Pharmaceutical Chemistry Journal (v.49, #6)

The native hormone somatostatin plays an important role in vivo by acting on multiple targets via a family of five receptors to produce a broad spectrum of biological effects. Some peptide analogs of this enzyme are widely used in clinical practice. However, their clinical efficacy is limited because of some disadvantages. In this respect, the search for new drugs of this type is a critical task. In this review, we have summarized trends in the synthesis and biological effects of peptide somatostatin analogs since 1978 and future prospects for the development of these anticancer drugs.
Keywords: somatostatin; peptide analogs; SST receptors; anticancer peptides

New Heterocyclic Hepatitis C Virus (HCV) Inhibitors Containing A 2-Aminomethyl-1H-Indole Fragment by A. V. Ivachtchenko; P. M. Yamanushkin; O. D. Mit’kin; E. V. Ezhova; O. M. Korzinov; E. A. Bulanova; V. V. Bichko; A. A. Ivashchenko (352-361).
A focused library of heterocyclic compounds including a 2-aminomethyl-1H-benzimidazole (119), 2-aminomethylindole (2083), benzofuran-2-ylmethylamine (8492), or 2-piperazin-1-ylmethylbenzoxazole (93) fragment was screened for the ability to inhibit in vitro hepatitis C virus (HCV). The synthetic methods were described. The antiviral activity and cytotoxicity data were presented. Most of the compounds carrying a benzoxazol-2-ylmethylamine fragment inhibited Huh7.3 human hepatoma cells infected in vitro with HCV with nanomolar potency but were inactive against the HCV RNA-replicon. The only exception was 9-methyl-N(6)-(3-nitrophenyl)-2,3,4,9-tetrahydro-1H-carbazole-1,6-diamine (67), which demonstrated nanomolar potency against HCV in both models. The most active and selective compounds were (piperazin-1-yl)-[(1Hindol-2-ylmethyl)piperidin-4-yl]-ketones (EC50 0.31 – 2.2 μM, CC50 10.2-110 μM) and 2-(1,2,3a,4,5,6-hexahydropyrazino[3,2,1-jk]carbazol-3-yl)acetamide (EC50 1.69 ± 0.5 μM, CC50 114 ± 42 μM). The two most selective inhibitors (28, TI50 = 52 and 77, TI50 = 68) were selected for further preclinical trials.
Keywords: 2-aminomethyl-1H-benzimidazoles; 2-aminomethylindoles; benzofuran-2-ylmethylamine and 2-piperazin-1-ylmethylbenzoxazoles, antiviral activity; cytotoxicity; therapeutic index; hepatitis C virus; HCV

A simple and convenient method for the synthesis of biologically active 3-(2-oxoalkylidene)-3,4-dihydro-2H-1,4-benzoxazin-2-ones was proposed. The structures of the synthesized compounds were established using NMR and IR spectroscopy and mass spectrometry. It was established that the synthesized compounds possessed antioxidant, antiradical, and strong antihypoxant activity and exhibited low acute toxicity, which allowed the search for new antioxidants and antihypoxants among benzoxazines to continue.
Keywords: 1,3,4,6-tetracarbonyl compounds; 3-(2-oxoalkylidene)-3,4-dihydro-2H-1,4-benzoxazin-2-ones; 2-alkanoylmethyl-2-hydroxy-3,4-dihydro-2H-1,4-benzoxazines; Escherichia coli BW 25113; antihypoxant activity; antioxidant activity; antiradical activity; acute toxicity

The present manuscript describes synthesis of some new 1,3,4-thiadiazole derivatives and evaluation of their antimicrobial, antifungal and anthelmintic activity quantitatively and qualitatively. First, thiosemicarbazide was cyclized with different aromatic acids and ethanol to yield 5-phenyl-1,3,4-thiadiazol-2-amine. Then, N-substituted alpha-chloroacetanilides were synthesized from aromatic amines and chloroacetyl chloride in a mixture of glacial acetic acid and sodium acetate under cold conditions. Finally, 5-phenyl-1,3,4- thiadiazol-2-amine was reacted with N-substituted alpha-chloroacetanilides using potassium hydroxide to yield the corresponding N-phenyl-2-[(5-phenyl-1,3,4-thiadiazol-2-yl)amino] acetamides. The structures of synthesized compounds were confirmed by IR and 1H NMR spectra and elemental analysis. These molecules were evaluated for antimicrobial, antifungal and anthelmintic activity.
Keywords: 1,3,4-thiadiazole; cyclization; antimicrobial; antifungal; anthelmintic activities

