Plasma prostaglandin F 2-alpha levels in dysmenorrehic women

The conversion of dihydrothebainone to codeine or thebaine has been achieved in high yield. Bromination and dehydrobromination constructs the 4,5-oxide bridge to give 1-bromo- and 1,7-dibromodihydrocodeinone which yield dihydrocodeinone practically quantitatively after catalytic debromination. Ketalization and acid-catalyzed elimination of methanol give excellent yields of delta6-dihydrothebaine to which is added methyl hypobromite using N-bromoacetamide in methanol. The action of potassium tert-butoxide in Me2SO on the resulting 7-bromodihydrocodeinone dimethyl ketal gives codeinone dimethyl ketal selectivity at 60 degrees while at 120 degrees thebaine is the exclusive product. Hydrolysis to codeinone and borohydride reduction give codeine in 70% overall yield. The bromo intermediates in the formation of the 4,5-oxide bridge have been examined. 1,5beta, 7alpha-Tribromodihydrothebainone has been identified as the main product in the tribromination of dihydrothebainone.     

Gas chromatographic/mass spectrometric detection of narcotine, papaverine, and thebaine in seeds of Papaver somniferum

In addition to codeine and morphine, three more compounds: narcotine (noscapine), papaverine, and thebaine were found in Indian and Netherlands poppy seeds (Papaver somniferum L). The compounds were detected by a GC/MS technique and the identities were confirmed by comparing retention times and ion ratios with the known references. The concentrations of codeine, morphine, thebaine, papaverine, and narcotine were 44, 167, 41, 67, and 230 micrograms/g in Indian poppy seeds, and were 1.8, 39, 1.0, 0.17, 0.84 micrograms/g in Netherlands poppy seeds, respectively. Because these compounds may be urinary products after poppy seed consumption, the lowest detectable concentrations of codeine, morphine, thebaine, papaverine, and narcotine in urine are of interest and were found to be 4, 4, 5, 0.4, and 4 ng/ml, respectively. The detection of urinary narcotine, papaverine, or thebaine may be utilized to differentiate poppy seed consumption from illicit codeine, morphine, or heroin use.     

磷钨酸催化剂催化合成缩酮

以磷钨酸为催化剂，系统探讨了丁酮、环己酮分别与乙二醇、1，2-丙二醇反应生成缩酮，乙酰乙酸乙酯分别与乙二醇、1，2-丙二醇反应生成苹果酯、苹果酯-B的优化条件。系统探讨了催化剂用量、反应物的物质的量之比、反应时间对产品收率的影响。结果表明，磷钨酸是合成缩酮的优良催化剂，在醇酮(酯)摩尔比为1．5：1，催化剂用量为反应物料总质量的0．5％，反应时间1．0h的优化条件下，苹果酯收率为82．2％，苹果酯-B收率为90．3％，环己酮乙二醇缩酮收率为74．0％，环己酮1，2-丙二醇缩酮收率为77．6％，丁酮乙二醇缩酮收率为52．4％，丁酮1，2-丙二醇缩酮收率为70．1％。     

Preparation of optically active succinic acid derivatives. III. Regioselective condensation reactions of optically active 2-substituted succinic acids with diimidazolide

We investigated the large scale synthesis of monocalcium bis [(2S)-2-benzyl-3-(cis-hexahydroisoindolin-2-ylcarbonyl) propionate] dihydrate (KAD-1229), which has a potent hypoglycemic effect, in a single reaction vessel. (2S)-2-Benzyl-3-(cis-hexahydroisoindolin-2-ylcarbonyl) propionic acid (7) was directly obtainable from (S)-2-benzylsuccinic acid (2) and cis-hexahydroisoindoline (4), without the isolation of intermediates by the method using thionyldiimidazole (9) and/or diimidazolide of the acid 2. Sequential reaction of imidazole with thionyl chloride, 2, and 4, followed by acid catalyzed hydrolysis gave amidecarboxylic acid 7 in 86% overall yield. The acid 7 was treated with 2 N NaOH, followed by the treatment with calcium chloride to give KAD-1229 in 91% yield.     

