Isolation and Chemical Structure of a New Fluorescent Compound in Spinach Leaves

The present paper describes, together with its isolation procedures, the chemical structure determined for an unknown blue-violet fluorescent compound present in spinach. The effective isolation procedures consisted of methanol extraction from 30 kg of spinach leaves, column chromatographies on cellulose powder and DEAE-cellulose, and gel filtration through Sephadex columns. The compound was obtained as colorless powder in the yield of 70 mg. It was identified as 2-acetyl-3-(p-coumaroyl)-meso-tartaric acid basing on the spectral data and the experimental results of alkaline hydrolysis and chemical synthesis.     

Isolation and Characterization of a Novel Chitosan-Binding Protein from Non-Heading Chinese Cabbage Leaves

To know the mechanism of ammonia assimilation in non-heading Chinese cabbage (Brassica campestris L. ssp. chinensis (L.) Makino) leaves regulated by chitosan (CTS), a CTS-binding protein was isolated from non-heading Chinese cabbage leaves using the chitosan affinity chromatography approach and this CTS-binding protein was partially characterized. The profile of the 53.1 kDa purified protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis was compared with the native molecular weight of 106.5 kDa, which indicated that the purified protein was a dimer with identical subunits. After isoelectric focusing, a band was obtained at pH 8.25. The agglutination test and periodic acid-Schiff staining further revealed that the protein was a glycoprotein with lectin activity. Moreover, the purified protein contained 17.4% (w/w) neutral carbohydrate and 82.56% (w/w) protein. The comparison of this protein and the 67 kDa CTS-binding protein isolated previously from Rubus culture tissue exhibited some differences in characterization. According to results of peptide mass fingerprinting analysis, the protein purified in the present study does not show any similarity with any protein in the protein data bank. Thus, it was deduced that the protein purified in the present study is a novel CTS-binding protein.     

Isolation and Characterization of a Novel Chitosan-Binding Protein from Non-Heading Chinese Cabbage Leaves

To know the mechanism of ammonia assimilation in non-heading Chinese cabbage (Brassica campestris L. ssp. chinensis (L.) Makino) leaves regulated by chitosan (CTS), a CTS-binding protein was isolated from non-heading Chinese cabbage leaves using the chitosan affinity chromatography approach and this CTS-binding protein was partially characterized. The profile of the 53.1 kDa purified protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis was compared with the native molecular weight of 106.5 kDa, which indicated that the purified protein was a dimer with identical subunits. After isoelectric focusing, a band was obtained at pH 8.25. The agglutination test and periodic acid-Schiff staining further revealed that the protein was a glycoprotein with lectin activity. Moreover, the purified protein contained 17.4 % (w/w) neutral carbohydrate and 82.56% (w/w) protein. The comparison of this protein and the 67 kDa CTS-binding protein isolated previously from Rubus culture tissue exhibited some differences in characterization. According to results of peptide mass fingerprinting analysis, the protein purified in the present study does not show any similarity with any protein in the protein data bank. Thus, it was deduced that the protein purified in the present study is a novel CTS-binding protein.     

Isolation of Zeanic Acid,a Natural Plant Growth-regulator from Corn Steep Liquor and Its Chemical Structure

Corn steep liquor markedly inhibited the growth of the grass, alfalfa, as previously reported. The active principles from corn steep liquor were isolated. From the acidic fraction of corn steep liquor, white needles and yellow needles were isolated. The compound of white needles, which inhibited the germination of alfalfa seeds at the concentrations above 500 ppm, was found to be identical with ferulic acid known as germination inhibitor of plant seeds. The compound of yellow needles did not inhibit the germination of alfalfa seeds, but stimulated the growth of the plant. It has a structure related to β-acid which has been isolated from rice-bran and has been identified as 2,6-dihydroxycinchoninic acid. This active substance is a new quinoline, 2,8-dihydroxycinchoninic acid and was named zeanic acid.     

Isolation and Structure Elucidation of a New Disaccharide, 6-Deoxy-D-glucobiose,from Acid Hydrolyzate of Asterosaponin A

Acid hydrolysis of asterosaponin A afforded a crystalline 6-deoxyglucobiose, whose structure has been established as O-(6-deoxy-α-d-glucopyranosyl)-(1→4)-6-deoxy-d-glucose. This is the first isolation of a 6-deoxyglucobiose. Its formation as a hydrolytic fragment of asterosaponin A suggests the presence of an α-1→4′-glycosidic linkage between the two 6-deoxy-d-glucose units in the saponin.     

