Glycine determination according to the European Pharmacopoeia

The treatment of an aqueous solution of glycine with hypochlorite yields formaldehyde and glyoxylic acid. After acidification and removing formaldehyde by boiling glyoxylic acid reacts with resorcinol to the lactone of bis-2,4-dihydroxyphenyl acetic acid. Under alkaline conditions the lactone is oxidized to the violet oxonol anion and subsequently, after hydrolysis of the lactone, to the yellow fluorescent carboxylate anion.     

The Marquis reaction of morphine (author's transl)

The Marquis Reaction of Morphine From the violet solution of morphine and formaldehyde in 60proc. sulfuric acid the substance I was obtained which gives the characteristic colour with sulfuric acid. The structure of I was elucidated. It arises from 2 molecules morphine and 2 molecules formaldehyde. With sulfuric acid coloured oxonium carbonium ions are formed. In the Marquis reaction apomorphine does not arise.     

Reactions of phenyl substituted barbiturates in concentrated sulfuric acid (author's transl)]

Reactions of Phenyl Substituted Barbiturates in Concentrated Sulfuric Acid Three reactions of phenobarbitone in concentrated sulfuric acid were investigated. (1) With sodium nitrite in concentrated sulfuric acid phenobarbitone forms an orange EDA-complex (Ph. Eur.). (2) With an excess of formaldehyde in 83, 7% sulfuric acid phenobarbitone gives a ruby colour (DAB 7) which is due to the formation of carbenium ions. The final product of the reaction is a yellow substance with methylene- and oxymethylene bridges. (3) The reaction of phenobarbitone with piperonal in sulfuric acid (DAB 7-DDR) is in reality a reaction with formaldehyde, which is formed as an intermediate, Only 1/13 mole of formaldehyde is formed per mole of phenobarbitone. The green colour is due to a quinone structure without methylene- or oxymethylene bridges. In this reaction piperonal can be replaced by hexamethylentetramine or trioxane.     

Structure of side-chain-3-substituted indoles and color intensity in reaction with glyoxylic acid-sulfuric acid

The Structure of the Side Chain of 3-Substituted Indoles and the Colour Intensity of their Reaction Products with Glyoxylic Acid The reaction-products from indolyl-3-acetic acid ( 5 ) and tryptophane ( 2 ) with glyoxylic acid/sulfuric acid have a smaller colour intensity than the product of indolyl-3-propionic acid ( 1 ). This is caused by protonation of the carbonyl group of 5 and of the amino group of 2 .     

5-Methoxymethyl-2-furaldehyde: A Natural Furanoid from Jaborosa Magellanica (Solanaceae) 5-Methoxymethyl-furfural: ein natürliches Furanoid aus Jaborosa magellanica (Colanaceae)

It is known that when fructose or a carbohydrate which yields fructose, such as saccharose or inulin, is heated with methanol in the presence of dilute hydrochloric acid, dehydrative cyclization occurs with formation of 5-methoxymethyl-2-furaldehyde ( 1 )^1–3). In 1958, it was reported that furan 1 was present as a component of the roots of Asparagus lucidus, but it was assumed that this product had been formed as an artifact from fructose during the isolation process. Similarly, in 1978, it was stated that 5-methoxymethyl-2-furaldehyde was present in the extracts from flue-cured tobacco, apparently formed as an artifact from the reaction of fructose with sulfuric acid in methanol.     

防治血吸虫病药物的研究XXIX.生物样品中酒石酸的新比色测定法

用过碘酸使酒石酸氧化断裂为乙醛酸,然后与对硝基苯肼縮合.生成的乙醛酸对硝基苯腙經提取純化后,用氫氧化鈉显色,建立了生物样品中酒石酸的新比色测定法.应用光电比色計时,检出限度可达5微克.光密度讀数的平均相对偏差为4±3%.生物样品测定的回收率兔尿为106±15%,狗血浆为74±6%。大量銻的存在对测定可无干扰,因此本法适用于酒石酸銻鉀分子中酒石酸部分的代謝研究.     

