Cleavage of the natural lignin of cotton-plant stems with thioacetic acid in the presence of anthraquinone

The influence of additions of catalytic amounts of anthraquinone on the stages of hydrolysis in the cleavage of natural lignin by thioacetic acid has been investigated. The degree of delignification does not change under these conditions, but the yield of low-molecular-weight cleavage products increases, which indicates a profound degradation of the lignin macromolecule. The qualitative and quantitative compositions of the monomeric fractions of cleavage products do not undergo appreciable changes in the presence of anthraquinone.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 99–101, January–February, 1986.     

Hydrogenolysis of Willst?tter lignin

Summary 1. The hydrogenolysis of Willstätter spruce lignin has been performed under the optimum conditions. It has been shown that on hydrogenolysis in an aqueous alkaline medium in the presence of an inhibitor (phenol) the lignin macromolecules can be converted into low-molecular-weight ether-soluble products with a yield of about 80%.2. A comparative study of the ether-soluble fractions of Willstätter spruce lignin and hydrolysis spruce lignin has shown that hydrogenolysis takes place similarly in the two cases: the yields of phenols and the proportion of cresols in them are similar. In the Willstätter spruce lignin, the yield of acids is higher and that of neutral products lower than in the hydrolysis spruce lignin.3. Investigations of the group compositions of the hydrogenolysis products and of model substances have permitted the hypothesis that the Willstätter lignin contains a considerable amount of biphenyl structures.Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 106–112, January–February, 1972.     

An investigation of the dioxane lignin of cotton bolls

Summary 1. Dioxane lignin has been isolated from mature stems of the cotton plantGossypium hirsutum by mild acidolysis in an atmosphere of nitrogen.2. Its expanded semiempirical formula has been established by elementary and functional analyses.3. The molecular-weight distribution of the dioxane lignin has shown that it consists of high-molecular-weight and low-molecular-weight fractions.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 645–648, September–October, 1974.     

Refinement of the structure of asperumine

Summary 1. Asperumine has been isolated from the combined alkaloids ofSymphytum caucasicum.2. The hydrolysis and hydrogenolysis of asperumine has given heliotridine, acetone, and angelic and asperuminic acids.3. The structure of asperumine has been refined on the basis of the products of hydrolysis and hydrogenolysis and also of features of the mass and NMR spectra.4. It has been established that asperumine is an isomer of heliosupine in the 2,3,4-trihydroxy-2-methylpentane-3-carboxylic acid moiety.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 478–480, July–August, 1974.     

Metabolites of the pathogenic fungus Verticillium dahliae VII. The phytotoxic pigment PKZh-1 from the culture liquid

Summary The phytotoxic pigment PKZh-1 that causes the characteristic symptoms of wilt in tests on cotton-plant shoots in a concentration of 100–150 µg/ml, has been isolated from the culture liquid of the fungusVerticillium dahliae Kleb.On the basis of qualitative reaction, spectral characteristics, and a study of hydrolysis products, PKZh-1 has been assigned to the peptide group. A red substance identified as 3,6,8-trihydroxy-1,4-naphthaquinone has been isolated from an acid hydrolyzate of PKZh-1.V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 690–693, September–October, 1977.     

Inhibiting properties of lignin

Inhibitory efficacy has been determined by the method of the weight losses of steel in acid with native lignin, hydrolysis lignin, ammoniated native lignin, chlorinated hydrolysis lignin, and ammoniated hydrolysis lignin, and without these additives. It has been established that the efficacy of lignin and its modifications as inhibitors of acid corrosion increases with a rise in the number of carboxy groups in the macromolecule, and therefore the ammoniated hydrolysis lignin is the most effective.Central Scientific-Research and Planning Technological Institute for the Mechanization and Electrification of Animal Husbandry of the Southern Zone of the USSR. Zaporozh'e Astrakhan Technical Institute of the Fisheries Industry and Economy, Astrakhan'. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 378–380, May–June, 1983.     

Phospholipids of Gossypium barbadense

Summary From the total phospholipids of the cotton plant of the thin-fibered variety 5904-I(Gossypium barbadense) chromatographically homogeneous fractions of phosphatidylethanolamines, phosphatidylcholines, and phosphatidylinositols have been isolated. The well-known glycerophospholipid structure of these fractions has been established on the basis of their IR spectra and the products of their acid hydrolysis.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 558–560, September–October, 1974.     

Ammonolysis of technical lignins

The oxidative ammonolysis of hydrolysis lignin, cellolignin, and lignosulfonate takes place effectively with the greatest formation of a water-soluble fraction at 140–150°C in 2 h. On oxyammonolysis, cellolignin forms approximately twice as much water-soluble fraction as hydrolysis lignin, while lignosulfate desulfonates under conditions exceeding the optimum. The maximum amount of nitrogen in the water-soluble fraction of lignin (nitrogen-containing lignin) amounts to 9.0% for cellolignin and is 2–3% less for the others.M. V. Frunze Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 275–278, March–April, 1987.     