王不留行中抗人微血管内皮细胞增殖的有效组分的分离和纯化

从中药王不留行中筛选具有抑制内皮细胞增殖的有效单一组分.大孔树脂吸附法进行总皂甙的分离纯化,分别收集不同浓度乙醇溶液洗脱液用SRB法进行细胞活性检测,选择有效部分用AKTA Resource柱分离,按紫外吸收峰收集洗脱液并进行活性验证,通过蒸发光散射检测组分复杂程度,选择活性高、丰度大、成份简单的峰进行C18柱分离.结果表明,王不留行提取液经大孔树脂分离和细胞活性检测发现50%～90%醇浓度洗脱液具有细胞活性,经AKTAResource柱分离得7种组份群(0～6),细胞活性测得3～6号组分有活性,选择4号组分过C18柱得5组分(A～E),B组分为有紫外吸收的主峰,但无细胞活性,其活性分布于D和E组分中,其IC50值为3.75 ug/ml,D组分经蒸发光散射检测为单峰.经上述方法分离纯化获得抑制人微血管内皮细胞增殖的单一组分群,其单一化合物具有潜在的利用价值.     

5-Hydroxyquinoline-2-Carboxylic Acid, a Dead-End Metabolite from the Bacterial Oxidation of 5-Aminonaphthalene-2-Sulfonic Acid

5-Aminonaphthalene-2-sulfonate (5A2NS) is converted by strain BN6 into 5-hydroxyquinoline-2-carboxylate (5H2QC). The authenticity of this new compound is confirmed by nuclear magnetic resonance and mass spectrometry. Its formation is explained by a spontaneous cyclization of the hypothetical metabolite 6′-amino-2′-hydroxybenzalpyruvate. The formation of 5H2QC as a dead-end product of 5A2NS prevents NADH regeneration so that 5A2NS oxidation is limited by the internal NADH pool.     

Isolation and Structure of Neoannonin,a Novel Insecticidal Compound from the Seeds of Annona squamosa

Two insecticidal compounds were isolated from the seeds of Annona squamosa. One was identified as annonin (squamocin) and the other was characterized as a novel dihydroxy-bistetrahydrofuran fatty acid lactone (acetogenin) with 35 carbons. These two compounds were toxic to eggs, larvae and adults of the fruitfly.     

Alpha Sarcin, a New Antitumor Agent: I. Isolation, Purification, Chemical Composition, and the Identity of a New Amino Acid

Isolation and purification procedures are given for the new antitumor agent, alpha sarcin. These procedures include the use of column ion exchange with a carboxylic resin (Amberlite IRC50), dialysis, decolorization with activated charcoal, gradient salt chromatography, salt removal, and drying from the frozen state. The final product has an activity of 800 sarcoma 180 mouse dilution units per mg. The amino acid composition of the purified material is reported. All of the usual amino acids found in proteins were present except methionine. In addition to the usual amino acids, an unknown amino acid was present in the acid hydrolysate. The latter was isolated, and was found to yield phenylalanine and kynurenine. This compound, which has been named “sarcinine,” is extremely stable in 6 n hydrochloric acid in the absence of air, and is unstable in alkali. Sarcinine has also been found in two other antitumor peptides produced by aspergilli, and so may relate significantly to the antitumor properties of these peptides.     

Isolation of a New Quinoline, 2,8-Dihydroxycinchoninic Acid from Corn Steep Liquor

Androgen receptor (AR) signaling is the master regulator of prostate cell growth. Here, to better understand AR signaling, we searched for AR-interacting proteins by yeast two-hybrid screening and identified protein arginine methyltransferase 10 (PRMT10) as one of the interacting proteins. PRMT10 was highly expressed in reproductive tissues, such as prostate. Immunostaining showed that PRMT10 was expressed in the nucleus of both epithelia and stroma of rat prostate. In human prostate cancer LNCaP cells, PRMT10 co-immunoprecipitated with AR in both the presence and absence of dihydrotestosterone (DHT). Knockdown of PRMT10 by siRNA decreased DHT-dependent LNCaP cell growth and induction of prostate-specific antigen, an AR-target gene, without apparent loss of AR. DHT decreased PRMT10 at both the mRNA and protein levels. The decrease in PRMT10 was canceled by knockdown of AR or an AR antagonist. These results indicate that PRMT10 plays an important role in androgen-dependent proliferation of prostate cancer cells.     

New Physiological Effects of 5-Aminolevulinic Acid in Plants: The Increase of Photosynthesis,Chlorophyll Content,and Plant Growth

5-Aminolevulinic acid (ALA) promoted the growth and yield of several crops and vegetables at concentrations lower than those eliciting herbicidal responses, i.e., less than 1.8 mm by foliar spray and 60 μm by root soaking. To evaluate the physiological action of ALA, the effects of ALA on plants were examined by several bioassay systems at 0.0006–600 μm. ALA at 0.06–6 μm by root soaking increased the growth of rice seedlings in light, but did not affect this in darkness. In horseradish shoot primordia, promotion by ALA was not proportional among total chlorophyll content, chlorophyll concentration, and fresh weight. In the test using pothos, ALA at 0.06 μm elicited the accumulation of chlorophyll, but the photosynthesis of the plants was promoted by treatment together with ALA and nutrients. These results suggest that ALA have a variety of plant physiological effects on chlorophyll synthesis, photosynthesis, and plant growth, and ALA acts as a growth regulator in plants at low concentrations. These effects of ALA were also assumed to be linked to light irradiation and an uptake of fertilizer by plants. However, excess ALA suppressed these effects.     

