commercially available tartaric acid in large scale and was used to resolve the racemic 6,6′-dimethoxy-2,2′-diaminobiphenyl. The chiral 6,6′- dimethoxy-2,2′-diaminobiphenyl obtained was proved to be enantiomerically pure.

A new chiral ligand N-p-toluenesulfonyl-2,2′-dimethoxy-6,6′-diaminobiphenyl (Ts-DMBDPPA) was prepared from 2,2′-dimethoxy-6,6′-diaminobiphenyl via N-tosylation. Its Ru(II) complex was effective catalysts for catalytic asymmetric transfer hydrogenation of aromatic ketones (with ee's up to 69.3%).

The use of a chiral iridium catalyst gener- ated in situ from the (cyclooctadiene)iridium chlo- ride dimer, (IrA2, the P-Phos ligand (4,4'- bis(diphenylphosphino)-2,2',6,6'-tetramethoxy-3,3'-bi- pyridine) and iodine (I2) for the asymmetric hydroge- nation of 2,6-substituted quinolines and trisubstituted pyridines (2-substituted 7,8-dihydroquinolin-5(6H)- one derivatives) is reported. The catalyst worked ef- ficiently to hydrogenate a series of quinoline deriva- tives to provide chiral 1,2,3,4-tetrahydroquinolines in high yields and up to 96% ee. The hydrogenation was carried out at high S/C (substrate to catalyst) ratios of 2000-50000, reaching up to 4000 h 1 TOF (turnover frequency) and up to 43000 TON (turn- over number). The catalytic activity is found to be additive-controlled. At low catalyst loadings, de- creasing the amount of additive I2 was necessary to maintain the good conversion. The same catalyst system could also enantioselectively hydrogenate tri- substituted pyridines, affording the chiral hexahydro- quinolinone derivatives in nearly quantitative yields and up to 99% ee. Interestingly, increasing the amount of I2 favored high reactivity and enantiose- lectivity in this case. The high efficacy and enantiose- lectivity enable the present catalyst system of high practical potential.

A homologous set of 9,9-dialkyl-4,5-diazafluorene compounds were prepared by alkylation of 4,5-diazafluorene with the appropriate alkyl bromide and under basic conditions. The structures of these simple organic compounds were confirmed by spectroscopic techniques (FTIR, NMR, and FABMS). Their biological effects toward a panel of human carcinoma cells, including Hep3B hepatocellular carcinoma, MDAMB-231 breast carcinoma, and SKHep-1 hepatoma cells, were investigated; a structure-activity correlation was established with respect to the length of the alkyl chain and the fluorene ring structure. The relationship between the mean potency [log(1/IC(50))] and alkyl chain length was systematically studied. The results show that compounds with butyl, hexyl, and octyl chains exhibit good growth inhibitory effects toward these three human carcinoma cell lines, and the 9,9-dihexyl-4,5-diazafluorene further exhibits antitumor activity in athymic nude mice Hep3B xenograft models. For the structurally related dialkylfluorenes that lack the diaza functionality, in vitro cytotoxicity was not observed at clinically relevant concentrations.

The ‘one pot’ condensation reaction for the synthesis and potent antiproliferative inhibition of α -phthalimide based ketones is reported here. 2-Phthalimide-1-(4-fluoro-phenyl)ethanone ( 5 ) showed the best growth inhibition on human MDAMB-231 breast carcinoma and SKHep-1 hepatoma cell lines. Preliminary studies showed that the reported bioactivity may be due to the presence of strong electronegative fluorine group at the para -position of the aryl ring.

Phthalic anhydride is a highly toxic substance, facing, however, the problem of hydrolysis. In fact, it is rapidly hydrolyzed in aqueous medium, generating phthalic acid as the final product, which is almost harmless to viable cells. Here we describe the 'one pot' condensation reaction for the synthesis of phthalic imide derivative (benzothiazole containing phthalimide), exhibiting in vitro cytotoxic potential on human cancer cell lines. We further demonstrated that both caspase-dependent and -independent pathways are involved in our novel benzothiazole containing phthalimide induced apoptosis on cancer cells.

The iridium complex-catalyzed asymmetric hydrogenation of quinolines in a DMPEG/hexane biphasic system was studied. Catalysts with C2-symmetric ligands such as Xyl-P-Phos, Cl–MeO–BIPHEP, SYNPHOS, and DifluorPhos are highly effective for this type of reaction. Most of the catalysts tested can be retained in DMPEG (Mn = 500), and the asymmetric hydrogenation of various quinoline substrates can be carried out in DMPEG/hexane biphasic system with up to 92% ee. The catalysts and the products can be separated via simple phase separation, and the reactivity/stereoselectivity of the catalysts can be retained for at least three reaction cycles.