Evidence indicating that the extracellular loops of the mouse MC5 receptor do not participate in ligand binding

Inulin ethers carrying primary amino groups have many potential applications. O-(Aminopropyl)inulin is obtained from O-(cyanoethyl)inulin by reduction of the nitrile groups. Heterogeneously catalyzed hydrogenation using Raney-cobalt as the catalyst resulted in only partial conversion of the O-cyanoethyl into O-aminopropyl groups. Complete conversion of the nitriles to primary amines was achieved by a homogeneous reduction with an excess of sodium borohydride and cobaltous chloride or with metals in liquid ammonia-methanol. Optimal results were obtained with the latter method; 83% of the substituents were converted into primary amines and 17% were lost by dealkylation.     

实验室废旧贵金属材料中铂的回收利用

实验室使用的含铂耗材会因为长时间使用形成损耗、变性或功能失效,长期搁置或丢弃造成极大的浪费,工业上常使用硼氢化钠作还原剂还原回收铂。实验依据硼氢化钾相比硼氢化钠具有分解温度高、稳定性好、在使用过程中较安全的特性,与氯化铵相结合利用二次沉淀法,以实验室含铂废旧耗材为原料,建立了硼氢化钾还原-氯化铵沉淀法回收铂的方法。为了获得纯净的金属铂,实验采用硝酸分离杂质元素,王水溶解铂,反复用盐酸驱赶氮氧化物,使铂充分转化为氯铂酸。在40℃、5%(V/V)盐酸介质中用硼氢化钾还原氯铂酸及少量难溶于王水的氧化铂,再用王水溶解铂黑并完全转化为氯铂酸,氯铂酸与过量的氯化铵形成黄色氯铂酸铵沉淀,陈化过夜。选择分段缓慢升温分解氯铂酸铵,在750℃和900℃煅烧,分别获得松散的金属铂粉和较致密的金属铂。两次沉淀溶液中残余的铂离子均小于20μg/mL。回收铂的纯度不小于99.9%,回收率大于99.5%。     

Synthesis of betulinic acid from betulin and study of its solubilization usingliposomes

A method for betulinic acid synthesis from betulin was developed. Betulin was oxidized with chromium oxide (VI) into betulonic acid, which was reduced with sodium borohydride to yield a mixture of 3-hydroxy epimers containing 85% of the natural beta-epimer. Studying changes in light scattering by dispersions of liposomes with different contents of betulinic acid revealed that up to 10 mol % of this compound may be entrapped in liposomes. The dependence of the efficiency of the betulinic acid entrapment on liposome composition was studied. The presence of polyvinylpyrrolidone or Proxanol increased the resistance of betulinic acid-containing liposomes to aggregation. These polymers solubilized betulinic acid with the same efficiency as liposomes.     

Synthesis of 9-oxononanoyl cholesterol by ozonization

A new route for the preparation of 9-oxononanoyl cholesterol (5) and its stable dimethylacetal (4) is described. The core aldehyde 5 is one of the major products formed during lipid peroxidation. The synthesis starts with the ozonization of oleic acid in methanol and further reduction with dimethyl sulfide to yield 9,9-dimethoxy nonanoic acid (2a). The condensation of 2a with cholesterol is achieved with N,N'-dicyclohexylcarbodiimide in dichloromethane to give 4. Further hydrolysis of 4 with the help of an acidic ion exchange resin yields 9-oxononanoyl cholesterol.     

Thio-sugars. IV: Design and synthesis of S-linked fucoside analogs as a new class of alpha-L-fucosidase inhibitors

alpha-1-Thio-L-fucose derivative 4 and 5 as new alpha-fucosidase inhibitors (K1 = 4.6, and 5.9 microM) have been synthesized in three steps by base catalyzed coupling with bromonitromethane followed by reduction of the nitro group with sodium borohydride/cobalt chloride complex and acetylation.     

