Ph3P/ICH2CH2I-promoted reductive deoxygenation of alcohols.

Owing to the ubiquity of the hydroxyl group, reductive deoxygenation of alcohols has become an active research area. The classic Barton-McCombie reaction suffers from a tedious two-step procedure. New efficient methods have been developed, but they have some limitations, such as a narrow substrate scope and the use of moisture-sensitive Lewis acids. In this work, we describe the Ph3P/ICH2CH2I-promoted reductive deoxygenation of alcohols with NaBH4. The process is applicable to benzyl, allyl and propargyl alcohols, and also to primary and secondary alcohols, demonstrating a wide substrate scope and a good level of functional group tolerance. This protocol features convenient operation and low cost of all reagents.

Long-chain alkanol-alkyl carboxylic acid-based low-viscosity hydrophobic deep eutectic solvents for one-pot extraction of anthraquinones from Rhei Radix et Rhizoma.

Natural long-chain alkanol and alkyl carboxylic acid were used to prepare novel hydrophobic deep eutectic solvents (HDESs). These HDESs are liquid at room temperature and have low viscosity (<12.26 mPa‧s), low polarity (lower than that of methanol, ChCl-based deep eutectic solvents and other reported HDESs), and low density (<0.928 g/mL). A simple one-pot method based on a novel HDES-water two-phase extraction system was constructed for the extraction of weak-polarity bioactive components, anthraquinones, from Rhei Radix et Rhizoma. This HDES-based new extraction method does not consume hazardous organic solvents and can obtain a total anthraquinone yield of 21.52 mg/g, which is close to that obtained by the Chinese pharmacopoeia method (21.22 mg/g) and considerably higher than those by other reported HDESs-based extraction methods (14.20-20.09 mg/g, p < 0.01). The high extraction yield can be mainly attributed to the severe destruction of the RRR cell walls by the extraction system and the excellent dissolving ability of novel HDESs for anthraquinones.

A density-tunable liquid-phase microextraction system based on deep eutectic solvents for the determination of polycyclic aromatic hydrocarbons in tea, medicinal herbs and liquid foods.

A novel density-tunable liquid-phase microextraction (DT-LPME) system was developed with high-density deep eutectic solvents (DESs) as extractant and low-density organic solvents as emulsifier and density regulator. DES-rich phase was induced to form in the bottom or in the top by adjusting the emulsifier amount. This system was used to directly extract polycyclic aromatic hydrocarbons (PAHs) from liquid and solid foods, and the obtained DES-rich phase was easy to be collected for quantification. The method (LPME with HPLC-fluorescence detector) has linearity (R2 > 0.9974), detection limits of 0.6-4.2 ng L-1 for liquid foods and 0.05-0.35 ng g-1 for solid foods, recoveries of 86.2-114.9%, and intra-day/inter-day RSDs below 6.6%. The method was applied to detect PAHs in real samples, and the PAHs residue was found in honey and five solid foods. The DT-LPME method is simple, fast, green and suitable for direct extraction of analytes from both liquid and solid samples.

Double-Color Lanthanide Metal-Organic Framework Based Logic Device and Visual Ratiometric Fluorescence Water Microsensor for Solid Pharmaceuticals.

Water is one of the most widespread impurities and contaminants for pharmaceuticals and chemical products. A simple, fast and reliable water assay method is of high significance for the pharmaceutical and chemical manufacturing industries. In this work, lanthanide metal-organic framework Eu-dipicolinic acid/2-aminophthalic acid (Eu-DPA/PTA-NH2) was prepared as a double-color ratiometric fluorescent water sensor, which shows ultrasensitive (limit of detection 0.01% v/v) and linear broad-range (0-100% v/v) response to water. An innovative analytical device based on a one-to-two logic gate was constructed by using the water content and the two fluorescence responses as the input and output signals, respectively. The direct analysis of water content can be achieved by the four output types, NOT (0, 1), PASS 0 (0, 0), PASS 1 (1, 1), and YES (1, 0). Importantly, the metal-organic framework (MOF)-loaded fiber paper was prepared as a microsensor, and a water assay tube was designed for rapid water detection of solid pharmaceuticals via ratiometric chromaticity, coupled with a portable visual determination device. The paper-based microsensor is response-rapid (20 s), long-term stable (at least 30 days), and can achieve the accurate (relative error <9.8%) visual assay of trace water in solid pharmaceuticals. To our knowledge, this is the first time to report an MOF-based double-color ratiometric fluorescent water sensor, a water analytical logic device, and a paper-based water microsensor for point-of-care visual water assay in solid samples via ratiometric chromaticity.

Diastereoselective Synthesis of CF3-Containing Vicinal Diamines.

The highly diastereoselective synthesis of CF3-containing vicinal diamines by a convenient two-step procedure without the need to isolate the intermediate products is described.

Synthesis and antioxidant activity of curcumin analogs.

Numerous biological activities including antioxidant, antitumor, anti-inflammation, and antivirus of the natural product curcumin were reported. However, the clinical application of it was significantly limited by its instability, poor solubility, less body absorbing, and low bioavailability. This review focuses on the structure modification and antioxidant activity evaluation of curcumin. To study the structure-activity relationship (SAR), five series of curcumin analogs were synthesized and their antioxidant activity were evaluated in vitro. The results showed that electron-donating groups, especially the phenolic hydroxyl group are an essential component to improve the antioxidant activity.

Synthesis and Anti-thyroid Cancer Effect of Iodo-chrysin Derivatives.

A novel series of iodo-chrysin derivatives with resorcinol as raw materials were synthesized according to Baker-Venkataraman reaction and their inhibitory activities in vitro against thyroid cancer cell lines (SW-579 and TT) were evaluated by the standard methyl thiazole tetrazolium (MTT) method. Biological test results showed that these derivatives possessed stronger anti-thyroid cancer activities than 5-FU. Compound 21 showed the strongest activity against SW-579 cell lines with IC50 value of 3.4µM and compound 10 showed the strongest activity against TT cell lines with IC50 value of 6.2µM, it was better than 5-FU (59.3µΜ, 18.4µM respectively).

Pharmacological activities and structure-modification of resveratrol analogues.

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a well-known natural polyphenol compound. It is reported that resveratrol possesses strong anti-oxidative, anti-inflammatory, cardiovascular protective and cancer chemo-preventive effects. Therefore, there has been a considerable interest in its biological activity, pharmacological activity and also synthetic resveratrol analogues in recent years. Up to now, many new resveratrol derivatives have been synthesized and some new biological activities of these compounds have been found, so in the treatment of Alzheimer's disease and the inhibition of influenza H1N1 neuraminidase. Structure-activity studies revealed that crucial elements of parental components are required for specific effects. This review summarizes the available literatures on the structure-activity relationships and pharmacological properties of resveratrol analogues.