Controlling the production of phytotoxin pyriculol in Pyricularia oryzae by aldehyde reductase.

Pyricularia oryzae is one of the most devastating plant pathogens in the world. This fungus produces several secondary metabolites including the phytotoxin pyriculols, which are classified into 2 types: aldehyde form (pyriculol and pyriculariol) and alcohol form (dihydropyriculol and dihydropyriculariol). Although interconversion between the aldehyde form and alcohol form has been predicted, and the PYC10 gene for the oxidation of alcohol form to aldehyde is known, the gene responsible for the reduction of aldehyde to alcohol form is unknown.

Biosynthetic gene cluster identification and biological activity of lucilactaene from sp. RK97-94.

We identified the biosynthetic gene cluster for lucilactaene, a cell cycle inhibitor from a filamentous fungus sp. RK 97-94. The knockout strain accumulated demethylated analogs, indicating the involvement of Luc1 methyltransferase in lucilactaene biosynthesis.

Safety of radiotherapy for hemodialysis patients with cancer.

Background: The number of hemodialysis (HD) patients is increasing worldwide, and they are at a higher risk of cancer than the general population. Because HD patients are more likely to have inflammation, radiotherapy (RT)-induced adverse effects (AEs) are theoretically expected to be worse for HD patients. Since only a few reports have been published on this subject, we aimed to evaluate the tolerability of RT in HD patients.

Steroid Degradation in Comamonas testosteroni TA441: Identification of the Entire β-Oxidation Cycle of the Cleaved B Ring.

TA441 degrades steroids via aromatization of the A ring, followed by degradation of 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid, mainly by β-oxidation. In this study, we revealed that 7β,9α-dihydroxy-17-oxo-1,2,3,4,10,19-hexanorandrostanoic acid-coenzyme A (CoA) ester is dehydrogenated by (3)-3-hydroxylacyl CoA-dehydrogenase, encoded by (ORF27), and then the resultant 9α-hydroxy-7,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid-CoA ester is converted by 3-ketoacyl-CoA transferase, encoded by (ORF23). With these results, the whole cycle of β-oxidation on the side chain at C-8 of 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid is clarified; 9-hydroxy-17-oxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid-CoA ester is dehydrogenated at C-6 by ScdC1C2, followed by hydration by ScdD.

Induction of Nectriapyrone Biosynthesis in the Rice Blast Fungus Pyricularia oryzae by Disturbance of the Two-Component Signal Transduction System.

Most fungal secondary metabolism genes are poorly expressed under laboratory conditions. Nectriapyrones are known as secondary metabolites produced mainly by symbiotic fungi, including endophytes and plant pathogens. Herein, we show the induction of nectriapyrone production in the rice blast fungus Pyricularia oryzae.

Steroid Degradation in Comamonas testosteroni TA441: Identification of Metabolites and the Genes Involved in the Reactions Necessary before D-Ring Cleavage.

Bacterial steroid degradation has been studied mainly with () and as representative steroid degradation bacteria for more than 50 years. The primary purpose was to obtain materials for steroid drugs, but recent studies showed that many genera of bacteria (, , , etc.) degrade steroids and that steroid-degrading bacteria are globally distributed and found particularly in wastewater treatment plants, the soil, plant rhizospheres, and the marine environment.

Identification of 4-methyl-5-oxo-octane-1,8-dioic acid and the derivatives as metabolites of steroidal C,D-ring degradation in Comamonas testosteroni TA441.

Comamonas testosteroni TA441 degrades steroids via 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid, which is presumed to be further degraded by β-oxidation. In the β-oxidation process, Coenzyme A (CoA)-ester of 9-oxo-1,2,3,4,5,6,10,19-octanor-13,17-secoandrost-8(14)-ene-7,17-dioic acid is produced and converted by β-ketoacyl-CoA-transferase encoded by ORF1 and ORF2 (scdL1L2) to cleave the remaining C-ring. In this study, we isolated and identified 4-methyl-5-oxo-octane-1,8-dioic acid and 4-methyl-5-oxo-3-octene-1,8-dioic acid from the culture of the ORF3 (scdN)-null mutant as metabolites of steroid degradation (ADD and cholic acid analogues; cholic acid, chenodeoxycholic acid, deoxycholic acid, and lithocholic acid).

Identification of 9-oxo-1,2,3,4,5,6,10,19-octanor-13,17-secoandrost-8(14)-ene-7,17-dioic acid as a metabolite of steroid degradation in Comamonas testosteroni TA441 and the genes involved in the conversion.

Comamonas testosteroni TA441 degrades steroid compounds via aromatization of the A-ring to produce 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid (a metabolite with C- and D-rings), which is presumed to be further degraded via β-oxidation. In elucidating the complete steroid degradation process in C. testosteroni, we isolated 9-oxo-1,2,3,4,5,6,10,19-octanor-13,17-secoandrost-8(14)-ene-7,17-dioic acid and several other metabolites containing only C-ring.

Total Synthesis of Highly Oxygenated Bisabolane Sesquiterpene Isolated from Ligularia lankongensis: Relative and Absolute Configurations of the Natural Product.

