Co-hydrolysis products of tetraethoxysilane and methyltriethoxysilane in the presence of tetramethylammonium ions: Part 2 [1]

²⁹Si NMR peaks due to species with the double four-membered ring siloxane backbone composed of both Si(O^–)_4/2 and CH₃Si(O^–)_3/2 units, (CH₃) _n Si₈O _{20 – n} ^{/(8 – n) –} (n=1–3), formed by co-hydrolysis of tetraethoxysilane and methyltriethoxysilane in the presence of tetramethylammonium ions in methanol have been assigned. It has been found that ²⁹Si NMR peaks due to Si(OSi)₃(O^–) units shift to lower frequencies by replacement of the adjacent Si(O^–)_4/2 units by CH₃Si(O^–)_3/2 units, in other words, with increasing m value in Si[OSi(O^–)₃]_{3 – m} [OSi(CH₃) (O^–)₂] _m (O^–) (m=0–2). Peaks from CH₃ Si(OSi)₃ units in the species have also appeared as separated due to the kind of neighbor structural units. On the basis of the assignments, positions of CH₃Si(O^–)_3/2 units in the cubic octameric siloxane framework of (CH₃) _n Si₈O _{20 – n} ^{/(8 – n) –} (n=2, 3), for both of which three isomers are present, have been estimated.     

Oxygenated acids of the reserve lipids of Rumex paulsenianus

The composition of the fatty mono- and dihydroxy acids of the fruit ofRumex paulsenianus Rech. fil. (familyPolygonaceae) has been determined by a combination of IRS, UVS, GLC, and mass-spectrometric methods. (22) Monohydroxy acids of the C₁₄–C₂₀ series, including isomers and isologues, and four dihydroxy acids from C₁₈ to C₂₀, including a new isomeric 9-OH-10, 12–17:2 acid have been detected.Institute of the Chemistry of Plant Substances, Uzbek Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 762–765, November–December, 1991.     

Alkaloids ofAndrachne rotundifolia

Summary 1. The content of total alkaloids in the hypogeal parts ofAndrachne rotundifolia C. A. Mey. (family Euphorbicease) is 0.2–0.3% and in the epigeal parts 0.06–0.08%.The total alkaloids in both the hypogeal and the epigeal parts ofAndrachne rotundifolia consist of five or six non-phenolic bases.2. Three individual substances have been isolated: andrachnine C₁₁H₁₇NO₂, which is a new alkaloid; base (II), giving a perchlorate with mp 139°–140° C; and base (III) with mp 135°–136° C.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 4, pp. 257–260, 1966     

Chromatopolarographic determination of the alkaloids from the seeds ofHaplophyllum perforatum

Summary 1. The polarographic behavior of haploperine, haplopine, haplophyllidine, and perforine in Britton-Robinson buffer solutions and in (C₂H₅)₄NOH solutions has been studied. Optimum conditions for their quantitative determination in solutions within the range of concentrations from 5×10^–4 to 1×10^–2 M have been found.2. A method for the separate quantitative determination of the alkaloids in the seeds ofH. perforatum has been developed.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 5, pp. 333–337, 1966     

General characteristics of the polysaccharides of brown algae

Summary From an acetonic extract of the roots ofFerula samarcandica Kor. have been isolated farnesiferol A, gummosin, and two new coumarin substances, samarcandin C₂₄H_30–32O₅ and samarcandone C₂₄H_28–30O₅. Samarcandin has been converted into samarcandone and their probable structures-I and II-have been established.Khimiya Prirodnykh Soedinenii, Vol. 4, No. 2, pp. 73–77, 1968     

Coumarins of Fraxinus mandschurica and F. potamophila

Summary The leaves ofFraxinus mandschurica Rupr. and the bark ofF. potamophila Herd. have yielded esculetin, fraxinol, and a new coumarin C₁₀H₈O₅, mp 228–230°C which we have called isofraxetin. On the basis of NMR and UV spectroscopy it has been established that isofraxetin is 5,7-dihydroxy-7-methoxycoumarin.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Institute of Chemistry, Academy of Sciences of the Turkmen SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 493–497, July–August, 1973.     

The structure of gummosin

Summary From the neutral fraction of an acetone extract of the roots of plants of the genusFerula,F. gummosa Boiss.,F. pseudoreoselinum Rgl. et Schmalh. (K-Pol.) andF. Samarkandica Eug. Kor., we have isolated a coumarin gummosin with the composition C₂₄H₃₀O₄, mp 176–177°C, [a]_D –54°C. The structure of gummosin corresponds to formula (III).With respect to structure, gummosin is a spatial isomer of farnesiferol A; it differs from the latter by the fact that the secondary OH group in gummosin is axial.Khimiya Prirodynkh Soedinenii, Vol. 2, No. 6, pp. 383–387, 1966     

Feropodin-a sesquiterpene lactone from the roots ofFerula oopoda

Conclusions From the resin of the roots ofFerula oopoda (Boiss. et Buhse) Boiss. a new sesquiterpene lactone, feropodin, with the composition C₁₅H₂₀O₂, mp 140–141° C, has been isolated. The alternative hypothetical structures I and II have been proposed for feropodin.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 4, pp. 245–247, 1969     

