13C NMR spectra of the aminoglycoside antibiotic neomycin B,monomycin A,and kanamycin A. Complete assignment of the signals

On the basis of the results of a study of the dependence of the chemical shifts of the signals in the¹³C NMR spectra of neomycin B, monomycin A, and kanamycin A, over a wide pH range (from 1.0 to 10.0) a complete assignment of the spectra signals of these antibiotics has been made. Optimum pH values of solutions are proposed for which the more complete resolution of the resonance signals in the spectra of neomycin B, monomycin A, and kanamycin A is observed. All-Union Scientific-Research Institute of Antibiotics, Moscow. I. M. Sechenov 1st Moscow Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 686–695, September–October, 1980.     

Structure of the alkaloids of Aerva lanata

By the NOE method using¹³C NMR and UV spectra we have confirmed the structures of four new alkaloids isolated previously: 10-hydroxycanthin-6-one (ervine), 10-methoxycanthine-6-one (methylervine), 10-β-D-glucopyranosyloxycanthin-6-one (ervoside), and 6-methoxy-β-carbolin-l-ylpropionic acid (ervolanine). All-Union Scientific-Research Institute of Drugs Scientific-Production Association, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 821–824, November–December, 1991.     

Synthesis of an analogue of the phospholipid platelet activation factor from a natural ethanolamine plasmalogen

The synthesis has been performed of an analogue of the phospholipid platelet activation factor — 1-0-(alk-1′-enyl)-2-acetyl-sn-glycero-3-phospho-N-(N′-acetylglycylethanolamine). In concentrations of 10⁻⁷-10⁻⁶ M, the analogues so obtained inhibited the aggregation of human platelets stimulated by the phospholipid activation factor. Scientific-Research Institute of Biomedical Technology, USSR Ministry of Health, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 325–330, May–June, 1990.     

Structure and stereochemistry of galbanic acid

On the basis of the¹H NMR spectrum at 300 MHz and the results of chemical degradation, the structure of 7-[6-(β-carboxyethyl)-5-isopropylidene-1,2-dimethylcyclo-hexylmethoxy]coumarin has been proposed for galbanic acid. V. L. Komarov Institute of Botany, Academy of Sciences of the Azerbaidzhan SSR, Baku. All-Union Scientific-Research Institute of Medicinal Plants, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 620–623, September–October, 1980.     

Secondary-ion mass spectra of pennogenin glycosides

LSIMS mass spectra of pennogenin glycosides have been studied; the most characteristic ions are (M+H−H₂O)⁺ (with glycerol as the liquid matrix) and (M+Na)⁺ (with glycerol +NaCl as matrix). In both cases the peaks of ions formed as the result of the successive elimination of the carbohydrate units, the breakdown of the bonds of the terminal pyranoses, the cleavage of the bonds of the rings D and E, and the peaks of the ions Agl⁺ and (Agl−H₂O)⁺ were observed. Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. All-Union Scientific-Research Institute for Agricultural Biotechnology, All-Union Academy of Agricultural Sciences, Moscow. Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 523–525, July–August, 1991.     

Some properties of glycyrrhizic acid

The chemical and spectral properties of crystalline specimens of glycyrrhizic acid and its monoammonium salt have been studied. On the basis of¹H and¹³C NMR results, diagnostic parameters of the 18β/18α-epimers have been revealed, and features of the structure of the carbohydrate moiety of these compounds are discussed. All-Russian Scientific Research Institute of Medicinal and Aromatic Plants, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 772–780, November–December, 1994.     

