Preparation of hydrazides of amino acids and peptides

A new method of synthesizing hydrazides of amino acids and peptides is considered which involves the hydrazinolysis of the silyl esters of the corresponding compounds. A number of hydrazides of derivatives of amino acids and peptides has been obtained in high purity with yields close to quantitative. The physicochemical characteristics of the compounds synthesized are given.     

A comparative study of the reactions of thiophene-2-carboxanilides and related compounds

Thiophene-2-carboxanilide and itsp-chloro andp-bromo derivatives react with chlorosulfonic acid to give the corresponding sulfonyl chlorides, which react with amino acids to give the respective derivatives. Several methyl esters of the latter were prepared. Hydrazinolysis of these methyl esters yielded the hydrazides. Coupling reactions of some sulfonylamino acids with amino acid methyl ester hydrochlorides in THF-Et₃N medium using the dicyclohexylcarbodiimide method give the corresponding dipeptide methyl esters. The spectral data of the compounds are briefly discussed.Chemistry Department, Faculty of Science, Al Azhar University, Nasr City, Cairo, Egypt. Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 921–926, July, 1998.     

Synthesis and properties of furan derivatives. 4. Synthesis of 2,5-disubstituted 1,3,4-oxadiazoles containing furan fragments

The condensation of hydrochloride sats of iminoesters of furan acids with hydrazides of carboxylic acids gives 2,5-disubstituted 1,3,4-oxadiazoles containing furan fragments. Such compounds are also formed in the condensation of hydrazides of 5-R-furan-2-carboxylic acids with hydrocloride salts of carboxylic acid iminoesters. The reaction of furan acids with hydrazine dihydrochloride in polyphosphoric acid gave symmetrically disubstituted 1,3,4-oxadiazoles containing furan fragments.Communication 3, see ref. [1].I. M. Gubkin State Petroleum and Natural Gas Institute, 117917, Moscow. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 238–249, February, 1995. Original article submitted January 24, 1995.     

Investigation of naphthyridines. 16. Synthesis of derivatives of 2,5-dioxo-1,2,5,6,7,8-hexahydro-1,6-naphthyridine-3-carboxylic acids from anilides (hydrazides) of 6-oxo-2-styrylnicotinic acids

Heating anilides (hydrazides) of 5-cyano-6-oxo-2-styrylnicotinic acids in polyphosphoric acid (PPA) leads to amides of 7-aryl-2,5-dioxo-6-phenyl(amino)-1,2,5,6,7,8-hexahydro-1,6-naphthyridine-3-carboxylic acids, which on heating with perchloric acid in acetic acid give the corresponding acids.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1809–1812, December, 2004.For Part 15 see [1].     

Synthesis of a modified fragment 13–19 of the sequence of ACTH using silyl protection

A new scheme for the synthesis of a peptide representing a modified analog of fragments 13–19 of the sequence of the adrenocorticotropic hormone has been described, which uses a number of stages the trimethylsilyl grouping for the protection of the carboxy groups of amino acids and peptides. The final and intermediate products were obtained with high yields and were distinguished by chromatographic homogeneity.¹³C NMR was used as a supplementary method for the identification of the compounds. The physicochemical characteristics of the compounds synthesized are given.All-Union Scientific-Research Institute of the Technology of Blood Substitutes and Hormone Preparations, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 374–379, May–June, 1980.     

糖基修饰的氨基酸类化合物的合成

通过对5种氨基酸酯化和氨基保护得到苄氧羰基氨基酸甲酯, 经肼解制备苄氧羰基氨基酸酰肼, 然后分别与3种不同的糖基异硫氰酸酯反应, 制备了相应的目标化合物15个, 且产率均在60%以上. 所有新化合物均经元素分析, IR, MS和¹H NMR确证. 同时探索了苄氧羰基氨基酸甲酯肼解的最佳反应条件.     

