Investigation of Isomerization of 2—Seleno—1,3,2—diazaphospholidine Derivatives

For the first time the isomerization of 1,3,2-diazaphospholidine-2-sclenide dervatives in refluxing benzene in the presence of trace water was observed. The structures of isomerized products were determined by IR, ^1H NMR,^31P NMR, elemental analysis and X-ray crystallography. The mechanism of isomerization was also proposed.     

Analysis of Chemical Incredients of Angelica Sinnesis——Analysis of Non-Volatile Constituents of Roots

In the present investigation,the non-volatile constituents of Danguei (Tang-Kuei) roots of Gansu origin [Angelica sinensis (Oliv.) Diels] were analyzed and thirty seven organic constituin s were also identified,fifteen of which have not been recorded in literature before,including a new optically active compound named as Angelicide and an antibiotie,Brereldin A.By plasma emission spectrometry,thirteen minor elements were also detecled     

Synthesis of Alkylene—linked Dimers of （—）—Huperzine A

Six alkylene-linked dimers of (-)-huperzineA(6) were prepared. All these dimers are less potent than (-)-Hup A in inhibition of AChE.     

Dehydrodimers of arylaldoxime——a convenient source of iminoxy radicals

Arylaldoxime dehydrodimers 3a—1 have been prepared from the corresponding oximes 1a—1by using (HCrO_4)_2(Py)_4Co as oxidant.Their structures were assigned to be bisnitrone by XPS studies.ESR studies of 3a—1 in hot chloroform show that iminoxy radicals 2a—1 are formed.Therefore thedehydrodimers can provide a convenient source of these radicals.     

Chemo-enzymatic Synthesis of Z-Asp-Val-Tyr-NH_2——A Precursor Tripeptide of Thymopentin

Z-Asp-Val-Tyr-NH2,a precursor tripeptide of thymopentin(TP-5),was successfully synthesized by a combination of chemical and enzyme methods.Firstly,the precursor dipeptide Val-Tyr-NH2 was synthesized by a novel chemical method in four steps including the preparation of NCA-Val,the esterification of L-tyrosine and the ammonolysis of L-tyrosine ethyl ester,and the formation of Val-Tyr-NH2 from NCA-Val and L-Tyr-NH2.Secondly,a thermolysin,thermoase PC 10F was used to catalyze the formation of Z-Asp-Val-Tyr-NH2 in an aqueous/organic solvent diphase system with Z-Asp-OH and Val-Ty-NH2 as the substrates under thermodynamic control.The optimum conditions were pH=6.5,40 ℃,thermoase 100 mg,in 2-(N-morpholino) ethanesulfonic acid MES/NaOH(containing 5 mmol/L CaCl2) of n-butanol system(15/85,volume ratio) for 20 h in a maximum yield of 27.02%.     

Synthesis of 5—Aryl—1,2—dihydro—1—pyrrolizinones

In order to search for new potent anti-inflammatory and analgesic agents in pyrrolizinones,the title compounds were designed and synthesized.A series of the compounds were prepared with two different synthetic schemes.Some of the compounds showed remarkable anti-inflammatory and/or analgesic activities on mice.     

Synthesis and Insulin—sensitizing Activity of a Series of 2—Benzyl—1,3—dicarbonyl Derivatives

A series of 2-benzyl-1,3-dicabonyl derivatives was synthesized.Their insulin-sensitizing activity was evaluated in 3T3-L1 preadipocyte cells.Compounds3,26 and 27 were found to possess strong insulin-sensitizing activity in vitro and were selected for further hypoglycemic evaluation in vivo.     

First example of the Chan—Lam—Evans N-arylation of bispidines

Russian Chemical Bulletin - The N-arylation of N-Boc-bispidine with arylboronic acids was accomplished under the copper-catalyzed Chan—Lam—Evans reaction conditions. The reaction...     

Synthesis of N1—Substituted—3—aryl—4—alky1—4,5—dihydro—1H—1—pyra—zolethiocarboxamide as Novel Small Molecule Inhibitors of Cysteine Protease of T.cruzi

A series of N1-substituted-3-ary1-4-alky1-4,5-dihydro-1H-1-pyrazolethiocarboxamide were prepared from the Mannich bases of aryl ketones in good yields.Some derivatives were found to be active against the cysteine protease of T.cruzi.     