Studies on alpha-sialylation using sialyl donors with an auxiliary 3-thiophenyl group

Reaction of the methyl ester of 2-chloro-3-S-phenyl-3-thiosialic acid (4) with sodium thiomethoxide in acetonitrile at 0 degrees C affords the methyl ester of 2-S-methyl-3-S-phenyl-2,3-di-thio-alpha-sialic acid (6a) in quantitative yield. Sialylation of tetrahydropyran-2-methanol (7) and 2-(trimethylsilyl)ethyl 2,2'3,6,6'-penta-O-benzyl-alpha-lactoside (8) with 6a in the presence of phenylsulfenyl triflate (PST) as promotor in CH3 CN at -40 degrees C gives alpha-sialosides 9 and 10 in good yield and excellent stereoselectivity. No beta-sialosides are formed in either case. Acetylation of product 10, and the subsequent reductive removal of the 3-thiophenyl group using Ph3SnH, affords 12--protected GM3 trisaccharide--in 82% yield after two steps. Sialylation of acceptor 8 with chloride 4 using silver triflate as promotor afforded 10 in 48% yield after two days at -15 degrees C in THF. A possible mechanism of sialylation with 6a that involves intermediate alpha- and beta-nitrilium ions is discussed.     

Synthesis and characterization by 1H and 13C nuclear magnetic resonance spectroscopy of 17 alpha-cyano, 17 alpha-aminomethyl, and 17 alpha-alkylamidomethyl derivatives of 5 alpha-dihydrotestosterone and testosterone

17 alpha-Aminomethyl, 17 alpha-acetamidomethyl, and 17 alpha-hemiglutaramidomethyl derivatives of dihydrotestosterone and testosterone have been prepared by hydrocyanation of 3,3'-(ethylenedioxy)-5 alpha-androstan-17-one and 3,3'-ethylenedioxyandrost-5-en-17-one, reduction of the corresponding acetylated 17 alpha-cyanohydrins with lithium aluminium hydride, and acylation of the resulting 17 alpha-aminomethyl derivatives with either acetic anhydride or the mono acid chloride of glutaric acid mono methyl ester. Saponification of the 17 alpha-hemiglutaramidomethyl methyl esters gave the corresponding hemiglutaramido derivatives, while acid hydrolysis of the 3-ethylene ketal group of 17 alpha-acetamidomethyl and 17 alpha-hemiglutaramidomethyl derivatives regenerated the 3-oxo and 3-oxo-4-ene functions. The 17 alpha-configuration of 17-substituted steroids was determined by 1H and 13C NMR and confirmed by comparing with NMR data for 17 alpha- and 17 beta-cyano-17-hydroxyandrost-4-en-3-one, 17 beta-cyano-3,3'-(ethylenedioxy)androst-5-en-17-ol, 17 alpha-alkynyl, and 17 alpha-hexanoic derivatives of dihydrotestosterone and testosterone, of known 17-configurations. Several ambiguous assignments of 13C NMR signals of 17 alpha-substituted steroids and unsubstituted 17 beta-hydroxy or 17-oxo precursors have been resolved using steroid analogs deuterated at positions C5-7, or C16 for androstane derivatives, and at positions C6-7, or C7 for androstene derivatives. 17 alpha-Aminomethyl and 17 alpha-alkylamidomethyl derivatives of dihydrotestosterone and testosterone are useful intermediates for the access to potential ligands of androgen-binding proteins necessary for affinity chromatography purification or affinity-labeling experiments.     