4-Hydroxy-2H-[1]benzopyran-2-on als Baustein zur Synthese von Bisbenzopyranopyridinen

4-Hydroxy-2H-[1]benzopyran-2-one as Starting Material for the Synthesis of Bisbenzopyranopyridines A mechanism for the formation of 4 and 6 from 1 via 5a is discussed. Under acid catalysis, 1 and 3 react to yield 6 and 7. In the presence of DBN of 6 is formed from 3 and 8. When the reaction is catalyzed with piperidine, the major product is 9a , whose structure was elucidated by degradation reactions: KOH transforms 9a into the pyridone 10. Hydrazine converts 9a via 11 to the hydrazone 12a , which can be hydrolyzed to the lactone 12b     

Untersuchungen zur „Carbolin-Blau-Reaktion”︁

The Carboline Blue Reaction In the course of the carboline blue reaction 1,2,3,4-tetrahydro-β-carbolines with an unsubstituted A ring (yohimbine type compounds) are oxidised by Fe³⁺ ions in concentrated sulfuric acid via the intermediate 6,9′-bi-1,2,3,4-tetrahydro-β-carbolines 2 to yield the cyanine chromophor 3 . 7-Methoxy-1,2,3,4-tetrahydro-β-carbolines (reserpine type compounds) are oxidised by the same reagents via the intermediate 7,7′-dimethoxy-8,8′-bi-1,2,3,4-tetrahydro-β-carbolines 5 to yield the cyanine type chromophor 6 . The specificities of these colour reactions are discussed.     

隣苯二酚的锑络合物

隣苯二酚锑在水溶液中与碳酸钠、碳酸氢纳、氨或若干胺类化合物作用,形成一个锑原子与二分子隣苯二酚相联结的络盐(V),这个化合物也可从一分子锑化合物与二分子隣苯二酚作用生成.在生成络盐的反应中如有醇、甘油、羟基酸等存在时,并不参加反应而影响产物,因此修正了文献上所提出的Ⅱ、Ⅲ、Ⅳ等络盐结构.若干V的盐类用在血吸虫病实验治疗,疗效与酒石酸锑钾相仿。     

Comparison of the metabolism of ethylene glycol and glycolic acid in vitro by precision-cut tissue slices from female rat,rabbit and human liver

1.?The metabolism of [1,2-¹⁴C]-ethylene glycol and [1,2-¹⁴C]-glycolic acid was studied in vitro using precision-cut tissue slices prepared from the livers of female Sprague—Dawley rats, New Zealand white rabbits and humans. The time-course for production of metabolites formed from ethylene glycol at concentrations from 3 to 40 mM was determined to compare quantitatively the differences between species in the rates and amounts of formation of glycolic acid, the presumed developmental toxicant of ethylene glycol. The rates of metabolism of glycolic acid to glyoxylic acid at concentrations from 0.05 to 16 mM by liver tissue from the different species were also determined. The apparent V_maJK_m for the metabolic conversions of ethylene glycol to glycolic acid and for glycolic acid to glyoxylic acid in liver tissue from the different species were obtained.

2.?There were qualitative differences in the metabolic profiles and quantitative differences in the formation of glycolic acid between the mammalian liver systems. There was an average of 10-fold less glycolic acid produced by liver slices from rabbits compared with rats. With the human liver, the formation of glycolic acid was not detectable using tissue from three of four human donors. A low level of glycolic acid was detected in one liver slice incubation from one of the four subjects, but only at one extended time point; glyoxylate was detected with liver slices from all four humans.

3.?Liver slices prepared from female Sprague—Dawley rats, female New Zealand White rabbits and three female human subjects all metabolized glycolic acid to glyoxylic acid. Human liver tissue was the most effective at further metabolizing glycolic acid to glyoxylic acid. The ratios of F"_max/-/C_m, representing the relative clearance of glycolic acid from liver tissue, were approximately 14:9:1 for human, rat and rabbit liver, respectively.

4.?Precision-cut liver slices maintained in dynamic organ culture are good predictors of metabolism by liver tissue in vivo. The results of the present study therefore indicate that levels of glycolic acid, if formed in vivo, following exposures to similar concentrationsof ethylene glycol, would be lower in humans than in rabbits and rats.     

氯霉素之合成研究(三) 对硝基乙苯自动氧化制造对硝基苯乙酮的新方法

發展了自对硝基乙苯經自动氧化以制取对硝基苯乙酮方法。产品可用冷冻法析出。最好的接触剂为附着于碳酸鈣上的醋酸錳(10:1).在攪拌下向对硝基乙苯中通氧,速度为每克每分鐘0.55ml.,温度140～145°C,接触剂用量相当于0.005～0.01%Mn⁺⁺,在18至30小时內对硝基苯乙酮含量可达62%。接触剂中的碳酸鈣的作用,並非一單純的不活潑性載体。我們証明了:它具有延緩过氧化物分解的重要作用,而过氧化物的存在,对于自动氧化反应链锁的得以持续是必要的。它也能抵消可能存在于原料中的微量銅鹽和铁鹽对过氧化物的强力破坏作用,以得到酮含量高、色澤淺的产物。此外尚發現在反应过程中有一种未經証实的抑制物生成並积累。     

Metabolic fate of pitavastatin,a new inhibitor of HMG-CoA reductase: similarities and difference in the metabolism of pitavastatin in monkeys and humans

1. To elucidate any potential species differences, the in vitro metabolism of pitavastatin and its lactone was studied with hepatic and renal microsomes from rats, dogs, rabbits, monkeys and humans.