Synthesis and Characterization of Charge—transfer Complexes of Aminoethylphoshphono—and Dimethylaminoethylphosphono—heteropolytungstic Acids of Keggin Type Structure

Two charge-transfer complexes of 2a and 2b of Keggin type were synthesized and characterized by elemental analysis,IR spectra,UV spectra,XRD,TG-DSC;and were compared with Hquin-PW12.The primary structure of the heteropolyanions had not been changed after the formation of the charge transfer complexes.     

Synthesis of 3,7—Disubstituted 1,4—Benzodiazepin—2—one

A series of 3-methoxycarbonylpropoxy-7-(imidazol-4-ylpropinamide)-1,3-dihydrogen-1-methyl-5-phenyl-2H-1,4-benzodiazepin-2-ones,as farnesyltransferase(Ftase) inhibitors,were synthesized. The preparation of the key intermediate,7-amino-3-methoxycabonylpropoxy-1-methyl-5-phenyl-2H-1,4-benzodiazepin-2-one,was improved.     

Crystal Structure of Indenyl—3—indenyl

1 INTRODUCTION Indene is an intermediate used for the synthesis of organometallic complexes involving silylene-bridged indenyl[1～5]. In the process of synthesizing (CH3)(C6H5)Si(Ind)2[6], a new compound as a by-product which is a dimer of indene was obtained, and only one similar crystal was found in CCDC[7]. Up to now, there are no crystal structure reports on this kind of structure. The present paper will describe the crystal structure of the title compound. 2 EXPERIMEN…     

Synthesis of 3—Biaryl—1—ferrocenyl—2—propene—1—ones

The novel structures of organometallic compounds 3-biaryl-1-ferrocenyl-2-propene-1-ones 5 were synthesized for nonlinear optical chromophores by Suzuki cross-coupling reaction.Their structures were determined with elemental analyses,^1H NMR spectra and ^13C NMR spectra.     

441 — Polarography of biopolymers

A short history of the development of the polarography of biopolymers is presented. Polarography was applied to the analysis of biopolymers soon after its invention. At the beginning of the 1930s to so-called presodium wave of proteins was found, and shortly afterwards Brdic̈ka discovered the catalytic double wave of proteins in solution containing cobalt ions. This double wave has been exploited mainly in clinical investigations. The d.c. polarographic reduction of —S—S— groups in proteins was demonstrated in 1964 and the reduction of non-protein groups was shown only at the beginning of the 1970s.First reports on the polarographic reducibility of a nucleic acid component — adenine — appeared in 1946. By the end of the 1950s the electroactivity of nucleic acids was demonstrated. Soon it was shown that polarographic methods were a useful tool in nucleic acid structure research. In the last 10–15 years double-helical and single-stranded DNAs have been studied using a number of modern polarographic techniques, including a.c. polarography, differential and normal pulse polarography, cyclic voltammetry, etc. By these means, information on the details of DNA double-helical structure and on the way the DNA molecule interacts with the mercury electrode surface have been obtained.     

Studies on Agarofurans Ⅷ.Synthesis of the Metabolites of 4—Butyl—α—agarofuran

The structures of five metabolites (2-6) of agarofuran 1 were confirmed by synthesis. The configuration of the secondary hydroxyl in 7 was determined by Horeau′s method. The configuration of C-2 in compound 4 and 5 was determined by their stereochemistry and NMR.     

Efficient Synthesis of 2—Ethyl—A—ring Analogues of 19—Nor—1α,25—dihydroxy Vitamin D3

The novel 19-nor-1α,25-dihydroxy vitamin D3 analogues possessing an ethyl at the 2-position(4 and 5).were synthesized by coupling 25-hydroxy Windaus-Grundmann ketone derivative 20 with A-ring synthons(15 and 19)respectively.The enantioselective synthesis of substituted bicyclic[3,1,0]hexanes structure A-ring synthons,started from all-cis-3,5-dihydroxy-4-ethyl-1-(methoxycarbonyl)cyclohexane via lipase-catalyzd asymmetrization,was demonstratcd.