Phenols of Ferula prangifolia

Summary From the roots ofFerula prangifolia (Boiss) Korov. two phenolic components have been isolated that are esters of p-hydroxybenzoic acid and sesquiterpene alcohols. On the basis of their physicochemical constants and hydrolysis products it has been shown that one of them isl-chimgin (borneol p-hydroxybenzoate) and the second, which has been called ferungin, is ferutinol p-hydroxybenzoate.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 718–721, November–December, 1972.     

A study of the process of lignification of one-year willow wood

Conclusions 1. The content of lignin in the wood ofSalix viminalis andSalix acutifolia increases with the growth of the shoots during shortened days and also in drier climatic periods.2. The monosaccharides, glucose, fructose, and arabinose take part in the synthesis of the lignin of young wood ofSalix viminalis andSalix acutifolia. The formation of lignin of one-year willow wood takes place from May to January (with a maximum in June–July). The content of methoxyl groups in it gradually rises.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 6, pp. 546–550, 1969     

The lignin of the sea island cotton plant of variety S-6030 affected by fusarial wilt. I

A comparative study of the dioxane lignins isolated from healthy and wilt-affected cotton plant stems has shown thatFusarium fungi demethylate lignin and make it more oxidized than the lignin from healthy stems.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 825–827, November–December, 1985.     

Hydrogenolysis of rice husk lignin. IV

The hydrogenolysis of rice husk protolignin and of rice husk hydrolysis lignin in the presence of catalyst D-101, which is used in the hydrocracking of petroleum, has been studied. A substantial amount of products with syringyl structures has been found in the lignin cleavage products. The hydrogen content of the hydrol lignins isolated was considerably higher than that of the analogous lignins obtained on hydrogenolysis with the use of other catalysts.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan. Scientific-Research Chemical and Technical Institute of the Medical and Microbiological Industry, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 602–605, July–August, 1993.     

Alkaline hydrolysis of the natural lignin of cottonplant stems in the presence of anthraquinone

The study of a three-stage alkaline hydrolysis of the natural lignin of cottonplant stems has shown that the bulk of the lignin undergoes fragmentation during stage I. The addition of anthraquinone leads to an appreciable increase in the yield of low-molecular-mass hydrolysis products.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 743–748, September–October, 1996. Original article submitted March 1, 1993.     

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.     

Oxidation of lignin in aqueous alkaline solution

Conclusions The hydrogenolysis and hydrolysis of lignin in an aqueous alkaline medium must be considered as an oxidative degradation of the lignin macromolecule by hydroxyl radicals. This process takes place even in a reducing medium in the presence of a catalyst. This was shown by a study of the hydrogenolysis process using model compounds. The oxidative processes in lignin are connected with the appearance in the system (lignin or its model) of alkali-induced quinoid structures which, being electron-acceptors, abstract electrons from hydroxyl ions and form hydroxyl radicals. The latter lead to oxidative processes through the the hydroxylation of the system. The correctness of this has been confirmed by studying the composition of the products, which shows the oxidative nature of the hydrogenolysis process.Scientific-Research Institute for the Chemistry and Technology of Cotton Cellulose, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 512–517, September–October, 1970.     

Functional composition and IR spectra of cottonseed husk hydrolysis lignin and its derivatives

The functional compositions of cottonseed husk hydrolysis lignin and its derivatives have been determined and their IR spectra have been studied. A possible formation of stronger hydrogen bonds in derivatives of hydrolysis lignin has been shown.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 40 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 392–397, May–June, 1999.     

Alkaloids of Stephania hernandifolia VIII. Methylhernandine

Summary A new hasubanan alkaloid with the composition C₂₀H₂₇O₆N, mp 152–153°C (ether-methanol) has been isolated from the herbStephania hernandifolia and has been called methylhernandine. The alkaloid has been shown to be identical with the methylamino alcohol obtained in the hydrolysis of hernandifoline.All-Union Scientific Research Institute of Medicinal Plants. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 455–457, July–August.     

Investigation of the core of the lipopolysaccharides ofYersinia pseudotuberculosis

Lipopolysaccharides have been isolated from two R mutants of the pseudotuberculosis microbeYersinia tuberculosis, serovar VA. Mild acid hydrolysis followed by gel filtration on Sephadex G-25 gave the core oligosaccharides OS I and OS II. Complete acid hydrolysis showed that OS I consisted of residues of D-galactose, G-glucose, two heptoses (D-glycero-D-mannoheptose and L-glycero-D-mannoheptose), and D-glucosamine in a ratio of 1:2.5:4:1, while OS II consisted of residues of D-glucose, heptoses, and D-glucosamine in a ratio of 1:2.5:0.2. On the basis of the results of monosaccharide analysis, methylation, Smith degradation, etc., a partial structure of the core oligosaccharide of the LPS ofY. pseudotuberculosis has been put forward.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 751–755, November–December, 1985.     

Resistance of vasoactive peptides from venom of Vespa orientalis to action of proteolytic enzymes

The kinetics of the hydrolysis by proteolytic enzymes of vasoactive peptides isolated from the venom of the hornetVespa orientalis has been investigated. It has been found that the half-period of decomposition of the peptides exceeds that of bradykinin. These facts are in harmony with in vivo results on the prolonged hypotensive action of the peptides.A. S. Sadykov Institute of Bioorganic Chemistry, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 658–661, September–October, 1988.