Gravimetric and Colorimetric Determinations of Copper,Cobalt, Zinc and Mercury with 1-(2-Methylindole-3-Acetyl)-4-Arylthiosemicarbazide

1-(2-Methylindole-3-acetyl)4-arylthiosemicarbazides have been prepared and were used as reagents for gravimetric and colorimetric determinations of copper, cobalt, zinc and mercury. The synthesis of the same metal complexes of these thiosemicarbazides as a potential biological derivatives was also described.     

Syntheses of Novel Flavones Containing Schiff Base Moiety

Introduction Flavones and their derivatives existing in naturae are commonly contained in plants. The members of the flavone class show a wide variety of biological activities, such as anti-inflammatory[1], antimicrobial[2] and antitumor activities[3]. Schiff bases have been intensively investigated due to their antibacterial activity and antitumor property[4,5].     

Synthesis and properties of azoles and their derivatives. 36. Synthesis of 2-amino-1,3,4-oxadiazoles, 2-amino-1,3,4-thiadiazoles,and 1,2,4-triazoline-3-thiones containing indolyl radicals

On the heterocyclization of 1-(indol-3-ylcarbonyl)thiosemicarbazides, depending on the conditions of performing the reaction, either 1,2,4-triazoline-3-thiones, 2-amino-1,3,4-thiadiazoles, or 2-amino-1,3,4-oxadiazoles containing an indolyl residue in position 5 are obtained. 1,2,4-Triazoline-3-thiones and 2-amino-1,3, 4-thiadazoles have also been synthesized by the reaction of the hydrochloride of ethyl indol-3-carboximidate with thiosemicarbazides.For communication 35, see [1].Translated from Khimiya Geterotsilicheskikh Soedinenii, No. 9, pp. 1271–1276, September, 1984.     

Synthesis,structural and biochemical aspects of titanocene and zirconocene chelates of acetylferrocenyl thiosemicarbazones

The reactions of bis(cyclopentadienyl)titanium(IV)/zirconium(IV) dichloride with a new class of organometallic thiosemicarbazones (LH), derived by condensing acetylferrocene with substituted thiosemicarbazides, have been studied and two types of bimetallic products, viz. [Cp₂M(L)Cl] (M = Ti or Zr) and [CpZr(L)₃], have been isolated. On the basis of various physicochemical and spectral studies, five- and seven-coordinate structures have been assigned to these derivatives, respectively. Attempts have been made to establish a correlation between biological activity and the structures of the products.     

Reactions of heterocyclic cations with n-containing nucleophiles. 15. Reaction of 2,6-diphenylpyrylium perchlorate with semi- and thiosemicarbazides

The reaction of 2,6-diphenylpyrylium perchlorate with semi- and thiosemicarbazides in ethanol leads to 1-carbamoyl- and 1-thiocarbamoyl-3-phenyl-5-phenacyl-4,5-dihydropyrazoles, the cyclization of which yields 2,5-diphenyl-7-oxo(thio)-pyrazolo[1,5-c]pyrimidines. The tautomeric form of the latter is established by comparing their electronic absorption spectra with the spectra of the methyl derivatives.For Communication 14, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1635–1640, December, 1986.     

Five-membered 2,3-dioxoheterocycles. 28. Reaction of 5-aryl-2,3-dihydrofuran-2,3-diones with thioamides and thiosemicarbazides

The reaction of 5-aryl-2,3-dihydrofuran-2,3-diones (I) with thiocarbonyl compounds has been described only for thiourea. The products of this reaction are 3-aryl-5-phenacylidene-4-oxoimidazolidine-2-thiones [2]. It seemed of interest to study the conversion of the furandiones (I) with a wider range of thiocarbonyl compounds such as thioamides and thiosemicarbazides.For Communication 27 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1461–1464, November, 1992.     

Synthesis and antibacterial activity of 1-(2,4-dichlorobenzoyl)-4-substituted thiosemicarbazides, 1,2,4-triazoles and their methyl derivatives

A series of 1-(2,4-dichlorobenzoyl)thiosemicarbazides, s-triazoles and their methyl derivatives have been synthesised by condensation of 2,4-dichlorobenzoyl hydrazine with aryl isothiocyanates. Subsequent ring closure of the substituted thiosemicarbazides yielded the s-triazoles, and reaction with methyl iodide resulted methyl derivatives. All the compounds were subjected to in vitro testing against two gram-positive and two gram-negative bacteria. Antibacterial activity was found to be moderate to good in most of the compounds.     