Alkaloids ofNuphar luteum

Summary 1. The dry rhizomes ofNuphar luteum L. have yielded three sulfur-containing alkaloids: two — thiobinupharidine and neothiobinupharidine — were known substances, the third with composition C₃₀H₄₂O₄N₂S being new and having been given the name of nuphleine.2. A possible structure has been proposed for nuphleine.Khimiya Prirodnykh Soedinenii, Vol. 3, No. 2, pp. 178–182, 1967     

The structures of chimganin and chimgin

Summary The roots ofFerula tschimganica Lipsky have yielded two new compounds with the compositions C₁₈H₂₄O₄ (mp 85°C) and C₁₇H₂₂O₃ (mp 155°C), which have been calledchimganin andchimgin. On the basis of their UV, IR, and NMR spectra and the products of alkaline hydrolysis, it has been shown that chimganin is the ester of 4-hydroxy-3-methoxybenzoic acid and chimgin that of 4-hydroxybenzoic acid with (+)-borneol.Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 59–63, January–February, 1972.     

Gibberellins and substances related to them

Summary 1. Column and thin-layer chromatography have been used to analyze the metabolite composition of the culture liquid ofFusarium moniliforme. 2. On fermentation in a medium containing sunflower oil and ammonium nitrate, the content of gibberellins of the A₃-A₁ group was 650–680 mg/l, of the gibberellins of the A₄-A₇ group 85–90 mg/l, and of gibberellin A₉ about 5 mg/l.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 1, pp. 55–58, 1966     

Investigation of Aconite alkaloids

Summary The composition of the alkaloids in plants of the genus Aconitum —A. kirinense,A. altaicum, A. coreanum, andA. nemorosum — has been studied. Four new alkaloids of composition C₂₆H₄₁O₈N·HNO₃, C₃₅H₄₁O₁₀N·HBr, C₂₀H₂₅O₃N, and C₂₃H₂₉O₆N have been isolated.Khimiya Prirodnykh Soedinenii, Vol. 1, No. 2, pp. 113–116, 1965.     

A new plant growth regulator of microbial origin

A new plant growth regulator — an inhibitor of the germination of mustard seeds — has been isolated from a culture filtrate of a phytopathogenic fungus of the genusPhoma. The methyl and trimethylsilyl derivatives of this compound have been obtained. Its empirical formula — C₁₆H₂₂O₅ — has been determined. On the basis of the results of IR and NMR spectroscopy and mass spectrometry, the compound isolated has been assigned the structure of 3,5-dihydroxy-2-octanoylphenylacetic acid.All-Union Scientific-Research Institute of Applied Molecular Biology and Genetics. V. I. Lenin Academy of Agricultural Sciences, Moscow. Translated from Khimiya Prirodnykh Soedinenii No. 3, pp. 387–391, May–June, 1985.     

An isomer of coronopilin

Conclusions From the racemes ofC. xanthifolia Fresen. have been isolated a sesquiterpene lactone C₁₆H₂₀O₄, the structural (+)-isomer of (–)-coronopilin, which has not been studied previously; structure I has been proposed for it.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 5, pp. 375–377, 1969     

Development of a method for determining bornyl acetate in the products of the processing of Abies sibirica

Summary The conditions for the reaction of esters—bornyl acetate—with an alkaline solution of hydroxylamine have been studied by the method of steepest ascent. A method has been developed for determining esters in a CO₂ extract ofAbies sibirica.Krasnodar Scientific-Research Institute of the Food Industry. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 303–306, May–June, 1976.     

Synthesis of polypeptides with the sequences-Gly-Gly-Ala-, -Gly-Gly-Lys(Tos)-, and-Gly-Gly-Glu(OCH3)- and the influence of triethylamine on the degree of their polycondensation

Summary From the herbGlaucium flavum have been isolated O-methylatheroline, sinoacutine, and a new alkaloid of the aporphine series, C₂₀H₁₇NO₅, which has been called glauvine.A structural formula has been proposed for glauvine on the basis of chemical reactions and spectral information.All-Union Scientific-Research Institute of Medicinal Plants. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 214–218, March–April, 1972.     

Structure and stereochemistry of pallinin

The roots ofFerula pallida Korov. have yielded pallinin, C₂₅H₃₈O₅, mp 79–80°C, []D²⁰ –148.5° (c 0.1; CHCl₃) — an ester of the new carotane alcohol pallinol and angelic acid. A structure and absolute configuration have been proposed for it on the basis of chemical transformations and spectral characteristics.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 53–56, January–February, 1986.     

Structures of four new triterpene glycosides from the holothurian Cucumaria japonica

Four new triterpene glycosides of the holostane series have been isolated from an alcoholic extract of the economically important Pacific Ocean holothurianCucumaria japonica: cucumariosides A₁-2 (I), A₂-3 (II), A₂-4 (III), and A₄-2 (IV). The structures of these substances have been established by the methods of carbohydrate chemistry and¹³C NMR spectroscopy.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 787–793, November–December, 1990.     

New glycosides from the holothurian Cucumaria japonica

Four new compounds have been isolated from the fraction of weakly polar triterpene glycosides of the holothurianCucumaria japonica: cucumariosides A₁-2 (I), A₀-1 (II), A₀-2 (III), and A₀-3 (IV). The structures of these substances have been established by chemical and physical methods.Deceased.Pacific Ocean Institute of Bioorganic Chemistry, Far-Eastern Scientific Center, Russian Academy of Sciences, Vladivostok. Institute of Chemistry of Plant Substances, Uzbekistan Republic Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 242–248, March–April, 1993.