Studies on the Basic Conformation of Lysozyme by Electrospray Ionization-Mass Spectrometry (ESI- MS)

In the present work, 2-mercaptoethanol and dithiothreitol were used to hydrogenise the internal disulfide bond in lysozyme. The experimental results indicate that the charge distribution of the proteins are different in the reaction process. From the calculated molecular weight, the reduction process of the disulfide bond in the molecules can be described, and the number of the disulfide bonds in the molecule can also be determined.     

Asymmetric Synthesis of (3R, 5R)-3-((tert-Butyldimethylsily)oxy)-5-((Z)-2-Bromovinyl)-Tetrahydro-Furan-2-one, an Intermediate for the Synthesis of Fostriecin

Fostriecin(CI-920) 11 a potential anticancer agent presently in phase I clinical trials at NCI is a novel phosphate ester produced by Streptomyces pulveraceus. Scheme 1 1 2 3 5 4 Synthesis of C10 epimer of compound 1 had been reported by Just G2. during the determination of its structure. On the basis of Just’s synthesis, a revised retro-asymmetric synthetic route of Fostriecin (scheme 1) was designed here of which compound 3 was synthesized from 5 with C3 in R configuration correspondi…     

Synthesis of Bis 〔bis (tert-butylcyclopentadienyl) neodymium chloride〕 and Structural trend of Bis〔bis(tertbutylcyclopentadienyl) lanthanide chloride〕

１　ＩＮＴＲＯＤＵＣＴＩＯＮＢｉｓｃｙｃｌｏｐｅｎｔａｄｉｅｎｙｌｌａｎｔｈａｎｉｄｅｃｈｌｏｒｉｄｅｓｆｏｒａｌｌｔｈｅｌａｎｔｈａｎｉｄｅｅｌｅｍｅｎｔｓｈａｖｅｂｅｅｎｓｙｎｔｈｅｓｉｚｅｄａｎｄｓｔｒｕｃｔｕｒａｌｌｙｃｈａｒａｃｔｅｒｉｚｅｄ〔１〕．Ｔｅｒｔ－ｂｕｔｙｌｃｙｃｌｏｐｅｎｔａｄｉｅｎｙｌｉｓａｓｕｉｔａｂｌｅｌｉｇａｎｄｆｏｒｐｒｅｐａｒａｔｉｏｎｏｆｌａｎｔｈａｎｏｃｅｎｅｃｈｌｏｒｉｄｅｓ．Ｔｈｅｓｙｎｔｈｅｓｅｓａｎｄｍｏｌｅｃｕ－ｌａｒｓｔｒｕｃｔｕｒｅｓｏｆ〔（…     

Crystal Structure of 1-Methyl-5-phenylhydantoin

1　INTRODUCTIONInourinvestigationofhemithioacetals,wediscoveredthatα-benzoylhemithioac-etalisquitestableandhastwoelectrophilicsitesthatcanreactwithalkylureastoformahydantoinring[1].Althoughthehydantoinringitselfdoesnotpresentanymedicinalactivity,somedisubstitutedhydantoinshavebeenwidelyusedasmedicineforitsregulareffectonthebioelectricactivityofthenervoussystem.Inordertoim-proveandexpandtheactivityaswellastopreventsideeffects,variouskindsofhy-dantoinderivativeshavebeenpreparedandtested[2].…     