2. With the addition of UDP-glucuronic acid to hepatic microsomes, pitavastatin lactone was identified as the main metabolite in several animals, including humans.

3. Metabolic clearances of pitavastatin and its lactone in monkey hepatic microsome were much greater than in humans.

4. M4, a metabolite of pitavastatin with a 3-dehydroxy structure, was converted to its lactone form in monkey hepatic microsomes in the presence of UDP-glucuronic acid as well as to pitavastatin. These results implied that lactonization is a common pathway for drugs such as 5-hydroxy pentanoic acid derivatives.

5. The acid forms were metabolized to their lactone forms because of their structural characteristics.

6. UDP-glucuronosyltransferase is the key enzyme responsible for the lactonization of pitavastatin, and overall metabolism is different compared with humans owing to the extensive oxidative metabolism of pitavastatin and its lactone in monkey.     

10-Acyldithranol dimers; new derivatives of the antipsoriatic dithranol; synthesis, characterization and biochemical properties

With regard to the synthesis of 10-(omega-carboxyacyl)-derivatives dithranol 1 was reacted with the carboxylic acid dichlorides of succinic acid, glutaric acid, adipic acid and pimelic acid in toluene and collidin as a base. Instead of the expected derivatives the 10-acyldithranol dimers 5-7 were isolated as main products except for the reaction of succinyl chloride where only lactone 2 was formed. Moreover the 6-ring lactone 3 as a side product and traces of the 7-ring lactone 4 could also be isolated and characterized. All compounds revealed to be inhibitors of the enzyme glucose-6-phosphate dehydrogenase, indicating antipsoriatic activity.     

大茴香酸-硫酸荧光体系测定黄芪甲苷

黄芪甲苷 (ａｓｔｒａｇａｌｏｓｉｄｅ)是中药膜荚黄芪Ａｓｔｒａｇａｌｕｓｍｅｍｂｒａｎａｃｅｕｓ (Ｆｉｓｃｈ .)Ｂｇｅ .和蒙古黄芪Ａｓｔｒａｇａｌｕｓｍｅｍｂｒａｎａｃｅｕｓ (Ｆｉｓｃｈ .)Ｂｇｅ .ｖａｒ .ｍｏｎｇｈｏｌｉｃｕｓ (Ｂｇｅ .)Ｈｓｉａｏ的主要活性成分 ,有抗炎、降压、镇痛、镇静、升高血浆中ｃＡＭＰ水平、促进小鼠再生肝ＤＮＡ的含量[1,2 ] 以及促进免疫功能等生理活性。黄芪甲苷的测定方法主要有 :紫外分光光度法[3 ,4 ] 、薄层扫描法[5,6] 和ＨＰＬＣ法[7,8] 。光度法常用香草醛在浓硫酸作用下与甲苷显色…     

Novel cyclization chemistry especially suited for biologically derive unprotected peptides

A novel method is described for the cyclization of peptides - or segments of polypeptides - which requires a free A′-terminal α-amino group and a distal amino acid residue containing a nucleophilic side chain. The reaction is conducted in two steps, both in the aqueous phase. The first step involves acylation of the N-terminal α-amino group with iodoacetic anhydride at pH 6. This acylation reaction has >90% specificity for peptide α-amino groups and gives no alkylation of Arg, His, Lys or Met by the iodoacetate side product (R. Wetzel et al, Bioconjugate Chem., 1, 114-122, 1990). In the second step, the acylation reaction mixture or the isolated iodoacetyl-peptide is incubated at room temperature to give the cyclic peptide formed by reaction of the nucleophilic side chain with the iodoacetyl moiety. The pH dependence of the cyclization reaction by Met, Lys, Arg or His is consistent with the pK_a of the nucleophilic side chain. Thus, peptides containing Met plus other nucleophilic amino acids should preferentially cyclize via Met at low pH. In this paper, preparation of cyclic peptides containing 3-6 amino acids is described; the full range of ring sizes and sequences which can undergo this cyclization has not been further explored. Preliminary results suggest that this method is also fairly general with respect to the amino acid sequence being cyclized. The reaction appears to be particularly suited for cyclization via Lys and Met side chains. All of the cyclized products are sufficiently stable for many biological applications. However, peptides cyclized via Met slowly decompose at 37° with ring cleavage to yield a C-terminal lactone peptide in which the Met methylthio-group is effectively transferred to the JV-terminus. The reactions described here have several applications which take advantage of their unique ability to efficiently cyclize naturally-derived (as well as chemically synthesized) peptides in aqueous solution with little or no protection/deprotection chemistry.     

