Phosphorylation of hydrolysis lignin by dialkyl phosphorochloridates

It has been established that the phosphorylation of lignin by dialkyl phosphorochloridates takes place through the hydroxy groups of the lignin macromolecule.Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 750–752, September–October, 1997.     

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.     

Dioxane lignin from shoots of the cotton plant of variety 108-F. I

The dioxane lignin has been isolated by Pepper's method from two-week shoots of the cotton plant of variety 108-F and has been separated into two fractions — insoluble and soluble in ether — DLA-A and DLA-B, respectively. It has been shown that in the early stage of development of the cotton plant a low-molecular-weight lignin with a low degree of methoxylation and distinctly different from the lignin from ripe stems of the same cotton plant is synthesized.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 96–98, January–February, 1984.     

Phosphorylation of emodin

A convenient method has been developed for the interaction of dialkyl phosphites with 1,6,8-trihydroxy-3-methylanthraquinone (emodin) under the conditions of the Todd—Atherton reaction. It has been shown that the -hydroxy groups of emodin are not phosphorylated at an equimolar ratio of emodin and dialkyl phosphite. The phosphorylation of 7-bromo-1,6,8-trihydroxy-3-methylanthraquinone with potassium dialkyl phosphorothioates has been studied. The reaction takes place at the sulfur atom, with the formation of of the product of S-alkylation.Al-Farabi Kazakh State National University, Almaty. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 212–216, March–April, 1994.     

Quantitative1H and13C NMR spectroscopy of lignins isolated from aspen wood by various methods

A comparative analysis has been made of the chemical structures of aspen milled wood lignin, aspen dioxane lignin, and lignin from the explosive autohydrolysis of aspen wood.Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 878–886, November–December, 1995. Original article submitted November 22, 1994.     

A study of the lignin of the sea island cotton plant of variety S-6030

The dioxane lignin has been isolated by Pepper's method with a yield of 9.5% on the Komarov lignin from the ripe stems of the sea island cotton plant of variety S-6030. The developed emperical formula has been calculated, the IR and UV spectra have been taken, and the molecular-mass distribution has been studied. The dioxane lignin is polydisperse. M_w=10,100, M_n=5350.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 628–630, September–October, 1983.     

Investigation of the dihydroxylignin ofAlthaea rhyticarpa

Summary 1. The developed semiempirical formula for the dioxane lignin from the stems ofAlthaea rhyticarpa has been found from the results of elementary and functional analyses.2. It has been shown that the lignin consists of high- and low-molecular-weight fractions.3. It has been shown by the nitrobenzene oxidation method that p-coumaryl, guaiacyl, and syringyl structural units are present in the lignin.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 242–246, March–April, 1976.     

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.     

Hydrogenolysis of rice husk lignins

The hydrogenolysis of the protolignin, the hydrolysis lignin, and the dioxane lignin of rice husks in the presence of demethylated lignin as catalyst has been studied. The breakdown of the lignins into low-molecular-mass compounds took place with yields comparable with those obtained by hydrogenolysis using other catalysts.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. 4, pp. 611–613, July–August, 1995. Original article submitted November 21, 1994.     

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.     

Study of the IR spectra of the products of the ethanolysis of oak and pine lignins

Summary The IR spectra of a number of compounds formed in the ethanolysis of the lignin of foliate and coniferous species have been studied using samples of ethanol lignin, vanillin, syringic aldehyde, p-hydroxybenzaldehyde, guaiacylacetone, coniferyl and sinapic aldehydes, vanilloyl methyl ketone, -hydroxypropiovanillone, -ethoxypropiosyringone, and vanillic and gallic acids. Differences in the absorption at 1330–1340 cm^–1 have been found in the spectra of samples of ethanol lignin from oak and pine. Oak lignin has a strong maximum which is absent in pine lignin. Thus, the lignins of foliate and confierous species can be distinguished by the absorption in the spectral region from 1330 to 1340 cm^–1.Khimiya Prirodnykh Soedinenii, Vol. 3, No. 2, pp. 208–213, 1967     

Study of the conditions of enzyme formation and the secretion of extracellular ligninases by the funguspleurotus ostreatus UzBI-1108

The possibility has been shown of the rational use of lignocellulose wastes as components of a nutrient medium for the deep cultivation of some wood-destroying basidial fungi isolated from various sources and actively breaking down natural polysaccharides and lignin with the formation of ligninolytic enzymes and biologically valuable products. An active producing agent of ligninolytic enzymes (laccase, peroxidase, lignin peroxidase, polyphenoloxidase, Mn-dependent peroxidase) has been revealed as Pleuroms ostreatus, strain UzBI-I108. The optimum conditions have been determined for the formation of enzymes and the secretion of total ligninase preparations with a fairly high specific activity of lignin peroxidase.Institute of Microbiology Academy of Sciences, Republic of Uzbekistan, Tashkent, fax (3712) 41 7129. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 739–747, September–October, 1995. Original article submitted November 11, 1994.     

