Enzymatic Synthesis of [3-14C]Cinnamic Acid

Convenient and efficient route of the synthesis of [3-¹⁴C] cinnamic acid is reported. [1-¹⁴C]Benzoic acid, prepared by carbonation of Grignard reagent with [¹⁴C]carbon dioxide, was reduced to [1-¹⁴C]benzyl alcohol. In the enzymatic step this alcohol was selectively oxidised to [1-¹⁴C]benzaldehyde using enzyme YADH (Ec. 1.1.1.1) and immediately condensed with malonic acid. This combined chemical and enzymatic approach allows to obtain [3-¹⁴C]cinnamic acid with radiochemical yield higher than 50% in respect to the starting alcohol.     

Synthesis of uridine diphosphate [1-3H]glucose and uridine diphosphate [6-3H]glucose

Information is given on the synthesis of tritium-labeled UDPG by the successive transformation of D-[1-³H]glucose or D-[6-³H]glucose by the action of the enzymes hexokinase (EC 2.7.1.1), phosphoglucomutase (EC 2.7.5.1), and UDPG-pyrophosphorylase (EC 2.7.7.9) under conditions ensuring the retention of the tritium label. Methods of obtaining tritium-labelled substrates and intermediate products of their enzymatic transformations in the synthesis of [³H]UDPG are discussed.V. G. Khlopin Radium Institute, Leningrad. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 125–128, January–February, 1987.     

硒钼钒杂多配合物的合成与表征

由钒原子取代杂多阴离子中的钼或钨原子后,形成的多元配合物具有与原来杂多配合物显著不同的催化性质,有关钼钒的同多阴离子,近年报道的有[V2Mo6O26]^6-、[V5Mo8O40]^7-、[V8Mo4O36]^8-等,而三元硒钼钒杂多分配物仅见于[Se2Mo2V6O28]^6-。本文合成了两种硒钼钒三元杂多配合物,并对其进行了表征。     

Zur Reaktion von 2,2′-Dilithiumbiphenyl mit SmBr3 Die Struktur von [(C24H16)SmBr(thf)2]2 · [C24H14]

On the Reaction of Dilithiumbiphenyl with SmBr₃. The Crystal Structure of [(C₂₄H₁₆)SmBr(thf)₂]₂ · [C₂₄H₁₄] In THF SmBr₃ forms with [(biph)Li₂] the dimeric complex [(quaph)SmBr(thf)₂]₂ · [C₂₄H₁₄]. The structure was characterized by X-ray single crystal structure analysis (space group P1 (No. 2), Z = 1, a = 943.3(6) pm, b = 1 350.3(1) pm, c = 1 599.9(9) pm, α = 64.99(5)°, β = 89.02(5)°, γ = 73.02(6)°). The Sm iones are bridged by two Br iones. Coordination by one quaph and THF ligands leads to distorded octahedra coordination of the Sm iones. Additionally crystallizes one molecule dibenzonaphthacene.     

Synthesis of [1,2-3H2]-polystyrene

The synthesis of [1,2-³H₂]-polystyrene consisted of a two step reaction. First catalytic tritium gas addition to phenylacetylene was used to prepare [1,2-³H₂]-styrene and then it was polymerized to [1,2-³H₂]-polystyrene in the present of an initiator.     

Synthesis of ammonium [14C]thiocyanate

Ammonium [¹⁴C]thiocyanate was prepared from potassium [¹⁴C]cyanide with a radiochemical yield of 90%. [¹⁴C]hydrocyanic acid, generated from potassium [¹⁴C]cyanide by sulphuric acid, reacts with aqueous ammonia and elemental sulphur in the presence of trace amounts of ammonium sulphide to yield ammonium [¹⁴C]thiocyanate.     

[C6H6, C3H7 +]and [C6H7 +, C3H6] ion-neutral complexes intermediate in the reactions of protonated propylbenzenes

From the mass-analysed ion kinetic energy spectra of labelled ions, kinetic energy releases and thermodynamic data, it is proved that protonated n-propylbenzene (1) isomerizes into protonated isopropyl benzene (2). It is also shown that the dissociation of the less energetic metastable ions of (2), leading to [iso-C₃H₇]⁺ and [C₆H₇]⁺ product ions, is preceded by H exchange. This H exchange involves two interconverting ion-neutral complexes [C₆H₆, iso-C₃H₇⁺] (2π) and [C₆H₇⁺, C₃H₆] (2α).     

3-氧代-3-[3-三氟甲基-5,6-二氢[1,2,4]三唑并[4,3-α]吡嗪-7(8H)-基]-1-苯基丙烷-1-胺的合成

三唑类衍生物是重要的化工和药物合成中间体,而稠合三唑类衍生物因其独特的生理活性更是得到了广泛关注[1-2],其中3-三氟甲基-5,6,7,8-四氢[1,2,4]三唑并[4,3-α]哌嗪与β-氨基酸缩合得到的化合物是一类重要的二肽基肽酶-Ⅳ抑制剂 [3-4],可作为2型糖尿病的治疗药物,如2006年经美国FDA批准在美国上市的西他列汀(sitagliptin),此外二肽基肽酶-Ⅳ抑制剂还可用于肥胖症和高血压等疾病的预防和治疗[5].     

Synthesis of 2-dichloromethyl-2-methyl [2-14C]-1,3-dioxolane

The labelled compound was prepared by chlorination of [2-¹⁴C]acetone obtained from the barium salt of [1-¹⁴C]acetic acid by pyrolysis. The reaction product 1,1-dichloro [2-¹⁴C]acetone was converted to 2-dichloromethyl-2-methyl [2-¹⁴C]-1,3-dioxolane by condensation with ethylene glycol in the presence of thionyl chloride. Radiochemical yield: 62% based on [1-¹⁴C]acetic acid.     

Synthesis of [3H] Dapsone

Abstract

An efficient synthesis of [³H] dapsone at high specific activity is described.     

Synthesis of [3H]-higenamine

The synthesis of [³H]-higenamine by a four steps reaction, namely condensation, cyclization, catalytic tritiation and demethoxylation is described. The acidulated product was purified by thin layer chromatography and the final component has a high specific activity and radiochemical purity.