Isolation of a 2-Pyrone Compound as an Antioxidant from a Fungus and Its New Reaction Product with 1,1-Diphenyl-2-picrylhydrazyl Radical

The indophenol-reducing compound, 4-hydroxy-3,6-dimethyl-2H-pyrane-2-one (I), was isolated from the culture filtrate of an unidentified fungus. I also reacted with the DPPH radical to form a reaction product IV which was determined to be 1-[4-(3,4-dihydro-3,6-dimethyl-2,4-dioxo- 2H-pyran-3-yl)phenyl]-1-phenyl-2-picrylhydrazine. This is the first report describing the formation of an adduct of the DPPH radical and its scavenger.     

Isolation and Structure of a New Steroid,Asterosapogenine I,from Asterosaponins A and B

A new steroid, asterosapogenine I, was isolated as the main component in acid hydrolyzates of asterosaponins A and B. The structure of the compound was assigned to be 3,β,6α-dihydroxy-5α-pregn-9(11)-en-20-one.     

Isolation and Structure of Maingayic Acid,a Piscicidal Constituent of Callicarpa maingayi

A piscicidal constituent (1), C₂₀H₂₈O₃, (chloroform), which was named maingayic acid, was isolated from the leaf of Callicarpa maingayi. On the basis of the chemical spectral studies, the pK_MCS evaluation and the octant rule on the ORD curves, we have and deduced that maingayic acid is a furanoid diterpene acid possessing a rearranged labdane skeleton shown as 1’a.     

Isolation and Structure of a Novel Indophenol-reducing and 1,1-Diphenyl-2-picrylhydrazyl Radical-scavenging Compound from a Fungus

A novel indophenol-reducing and DPPH radical-scavenging compound (1) was isolated from a fungal metabolite. The structure of 1 was determined by a spectroscopic analysis, and the absolute configuration of 1 was determined by the modified Mosher’s method. Compound 1 showed slow-reacting DPPH radical-scavenging activity (ED₅₀ value of 298 μM after 96 hr).     

Isolation and Structure Elucidation of a New Indole Metabolite from Aspergillus ruber

A bacterial two-component signal transduction system, WalK/WalR, is essential to the cell viability of Gram-positive bacteria and is therefore a potential target for the development of a new class of antibiotics. We have solved the X-ray crystal structure of the DNA-binding domain of the response regulator WalR (WalRc) from a Gram-positive pathogen Staphylococcus aureus, currently causing serious problems in public health through the acquisition of multi-drug resistance. The structure contains a winged helix-turn-helix motif and closely resembles those of WalRs of Bacillus subtilis and Enterococcus faecalis, and also that of PhoB of Escherichia coli. Gel mobility shift assays with mutant WalRs revealed specific interactions of WalR with the target DNA, as elaborated by in silico modeling of the WalRc-DNA complex.     

Isolation and structure of stephalic acid,a new clerodane diterpene from Stevia polycephala

From the methanolic extract of Stevia polycephala a new clerodane-type diterpene, stephalic acid, was isolated. The structure and stereochemistry were determined by a combination of spectral data and single-crystal X-ray analysis.     

Isolation and Identification of the 3-Hydroxy-5-hydroxymethyl-pyridinium Compound as a Novel Advanced Glycation End Product on Glyceraldehyde-related Maillard Reaction

Glyceraldehyde (200 mM) and N^α-acetyllysine (100 mM) were incubated in 0.2 M sodium phosphate buffer (pH 7.4) at 37°C for a week. A major compound, glyceraldehyde-related Maillard reaction product, was purified from the reaction mixture using reverse phase (ODS)-HPLC. It was identified as 1-(5-acetylamino-5-carboxypentyl)-3-hydroxy-5-hydroxymethyl-pyridinium, named as GLAP (Glyceraldehyde derived Pyridinium compound), using NMR and MS analyses. It was suggested that GLAP as a novel advanced glycation end product (AGE) is one of the key compounds in the glyceraldehyde-related Maillard reaction.     

Isolation and Structure of a New Gibberellin from Immature Seeds of Prunus persica

New antibiotics, T1801 A, B, C, and D, were isolated from the culture broth of Pseudomonas sp. SC-1801. Their structures were found by spectroscopic analyses to be tri- and tetra(methylthio) derivatives of hydro quinone (T1801 A and C) or p-benzoquinone (T1801 B and D). They are new quinone and hydroquinone antibiotics and are active against Gram-positive bacteria, some fungi, and yeasts.