Language：English   Publisher：AMER CHEMICAL SOC  

The 7',8'-stereochemistry of the tetrahydropyran sesquineolignans morinols A and B was determined as threo via synthetic studies and by comparison of NMR data of 7',8'-threo-morinol and 7',8'-erythro-morinol. This study also confirmed that the biosynthetic process produces enantiomeric mixtures of morinols A and B. This was ascertained by comparing the specific rotations of synthesized morinols A and B with those of naturally occurring morinols A and B.

DOI： 10.1021/np060461j

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Language：English  

The relationship between antibacterial activity of tetra-substituted tetrahydrofuran lignans (1-4) and their absolute configurations was tested. Only compound 4 among two virgatusins and two related compounds exhibited growth inhibitory activity against the Gram-positive bacteria Bacillus subtilis, Staphylococcus aureus and Listeria denitrificans. Compound 4 affected the growth of B. subtilis in a bactericidic manner, and its ability to dissipate the cytoplasmic membrane potential was investigated using the fluorescence probe 3,3′-dipropylthiadicarbocyanine iodide. These results suggested that compound 4 damages cells by causing the loss of the proton motive force and disruption of the cellular integrity of the membrane, leading to cell death. In addition, it was shown that the antibacterial activity of a lignan was closely related to its absolute configuration and functional groups.

DOI： 10.1271/bbb.60429

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Language：English   Publisher：TAYLOR & FRANCIS LTD  

The cytotoxic activity for colon 26 cell line of matairesinol, oxidized matairesinol, 9,9'-epoxylignan and oxidized 9,9'-epoxylignan were examined. (-)Matairesinol (Mat 1) showed greatest cytotoxic activity (LC50 = 9 mu g/ml) of the lactone-type lignans. 7,7'-Oxomatairesinol having same steric configuration as that of (-)-matairesinol showed greater activity (LC50 = 25 mu g/ml) than hydroxy or mono-oxomatairesinol. The activities of 9,9'-epoxylignan and 7,7-oxo-9,9'-epoxylignan having same steric configurations as (-)-matairesinol were weaker than that of corresponding matairesinols. Different activity levels were observed between enantiomers.

DOI： 10.1271/bbb.60353

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Language：English   Publisher：TAYLOR & FRANCIS LTD  

The radical and superoxide scavenging activities of oxidized matairesinols were examined. It could be assumed that the free benzylic position was important for higher radical scavenging activity. The different level of activity was observed between 7'-oxomatairesinol (Mat 2) and 7-oxomatairesinol (Mat 3). The activity of 8-hydroxymatairesinol was lower than that of matairesinol (Mat 1). The superoxide scavenging activity of the oxidized matairesinols was also demonstrated for the first time. It is assumed that the pKa value of phenol in the oxidized matairesinols affected this activity.

DOI： 10.1271/bbb.60096

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DOI： 10.1016/0378-1097(94)90328-X

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DOI： 10.1016/0378-1097(94)90328-X

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Language：English   Publisher：PORTLAND PRESS  

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Language：English   Publisher：WILEY-BLACKWELL  

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Language：English   Publisher：PORTLAND PRESS  

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DOI： 10.1271/bbb1961.55.2399

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DOI： 10.1271/bbb1961.55.2399

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DOI： 10.1271/bbb1961.54.599

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DOI： 10.1271/bbb1961.54.599

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DOI： 10.1271/bbb1961.53.1789

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DOI： 10.1271/bbb1961.53.1789

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Language：English  

Water-soluble phospholipase B was purified to homogeneity from Torulaspora delbrueckii cell washings. The washings were concentrated by ultrafiltration, and then a fraction with phospholipase B activity was precipitated with ammonium sulfate, and purified by sequential column chromatographies on Octyl-Sepharose CL-4B, DEAE-Sephacel, and Spharose 6B. The molecular weight of the enzyme was etimated to be 170,000~200,000 by SDS-polyacrylamide gel electrophoresis and by gel filtration with a Sephadex G-200 column. The isoelectric point of the enzyme was 4.0. The purified enzyme had two pH optima at pH 2.5 and pH 7.5. The activity at acidic pH was greatly stimulated by the divalent metal ions tested, but the activity at alkaline pH was stimulated mainly by Ca2+ and Fe2+. The purified enzyme had both lysophospholipase activity and phospholipase B activity in a ratio of 37 : 1 at acidic pH adn 73 : 1 at alkaline pH. The amino acid composition of the enzyme was characterized by high contents of Asp, Ser, Leu, and Gly. © 1988, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.

DOI： 10.1271/bbb1961.52.2451

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Language：English   Publisher：Oxford University Press  

Membrane-bound phospholipase B was purified to a homogeneous state from Torulaspora delbrueckii cell homogenate. Cell homogenate was extracted with Triton X-100, and the enzyme was precipitated with acetone. The acetone powder was washed repeatedly with Tris-HC1 buffer (pH 8.0) until no phospholipae B activity was detected in the soluble fraction. The enzyme was extracted with Triton X-100 from the final residue and purified about 1,390-fold by sequential chromatofocusing, Sepharose 6B, and DEAE-Sephadex A-50 column chromatography. The final preparation showed a single broad protein band on SDS-polyacrylamide gel electrophoresis when stained with silver stain reagent and PAS-reagent. The molecular weight of phospholipase B was about 390,000 and 140,000-190,000 as estimated by gel filtration on Sepharose 6B'' and SDS-polyacrylamide gel electrophoresis, respectively, suggesting that phospholipase B is an oligomeric protein. The isoelectric point was at pH 4.5. Phospholipase B has two pH optima, one acidic (pH 2.5-3.0) and the other alkaline (pH 7.2-8.0). At acidic pH the phospholipase B activity was greatly increased in the presence of divalent metal ions, although metal ions are not a factor for enzyme activity. On the other band, at alkaline pH the enzyme required Ca2+ or Mn2+ for activity. The pH- and thermal-stabilities at both pHs were similar. The phospholipase B hydrolyzed all diacyiphospholipids tested at acidic pH, but hydrolyzed only phosphatidylcholine at alkaline pH. The hydrolysis rates of lysophospholipids were much higher (about 10-fold) than those of diacylphospholipids at both pHs. © 1988 BY THE JOURNAL OF BIOCHEMISTRY.

DOI： 10.1093/oxfordjournals.jbchem.a122449

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DOI： 10.1271/bbb1961.52.2451

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