The chiral diphosphinite H8-BINAPO derived from H8-BINOL has been used in the Ir-catalyzed asymmetric hydrogenation of quinolines, and high enantioselectivity (up to 97% ee) was obtained. Immobilization of the iridium catalyst in poly(ethylene glycol) dimethyl ether (DMPEG) is also discussed. With DMPEG/hexane biphasic system, better enantioselectivities were obtained as compared to those observed in aprotic organic solvents.

Chiral dipyridylphosphine ligand P-Phos was used in the Ru catalyzed asymmetric hydrogenation of α- and β-keto esters in room temperature ionic liquids (RTILs) with high conversions and good to excellent enantioselectivities. The catalyst was recycled by simple extraction and reused five times without loss of activity and enantioselectivity.Key words: ruthenium, asymmetric hydrogenation, keto ester, ionic liquids, P-Phos.

A series of monodentate phosphoramidite ligands derived from H 8 -BINOL have been synthesized. The ligands are used in the Rh-catalyzed asymmetric hydrogenation of enamides to give the acetamides in up to 99% ee.

Parkinson’s disease (PD) is a chronic neurodegenerative disorder having close relationship with oxidative stress induced by reactive oxygen species (ROS). Cortex Fraxini (QP) is a kind of traditional Chinese medicinal herb with antioxidant properties. It may be a potential candidate for preventing the development of chronic neurodegenerative diseases. Thus, the key objective of the current study was to investigate the neuroprotective effect of QP water extract on 6-hydroxydopamine (6-OHDA) induced apoptosis in rat pheochromocytoma (PC12) cells. It was found that QP water extract possesses strong antioxidant property with SC50= 0.15 mg/mL. Total phenolic content of QP water extract was found to be 200.78 ± 2.65 mg GAE/g. QP water extract’s free radical scavenging capacity was demonstrated by reversing the increased level of intracellular ROS induced by 6-OHDA, using 2′,7′-dichlorodihydrofluorescein diacetate. Moreover, QP water extract (0.5 mg/mL) could remarkably increase the viability of PC12 cells treated with 6-OHDA. The protective effect of QP water extract was found to be via inhibiting MEK/ERK pathway and reversing PI3-K/Akt/GSK3βpathway. The current results suggest that QP might be a potential candidate for preventing the development of neurodegenerative diseases, such as PD.

A new chiral dipyridylphosphine ligand Xyl-P-Phos has been synthesized and the structure of (S)-Xyl-P-Phos oxide has been characterized by single crystal X-ray diffraction. The ruthenium complex of this ligand, Ru(R-Xyl-P-Phos)(C6H6)Cl2, has been found to be a highly active, enantioselective and air-stable catalyst for the asymmetric hydrogenation of β-ketoesters and shows good potential for industrial applications.

l-ascorbic acid is an abundant water-soluble nutrient found in vegetables and fruits. It enhances the cell proliferation, which is helpful in wound healing process. However, it is relatively unstable and easily degraded under external environments including acidity, alkalinity, evaporation, heat, oxidization, light or moisture. Its storage remains challenged. This study reported the development of l-ascorbic acid microcapsules using the natural protein, gelatin, and the natural polysaccharide, agar, as the wall protection carrier. The physical properties including entrapment efficiency, particle size, surface morphology, chemical compositions and release profile were identified. The cell proliferation of l-ascorbic acid microcapsules was stronger than the free drug. Significant cell growth in microencapsulated l-ascorbic acid-treated human epithelial HaCaT cells was observed when compared with untreated control. Since cell proliferation and wound repair are closely related, it is believed that l-ascorbic acid microcapsules would effectively increase the potential effect of wound healing activity in human skin.

Aspergillus niger (A. niger) is a common species of Aspergillus molds. Cutaneous aspergillosis usually occurs in skin sites near intravenous injection and approximately 6% of cutaneous aspergillosis cases which do not involve burn or HIV-infected patients are caused by A. niger. Biomaterials and biopharmaceuticals produced from microparticle-based drug delivery systems have received much attention as microencapsulated drugs offer an improvement in therapeutic efficacy due to better human absorption. The frequently used crosslinker, glutaraldehyde, in gelatin-based microencapsulation systems is considered harmful to human beings. In order to tackle the potential risks, agarose has become an alternative polymer to be used with gelatin as wall matrix materials of microcapsules. In the present study, we report the eco-friendly use of an agarose/gelatin-based microencapsulation system to enhance the antifungal activity of gallic acid and reduce its potential cytotoxic effects towards human skin keratinocytes. We used optimal parameter combinations, such as an agarose/gelatin ratio of 1:1, a polymer/oil ratio of 1:60, a surfactant volume of 1% w/w and a stirring speed of 900 rpm. The minimum inhibitory concentration of microencapsulated gallic acid (62.5 µg/ml) was significantly improved when compared with that of the original drug (>750 µg/ml). The anti-A. niger activity of gallic acid -containing microcapsules was much stronger than that of the original drug. Following 48 h of treatment, skin cell survival was approximately 90% with agarose/gelatin microcapsules containing gallic acid, whereas cell viability was only 25-35% with free gallic acid. Our results demonstrate that agarose/gelatin-based microcapsules containing gallic acid may prove to be helpful in the treatment of A. niger-induced skin infections near intravenous injection sites.

