Chrysin and its derivatives in plants of the genusScutellaria

Summary 1. A glycoside (II) identified by chrysin 7--glucopyranosiduronic acid has been isolated from the epigeal part ofScutellaria scordiifolia in a yield of 2.0–2.2%.2. A glycoside (IV), characterized as 2-methoxychrysin 7--D-glucopyranosiduronic acid has been isolated from the roots ofS. granulosa.3. This is the first time that chrysin and 2-methoxychrysin and their 7-glucuronides have been isolated from theScutellaria species mentioned.Khar'kov Scientific-Research Institute of Pharmaceutical Chemistry. Ukrainian Zonal Research Station for Medicinal Plants, Poltava. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 730–735, November–December, 1976.     

Sinapoyl ester of glucoerysimoside inErysimum marschallianum

Summary A new cardenolide glycoside — sinapoylglucoerysimoside — having the structure of strophanthidin 3-0-[0-sinapoyl--D-glucopyranosyl-(14) 0--digitoxopyranoside — has been found in the seeds ofErysimum marshallianum.Kiev Institute for the Further Training of Doctors. Translated from Khimiya Prirodnykh Soedinenii No. 5, pp. 603–606, September–October, 1975.     

A new steroid saponin from the leaves ofYucca aloifolia

A new steroid saponin has been isolated from the air-dry leaves ofYucca aloifolia L., and it has been shown to be (25R)-5-spirostan-3-ol O-D-glucopyranosyl-(1 2)-D-galactopyranoside. The substance melts at 302–303°C []D²⁰ –27.2, (c 1.0; CHCl₃).I. G. Kutateladze Institute of Pharmacochemistry, Academy of Sciences of the Georgian SSR, Tbilisi. Translated from Khimiya Prirodnikh Soedinenii, No. 6, pp. 744–747, November–December, 1984.     

Triterpene glycosides ofSilphium perfoliatum. III. Structure of silphioside E

A new triterpene glycoside — silphioside E — has been isolated from the epigeal part ofSilphium perfoliatum L. and its structure has been established on the basis of chemical transformations and spectral characteristics as oleanolic acid 28-0--D-glycopyranoside 3-0-[0--D-glycopyranosyl-(1 2)--D-glucopyranoside].Pyatigorsk Pharmaceutical Institute. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnikh Soedinenii, No. 6, pp. 750–753, November–December, 1984.     

A chemical study of plants of the Mongolian flora lariside — A new scopoletin glycoside fromSalsola laricifolia

A new coumarin glycoside lariside — C₂₁H₂₆O₁₃, mp 155–156°C (from methanol) — has been isolated from the epigeal part ofSalsola laricifolia Turcz. et Litw. On the basis of acid hydrolysis and spectral characteristics the structure of lariside has been established as 7-[O--D-apiofuranosyl-(1 2)--D-glucopyranosyloxy]-6-methoxy-2H-1-benzopyran-2-one.Institute of Chemistry, Academy of Sciences of the Mongolian Peoples' Republic, Ultan-Bator. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 288–291, May–June, 1986.     

Phytoecdysones ofRhaponticum integrifolium II. Integristerone A

Summary A new phytoecdysone — integristerone A — has been isolated from the flower heads ofRhaponticum integrifolium. It has been shown that it is 1,2,3,14,20R,22R,25-heptahydroxy-5-cholest-7-en-6-one.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 813–819, November–December, 1977.     

The study of the structure of solutions of the H-complexes of diesters of tetracarboxylic acids with diammes by the light scattering method

The process of structurization in solutions of H-complexes of dimethyl 3,3,4,4 -benzophenonetetracarboxylate with 4,4 -diaminodiphenylmethane has been investigated in 90 % aqueous methanol in the concentration range 6 to 0.2 g L^–1. Structural instability of the solutions has been found in the concentration range from 1.2 to 2 g L^–1. The addition of an ionogenic substance stabilizes the solution and results in monotonic changes in the structural parameters as solution is diluted. A tendency toward variation of the extemum in the mean correlation radius of the polarizability fluctuation has been found in the concentration range 0.6-–1 g L^–1, which had been observed previously for polymer systems.For Part 1, see Ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1219–1221, July, 1994.     

