Enzymatic-chemical isolation of lipids,proteins, and gossypol from cotton seeds and meal. I

An enzymatic-chemical method of isolating the complex of lipids, gossypol pigments, and water-soluble proteins from cotton seeds and meal has been developed which permits: a) the achievement of the maximum yield of all types of lipids without their degradation; b) a rise in the qualitative and food value of the oil and protein products isolated from the seeds, with an increase in the solubility of the latter; c) the extraction from cotton seeds of more than 75% and from cottonseed meal of 42% of the free gossypol. The method, in combination with Folch's procedure, is suitable for the quantiative estimation of the lipids, strongly bound to the protein of the nucleus.     

Cotton-plant protein isolates

The seeds of the cotton plant are an important source of food protein. The presence of gossypol in the seeds limits the use of protein isolates as additives to food products. The use of salt and alkaline solutions for extracting the proteins leads to the formation of isolates with relatively high gossypol constants. Extraction in an acid medium permits the presence of the toxin to be excluded. In this process, a number of problems arise which are connected with the presence of a large amount of phytin (about 5%) in the seeds of the cotton plant. The latter affects both the yield of food protein on extraction and functional properties. A method is proposed for eliminating traces of phytin from an acid isolate. A substantial influence of phytin on the properties of the proteins has been observed in those cases where the latter is strongly bound to the proteins at acid pH values.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 366–369, May–June, 1983.     

Isolation of proteins from cottonseed meal II. The salt method

Summary On the basis of the results of a study of the amino acid compositions of various protein fractions from cottonseed flour and meal it has been established that the fraction of salt-soluble proteins (globulins) does not change its composition and properties in the processing of cotton seeds. The yield of protein from the industrial meal using the salt-extraction method is 16%.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 626–628, September–October, 1974.     

Lipids ofGossypium mexicanum

The surface lipids of the coat and the lipids of the kernel of the seeds of a wild form of the medium-fibered cotton plantGossypium mexicanum var.nervosum have been studied in comparison with cultured species. Using the methods of CC, TLC, and GLC, and UV and mass spectrometry, in the cuticular lipids ofG. mexicanum three classes of neutral lipids have been detected, and in the kernel lipids 10 classes of neutral lipids, 2 classes of glycolipids, and 7 classes of phospholipids. The structures of the epoxyacyl-, hydroxyacyl-, and diacylglycerols of the kernel have been established. The greatest differences between the seeds of the wild form of the cotton plant and the cultured species are the greater weight of the seed coat, the presence in it of a considerable amount of the 18:1 and of medium-molecular-weight fatty acids, and a higher level in the kernel of gossypol pigments, polar lipids, and acylglycerols containing the 18:2 acid.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 57–62, January–February, 1987.     

Lipid composition of the seeds of the cotton plant infected with wilt

The qualitative and quantitative set of lipid components of the seeds of healthy cotton plants of the variety Tashkent-1 and plants infected with verticillium wilt have been studied. It has been established that the compositions of the lipids of the two samples differ considerably. The greatest differences are observed in the amounts of total lipids, gossypol, and low-molecular-weight volatile acids.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 319–325, May–June, 1980.     

Influence of wilt infection on the gossypol pigments of seeds and roots of a cotton plant of the variety Tashkent-1

A study has been made of the gossypol pigments of the seeds and roots of a cotton plant of the variety Tashkent-1 infected with wilt in comparison with a healthy plant. The amount of gossypol in the infected plant was lower than in the healthy plant. In the diseased plant, gossypurpurin was concentrated in the roots, and in the healthy plant it was concentrated in the seeds. Gossypol possessing optical activity was detected in the seeds and roots of both the healthy and the diseased plants.Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 63–66, January–February, 1989.     

