A new biisoflavonoid from the roots of Erythrina variegata

A new biisoflavonoid, biseryvarin A (1a), together with two known compounds were isolated from the roots of Erythrina variegata. The structure of biseryvarin A was established on the basis of spectroscopic evidence. Biseryvarin A is the first dimeric isoflavonoid possessing isoprenoid groups from the genus Erythrina. Biseryvarin A showed low activity against methicillin-resistant Staphylococcus aureus (MRSA).     

Four new isoflavonoids from the stem bark of Erythrina variegata

Bioassay-directed fractionation of the stem bark extract of Erythrina variegata L. has resulted in the isolation of three new isoflavones: 5,4'-dihydroxy-8-(3,3-dimethylallyl)-2'-methoxyisopropylfurano[4,5:6,7]isoflavone (1), 5,7,4'-trihydroxy-6-(3,3-dimethylallyloxiranylmethyl)isoflavone (2), 5,4'-dihydroxy-8-(3,3-dimethylallyl)-2'-hydroxymethyl-2'-methylpyrano[5,6:6,7]isoflavone (3) and a new isoflavanone, 5,4'-dihydroxy-2'-methoxy-8-(3,3-dimethylallyl)-2',2'-dimethylpyrano[5,6:6,7]isoflavanone (4) together with seven known compounds, euchrenone b10 (5), isoerysenegalensein E (6), wighteone (7), laburnetin (8), lupiwighteone (9), erythrodiol (10), and oleanolic acid (11). The structures were determined on the basis of spectroscopic analyses and chemical evidence. The effect of these compounds on the proliferation of rat osteogenic sarcoma (UMR106) is also reported.     

Erythrinan alkaloids from seeds of Erythrina velutina

Four new Erythrinan alkaloids (1-4) were isolated from the seeds of Erythrina velutina. The structures of these new compounds 1-4 were elucidated by spectroscopic methods including 2D-NMR. Three of four were found to be novel sulfated Erythrinan alkaloids.     

Isolation and characterization of protease inhibitors from cotton seeds

Protease inhibitors of protein nature have been isolated from dormant cotton seeds. The participation of protease inhibitors in the mechanism of protecting the plant from wilt damage is discussed.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. 3, pp. 445–448, May–June, 1995. Original article submitted June 27, 1994.     

Antifeedants from Chinese medicinal herb, Erythrina variegata var. orientalis, against maize weevil Sitophilus zeamais

The screening for insecticidal principles from several Chinese medicinal herbs showed that the stem bark of Erythrina variegata var. orientalis possessed significant feeding deterrence against maize weevils, Sitophilus zeamais. Bioassay-directed fractionation of the stem bark extract of E. variegata var. orientalis resulted in the isolation of two alkaloids, identified as erysopine and erysovine from their spectroscopic data. Erysopine and erysovine possessed antifeedant activity against S. zeamais adults with EC50 values of 108.5 and 89.7 ppm, respectively.     

Isolation of ribosomes from cotton seeds

Summary 1. It has been established that the method of precipitation with ethanol in the presence of an increased concentration of Mg²⁺ can be used for the rapid isolation of the ribosome fraction from plant material.2. The optimum conditions for the complete precipitation of the ribosome fraction from a homogenate of cotton seeds have been selected.3. By treating an extract of the seeds with 0.5 M KCl it was possible to reduce the amount of tRNA in a preparation of the total rRNA.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 852–856, November–December, 1977.     

HPLC-DAD-SPE-NMR isolation of tetracyclic spiro-alkaloids with antiplasmodial activity from the seeds of Erythrina latissima

Abstract

Seven tetracyclic spiro-alkaloids, i.e. glucoerysodine (1), erysodine (2), epi-erythratidine (3), erysovine (4), erythratidine (5), erysotrine (6) and erythraline (7) were isolated from the seeds of Erythrina latissima by means of conventional separation methods and HPLC-DAD-SPE-NMR. Their structures were elucidated by spectroscopic means. This is the first report on the isolation of compounds 3, 5 and 6 from this plant. Antiplasmodial activity against the chloroquine-resistant strain Plasmodium falciparum K1 and cytotoxicity against MRC-5 cells (human fetal lung fibroblast cells) was assessed in vitro. Erysodine (2) and erysovine (4) showed moderate activity (IC₅₀ 6.53?µM and 4.05?µM, respectively), compared with the standard chloroquine (IC₅₀ = 0.14?µM). No cytotoxicity was observed in a concentration up to 64.0?µM.     

Erythrina alkaloids from leaves of Erythrina arborescens

Continued interest in Erythrina alkaloids resulted in the isolation of 38 alkaloids including 7 undescribed ones from the leaves of Erythrina arborescens Roxburgh. Among the new compounds, erythrivarines H-I were two dimeric alkaloids, while others were Erythrina alkaloid glucosides. Dimeric Erythrina alkaloids and monomers, turcomanidine and isoboldine, showed medium xanthine oxidase inhibition.     

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.     

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.     

Isolation of protease B from cotton seeds

Protease B has been isolated from dormant cotton seeds by fractionation with ammonium sulfate, ion-exchange chromatography on CM-cellulose, and gel filtration through Acrilex P-10 and Sephadex G-75, with 128-fold purification. The enzyme exists in dimeric and monomeric forms. According to the results of gel filtration, their molecular weights are 72,000 and 36,000, respectively. The enzyme consists of a single polypeptide chain including sugars. The N-terminal amino acid of protease B is alanine. The enzyme possesses proteolytic activity in the pH range from 4 to 6.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 506–510, July–August, 1984.     

Isolation of protease B from cotton seeds

Protease B has been isolated from dormant cotton seeds by fractionation with ammonium sulfate, ion-exchange chromatography on CM-cellulose, and gel filtration through Acrilex P-10 and Sephadex G-75, with 128-fold purification. The enzyme exists in dimeric and monomeric forms. According to the results of gel filtration, their molecular weights are 72,000 and 36,000, respectively. The enzyme consists of a single polypeptide chain including sugars. The N-terminal amino acid of protease B is alanine. The enzyme possesses proteolytic activity in the pH range from 4 to 6.     

Isolation of biocidal peptides from Anethum graveolens seeds

Three peptides with fungicidal activity with molecular weights 4–8 kDa were isolated from Anethum graveolens L. seeds. The cationic peptides were tested in vitro and inhibited the pathogenic strain Verticillium dahliae. The effective concentrations required for 50% inhibition (IC₅₀) growth of fungi were in the range 1.3–31 μg/mL. Peptide D-AFP-3 was the most active biocidal peptide. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 474–476, September–October, 2006.     

Isolation of frutitsin from the seeds ofAmorpha fruticosa

The conditions for the isolation and purification of frutitsin by various solvents and mixture of solvents have been studied. The proposed method for the isolation of frutitsin permits the yield of the substance to be increased.     

Isolation of the total tRNA from cotton seeds

Summary 1. A comparative study has been made of various methods of isolating the tRNA from cotton seeds. It has been found that the best results are given by extraction of cotton seeds with a mixture of 80% phenol and 0.14 M NaCl.2. The conditions have been worked out for the preparative isolation of the total tRNA.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 621–624, September–October, 1978.