Characterization of Glutathione-Homocystine Transhydrogenase as a Novel Isoform of Glutathione S-Transferase from Aspergillus flavipes by Ashraf S. A. El-Sayed; Abdalla E. Hassan; Marwa A. Yassin; Asmaa M. F. Hassan (373-383).
Glutathione-homocystine transhydrogenase/oxidoreductase (GHTHase) is an enzyme that catalyzes the reversible oxidation/reduction of reduced glutathione (GSH) and homocystine (Hcy2) to oxidized glutathione and homocysteine (Hcy). GHTHase is implicated in regulation of the metabolism of homocysteine and glutathione. Aspergillus flavipes JF831014 exhibits the highest productivity of GHTHase, using GSH as electron donor and Hcy2 as acceptor. GHTHase yield from A. flavipes has been nutritionally optimized to reach the maximum activity (21.14 U/mg) using GSH (0.4%) combined with Hcy2 (0.01%) and glucose (0.4%), NADH + H (30 mM) at medium initial pH 7.8. The yield of GHTHase was increased about 1.2 times upon starvation of the culture of A. flavipes for two days, as compared to the non-sulfur starved culture. The GHTHase activity was increased by 13.7 fold with total yield of 8.8%. According to denaturing PAGE, GHTHase had 35 kDa, and 75 kDa by non-denaturing PAGE, gel-filtration and DLS analysis, ensuring its homodimeric identity. The enzyme displayed a highest activity at pH 6.5 – 7.6, 40°C, and pH stability within 6.0 – 8.0. GHTHase has higher affinity for GSH (K m = 14.3 mM) and cysteine (K m = 15.1 mM) as hydrogen donor for Hcy2 reduction, other than CDNB for glutathione S-transferase. The variant catalytic response to standard glutathione S-transferase substrates, esteem the unique catalytic properties of GHTHase. The enzyme was significantly inhibited by iodoacetate, hydroxylamine, and propargylglycine, revealing their sulfur active site dependence. Thus, a new isoform of glutathione S-transferase, GHTHase, with unique potency to reduce Hcy2 to soluble Hcy using GSH as hydrogen donor, was discovered. The specificity of GHTHase to oxidize toxic insoluble Hcy2 (cardiovascular disorder risk factor) can be a novel route to attack cardiovascular diseases.
Keywords: Aspergillus flavipes ; glutathione-homocystine transhydrogenase; activity assay; nutritional optimization; biochemical properties

The relationship between the contents of heavy metals and principal groups of biologically active substances in plant raw material was traced using Polygonum aviculare L. and Plantago major L. collected in ecologically different regions of Voronezh Oblast as examples. Close negative correlations were found between flavonoids of P. aviculare and copper, cadmium, and zinc and between water-soluble polysaccharides from P. major leaves and chromium, nickel, and arsenic. The results were relevant to research on plant pharmacognosy and physiology.
Keywords: Polygonum aviculare L; Plantago major L; pollutant accumulation; medicinal plant raw materials

Chemical Composition of the CO2-Extract of Acorus Calamus Obtained Under Subcritical Conditions by G. S. Ibadullaeva; G. M. Pichkhadze; G. O. Ustenova; R. Dil’barkhanov; S. A. Tikhonova; V. A. Grud’ko; N. Yu. Bevz; Yu. V. Yudina (388-392).
The obtained subcritical CO2 -extract of Acorus calamus was enriched with terpene hydrocarbons and oxygen- containing compounds (carotinoids, sterols, tocopherols, fatty acids) according to GC-MS investigations, which detected about 40 chemical compounds. Camphor, camphene, and β-pinene, which account for the anti-inflammatory effect of the plant extracts, had the greatest percentage contents.
Keywords: Acorus calamus ; CO2 -extract; subcritical conditions; gas chromatography; GC-MS; terpenes

Quality Assessment of Excipients at the Drug Registration Stage by M. M. Mironova; E. L. Kovaleva (393-397).
Amendments to Federal Law No. 61-FZ “On Circulation of Medicines” of April 12, 2010, come into force on January 1, 2016, and extend the requirements for information submitted by applicants in drug registration dossiers. The introduction of the new requirements necessitates the preparation of guidance materials concerning various sections of the registration dossier, including those for drug excipients. Regulations of the EU, USA, Japan, and Russia and the database of the Scientific Center for Expert Evaluation of Drugs were compared in order to justify the adopted approach to excipient quality assessment. In this article, current requirements for quality assessment of excipients at the drug registration stage in Russia and abroad were discussed.
Keywords: excipients; registration dossier; drugs

Development of a Reference Standard for the Determination of Human Immunoglobulin Anticomplementary Activity by M. A. Krivykh; O. G. Kornilova; N. D. Bunyatyan; É. Yu. Kudasheva; O. B. Runova; V. I. Malkova; O. B. Ustinnikova (398-400).
Results of studies devoted to determination of the anticomplementary activity of human immunoglobulin preparations in various formulations were presented. The optimal conditions for developing a positive control, i.e., a reference standard of human immunoglobulin that can be used for determining the anticomplementary activity, were defined. The first domestic reference sample of human immunoglobulin was developed. This standard is intended to be used for quality assessment of human immunoglobulin preparations for intravenous administration in terms of an anticomplementary activity parameter. Use of the proposed reference standard of human immunoglobulin for determination of anticomplementary activity will improve the evaluation accuracy of commercial human immunoglobulin preparations for intravenous administration.
Keywords: anticomplementary activity; reference standard; human immunoglobulin; standardization