3,4-二硒方酸芳香性和气相酸性的理论研究

在ＲＨＦ／６－３１１Ｇ水平优化得到３,４－二硒方酸（３,４－二氢硒基－３－环丁烯－１,２－二酮）３ 种平面构象异构体的平衡几何构型。进一步用ＭＰ２（ｆｕｌｌ）／６－３１１Ｇ／／ＲＨＦ／／６－３１１Ｇ方法计算单点能量,发现ＺＺ型异构体是能量最低构象,且ＺＺ和ＺＥ型能量非常接近。用优化的最稳定构象ＺＺ型异构体在ＲＨＦ／６－３１１Ｇ／／ＲＨＦ／６－３１１Ｇ、ＲＨＦ／６－３１１＋ Ｇ／／ＲＨＦ／６－３１１＋ Ｇ、ＭＰ２（ｆｕｌｌ）／６－３１１＋ Ｇ／／ＲＨＦ／６－３１１＋ Ｇ 和Ｂ３ＬＹＰ／６－３１１＋ Ｇ／／Ｂ３ＬＹＰ／６－３１１＋ Ｇ水平计算其气相酸性（ΔＧ°）和同键反应芳香性稳定化能（ＨＡＳＥ）。用基团加和法（ｇｒｏｕｐ ｉｎｃｒｅｍ ｅｎｔ ａｐ－ｐｒｏａｃｈ ） 在 ＲＨＦ／６－３１１ ＋ Ｇ／／ＲＨＦ／６－３１１ ＋ Ｇ 和 Ｂ３ＬＹＰ／６－３１１ ＋ Ｇ／／Ｂ３ＬＹＰ／６－３１１＋ Ｇ水平计算其磁化率增量（Λ）。计算结果指出标题化合物的同键反应芳香性稳定化能和磁化率增量均为负值,表明它具有芳香性,实现了标题化合物芳香性的几何、能量和磁性的判定。     

Synthesis and Structural Investigation of ｛CpEu〔CH(COOC_2H_5)_2〕〔μ-CH(COOC_2H_5)_2〕｝_2

１ＩＮＴＲＯＤＵＣＴＩＯＮＯｒｇａｎｏｌａｎｔｈａｎｉｄｅｃｏｍｐｌｅｘｅｓｉｎｖｏｌｖｉｎｇｂｏｔｈｃｙｃｌｏｐｅｎｔａｄｉｅｎｙｌａｎｄβ ｄｉｋｅｔｏｎａｔｏｃｈｅｌａｔｅｌｉｇａｎｄｓｈａｖｅｂｅｅｎｓｙｎｔｈｅｓｉｚｅｄ〔１ ４〕,ａｎｄｏ...     

Crystal Structure of Copper(Ⅱ) Complex with 3-Hydroxyl-1,5-diazacycloheptane-N,N'-diacetate

１ＩＮＴＲＯＤＵＣＴＩＯＮＡｌｏｔｏｆｓｔｕｄｉｅｓｈａｖｅｒｅｖｅａｌｅｄｔｈａｔｍｅｓｏｃｙｃｌｉｃｄｉａｍｉｎｅｓａｎｄｔｈｅｉｒｄｅｒｉｖａｔｉｖｅｓａｒｅｖｅｒｓａ ｔｉｌｅｃｈｅｌａｔｉｎｇａｇｅｎｔｓａｎｄｔｈｅｙｓｈｏｗｅｄｕｎｕｓｕ...     

Synthesis and Crystal Structure of di p Methyl pyridinium p methylpyridinidine Hexatungstate

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｒｅｓｅａｒｃｈｏｎｔｈｅｌａｙｅｒｅｄｃｏｍｐｏｕｎｄｓ,ｗｈｉｃｈｃｏｎｓｉｓｔｅｄｏｆａｌｔｅｒｎａｔｉｎｇｏｒｇａｎｉｃａｎｄｉｎｏｒｇａｎｉｃｌａｙｅｒｓ,ａｔｔｒａｃｔｅｄｃｏｎｓｉｄｅｒａｂｌｅａｔｔｅｎｔｉｏｎｉｎｔｈｅｐａｓｔｔｗｅｎｔｙｙｅａｒｓｄｕｅｔｏｔｈｅｉｒｓｐｅｃｉａｌｓｏｒｐｔｉｖｅ,ｃａｔａｌｙｔｉｃａｎｄｅｌｅｃｔｒｏｎｔｒａｎｓｐｏｒｔｐｒｏｐｅｒｔｉｅｓ［１,２］．Ｊｏｈｎｓｏｎｅｔａｌ．［３］ｏｂｔａｉｎｅｄａｎｅｗｌａｙｅ…