Chlorination of lignin at low temperatures

A high reactivity of the olefinic double bonds of the lignin (Lg) macromolecule in the reaction with molecular chlorine has been found which has permitted the chlorination of Lg to be carried out under cryogenic conditions at 150–250 K. The process takes place by a radical-chain mechanism with a length of the kinetic chain of approximately 1000 units. The bulk of the chlorine is consumed in the olefinic chains of the Lg. Other reaction products besides chlorolignin are hydrogen chloride and phenoxyl radicals, which have singlet ESR spectrum (ΔH=1.0−1.2 mT) and are retained in the chlorinated samples of Lg to ∼250 K. Institute of Chemical Physics, Academy of Sciences of the USSR, Chernogolovka, Moscow Province. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 671–676, September–October, 1990.     

X-ray and quantum chemical study of the electronic structure of glycine and its metal complexes

OK_α spectra of glycine and some transition metal complexes with glycine ligands were obtained. The electronic structure of the glycine zwitterion is calculated by a quantum chemical method, and a theoretical X-ray spectrum of the glycine molecule is constructed. The nature of the metal-ligand bond in the compounds is discussed on the basis of experimental spectra and theoretical calculations. Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Moscow State Academy of Light Industry, Novosibirsk Branch. Moscow State Academy of Light Industry. Novosibirsk State University. Translated fromZhurnal Strukturnoi Khimii, Vol. 34, No. 4, pp. 112–116, July–August, 1994. Translated by L. Smolina     

Structure of a new phenol aldehyde from the leaves of Eucalyptus viminalis

A new terpenoid phenol aldehyde has been isolated from an alcoholic extract of the leaves of the ribbon eucalyptus by column chromatography on silica gel, and on the basis of the results of¹H and¹³C NMR spectroscopy and mass spectrometry the structure of 4-[1-(3,5-diformyl-2,4,6-trihydroxyphenyl)-3-methylbutyl]-ledol is proposed for it. The relative configurations of the substituents in the terpenoid moiety of the molecule have been determined. All-Union Scientific-Research Institute of Medicinal Plants and Production Association, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 789–795, November–December, 1991.     

Liquid chromatography on an amide stationary phase with post-column derivatization and fluorimetric detection for the determination of streptomycin and dihydrostreptomycin in foods

The separation of streptomycin and its derivative dihydrostreptomycin using ion-pair liquid chromatography is proposed. The method is based on the use of a new stationary phase based on a ligand with amide groups and the endcapping of trimethylsilyl which avoids the appearance of tailed peaks. The isocratic mobile phase consisted of a 6:94 (v/v) acetonitrile/10 mM pentanesulfonic acid (pH 3.3) mixture at a flow-rate of 1 mL min⁻¹ and fluorescence detection involved a post-column derivatization reaction using β-naphthoquinone-4-sulfonate. Linearity, precision, recovery and sensitivity were satisfactory. The procedure was applied to the analysis of the aminoglycoside antibiotics in different types of foods, as honey, milk, egg and liver. Extraction was carried out by acidic hydrolysis to release protein-bound antibiotics. Detection limits in the food samples are 7.5 and 15 μg kg⁻¹ for streptomycin and dihydrostreptomycin, respectively.     

An investigation of the component composition of the essential oil of Monarda fistulosa

The composition of the essential oil of wild bergamot bee balm introduced into the Krasnodarsk Krai has been analyzed by chromatomass spectrometry. The essential oil contains 34 components of which the main ones are α-pinene (3.5%), β-pinene (2.9%), α-terpinene (1.7%), p-cymene (32.5), an aliphatic aldehyde (6.3%), sabinene hydrate (1.9%), β-caryophyllene (1.1%), the methyl ether of carvacrol (5.5%), citronellyl acetate (1.6%), thymol (12.6%), and carvacrol (24.0%). The compounds were identified on the basis of their mass-spectrometric characteristics and arithmetical retention indices. A. N. Severtsov Institute of Animal Evolutionary Morphology and Ecology, Academy of Sciences of the USSR, Moscow. All-Union Scientific-Research Institute of Drugs, Moscow. Translated from Khimiya Prirodnykh Soedinenii, Vol. 5, pp. 646–649, September–October, 1989.     