从铂铑合金王水不溶渣中回收铑

以铂铑合金王水不溶渣为原料,利用过氧化钡熔融、盐酸溶解、氯化铵沉淀分离铂铑、亚硝酸钠溶液络合、氯化铵沉淀铑、盐酸溶解、离子交换除去贱金属、水合肼还原、通氢还原工艺制备了纯度99.95%以上的铑粉,贵金属回收率大于95%。并考察了回收工艺的原理和操作参数。     

Identification and total synthesis of novel fatty acids from the Caribbean sponge Calyx podatypa

The phospholipid fatty acid composition of the Caribbean sponge Calyx podatypa was studied, and 85 different fatty acids were identified, in particular the 11-methylpentadecanoic acid and 10-tricosenoic acid, which have no literature precedence. Structural characterization was accomplished by means of gas chromatography-mass spectrometry on their corresponding methyl esters and dimethyl disulfide derivatives. The structure of 11-methylpentadecanoic acid was further confirmed by total synthesis (17% overall yield) starting from commercially available 10-hydroxydecanoic acid.     

Quantitative determination of thebaine in Papaver bracteatum by high-pressure liquid chromatography

A method is described for the quantitative analysis of thebaine from Papaver bracteatum, using a single high-pressure liquid chromatographic column. The procedure gives base-line separation of thebaine without the need for gradient elution equipment, and can be completed within 12 min. Thebaine isolated by this technique was shown to be pure, regardless of the age of plant or plant part from which it was obtained.     

Simultaneous Removal of Cd and Cr(VI) Using Fe-Loaded Zeolite

Current research focuses on the simultaneous removal of Cd and Cr(VI) in water by a newly developed material having both abilities of sorption and electrochemical reduction. The material was derived from the zeolite modified by Fe(II) chloride followed by sodium borohydride reduction. The Fe-loaded zeolite simultaneously removed Cd and Cr(VI) to below the detection limit at a fairly rapid rate within 1?h for Cd and within 20?h for Cr(VI), under the pH ranging from slightly acid to around neutral. At high concentration of coexisting Cr(VI), the removal efficiency of Fe-loaded zeolite for Cd slightly decreased due to surface fouling by Cr(III) hydroxide precipitations. On the contrary, the coexisting Cd was found to increase the removal rate of Cr(VI) by Fe-loaded zeolite. From the test results, the Fe-loaded zeolite was found to be a possible alternative in simultaneous removal of Cd and Cr(VI) in the aqueous phase.     

The recovery of potassium chloride from Dead Sea brines by precipitation and solvent extraction

A process is proposed for the recovery of potassium from brines by precipitation as potassium perchlorate, followed by conversion to potassium chloride by liquid anion exchange with a tertiary amine in the form of its hydrochloride. Regeneration of the amine salt is effected by means of lime and hydrochloric acid. The process was tested on Dead Sea brine, containing 13 g/l KCl. Precipitation at 30 °C gave a 40% yield of potassium, cooling to 0 °C increased the yield to over 80%. The anion exchanger used was the hydrochloride of trioctylamine dissolved in toluene; this performed satisfactorily and phase separation was easy. A separation factor of 130 was obtained for the ClO₄^?/Cl^? separation. Regeneration of the amine was tested with various bases.     

氯化蒸馏渣中锗提取技术的研究和利用

氯化蒸馏渣中的锗90％为硅锗酸盐,为酸不溶锗,可溶于碱。采用碱溶液,浸出渣中的硅锗酸盐,在一定条件下,使硅锗分离（除硅）,除硅后的溶液含Ge50mg·L^-1为贫锗溶液,为降低生产成本,贫锗溶液未加任何沉淀剂,直接水解沉淀锗而达到从氯化蒸馏渣中提取锗的目的。技术指标：锗浸出率〉85％,除硅率〉95％,沉锗率〉95％,锗的回收率〉70％。此工艺技术投入生产一年余,年处理氯化蒸馏渣2000余吨,回收锗1500kg。     

Human neutrophils employ the myeloperoxidase-hydrogen peroxide-chloride system to oxidize alpha-amino acids to a family of reactive aldehydes. Mechanistic studies identifying labile intermediates along the reaction pathway