Preparation of esters of amino acids and of peptides under mild conditions

A new method for obtaining esters of N-protected amino acids and peptides from complexes of their sodium salts with 15-crown-5 that are soluble in organic solvents is proposed.A. V. Bogatskii Physicochemical Institute, Academy of Sciences of the Ukrainian SSR, Odessa. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 224–225, March–April, 1986.     

Synthesis of Hydrazones from Amino Acids and their Antimicrobial and Cytotoxic Activities

Hydrazones 6a–6n were synthesized from different amino acids with various aldehydes under reflux in methanol/ethanol. The structures of synthesized compounds were ascertained by elemental analysis and spectroscopic techniques. A comparative study of the antimicrobial activity and cytotoxicity was carried out of the N‐protected amino acids, their esters, hydrazides, and the respective hydrazones, providing good results in cytotoxicity studies.     

Comparative investigation of the molecular structures of the species-specific proteins of the seeds ofGossypium hirsutum andG. barbadense

The N-terminal amino acids and the amino acid compositions of four species-specific proteins of two species of the cotton plant —Gossypium hirsutum andG. barbadense — have been determined. Peptide maps of tryptic hydrolysates of these proteins have been obtained and compared. Individual tryptic peptides have been isolated and purified. The N-ends, amino acid compositions, and amino acid sequences of individual peptides have been determined. The N-terminal sections of the proteins ofG. hirsutum andG. barbadense as far as the 16th amino acid residue have been sequenced. A comparative analysis has been made of the peptides and proteins of these cottonplant species.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 40 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 858–864, November–December, 1997.     

Isolation and study of the peptides from an alcoholic extract of the seeds ofGlycine hispida Max.

Summary Seven peptides have been isolated from soybean seeds. Twelve amino acids have been detected in the hydrolysis products of the peptides.Khimiya Prirodynkh Soedinenii, Vol. 2, No. 1, pp. 40–43, 1966     

Structural analogues of bradykinin and other vasoactive peptides in the venom of the wasp Polistes gallicus

Six vasoactive peptides have been isolated in the homogeneous state from the venom of the waspPolistes gallicus. Their full amino acid sequences have been determined. It has been shown that four of them are structural analogues of bradykinin with additional N- and C-terminal sequences and intramolecular substitutions of amino acids. Some structure-function relationships in bradykinin analogues are discussed.A. S. Sadykov Institute of Bioorganic Chemistry, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 389–393, May–June, 1990.     

Complexation and Separation of Amines, Amino Acids, and Peptides by Functionalized Calix[n]arenes

The ability of calix[n]arenes to form complexes, to act as extractants in liquid–liquid extraction, and run as carriers in transport through liquid membranes of different biological amine compounds (e.g., ammonium ion, amines, amino acids, and peptides) has been the central topics of many reports. These features recommend the calix[n]arenes as competitive candidates for studying the interactions involved in host–guest recognition as well as useful receptors in separation processes. Some specific aspects of their applications in binding and separation of various amine compounds by extraction, and in transport through liquid membranes have therefore been considered. The effect of the factors that might influence the separation of above compounds by extraction, and the transport through liquid membranes using the calix [n]arenes has been presented.     

Synthesis of derivatives of the androstane series. XXI. Synthesis and properties of some N-acylated androstano[3,2-c]pyrazoles

A method has been developed for synthesizing acylsteroidopyrazoles in which the acyl residues are radicals of natural amino acids. The compounds synthesized possess a high anabolic action and a low toxicity.Khar'kov Scientific-Research Institute of Endocrinology. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 76–81, January–February, 1981.     

Amino acid analysis of proteins and peptides by thin-layer electrophoresis in association with chromatography

Summary A rapid and simple method for the qualitative determination of the amino acid composition of proteins and peptides by thin-layer electrophoresis in combination with thin-layer chromatography has been developed which permits a map with the separation of 18–20 amino acids to be obtained in 3–4 hr.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 5, pp. 348–354, 1966     

Primary structure of subunit B of the 11S globulin of cotton seeds of variety 108-F. IV. High-molecular-weight peptides from the complete tryptic hydrolysis and from tryptic hydrolysis at the arginine residues of subunit B

The high-molecular-weight peptides from the complete tryptic hydrolysis and tryptic hydrolysis at arginine residues of subunit B, which contained uncleaved bonds of the basic amino acids, have been studied. In the investigation of these peptides, use was made of additional cleavage by trypsin at lysine residues and of cyanogen bromide cleavage.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 227–230, March–April, 1984.     