Synthesis,structure, and action of some gossypol derivatives on the peroxidation of the lipids of biosubstrates

The synthesis has been effected of new gossypol derivatives using piperidino-and morpholinoethylamines. According to their PMR spectra, these substances exist in the keto-amine form. Their action on the peroxidation of lipids (POL) of various biosubstrates has been studied. Gossypol bis(piperinoethylimine) and bis(morpholinoethylimine) in concentrations of 1·10⁻⁷–5·10⁻⁶ mM exert a pronounced antioxidant action on human blood serum and rat brain synaptosomes. In the same concentrations, these substances suppressed the POL in enzymatic and nonenzymatic systems of the oxidation of rat liver microsomes. A. S. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Institute of Hematology and Blood Transfusion, Ministry of Health of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 707–712, September–October, 1989.     

Molecular and crystal structure of the germacranolides salonitenolide and hanphyllin

A sesquiterpene lactone of the germacrane type, salonitenolide, has been isolated for the first time from the epigeal part ofCentaurea pseudomaculosa Dobrocz (spotted centaurea) and has been identified. The structures of the germacranolides and hanphyllin have been determined by the method of x-ray structural analysis: salonitenolide is 8-hydroxy-6β,8β(H)7α(H)-germacra-1(10),4,11(13)-trien-6,12-olide and hanphyllin is 3-hydroxy-3α,7α(H),6β(H)-germacra-1(10),4,11(13)-trien-6,12-olide. It has been established that the ten-membered rings of salonitenolide and hanphyllin are of the chair-chair type,₁D¹⁴,¹⁵D₅. On the basis of the results of CD spectroscopy, the chiral centers in the hanphyllin molecule have been assigned the 3S, 6R, and 7S configurations. Institute of Organic Synthesis and Coal Chemistry, Kazakh SSR Academy of Sciences, Karaganda. A. N. Nesmeyanov Institute of Heteroorganic Compounds, USSR Academy of Sciences, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 781–785, November–December, 1989.     

Transannular cyclization of the E,E-germacradienolide hanphyllin

The results are reported of the interaction of the trans,trans-germacradienolide hanphyllin with m-chloroperbenzoic acid and with 50% sulfuric acid. This leads to a cyclization reaction with the formation of eudesmanolides: 1β-hydroxy-3-oxo-1,4,5,7α(H),6β(H)-eudesm-11(13)-en-6,12-olide, ridentin B, and 3β-hydroxy-5,7α(H),6β(H)-eudesma-4(15),11(13)-dien-6,12-olide; and also products of the opening of the lactone ring as a consequence of transesterification. The structures of the compounds obtained are discussed on the basis of spectral results (IR, PMR, and mass spectra) and of x-ray structural analysis. Institute of Organic Synthesis and Coal Chemistry, Kazakhstan Academy of Sciences, Karaganda. A. N. Nesmeyanov Institute of Organometallic Compounds, Russian Academy of Sciences, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 508–517, September–October, 1992.     

Preconcentration of the lipid-lowering drug lovastatin at a hanging mercury drop electrode surface

Adsorption and reduction of lovastatin were investigated by cyclic and square-wave voltammetry on a hanging mercury drop electrode in aqueous solutions over a wide pH range (4–9). The electroreduction of lovastatin proceeds via a surface EC mechanism in the whole pH range investigated. Using adsorptive stripping voltammetry, the drug yielded a well-defined voltammetric response in Britton-Robinson buffer, pH 6 at −1.49 V which can be used to determine trace amount of lovastatin. The linear concentration range of application was 1.0 × 10⁻⁸–1.0 × 10⁻⁷ M by using an accumulation potential of −0.5 V and a 90 s pre-concentration time. The method has been successfully applied for the determination of lovastatin in a spiked human serum sample.     