Extraction and spectrophotometric determination of titanium(IV) withN 1-hydroxy-N 1,N 2-diphenylbenzamidine and thiocyanate

A precise, reliable, sensitive, and selective method for the determination of titanium(IV) is described. Titanium(IV) reacts withN ¹-hydroxy-N ¹,N ²-diphenylbenzamidine (HDPBA) and thiocyanate to form an orange-coloured mixed-ligand complex of stoichiometry 112 (Ti SCN^– HDPBA). The complex is quantitatively extractable into toluene from 0.05–0.15M hydrochloric acid. The spectrum of the complex exhibits an absorption maximum at 400 nm with a molar absorptivity of 20000M ^–1 cm^–1 and the coloured system obeys Beer's law in the concentration range 0.20–3.0 gml^–1 titanium. The effects of foreign ions and of various experimental parameters have been studied to establish the optimum conditions for the extraction and determination of titanium. The precision of the method has been evaluated and the relative standard deviation has been found to be 0.53%. The method has been successfully applied to the determination of titanium in synthetic matrices corresponding to titanium-containing ores, minerals, and alloys.     

Nucleation of the β-modification of isotactic polypropylene

The effects of the organic pigments C.I.P. RED 177 and C.I.P. Yellow 83 as nucleating agents on the crystallization of polypropylene were studied by DSC. The anthraquinone pigment exerted a significant effect, resulting in structural modifications with lower melting point, and particularly the -modification. The DSC curves exhibit four transition regions, with the following temperature intervals: I. 415–417 K, II. 423–425 K, III. 430–432 K and IV. 438–439 K. For evaluation of the -nucleation effect of pigments, the ratio (H ₁+H ₂)/(H ₃+H ₄) was suggested.     

Triterpene glycosides ofAstragalus and their genins. XVIII. 3-Dehydrocycloasgenin C fromAstragalus taschkendicus

A new genin — 3-dehydrocycloasgenin C — has been isolated from the roots of the plantAstragalus taschkendicus Bge. (Leguminosae) and its structure has been established on the basis of chemical transformations and spectral characteristics as 6,16,24, 25-tetrahydroxy-24R-cycloartan-3-one.Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 218–223, March–April, 1985.     

Sesquiterpene lactones ofPyrethrum pyrethroides. II. Pyrethroidin

A new sesquiterpene lactone, pyrethroidin, and a known one — 8-deoxycumambrin B — have been isolated from the epigeal part of the plantPyrethrum pyrethroides. The structure of 4,10-dihydroxy-1,5,7(H),6(H)-guaia-2,11(13)-dien-6,12-olide has been suggested for pyrethroidin.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 199–201, March–April, 1985.     

Development and Validation of an HPTLC–Densitometric Method for Determination of ACE Inhibitors

A high-performance thin layer chromatographic method coupled with densitometric analysis has been developed for measurement of benazepril and cilazapril, both pure and in their commercial dosage forms. The active substances were extracted from tablets with methanol (mean recovery 102%) and chromatographed on silica gel 60 F₂₅₄ HPTLC plates in horizontal chambers with ethyl acetate–acetone–acetic acid–water, 8:2:0.5:0.5 (v/v), as mobile phase. Chromatographic separation of these ACE inhibitors was followed by UV densitometric quantitation at 215 nm. Calibration plots were constructed in the range 0.4 to 2.0 g L^–1 for benazepril (2.0–10.0 g spot^–1) and from 0.5 to 1.5 g L^–1 for cilazapril (4.0–12.0 g spot^–1) with good correlation coefficients (r 0.990). The method was used to determine benazepril and cilazapril in pharmaceutical preparations with satisfactory precision (1.4% < RSD < 5.6%) and accuracy (1.7 < RE < 5.1).     

Synthesis of racemic 10-methyltridecan-2-one, the sex pheromone ofDiabrotica undecimpunctata

A new synthesis of racemic 10-methyltridecan-2-one, the sex pheromone ofDiabrotica undecimpunctata Howardi has been effected.InterBAV Scientific Production Company RM, Kishinev. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 558–560, July–August, 1994.     

Triterpene glycosides ofAstragalus and their genins. VIII. Askendoside C fromAstragalus taschkendicus

A new glycoside of the cycloartane series — askendoside C — has been isolated from the roots of the plantAstragalus taschkendicus Bge., and its structure has been established on the basis of chemical transformations and spectral characteristics as 24R-cycloartane-3,6,16,24,25-pentaol 3-[0--L-arabinopyranosyl-(12)--D-xylopyranoside].Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 173–180, March–April, 1983.     

