Simultaneous analysis of major ingredients of Gardenia fruit by HPLC-MS/TQMS method

An efficient, accurate HPLC-MS/TQMS method was introduced for the quantitative/qualitative simultaneous analysis of main ingredients, namely geniposide and genipingentiobioside, in the Gardenia fruit. The separation was successfully obtained using a C8 (100mm×2.1mm, 5μm, 30°C) column by gradient elution with ultrapure water as mobile phase, where flow rate was set to 0.2 ml/min and detection wavelength at 240 nm. The analytical method was validated and the quantification of active compounds, namely genipingentiobioside and gardenoside, was performed. Linearity, precision, repeatability, stability and recovery were also reported. The quantitative analysis revealed that both main ingredients as geniposide and genipingentiobioside have performed a good linear relationship in 0.1-100 mg/ml concentration range (r=1.00000 and r =0.99998). The average content was measured to be 4.842% with RSD 0.96% for geniposide and 1.1976% with RSD 0.47% for genipingentiobioside in the Gardenia fruit. Accordingly, this method would be feasible for the quantity and quality control of crude drugs

Evaluation of amyloid β42 aggregation inhibitory activity of commercial dressings by a microliter-scale high-throughput screening system using quantum-dot nanoprobes

The aggregation and accumulation of amyloid β (Aβ) in the brain is a trigger of pathogenesis for Alzheimer’s disease. Previously, we developed a microliter-scale high-throughput screening (MSHTS) system for Aβ42 aggregation inhibitors using quantum-dot nanoprobes. The MSHTS system is seldom influenced by contaminants in samples and is able to directly evaluate Aβ42 aggregation inhibitory activity of samples containing various compounds. In this study, to elucidate whether the MSHTS system could be applied to the evaluation of processed foods, we examined Aβ42 aggregation inhibitory activity of salad dressings, including soy sauces. We estimated the 50% effective concentration (EC50) from serial diluted dressings. Interestingly, all 19 commercial dressings tested showed Aβ42 aggregation inhibitory activity. It was suggested that EC50 differed by as much as 100 times between the dressings with the most (0.065 ± 0.020 v/v%) and least (6.737 ± 5.054 v/v%) inhibitory activity. The highest activity sample is traditional Japanese dressing, soy sauce. It is known that soy sauce is roughly classified into a heat-treated variety and a non-heat-treated variety. We demonstrated that non-heat-treated raw soy sauce exhibited higher Aβ42 aggregation inhibitory activity than heat-treated soy sauce. Herein, we propose that MSHTS system can be applied to processed foods

Amino Amide Organocatalysts for Asymmetric Michael Addition of β-Keto Esters with β-Nitroolefins

Asymmetric Michael addition of β-keto esters with trans-β-nitroolefins using chiral amino amide organocatalyst was tried and afforded synthetically useful chiral Michael adducts in both excellent chemical yields (up to 99%) and stereoselectivities (up to dr. 99:1, up to 98% ee)

A Microliter-Scale High-throughput Screening System with Quantum-Dot Nanoprobes for Amyloid-β Aggregation Inhibitors

The aggregation of amyloid β protein (Aβ) is a key step in the pathogenesis of Alzheimer’s disease (AD), and therefore inhibitory substances for Aβ aggregation may have preventive and/or therapeutic potential for AD. Here we report a novel microliter-scale high-throughput screening system for Aβ aggregation inhibitors based on fluorescence microscopy-imaging technology with quantum-dot Nanoprobes. This screening system could be analyzed with a 5-µl sample volume when a 1536-well plate was used, and the inhibitory activity could be estimated as half-maximal effective concentrations (EC50). We attempted to comprehensively screen Aβ aggregation inhibitors from 52 spices using this system to assess whether this novel screening system is actually useful for screening inhibitors. Screening results indicate that approximately 90% of the ethanolic extracts from the spices showed inhibitory activity for Aβ aggregation. Interestingly, spices belonging to the Lamiaceae, the mint family, showed significantly higher activity than the average of tested spices. Furthermore, we tried to isolate the main inhibitory compound from Satureja hortensis, summer savory, a member of the Lamiaceae, using this system, and revealed that the main active compound was rosmarinic acid. These results demonstrate that this novel microliter-scale high-throughput screening system could be applied to the actual screening of Aβ aggregation inhibitors. Since this system can analyze at a microscopic scale, it is likely that further minimization of the system would easily be possible such as protein microarray technology

Hybrid-Type Squaramide-Fused Amino Alcohol Organocatalysts for Enantioselective Nitro-Aldol Reaction of Nitromethane with Isatins

A series of new hybrid type squaramide-fused amino alcohol (SFAA) catalysts were synthesized and their catalytic efficiency in enantioselective nitro-aldol reaction of various isatins with nitromethane that afford the chiral 3-substituted 3-hydroxyoxindoles in excellent chemical yields (up to 99%) and high enantioselectivities (up to 95% ee) is described. The resulting chiral 3-hydroxyoxindoles could be used as synthetic precursors for the synthesis of several natural products with a broad spectrum of fascinating biological activities

Chiral primary amino alcohol organobase catalyst for the asymmetric Diels-Alder reaction of anthrones with maleimides

Simple chiral TES-amino alcohol organocatalysts containing a bulkysilyl [triethylsilyl: TES] group on oxygen atom at γ-position were designed andsynthesized as new organocatalysts for the enantioselective Diels-Alder (DA) reactionof anthrones with maleimides to produce chiral hydroanthracene DA adducts (up to99% yield with up to 94% ee)

Lipase-catalyzed domino Michael-aldol reaction of 2-methyl-1,3-cycloalkanedione and methyl vinyl ketone for the synthesis of bicyclic compounds

Synthesis of bicyclic compounds was achieved via a lipase-catalyzed, stereoselective, domino Michael–aldol reaction of 2-methyl-1,3-cycloalkanedione and methyl vinyl ketone. Appropriate reaction conditions, including the type of enzyme, solvent, and temperature, were determined. In addition, the effects of solvent polarity and addtives were investigated. The reaction proceeded in the presence of lipase AS in a solution of 20% acetone in dimethylsulfoxide (DMSO) at 10 °C for 8 days, followed by the addition of p-toluenesulfonic acid (TsOH) to afford bicyclic compounds in 51–83% yields with moderate stereoselectivity. Although this domino Michael–aldol reaction showed only moderate stereoselectivity, even with the acid-supported enhancement of the reaction, these results represent potential new applications for lipase

New Hybrid-type Squaramide-Fused Amino Alcohol Organocatalyst for Enantioselective Domino Michael Addition/Cyclization Reaction of Oxoindolines with Cyclic 1,3-Diketones

The new hybrid-type squaramide-fused amino alcohol containing both a Bronsted basic site and hydrogen bondingsites in the molecule showed a high catalytic activity as an l organocatalyst in the enantioselective domino Michael addition/cyclization reaction of oxoindohnes with cyclic 1,3-etones to afford\u27the chiralsproonjugate oxindoles featuring 2-aminopyrans fusing with l carbo-heterocyclic ring systems with l excellent chemical yields (up Ito 98%) and enantioselectivities (up to 95% ee). The obtained chiral spiroconjugated 2-aminopyrans bearing quaternary stereogenic carbon center could be used as l synthetic precursors for several natural products that ave a broad spectrum Iof fascinating biological activities