Secondary metabolites of Ulocladium chartarum. Ulocladols A and B — New phytotoxins of terpenoid nature

Ulocladols A and B — new exometabolites having a mixed sesquiterpenoid-polyketide nature that are structurally close to the host-specific toxins ofAlternaria citri — have been isolated from the deuteromyceteUlocladium chartarum. Both substances inhibit the growth of cotton seeds. All-Union Scientific Research Institute of Phytopathology, Moscow Province, Golitsyno. M. V. Lomonosov Moscow State University. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 642–648, September–October, 1991.     

Branched polycyclic tetrazole systems. 1. Synthesis and structure of 2-(5-tetrazolyl)ethyl derivatives of some CH-, OH-, and NH-acids

The cycloaddition of dimethylammonium azide to the nitrile groups of 2-cyanoethyl derivatives of CH-, OH-, and NH-acids leads to open-chain branched structures containing terminal NH-tetrazolyl groups. An x-ray diffraction structural analysis of tris[2-(5-tetrazolyl)ethyl]nitromethane revealed steric access of the equivalent NH-tetrazolyl rings of the branched system. In going from the branched nitrile substrates to the corresponding tetrazoles, the PMR spectra show a breakdown in the resolution of the multiplet components, which had not been observed previously for monocyclic 5-substituted tetrazoles. A dependence was found for the¹³C NMR chemical shifts on the pK_a values, reflecting the NH-acidity of the branched polycyclic tetrazoles in water. Dedicated to the memory of I. N. Goncharova. St. Petersburg State Technological Institute, 198013 St. Petersburg. V. A. éngel'gart Institute of Molecular Biology, Russian Academy of Sciences, 117984 Moscow. L. Ya. Karpov Physics and Chemistry Research Institute, 103062 Moscow. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1494–1501, November, 1997.     

Lignans of the bark of Syringa volgaris

Two lignans have been isolated from the bark ofSyringa vulgaris and identified: (+)-lariciresinol 4-β-D-glucopyranoside (I) and -olivil 4-β-D-glucopyranoside (II). This is the first time that glycoside (9) has been described. All-Union Scientific-Research Institute of Medicinal Plants Scientific-Production Association, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 768–771, November–December, 1991.     

Sum frequency generation spectroscopic study of the condensation effect of cholesterol on a lipid monolayer

Sum frequency generation (SFG) spectra and surface pressure–molecular area (π–A) isotherms have been obtained for mixed cholesterol–DPPC monolayers with cholesterol mole fractions, x(chol.), from 0 to 1.0, at the air–water interface, under same conditions, at 22 °C. Analysis of the spectra indicated that incorporation of cholesterol into the monolayers at 3 mN m⁻¹ greatly increases the conformational and orientational order of the alkyl chains of DPPC, maximizing these properties at x(chol.)=0.4. Analysis also indicated that order in the mixed monolayers at 15 and 35 mN m⁻¹ is not affected by incorporation of cholesterol. The π–A isotherms measured at 3 mN m⁻¹ for the mixed monolayer with x(chol.)=0.4 have the largest negative deviation of the molecular area relative to those of ideal mixtures (the so-called “condensation effect” of cholesterol), indicating the most thermodynamically stable state. Comparison of results from SFG spectra and π–A isotherms explicitly proved that the condensation effect can be interpreted in terms of conformational and orientational ordering of the alkyl chains of DPPC.     

Molecular and crystal structure of the germacranolide argolide from Artemisia glabella

The new germacranolide argolide has been isolated from the epigeal part ofArtemisia glabella, and its structure has been shown by its conversion into oxopelenolide B. From the results of an x-ray investigation it is suggested that argolide has the spatial structure of 3-oxo-4α,7α,6β(H)-germacra-1(10),11(13)-dien-6,12-olide. Institute of Organic Synthesis and Coal Chemistry, Kazakh Academy of Sciences, Karaganda. A. N. Nesmeyanov Institute of Organometallic Chemistry, Russian Academy of Sciences, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 653–657, September–October, 1991.