Identification and quantification of gossypol in cotton by using packed micro-tips columns in combination with HPLC

Self-packed micro-tip columns containing a C₁₈-bonded silica stationary phase, based on the same principles as solid-phase extraction methods, were used to obtain gossypol and related sesquiterpenoid aldehyde-enriched fractions. The enriched metabolite fractions were then analyzed by optimized high-performance liquid chromatography (HPLC) with a C₁₈ column (4.6 mm×25 cm) eluted with the binary mobile phase acetonitrile–0.1% aqueous TFA solution (80:20). This method has proven to be highly reproducible. The precision and accuracy, as %RSD and %RME values, were determined to be less than 15% for the method. The minimum detection limit of gossypol was determined to be 10 ng (absolute gossypol). Absolute recovery was greater than 94% with a standard deviation of ±3.68%. This is a simple, fast, and cost-effective method for isolation, identification, and quantification of gossypol and related secondary metabolites. Comparative analysis of gossypol content was performed on different parts of the cotton plant (seeds, stems and leaves) of two different cultivars of Gossypium hirsutum L. (Acala_1517–70 and OR₁₉). The results indicate that the OR₁₉ cv naturally contains higher gossypol levels than the Acala cv. It was also found that treatment of leaves with a Verticillium dahliae-derived elicitor induced production of deoxyhemigossypol rather than gossypol.     

Influence of some defoliants on the gossypol pigments of cotton seeds

The influence of a number of defoliants on the gossypol pigments of cotton seeds of variety S-4880 has been studied. It was established that the qualitative compositions of the pigments of the defoliant-treated plants and of the control plants were identical. However, their quantitative composition in seeds treated with defoliants having a severe action had changed substantially: they contained larger amounts of the bound forms of gossypol than in the variants with defoliants having a mild action.Institute of Chemistry of Plant Substances, Uzbekistan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 208–212, March–April, 1993.     

Composition of cottonseed soapstock fats

The compositions of cottonseed soapstocks from first-grade and low-grade cotton seeds have been studied by the methods of CC on polyamide and on silica gel, TLC, GLC, ESR, and UV, IR, and mass spectrometry. It has been found that saturated, and also oxygenated, fatty acids, nonpolar acylglycerols, glycolipids, sterols, arylalkanes, gossypol pigments, and ions of metals of variable valence are concentrated in the acid fat of the soapstock from low-grade seeds. The soapstock contains a very small amount of tocopherols and phospholipids, mainly phosphatidylinositols. The combined gossypol pigments of the soapstocks include stabilized gossypol radical ions.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 502–508, July–August, 1988.     

Extraction of cottonseed oil

Summary It has been shown that oil of the best quality is obtained on its selective extraction by hexane. Subsequent extraction from the meal of gossypol by 70–80% aqueous, and then dry, acetone permits meal to be obtained with a light cream color containing 0.02% of free gossypol. The omission of dry acetone leads to a darkening of the meal.It has been established that it is possible to achieve a reduction in the consumption of solvents on the direct extraction of cottonseed flake by using weak oil and gossypol miscellas.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 170–173, March–April, 1978.     

Protein-lipid complexes of cotton kernels and the products of their processing

The composition and lipid content of the lipoprotein complexes of cotton kernels (I), meal (II), and isolate (III) have been investigated. It has been shown that with the aid of an acidic alcohol-containing extractant it is possible to isolate up to 99% of the strongly bound lipids (SBLs) of their total mass. In the composition of the strongly bound lipids (I–III) have been found neutral lipids comparable with the free lipids of the kernel; of polar lipids, glycolipids were present. It was found that an acid extractant extracts polyphenolic compounds together with the SBLs.Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 466–472, July–August, 1990.     

Kinetics of the level of lipids in a cotton plant of variety 6524 S during maturation

The composition and amount of lipids in the seeds and leaves of the cotton plant of variety 6524 S over the vegetation periods have been investigated. The rate of biosynthesis of neutral lipids in cotton seeds in the 20-day period after flowering to the moment of maturation increases by a factor of 1.6 while the amounts of phospho- and glycolipids decrease by factors of 3.9 and 4.3, respectively. The fatty acid compositions of the neutral lipids and of the phospho- and glycolipids of the seeds and leaves have been determined.Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbekistan Republic, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 359–362, May–June, 1993.     

Lipids of the products of processing of cotton seeds

The free, bound, and strongly bound lipids of the crushed seeds, pulp, husks, and meal have been characterized. It has been shown that the bound and strongly-bound lipids differ from the free lipids by a higher level of saturated acids. The acid numbers of the bound lipids are 5–6 times higher than those of the free lipids.Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 66–68, January–February, 1989.     