Ternary complexes involving copper(II) and amino acids,peptides and DNA constituents. The kinetics of hydrolysis of α-amino acid esters

Binary and ternary complexes of copper(II) involving picolylamine (Pic) and amino acids, peptides (HL) or DNA constituents have been investigated. Ternary complexes of amino acids or peptides are formed by simultaneous reactions. Amino acids form the Cu(Pic)L complex, whereas peptides form Cu(Pic)L and Cu(Pic)(LH_–1). The ternary complexes of copper(II) with picolylamine and DNA are formed in a stepwise process, whereby binding of copper(II) to picolylamine is followed by ligation of the DNA components. The stability of the ternary complexes is compared with the stabilities of the corresponding binary complexes. The hydrolysis of glycine methyl ester (MeGly) is catalysed by the Cu(pic)²⁺ complex. The kinetic data is fitted assuming that the hydrolysis proceeds in two steps. The first step, involving coordination of the amino acid ester by the amino and carbonyl groups, is followed by rate-determining attack by the OH^– ion. The second step involves equilibrium formation of the hydroxo-complex, Cu(pic)(MeGly)(OH), followed by intramolecular attack.     

Use of trimetylsilyl protection in the synthesis of oxytocin fragments

The possibility has been studied of obtaining silyl derivatives of amino acids forming components of oxytocin and of obtaining the corresponding peptides from them by the mixed-anhydride method.All-Union Scientific-Research Institute of the Technology of Blood Substitutes and Hormone Preparations, Moscow. Translated from Khimiya Prirodynykh Soedinenii, No. 1, pp. 111–114, January–February, 1993.     

Complexation and Separation of Amines,Amino Acids,and Peptides by Functionalized Calix[<Emphasis Type="Italic">n</Emphasis>]arenes

The ability of calix[n]arenes to form complexes, to act as extractants in liquid–liquid extraction, and run as carriers in transport through liquid membranes of different biological amine compounds (e.g., ammonium ion, amines, amino acids, and peptides) has been the central topics of many reports. These features recommend the calix[n]arenes as competitive candidates for studying the interactions involved in host–guest recognition as well as useful receptors in separation processes. Some specific aspects of their applications in binding and separation of various amine compounds by extraction, and in transport through liquid membranes have therefore been considered. The effect of the factors that might influence the separation of above compounds by extraction, and the transport through liquid membranes using the calix [n]arenes has been presented.This revised version was published online in July 2005 with a corrected issue number.     

Form of the dihedral angle dependence of the spin-spin coupling constant JHNNH

Cyclic hydrazides (derivatives of phtalhydrazide,pyrozolidone-3, indazolone, cyclic hydrazide camphoric acid) are studied by the NMR¹H method. The size of the dihedral HNNH angle of several model compounds (pyrozolidone-3, cyclic hydrazide norcamphoric acid) are calculated by the MINDO/3 SSF MO LCAO method. It is shown that in the hydrazides with HNNH dihedral angle 0–70° the magnitude of the HNNH spin-spin interaction constant does not exceed 1 Hz. The form of its dependence on the dihedral angle is determined.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 3, pp. 363–366, 1989.     

2-Benzothiazolylmethylaminocarboxylic acids

A number of 2-benzothiazolylmethylaminocarboxylic acids and their derivatives (esters, amides, hydrazides, and alcohols) were synthesized. It is shown that the condensation of isatoic anhydride with o-aminothiophenol and o-phenylenediamine leads to the formation of o-aminophenyl-2-benzothiazole and o-aminophenyl-2-benzimidazole, respectively.Translated from Khimiya Geterotsilicheskikh Soedinenii, No. 12, pp. 1697–1700, December, 1970.