We have recently demonstrated that neutrophils oxidize nearly all of the amino acids commonly found in plasma to a corresponding family of aldehydes in high yield. The reaction is mediated by hypochlorous acid (HOCl), the major oxidant generated by the myeloperoxidase-H2O2-Cl- system of phagocytes. We now present evidence for the underlying mechanism of this reaction, including the structural requirements and reaction intermediates formed. Utilizing mass spectrometry and isotopically labeled amino acids, we rule out hydrogen atom abstraction from the alpha-carbon as the initial event in aldehyde formation during amino acid oxidation, a pathway known to occur with ionizing radiation. Aldehyde generation from amino acids required the presence of an alpha-amino moiety; beta- and epsilon-amino acids did not form aldehydes upon oxidation by either the myeloperoxidase system or HOCl, generating stable monochloramines instead. UV difference spectroscopy, high pressure liquid chromatography, and multinuclear (1H,15N) NMR spectroscopy established that the conversion of alpha-amino acids into aldehydes begins with generation of an unstable alpha-monochloramine, which subsequently decomposes to yield an aldehyde. Precursor product relationships between alpha-amino acid and alpha-monochloramine, and alpha-monochloramine and aldehyde were confirmed by high pressure liquid chromatography purification of the reaction intermediate and subsequent 1H and 15N NMR spectroscopy. Collectively, these results detail the chemical mechanism and reaction intermediates generated during conversion of amino acids into aldehydes by myeloperoxidase-generated HOCl.     

Mechanism-based inactivation of serine transhydroxymethylases by D-fluoroalanine and related amino acids

Serine transhydroxymethylase, from lamb or rabbit liver, is known to catalyze slow transamination of D-alanine, but not of L-amino acids, in a tetrahydrofolate-independent reaction. Both enzymes will process the D-isomer of beta-fluoroalanine for alpha, beta-elimination of HF to yield an aminoacrylate-pyridoxal-P-enzyme intermediate. This intermediate partitions between harmless hydrolysis to pyruvate, NH4+, and active enzyme-pyridoxal-P (catalytic turnover) and suicidal enzyme alkylation by covalent modification with an average partition ratio of 40-60 turnovers/inactivation event/monomer unit of this tetrameric enzyme. Enzyme inactivation occurs with stoichiometric incorporation of radioactive label from D-[1,2-14C]fluoroalanine. Titration of enzymic cysteinyl --SH groups with 5,5'-dithiobis(2-nitrobenzoate) indicates loss of 1 --SH group on inactivation. Acid hydrolysis of radioactive-inactive enzyme confirms cysteine residue modification. Treatment of inactive enzyme with 6 M urea, then KBH4, followed by acid hydrolysis yields two radioactive compounds, lanthionine and S-carboxyhydroxyethylcysteine, in about equal amounts. The addition of tetrahydrofolate stimulates both pyruvate production and inactivation to equal extents with about a 200-fold rate acceleration at 0.5 mM tetrahydrofolate to turnover numbers of approximately 120 min-1. The Km for D-fluoroalanine is high, 10-60 mM, and this low substrate affinity suggests D-fluoroalanine will not be a useful in vivo agent for selective inactivation of liver cell serine transhydroxymethylases.     

SO2-4/TiO2-WO3催化合成环己酮1,2-丙二醇缩酮

介绍了以固体超强酸SO42-/TiO2-WO3为多相催化剂,通过环己酮和1,2-丙二醇反应合成了环己酮1,2-丙二醇缩酮,探讨了SO24-/TiO2-WO3对缩酮反应的催化活性,较系统地研究了酮醇量比,催化剂用量,反应时间诸因素对产品收率的影响.实验表明:SO24-/TiO2-WO3是合成环己酮1,2-丙二醇缩酮的良好催化剂,在n(环己酮):n(1,2-丙二醇)=1:1.5,催化剂用量为反应物料总质量的1.25%,环己烷为带水剂,反应时间1.5 h的优化条件下,环己酮1,2-丙二醇缩酮的收率可达88.5%.