Synthesis of a New β-Mercaptoalcohol

Mercaptoalcohols are a rare class of natural products. Some optically active mercaptoalcohols have been used as catalysts in asymmetric reduction of prochiral Ketone1,2. In this letter, we report the synthesis of a new optically active (-mercaptoalcohols, (R)-1,1-diphenyl-2-mercapto-3-methyl-1-butanol 7, from L- valine.Our first attempt is showed in Scheme 1. According to literature's method L-valine was converted to (S)-2-Hydroxy-3-methylbutanoic acid 21,2. 2 was treated with MeOH/SOCl2…     

Intercalation of Epinephrine with Calf-thymus ds-DNA

Interactions of DNA with various molecules are interesting because of its importance in gene expression process of living cells. Several models for the interaction between DNA and some small molecules have been proposed1-4. We are interested in the possibility of the interaction between DNA/RNA and neurotransmitters, such as dopamine and epinephrine, because these species are very important substances for keeping normal physiological functions of brain and neuro system. However, no report…     

Baker''''s Yeast Mediated Reduction of Optically Active Diketone

Baker's yeast (BY) mediated reduction of synthetic substrate is a useful method for preparing chiral intermediate in synthesis chemistry1,2, because it is readily available and inexpensive. The selectivity is generally predicted by Prelog rule3, that is, a hydride is transferred to the re face of the prochiral ketone.The baker's yeast mediated reduction of bicyclic diketones was previously reported by several groups4-6, but to our knowledge, no application of this reduction to sesquiter-pene-…     

A Novel Synthesis of Some Hexasubstituted Cyclotriphosphazenes

In recent years, many efforts were focused on the preparation and characterization of phosphazene which contained a framework of alternating phosphorous and nitrogen atoms with two substituent groups attached to each phosphorous atom1. It is noticeable that cyclophosphazene, especially hexaaryloxyphosphazene and perfluoroaryloxyphosphazene exhibit excellent thermal and chemical stability which can be used as fireproof materials, high temperature lubricants, vacuum pump oils and hard disk surfac…     

The Synthesis of N-Morphine Hapten and Production of Monoclonal Antibody

The drug overdose and addiction is a serious international problem. Therefore developing a rapid, accurate, convenient and cheap method for detecting morphine in urea is useful and necessary, especially for investigation of epidemiology, identification of medical jurisprudence and determination of drug addict etc. There are many compounds that are similar to morphine in chemical structure and tend to have cross-reaction with the anti-morphine antibody. In order to reduce the cross reaction a…     

Preparing Nano-ZnS by Solid State Reaction at Room Temperature

Solid-state reaction has been studied for a long time1-3. In recent years, some researches have been focused on the preparation of coordination compounds at low temperatures or even at room temperature4-5. In this letter, preparation of ZnS nanoparticles by using solid state reaction at room temperature is reported.ZnS nanoparticles were prepared as follows: Zn(CH3COO)2 and Na2S?9H2O, in equal molar ratio, were ground in agate mortar. After 20 minutes, the powder was washed by water and …     

Concise Synthesis of(±)-epi-Chrysotricine

Chrysotricine 1 was isolated from the Chinese herb medicine Hedyotis Chrysotricha and was shown to possess antitumor activity1. Its structure has been elucidated as a novel zwitterionic (-carboline alkaloid containing a 2,2,5-trisubstituted tetrahydrofuranyl group. The (-carboline compounds have attracted considerable attraction in recent years because of their promising and intriguing biological activities2. Recently, we have established the absolute configuration of chrysotricine by the fir…     

New diterpenoid glucosides from Siegesbeckia pubescens

Plants of the genus Siegesbeckia are annual herbs widely distributed in tropical and temperate zones and they are used as a traditional medicine to treat rheumatic arthritis, hypertension, malaria, neurasthenia and snake-bite in China. In previous papers, we reported on five new ent-kaurane and ent-pimarane diterpenoids, siegesbeckioside, siegesbeckiol and siegesbeckic acid1, orientalin A and B, and eight know compounds2,3. The present paper describes the isolation and structural elucidation …     

A Novel Acoustic Emission Fiber Optic Sensor Based on a Single Mode Optical Fiber Coupler

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New Soluble Fluorinated Polyimides

Aromatic polyimides have been widely used in aerospace, electrical and electronic applications due to their outstanding thermal stability, mechanical strength at elevated temperature and electrical properties1-3. However, polyimide materials are usually difficulty to fabricate owing to their insolubility in most organic solvents and infusibility. Besides solubility, low moisture uptake of polyimide is also a major concern for microelectronics and optical applications. The present article descr…