The acute toxicity and pharmacological activity of a new dental gel containing Eucalyptus extract and Inonotus obliquus tincture were studied. The experiments revealed wound-healing and microbial activity of the gel with low toxicity upon enteral administration. Thus, the new preparation can be recommended for further in-depth studies with potential application for treating inflammatory diseases of the oral cavity.
Keywords: eucalyptus extract; Inonotus obliquus tincture; dental gel; acute toxicity

Microbial Biotransformation of Dexamethasone by Bacillus Subtilis (ATCC 6051) by Irfan Pervaiz; Saeed Ahmad; Muhammad Fahad Mukhtar; Adeel Arshad; Muhammad Imran; Wajahat Mahmood (405-408).
This article reports microbial biotransformation of dexamethasone, a synthetic glucocorticoid, by Bacillus subtilis. This bacterium can be used as a microbial metabolic model to investigate the metabolism of other synthetic glucocorticoids as it mimics mammalian metabolism to a certain extent. Incubation of dexamethasone with B. subtilis for 7 days yielded three compounds identified as 6-hydroxydexamethasone, 17-oxodexamethasone, and 6-hydroxy-17-oxodexamethasone. Structure elucidation of these compounds was done using 1H-NMR and 13C-NMR spectroscopy techniques.
Keywords: biotransformation; dexamethasone; Bacillus subtilis ; fungi

Influence of Various Factors on the Optical Absorption Coefficient of Aqueous Solutions of N-Vinylpyrrolidone and 2-Methyl-5-Vinylpyridine Copolymers by S. A. Kedik; A. A. Vagina; A. V. Panov; E. S. Zhavoronok; E. V. Vorfolomeeva; V. V. Suslov (409-412).
Aqueous solutions of three samples of N-vinylpyrrolidone and 2-methyl-5-vinylpyridine copolymers with different ratios of monomer units were studied by spectrophotometry. Concentration dependences of the solution optical density at 269 nm were obtained. Specific absorption coefficients of these solutions were calculated. Regions of pH and temperature with the most consistent determinations were found. The results could provide a basis for developing a quantitative determination method for N-vinylpyrrolidone and 2-methyl-5-vinylpyridine copolymers in aqueous solutions.
Keywords: N-vinylpyrrolidone and 2-methyl-5-vinylpyridine copolymers; specific optical absorption coefficient; phase separation; solution pH effect

Effect of Water Isotopic Composition on Galactose Mutarotation Kinetics by O. Yu. Zrelov; A. V. Syroeshkin; E. V. Uspenskaya; O. V. Titorovich; T. V. Pleteneva (413-416).
A number of new glycoprotein-based and chiral drugs possessing complex carbohydrate structures have been developed as a result of advances in organic synthesis. Specific features of glycosylation related to carbohydrate tautomerism can play an important role in determining the mechanism of action, pharmacokinetics, pharmacodynamics, stability, and immunogenicity of these drugs. Active discussion in the literature concerning the need for separating the active tautomer and its inert or even toxic optical counterpart stimulates the search for new quality control methods in the production of optically active drugs. Herein, we present results of an investigation of the kinetics of D- and L-galactose mutarotation in aqueous solutions with variable mole fractions of a heavy hydrogen isotope (D/H ratio).
Keywords: galactose mutarotation kinetics; optical activity; giant heterogeneous water clusters; kinetic isotope effect

Investigation of Tetramezine Binding to Plasma Proteins in Healthy Donors by L. I. Belyak; A. S. Berlyand; A. A. Prokopov (417-418).
It was established that about 30% of the administered dose of tetramezine was bound to plasma proteins in healthy donors. This should not significantly influence the strength of its pharmacological action in the absence of binding to blood cellular components.
Keywords: tetramezine; binding; proteins

Lovastatin, a fungal secondary metabolite, competitively inhibits 3-hydroxy-3-methylglutaryl coenzyme-A (HMG-CoA) reductase, which catalyzes the rate limiting step in the biosynthesis of cholesterol. Preparative thin-layer chromatography (TLC) followed by RP-HPLC was used for determination of lovastatin in the fermentation broth of Aspergillus terreus PM03. The TLC separated bands were cut, recovered, and analyzed by HPLC. The proposed HPLC method used a mobile phase comprising 1 : 1 mixture of acetonitrile and deionized water at a flow rate of 2 mL/min and spectrophotometric detection at a wavelength of 238 nm. The chromatograph revealed a single, sharp and symmetric peak at a retention time of 6.8 min that corresponded to an open β-hydroxy acid form and was comparable to the peak of standard β-hydroxy acid form of lovastatin with respect to both retention time and optical absorption at 238 nm. The data of UV–VIS and FTIR spectroscopy confirmed the presence of lovastatin in the purified extract. The structure of the obtained product was also confirmed by LC-MS and NMR analyses.
Keywords: lovastatin; Aspergillus terreus ; TLC; HPLC; FTIR