Aflatoxin B(1) (AFB(1) ) is a potent mycotoxin with mutagenic, carcinogenic, teratogenic, hepatotoxic, and immunosuppressive properties. In order to develop a bioremediation system for AFB(1) -contaminated foods by white-rot fungi or ligninolytic enzymes, AFB(1) was treated with manganese peroxidase (MnP) from the white-rot fungus Phanerochaete sordida YK-624. AFB(1) was eliminated by MnP. The maximum elimination (86.0%) of AFB(1) was observed after 48 h in a reaction mixture containing 5 nkat of MnP. The addition of Tween 80 enhanced AFB(1) elimination. The elimination of AFB(1) by MnP considerably reduced its mutagenic activity in an umu test, and the treatment of AFB(1) by 20 nkat MnP reduced the mutagenic activity by 69.2%. (1) H-NMR and HR-ESI-MS analysis suggested that AFB(1) is first oxidized to AFB(1) -8,9-epoxide by MnP and then hydrolyzed to AFB(1) -8,9-dihydrodiol. This is the first report that MnP can effectively remove the mutagenic activity of AFB(1) by converting it into AFB(1) -8,9-dihydrodiol.

Rings or arcs of fungus-stimulated plant growth occur worldwide; these are commonly referred to as "fairy rings". In 2010, we discovered 2-azahypoxanthine (AHX), a compound responsible for the fairy-ring phenomenon caused by fungus; AHX stimulated the growth of all the plants tested. Herein, we reveal the isolation and structure determination of a common metabolite of AHX in plants, 2-aza-8-oxohypoxanthine (AOH). AHX is chemically synthesized from 5-aminoimidazole-4-carboxamide (AICA), and AHX can be converted into AOH by xanthine oxidase. AICA is one of the members of the purine metabolic pathway in animals, plants, and microorganisms. However, further metabolism of AICA remains elusive. Based on these results and facts, we hypothesized that plants themselves produce AHX and AOH through a pathway similar to the chemical synthesis. Herein, we demonstrate the existence of endogenous AHX and AOH and a novel purine pathway to produce them in plants.

We investigated whether manganese peroxidase (MnP) and the laccase-mediator system with 1-hydroxybenzotriazole (HBT) as mediator can remove the estrogenic activities of the steroidal hormones 17beta-estradiol (E(2)) and ethinylestradiol (EE(2)). Using the yeast two-hybrid assay system, we confirmed that the estrogenic activities of E(2) and EE(2) are much higher than those of bisphenol A and nonylphenol. Greater than 80% of the estrogenic activities of E(2) and EE(2) were removed following 1-h treatment with MnP or the laccase-HBT system; extending the treatment time to 8h removed the remaining estrogenic activity of both steroidal hormones. HPLC analysis demonstrated that E(2) and EE(2) had disappeared almost completely in the reaction mixture after a 1-h treatment. These results strongly suggest that these ligninolytic enzymes are effective in removing the estrogenic activities of E(2) and EE(2).

The mushroom Stropharia rugosoannulata is called saketsubatake in Japanese, and wine-cap stropharia in English. It belongs to the family Strophariaceae, which is widespread in northern temperate zones throughout the world. It is edible and is cultivated for food. During screening for anti-endoplasmic-reticulum (ER) stress and anti-methicillin-resistant Staphylococcus aureus (MRSA) effects of the extracts of various mushrooms, we found activity in the extract of this mushroom. ER stress induces apoptotic pathways with signaling between the ER and mitochondria. By triggering apoptosis on neural cells, the stress is a major cause of degenerative diseases such as Alzheimers disease. [1,2] MRSA has developed resistance to most antibiotics and is one of the most prevalent pathogens in nosocomial infections. Therefore, anti-ER-stress and anti-MRSA substances are urgently required. Recently we reported that several active steroids were isolated from this mushroom. [3] In further search for bioactive compounds from the mushroom, we discovered four novel steroids having a very unique and unprecedented carbon skeleton. Herein, we describe the isolation, structure determination, and biological activity of the compounds from the mushroom.Fresh fruiting bodies of S. rugosoannulata were extracted with EtOH and then with acetone. After the solutions were combined and concentrated, they were partitioned between n-hexane and H 2 O, CHCl 3 and H 2 O, and then EtOAc and H 2 O. The hexane-soluble residue was fractionated by repeated chromatography. As a result, four novel compounds (1-4), which were named strophasterols A, B, C, and D, were isolated (Scheme 1).Strophasterol A (1) was obtained as white crystals. Its molecular formula was determined to be C 28 H 44 O 4 by HRESIMS with m/z 467.3100 [M+Na] + (calcd for C 28 H 44 NaO 4 467.3137), thus indicating the presence of seven degrees of unsaturation in the molecule. The planar structure of 1 was elucidated by interpretation of the NMR spectra, including DEPT, COSY, HMBC, and HMQC data. The DEPT experiment indicated the presence of six methyl, eight methylene, and eight methane groups, as well as six quaternary carbon atoms. In the NMR spectra of 1, typical signals of a sterol corresponding to two hydroxymethines [C3: d H = 3.94 ppm (m), d C = 68.2 ppm; C6: d H = 4.84 ppm (m), d C = 63.0 ppm], four doublet methyls [C2'CH 3 : d H = 0.97 ppm (d, J = 6.7 Hz), d C = 20.8 ppm; C4''CH 3 : d H = 0.72 ppm (d, J = 6.7 Hz), d C = 16.4 ppm; C2''CH 3 : d H = 0.74 ppm (d, J = 6.7 Hz), d C = 15.6 ppm; C3''CH 3 : d H = 0.83 ppm (d, J = Scheme 1. Structures of strophastrerols A-

Two peroxidases, CWPO-A and CWPO-C, were isolated from the cell walls of poplar (Populus alba L.) callus culture. The cationic CWPO-C showed a strong preference for sinapyl alcohol over coniferyl alcohol as substrate. Thus, the monolignol utilization of CWPO-C is unique compared with other peroxidases, including anionic CWPO-A and horseradish peroxidase (HRP). CWPO-C polymerized oligomeric sinapyl alcohol (S-oligo) and sinapyl alcohol, producing a polymer of greater molecular weight. In contrast, HRP, which is specific to coniferyl alcohol, produced sinapyl alcohol dimers, rather than catalyzing polymerization. Adding coniferyl alcohol as a radical mediator in the HRP-mediated reaction did not result in S-oligo polymerization. This report shows that CWPO-C is an isoenzyme specific to sinapyl alcohol that polymerizes oligomeric lignols. Its catalytic activity toward oligomeric lignols may be related to the lignification of angiosperm woody plant cell walls.