Catechins and proanthocyanidins ofAlhagi sparsifolia. I

Ten individual compounds have been isolated from the epigeal part ofAlhagi sparsifolia Shap. in various stages of vegetative growth. Their structures have been established by a study of PMR spectra, physicochemical properties, and the products of chemical transformations: (–)-epicatechin, (–)-epigallocatechin, (–)-epigallocatechin gallate, (+)-catechin, (+)-gallocatechin, proanthocyanidin B-2, (–)-epigallocatechin-(4–8)-(–)-epicatechin, epigallocatechin gallate-(4–8)-(–)-epicatechin, proanthocyanidin B-1, and (–)-epicatechin-(4–8)-gallocatechin.The materials of this paper were presented at the Second International Symposium on the Chemistry of Natural Compounds (SCNC, Eskiehir, Turkey, October 22–24, 1996).Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 232–237, March–April, 1997.     

Mechanism of the oxidation of L-ascorbic acid by the bis(pyridine-2,6-dicarboxylate)cobaltate(III) ion in aqueous solution

A detailed investigation of the oxidation of L-ascorbic acid (H₂A) by the title complex has been carried out using conventional spectrophotometry at 510 nm, over the ranges: 0.010 [ascorbate] _T 0.045 mol dm^–3, 3.62 pH 5.34, and 12.0 30.0 °C, 0.50 I 1.00 mol dm^–3, and at ionic strength 0.60 mol dm^–3 (NaClO₄). The main reaction products are the bis(pyridine-2,6-dicarboxylate)cobaltate(II) ion and l-dehydroascorbic acid. The reaction rate is dependent on pH and the total ascorbate concentration in a complex manner, i.e., k _obs = (k ₁ K ₁)[ascorbate] _T /(K ₁ + [H⁺]). The second order rate constant, k ₁ [rate constant for the reaction of the cobalt(III) complex and HA^–] at 25.0 °C is 2.31 ± 0.13 mol^–1 dm³ s^–1. H = 30 ± 4 kJ mol^–1 and S = –138 ± 13 J mol^–1 K^–1. K ₁, the dissociation constant for H₂A, was determined as 1.58 × 10^–4 mol dm^–3 at an ionic strength of 0.60 mol dm^–3, while the self exchange rate constant, k ₁₁ for the title complex, was determined as 1.28 × 10^–5 dm³ mol^–1 s^–1. An outer-sphere electron transfer mechanism has been proposed.     

Aquation of α-cis-chloroaquoethylenediamine-N,N'-diacetatocobalt(III) in aqueous and in mixed solvents: A mechanistic study

Summary The displacement of chloride ligands from -cis-chloro-aquoethylenediamine-N,N-diacetatocobalt(III) in nonacidic aqueous solutions was followed conductimetrically at 30–45° and the products of aquation were characterised by conductance, spectral and ion-exchange techniques. The rate constants for aquation in aqueous media and in 1 : 4 v : v mixed solvents at 25° are: 4.0 × 10^–5 s^–1 in H₂O, 2.71 × 10^–5 s^–1 in MeOH : H₂O, 2.74 × 10^–5 s^–1 in EtOH: H₂,O and 2.58 × 10^–5 s^–1 n in Me₂CO : H₂O. The corresponding H&#x002A; and S&#x002A; values have also been evaluated. Solvent polarity has a marked influence on the rate of chloride ion release. The aquation rate constants and the activation parameters have been correlated with solvent parameters,e.g. D, Y-values, Dimroth's E_T and Kosower's Z-values and, based on these correlations, a dissociative interchange (I_d) mechanism is proposed rather than dissociative as observed for some other cobalt(III) complexes.Senior author.     

Determination of methylviologen (Paraquat) by differential pulse polarography

Summary Determination of Methylviologen (Paraquat) by Differential Pulse Polarography The second reduction wave of methylviologen (Paraquat) has been studied at pH 2 by different polarographic techniques. The limiting current is diffusion-controlled. Evidence for dimerization of the radical formed in the first reduction step has been obtained. The n values for the reduction process have been calculated at concentration levels where the dimer and the monomer predominate. Paraquat can be determined by differential pulse polarography in the 6.0×10^–5–4.0×10^–7 M concentration range, the limit of determination being 1.7×10^–7 M. The method has been applied to paraquat determination in commercial herbicides.     

Extraction-spectrophotometric determination of iron with 2-(2′-benzothiazolylazo)-4,6-dimethylphenol

An extraction-spectrophotometric method for the determination of trace amounts of iron based on its extraction into chloroform with 2-(2-benzothiazolylazo)-4,6-dimethylphenol (BTADMP) from a pH 6.5 medium has been developed. The extracted 12 FeBTADMP complex species allow the determination of 4–30gmg of iron (=3.92×10⁴1·mol^–1·cm^–1 at 790 nm). The method is highly selective and has been applied to the determination of iron in polymineral-polyvitamin pharmaceutical products.