Green microparticles based on a chitosan/lactobionic acid/linoleic acid association. Characterisation and evaluation as a new carrier system for cosmetics

The association chitosan/linoleic acid/lactobionic acid in aqueous solution spontaneously led to the formation of stable microparticles with a liquid hydrophobic core consisting of linoleic acid surrounded by a shell of chitosan/lactobionic acid. The originality of the microparticles arises from the fact that they are formed by the association of three ingredients of cosmetic interest, including a skin penetration enhancer (linoleic acid). Dynamic light scattering (DLS) measurements showed microparticles with a mean diameter of 1–2?μm. The presence of a hydrophobic liquid core was observed by transmission electron microscopy (TEM). The ability of these microparticles to encapsulate phenylethyl resorcinol, a hydrophobic skin lightener, was evaluated and its encapsulation was confirmed thanks to T₂ measurements and nuclear Overhauser effects (nOe) signs.     

Cleavage of a model peptide at its glycine residue by alkaline mercuric oxycyanide

Treatment of peptides with excess HgO in the presence of alkaline cyanide leads to cleavage of the peptides at glycine residues. The reaction appears to involve both C- and N-mercuration with subsequent release of 2mol mercury per mol of glycine. An intermediate glyoxylic acid residue in Schiff base linkage is postulated. Treatment of the heptapeptide Phe-Ala-Lys-Gly-Leu-Asp-Val with alkaline HgO and KCN for 6 h at 25° resulted in greater than 90% cleavage, and the resultant reaction products were separated by reverse phase chromatography and identified by amino acid analysis. N-terminal products were approximately equimolar Phe-Ala-Lys, Phe-Ala-Lys-Gly, and Phe-Ala-Lys-amide. C-terminal products were predominantly Leu-Asp-Val (63%), plus Gly-Leu-Asp-Val (9%), and oxalyl-Leu-Asp-Val (8%). This method may be useful for cleavage of peptides or proteins containing glycine residues.     

Proton Acid-Catalysed Transformations of Estrogen Derivatives: New Results and Some Mechanistic Aspects of the Kober Colour Reaction

The 3-O-methylated estrogen derivatives 1a-d and α-estradiol ( 1e ) underwent sulfuric acid-catalysed transformations to furnish the steroids 2–6 . The processes involved in the reaction sequence are regioselective sulfonation and, above all, the Wagner-Meerwein rearrangement of the methyl group at C-13. With the objective of obtaining further information on the course of the Kober colour reaction of estrogens, some UV/VIS and ESR spectroscopic investigations were also carried out.     

麻黄鹼的高碘酸比色测定法

虽然麻黄鹼早在1885年已从麻黄草中分出,并且在1920年已经人工合成,但是麻黄鹼的含量测定,迄今仍缺乏满意的方法。考查文献上所见的麻黄鹼的含量测定法,主要可归纳为二大类,就是酸鹼滴定法和比色法。中华人民共和国药典(中国药典)的方法所根据的原理是先用鹼使样品(麻黄鹼鹽类的纯品或麻黄流浸膏)中的麻黄鹼游离,继用醚抽出,然后采用酸鹼滴定。英国药典和美国药典的含量测定法也如上述。这法的缺点是:(1)用醚和酸液反复抽取,手续麻     

The limiting effect of manganese phase of oceanic cobalt-rich crust reduction by sawdust in acid leaching

Ocean cobalt-rich crust is rich in Co, Cu, Ni, Mn and other valuable metals. In this study, the valuable metals in cobalt-rich crust, which was reduced using waste sawdust, can be effectively recovered by acid leaching. The results show the formation of manganese oxide in the reduction process has a certain restriction on sulfuric acid leaching. The reduction process is gradually completed from the surface layer to the core (MnO₂→Mn₂O₃→Mn₃O₄→MnO). The reduction products at any stage are always composed of one or two oxides of the adjacent valence state of manganese, which lead to different reaction processes and products with sulfuric acid. At the same time, manganese dioxide precipitates formed by Mn₂O₃ and Mn₃O₄ will remove a small amount of valuable metal ions from the solution, reducing the recovery of Mn, Cu, Co and Ni. The leaching efficiency of Mn, Cu, Co and Ni could reach 99.96%, 98.86%, 99.89% and 99.35% respectively using 0.5 mol/L sulfuric acid to leach 50 min at 25 °C.