The lignin of the algaFucus vesiculosus

Summary 1. The plant material ofFucus vesiculosus has been treated with metallic sodium in liquid ammonia. The total yield of products extractable by ether was 1.1%.2. In the products of the decomposition of the lignin ofFucus vesiculosus 12 phenols and acids have been identified by paper chromatography and gas-liquid chromatography and it has thereby been established that the lignin of algae consists of p-coumaryl, guaiacyl, and syringyl structural units.3. The composition of the decomposition products confirms the hypothesis expressed previously that the brown algaFucus vesiculosus contains lignin.S. M. Kirov Belorussian Technological Institute, Minsk. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 645–647, September–October, 1978.     

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.     

A comparison of the surface properties of lignin and sulfonated lignins by FTIR spectroscopy and wicking technique

The comparison of the FTIR spectra indicated that the sulfonation without caused changes in the main structure of lignin and only in the lignin chains. The surface properties, e.g. the surface free energy and related components, e.g. the Lifshitz–van der Waals and Lewis acid–base interactions components, of lignin and lignosulfonates, LGSs, with different ions, e.g. Na⁺–, Mg²⁺–, and Ca²⁺–, studied and compared by wicking technique indicated that the surface free energy of lignin is lower than that of all used LGSs. This suggests that the sulfonation can enhance the surface property for lignin by increasing of the Lifshitz–van der Waals component and Lewis base component of lignin.     

A study of the dioxane lignins of Althaea nudiflora and A. rosea

Summary 1. The lignin has been isolated from the stems of the cotton plant of a late period of vegetation by the hydrochloric acid method. The elementary composition and functional groups have been determined. The mean composition for a C₆-C₃ structural unit has been determined.2. By the oxidation of a powder of the stems of the cotton plant with nitrobenzene in the presence of alkali it has been established that the hydrochloric acid lignin is more condensed than the DLA.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 648–650, September–October, 1975.     

Cleavage of dioxane lignin of the cotton plant with thioacetic acid

Summary 1. It has been established that the dioxane lignin of mature cotton-plant stems is cleaved by thioacetic acid. About 3/4 of the bonds in the lignin are alkyl-aryl ether bonds and only 1/4 are C-C bonds.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 505–507, July–August, 1978.     

IR spectra of the hydrolysis lignin of cottonseed husks and its derivatives before and after the sorption of lead ions

The characteristic frequencies of the hydrolysis lignin of cottonseed husks and its derivatives before and after the sorption of lead ions have been studied. The possibility of the intermolecular coordination of the lignin macromolecules by lead ions with both the ionic and the coordination types of bonds has been shown by the IR spectral method.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (371) 120 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 521–525, July–August, 1999.     

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.     

Formation of peroxide compounds on the oxidation of lignin by oxygen in an organic solvent

The results are given of a determination of the steady-state concentrations of peroxide compounds on the oxidation of lignin by oxygen in dioxane. An iodometric method of determining peroxides was used, with spectrophotometric control of the amount of iodine formed. It was established that the achievable steady-state concentration of peroxide compounds on the oxidation of lignin is 0.28–0.44 wt. % of O_act (oxygen pressure 1 atm, temperature 50–80°C). With a rise in the temperature, the steady-state concentration of peroxide compounds decreased. The addition of water (30 vol. %) to the organic solvent led to an increase in the rate of accumulation of peroxide compounds. It has been shown that the presence of alkaline and acidic catalysts exerts no appreciable influence on the achievable steady-state concentration and the rate of accumulation of peroxide compounds during the oxidation of lignin.Bratsk Industrial Institute. All-Union Scientific Production Combine of the Pulp and Paper Industry, Leningrad. Translated from Khimiya Prirodnykh Soedinenii, Nos. 3,4, pp. 413–417, May–August, 1992.