Comparative investigation of the composition of the protease inhibitors of wilt-resistant and wilt-susceptible varieties of cotton

The amounts and the group, class, and fatty-acid compositions of the feebly-and the strongly-bound lipids of the total protein fraction of cotton seeds that inhibits the growth of the pathogenic fungusVerticillium dahliae Kleb. have been determined. The main differences of the indices for the seeds of healthy and infected plants of two varieties contrasted by their degrees of susceptibility to verticillium wilt have been established.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. 474–480, July–August, 1994.     

Investigation of the protein composition of the seeds ofCitrullus vulgaris

The total protein content amounts to 60% of the defatted flour or 14-15% of the weight of watermelon seeds. Water-, salt-, alcohol-, and alkali-soluble fractions of the proteins have been isolated and their percentage amounts in the seeds have been determined. More than half the total protein (53.3 %) consists of globulins - the reserve proteins of the seeds. The seeds contain about 30% of lipids, which form a valuable component of them and may serve as an additional source of nutrient plant oil. Using the method of amino acid scales a comparative analysis has been made of the biological value of the watermelon seed proteins with standard proteins.Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 431–434, May–June, 1995. Original article submitted May 30, 1994.     

Lipids of defective cotton seeds and the influence of microflora on their composition

A comparative study has been made of the lipid composition of defective and first-grade cotton seeds after their prolonged storage under industrial conditions. On the basis of the change in the lipids of the seeds subjected to thermal spoilage it is proposed to consider the process of spontaneous heating as a group of enzymatic processes taking place mainly in not fully ripe seeds when they are damaged by pathogenic microflora.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 677–686, November–December, 1986.     

Influence of ultradisperse iron and copper powders on the oil content of cotton seeds and on the fatty acid composition of the seed lipids

The oil contents and the fatty acid compositions of the lipids of cotton seeds of varieties AN-402 and AN-9 grown under the influence of ultradisperse powders (UDPs) of iron and copper have been studied. Changes in the absolute weight, oil content, and fatty acid composition of the seeds have been shown. The action of an iron UDP led to an appreciable fall in the amount of palmitic acid in the AN-402 variety and a rise in the oleic acid content.Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 165–167, March–April, 1998.     

Polar lipids of cotton seeds and the products of their processing

The compositions and amounts of polar lipids in cotton seeds and the products of their processing have been investigated. Six glycolipids have been identified, the main ones being monogalactosyldiglyceride (MGDGs), digalactosyldiglycerides (DGDGs), and sterol glycosides. The fatty acid compositions of the neutral lipids and of the phospho- and glycolipids have been determined. In the glycolipids, saturated fatty acids — palmitic and stearic — predominated.Institute of Chemistry of Plant Substances, Uzbekistan Republic Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 194–198, March–April, 1993.     

Protease A from cotton seeds. Isolation and purification of the enzyme

Protease A has been isolated in the homogeneous state from dormant seeds of cotton plants of the Tashkent-I variety. A scheme is proposed for the isolation and purification of the enzyme which includes the following stages: extraction of the defatted seeds with 0.1 M phosphate buffer, pH 7.4; precipitation of the protein with ammonium sulfate at 60% saturation; desalting by dialysis; and ionexchange chromatography on a column containing CM- and DEAE-celluloses. The molecular weight of the enzyme has been determined as 60,000. The enzyme efficiently hydrolyzes azocasein and the 7S and 11S reserve proteins of cotton seeds. Its maximum activity appears at pH 6.4–7.4 and a temperature of 35–40°C; it is not activated by sulfhydryl reagents and loses its activity in the presence of diisopropyl phosphorofluoridate. The assumption is made that protease A belongs to the serine type of trypsin-like proteases.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 738–741, November–December, 1986.     

Gossypol-like compounds of the cotton plant. Methods of determining gossypol

This review is devoted to the study of gossypol and gossypol-like pigments. It is reported that some of them are phytoalexins with respect to certain fungal pathogens of the cotton plant and possess a high toxicity. Methods of determining free and total gossypol in cottonseed processing products are discussed particularly.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 121–139, March–April, 1981.