A new chiral ligand 6, 6′-dihydroxy-5, 5′-biquinoline (BIQOL, 2) was prepared via Cu2+ mediated coupling. The resolution was carried out by separating the corresponding ditrifluomethanesulfonate on chiral column. When applied to the enantioselective addition of diethylzinc to aromatic aldehydes, this ligand induced the reaction with enantioselectivity equivalent to that induced by BINOL. The effects of solvent and reaction temperature on enantioselectivity were also studied. Chirality 12:510–513, 2000. © 2000 Wiley-Liss, Inc.

Ethanol has been commonly used as a vehicle for drug discovery purpose in vitro. The human breast cancer MCF-7 estrogen dependent cell line is a common in vitro model used for hormonal therapy study. However, special precaution is suggested when ethanol is used in pharmacological tests as solvent in order to evaluate the biological activity of potential drugs especially concerning about the MCF-7. Ethanol was shown to stimulate the proliferation of this estrogen receptor positive cell line. Here, we have further demonstrated that the dose responsive stimulatory effect of ethanol on the MCF-7 cells after pre-incubating the breast carcinoma cells with phenol red-free medium and stripped fetal bovine serum. Our findings open a discussion for the evaluation of ethanol as solvent for drug discovery and screening when using MCF-7 cells as a testing model.

This work describes the preparation of quinoline compounds as possible anti-bacterial agents. The synthesized quinoline derivatives show anti-bacterial activity towards Staphylococcus aureus. It is interesting to observe that the synthetic 5,7-dibromo-2-methylquinolin-8-ol (4) shows a similar minimum inhibitory concentration of 6.25μg/mL as compared to that of methicillin (3.125μg/mL) against Staphylococcus aureus.

Chitosan-based photocatalyst composites containing CdS nanocrystals with and without glutaraldehyde or epichlorohydrin cross-linking treatments were investigated and the catalyzed photodegradation of methyl orange in aqueous solution was examined. In addition, the effects of catalyst dosage, initial dye concentration, and initial pH of the dye solution on the photodegradation kinetics were investigated. In this study, the effect of initial solution pH was more important than other factors. The photocatalyst composite could remove 99% dye in 80 minutes at pH 4. The catalyst composite was characterized by using X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), fourier transform infrared (FT-IR), and visible reflectance spectroscopy. The dye removal mechanism of methyl orange involved an initial sorption process followed by photodegradation. The sorption process underwent the pseudo-second order kinetics, while photodegradation followed the Langmuir-Hinshelwood kinetics. Although the glutaraldehyde cross-linked chitosan enhanced the initial dye sorption, the epichlorohydrin cross-linked catalyst composite demonstrated a better overall dye removal performance, especially in the photodegradation step. Both chitosan encapsulated catalyst with and without epichlorohydrin cross-linking demonstrated the same pseudo-first order photodegradation kinetic constant of 0.026 min−1and the same dye removal capacity. The catalyst composite could be reused but the photocatalytic activity dropped successively in each cycle.

The quinolinium chloride salt of 8-hydroxyqinolinecarbaldehyde (2-Formyl-8-hydroxy-quinolinium chloride) was prepared as Galipea longiflora alkaloid analogue and its anticancer activity was evaluated both in vitro and in vivo. This chloride salt was found to show certain degree of selectivity between hepatoma cells and normal hepatocytes in vitro. Athymic nude mice Hep3B xenograft model further demonstrated that this 2-Formyl-8-hydroxy-quinolinium chloride could execute strong anti-tumour activity with the identification of extensive necrotic feature from the tumour xenograft and limited adverse toxicological effect.

We explore the possible cellular cytotoxic activity of an amphiphilic silicon(IV) phthalocyanine with axially ligated rhodamine B under ambient light experimental environment as well as its in vivo antitumour potential using Hep3B hepatoma cell model. After loading into the Hep3B hepatoma cells, induction of cellular cytotoxicity and cell cycle arrest were detected. Strong growth inhibition of tumour xenograft together with significant tumour necrosis and limited toxicological effects exerted on the nude mice could be identified.