Chemical Biology Studies on Molecular Diversity of Annonaceous Acetogenins

Annonaceous acetogenins, isolated from the Annonaceae plants, have been attracting worldwide attention in recent years due to their biological activities, especially as growth inhibitors of certain tumor ceils [ 1 ]. They have been shown to function by blocking complex I in mitochondria [2] as well as ubiquinone-linked NADPH oxidase in the cells of specific tumor cell lines, including some multidrug-resistant ones [3]. These features make these acetogenins excellent leads for the new antitumor agents. In our previous work, the compounds 1a to 1d (Figure 1), which relies on structure simplification while maintaining all essential functionalities of the acetogenins, was in vitro tested against several human solid tumor cell lines and showed interesting cell selectivity [4]. All four analogues show remarkable activity against the HCT-8 and HT-29 cell lines, while compound 1c was found the best [4bi. In order to further investigate the effects of key structural features, a convergent parallel fragments assembly strategy was developed [4e]. In addition, the biological relevancies of typical annonaceous acetogenin mimetics were also studied [4f].     

Synthesis of 1-Aroyl-4-(2-Chlorophenyloxyacetyl)-Thiosemicarbazides and Corresponding Semicarbazides

1,4-Diacyl thiosemicarbazides have attracted much attention in recent years because of their fungicidal1, bactericidal2 and tuberculostatic3 activities. Meanwhile, aryloxyacetic acid derivatives have also been used as herbicides and plant-growth regulators4-6. These applications prompt us to synthesize a new series of compounds bearing both thiosemicarbazide and aryloxyacetyl moiety, with the objective of further investigating the property and structure-activity relationship of these new compounds and obtaining new biologically active compounds. In addition, the species of 1,4-diacyl semicarbazides are still very scarce, so an efficient synthetic route from 1,4-diacyl thiosemicarbazides to 1,4-diacyl semicarbazides is also introduced in this paper.     

Synthesis and characterization of bis(2,2′-bipyridine) ruthenium complexes containing thiosemicarbazide ligands: unique redox series

Two series of heterochelates of ruthenium(II) containing two bipyridyl molecules and a bidentate chelating sulfur---nitrogen donor ligand in the form of 4-aryl substituted thiosemicarbazides have been synthesized and characterized. The first series of complexes are dicationic in which the ring substituted 4-aryl thiosemicarbazides (N---S) are chelated in the keto form through the hydrazinic nitrogen and the thione sulfur atom. They are of the [Ru(bpy)₂NS]⁺² type. The second series have the general formula [Ru(bpy)₂NS]⁺¹ in which the thiosemicarbazide moiety remains chelated to the Ru^II centre through the hydrazinic nitrogen and the deprotonated thiolato S-atom. All the complexes have been characterized by elemental analysis, UV-vis, IR and EPR spectroscopy. The complexes were found to constitute a three membered redox series which were investigated by cyclic voltammetry.     

Synthesis of 17-OH-Isosteviol

Stevioside(1), an ent-kaurene glycoside commer-cially extracted from Stevia rebaudiana Bertoni[1] is used as a non-caloric sweetener for food in many countries[2]. The increasing demand for low calory and natural food contributes to the increasing popularity of     

Synthesis and evaluation of AChE inhibitory activity of 5,6-diaryl-1,2,4-triazinyloxyacetyl-4-substituted thiosemicarbazides,triazoles and N-benzylidene derivatives

A series of 1,2,4-triazinyl thiosemicarbazides, triazoles and N-benzylidene derivatives have been synthesized by condensation of 5,6-diphenyl-1,2,4-triazin-3-yloxyacetyl hydrazine with aromatic aldehydes and aryl isothiocyanates. Subsequent ring closure of thiosemicarbazides yielded the triazoles. All the compounds were subjected to in vitro testing of cholinesterase inhibitory action. Percentage inhibition was found to be moderate to good in a few of the compounds.     

A Convenient and Easy-controlled Method for Preparation of 7,10-Bis(2,2,2-trichloroethyloxycarbonyl)-10-deacetyl Baccatin Ⅲ

Introduction The complex natural product paclitaxel(Tax-olR, 1a), first isolated from Taxus brevifolia[1], has an excellent clinical activity against ovarian and breast cancers[2] and shows promising results in the treatment of other cancers[3]. The structure-activity relationships(SAR) of taxoid derivatives have been extensively studied to search for the analogues bearing better physical, chemical and biological properties. One example is the discovery of TaxotereR(1b). The structures of Taxol and Taxotere are shown in Scheme 1.     

The reaction of substituted thiosemicarbazides and γ-haloketones

The reactions of substituted thiosemicarbazides and γ-halobutyrophenones afforded derivatives of the tetrahydro-1H-pyrrolo[1,2-b][1,2,4]triazole-2(3H)-thione ring system.     

Disulfide derivatives of thiosemicarbazones of 4-formyl-5-thiopyrazole

The reaction of 4-formyl-5-mercaptopyrazole with thiosemicarbazides in methanol has afforded novel disulfide derivatives of thiosemicarbazones, and their structure has been studied by NMR and IR spectroscopy. X-ray diffraction analysis of [5,5'-dithiobis(4-formyl-3-methyl-1-phenylpyrazole)]-4-allylthio-semicarbazone has shown that it exists as a dimer with two molecules linked via the disulfide S–S bridge between the heterocycles in the crystal.     

Synthesis and Structural Characterization of Chiral[(n-Bu)4N]2[Mo2O5(OC10H6O)2]

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Benzindazoles from triketones of the indan series

In the reaction of 2-acetonyl-and 2-phenacyl-2-phenylindan-1, 3-diones with hydrazine hydrate, the five-membered ring of the indandione system isomerizes into a six-membered ring forming derivatives of 5-hydroxy-1H-benz[g]indazole. Derivatives of 3,4-(CO)-benzoylenepyridazine have been isolated as intermediates. The benzindazoles mentioned have been obtained by independent synthesis from the corresponding 2-acyl-1, 4-dihydroxynaphthalenes.For part I, see [1].     

Spectroscopic studies of some thiosemicarbazide compounds derived from Girard's T and P

Three new derivatives of thiosemicarbazides, derived from the reactions of ethyl-, allyl- and phenyl isothiocyanates with Girard's T [(carboxymethyl) trimethylammonium chloride hydrazide] and P [1-(carboxymethyl) pyridinium chloride hydrazide], have been isolated and characterized by chemical analyses, conductivities, spectral (IR, 1H NMR) and molecular weight measurements. The most important assignments of the functional groups in the isolated solid organic compounds have been determined using IR spectra. Also, the main functional groups in the skeleton of these compounds have been characterized using 1H NMR spectra. Moreover, a comparative studies between the three thiosemicarbazide derivatives have been carried out. The role of the existence of ethyl-, allyl-, phenyl-, [(CH3)3N+-] and [C5H5N+-] on the position of the functional groups has been investigated. Finally, the absence of any type of hydrogen bonding (inter- and/or intra-) within these compounds is discussed on the basis of the data of melting points, IR and 1H NMR spectra and molecular weight measurements.     

Investigation of riboflavin analogs

Trifluoromethyl derivatives of riboflavin, galactoflavin, and 9-(-hydroxyethyl) isoalloxazine have been synthesized for biological tests.For part III, see [1].     

First total synthesis of hormaomycin, a naturally occurring depsipeptide with interesting biological activities

Some unique features were disclosed during the structure elucidation of the cyclic depsipeptide hormaomycin (1), first isolated in 1989 from a Streptomyces griseoflavus strain and found to have quite an interesting spectrum of biological activities. Besides one residue of the proteinogenic amino acid isoleucine [(S)-Ile], it contains two units of 3-methylphenylalanine [(betaMe)Phe], one of (2R)-allo-threonine [a-Thr] as well as two moieties of 3-(trans-2-nitrocyclopropyl)alanine [(3-Ncp)Ala] and one of 4-(Z)-propenylproline [(4-PE)Pro]. The latter two have never been found in any natural product before. The side chain of 1 is terminated with the residue of 5-chloro-1-hydroxypyrrole-2-carboxylic acid [Chpca]. This first synthetic access to hormaomycin 1 will make it possible to prepare structural analogues of this interesting natural depsipeptide in order to elucidate structure-activity relationships and the biologically active minimal unit.