The relative and absolute configurations of an oxygenated bisabolane natural product, isolated from Ligularia lankongensis, were determined by synthesis. All four possible stereoisomers and their tiglate analogues were synthesized from R-(-)-carvone, and their H and C NMR spectra were compared to establish the 6R,8S,10S configuration. The stereoselective synthesis of the natural product was also achieved, featuring Brown allylation, vanadium-catalyzed epoxidation, and the Mitsunobu reaction.

Development of SAAP3D force field and the application to replica-exchange Monte Carlo simulation for chignolin and C-peptide.

Single amino acid potential (SAAP) would be a prominent factor to determine peptide conformations. To prove this hypothesis, we previously developed SAAP force field for molecular simulation of polypeptides. In this study, the force field was renovated to SAAP3D force field by applying more accurate three-dimensional main-chain parameters, instead of the original two-dimensional ones, for the amino acids having a long side-chain.

The identification of ᴅ-tryptophan as a bioactive substance for postembryonic ovarian development in the planarian Dugesia ryukyuensis.

Many metazoans start germ cell development during embryogenesis, while some metazoans possessing pluripotent stem cells undergo postembryonic germ cell development. The latter reproduce asexually but develop germ cells from pluripotent stem cells or dormant primordial germ cells when they reproduce sexually. Sexual induction of the planarian Dugesia ryukyuensis is an important model for postembryonic germ cell development.

Two New Diterpenoids from Salvia przewarskii.

One abietane-type and one dinoricetexane-type diterpenoid, salviskin A (1) and salviskin B (2), respectively, together with fourteen known diterpenoids, were isolated from Salvia przewarskii. Structural elucidation of these compounds was performed by spectroscopic methods including 2D NMR. The compounds isolated were evaluated for their cytotoxicity against HeLa and HL-60 cells.

Identification of novel secreted fatty acids that regulate nitrogen catabolite repression in fission yeast.

Uptake of poor nitrogen sources such as branched-chain amino acids is repressed in the presence of high-quality nitrogen sources such as NH4(+) and glutamate (Glu), which is called nitrogen catabolite repression. Amino acid auxotrophic mutants of the fission yeast Schizosaccharomyces pombe were unable to grow on minimal medium containing NH4Cl or Glu even when adequate amounts of required amino acids were supplied. However, growth of these mutant cells was recovered in the vicinity of colonies of the prototrophic strain, suggesting that the prototrophic cells secrete some substances that can restore uptake of amino acids by an unknown mechanism.

Haenamindole, an unusual diketopiperazine derivative from a marine-derived Penicillium sp. KCB12F005.

During the chemical investigation of marine-derived fungus, an unusual diketopiperazine (DKP) alkaloid, haenamindole (1), was isolated from a culture of the marine-derived fungus Penicillium sp. KCB12F005. The structure of 1, which possesses benzyl-hydroxypiperazindione and phenyl-pyrimidoindole rings system in the molecule, was elucidated by analysis of NMR and MS data.

A new enzyme involved in the control of the stereochemistry in the decalin formation during equisetin biosynthesis.

Tetramic acid containing a decalin ring such as equisetin and phomasetin is one of the characteristic scaffolds found in fungal bioactive secondary metabolites. Polyketide (PKS)-nonribosomal peptide synthetase (NRPS) hybrid enzyme is responsible for the synthesis of the polyketide scaffold conjugated with an amino acid. PKS-NRPS hybrid complex programs to create structural diversity in the polyketide backbone have begun to be investigated, yet mechanism of control of the stereochemistry in a decalin formation via a Diels-Alder cycloaddition remains uncertain.

Identification of 9α-hydroxy-17-oxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid in steroid degradation by Comamonas testosteroni TA441 and its conversion to the corresponding 6-en-5-oyl coenzyme A (CoA) involving open reading frame 28 (ORF28)- and ORF30-encoded acyl-CoA dehydrogenases.

Comamonas testosteroni TA441 degrades steroids via aromatization and meta-cleavage of the A ring, followed by hydrolysis, and produces 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid as an intermediate compound. Herein, we identify a new intermediate compound, 9α-hydroxy-17-oxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid. Open reading frame 28 (ORF28)- and ORF30-encoded acyl coenzyme A (acyl-CoA) dehydrogenase was shown to convert the CoA ester of 9α-hydroxy-17-oxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid to the CoA ester of 9α-hydroxy-17-oxo-1,2,3,4,10,19-hexanorandrost-6-en-5-oic acid.

Detection of oxygen addition peaks for terpendole E and related indole-diterpene alkaloids in a positive-mode ESI-MS.

This report describes that a regular positive electrospray ionization mass spectrometry (MS) analysis of terpendoles often causes unexpected oxygen additions to form [M + H + O](+) and [M + H + 2O](+), which might be a troublesome in the characterization of new natural analogues. The intensities of [M + H + O](+) and [M + H + 2O](+) among terpendoles were unpredictable and fluctuated largely. Simple electrochemical oxidation in electrospray ionization was insufficient to explain the phenomenon.

Identification of 9α-hydroxy-17-oxo-1,2,3,4,10,19-hexanorandrost-6-en-5-oic acid and β-oxidation products of the C-17 side chain in cholic acid degradation by Comamonas testosteroni TA441.

Comamonas testosteroni degrades testosterone into 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid and 2-hydroxyhexa-2,4-dienoic acid via aromatization of the A-ring. The former compound is suggested to be degraded further by β-oxidation, but the details of the process remain unclear. In this study, we identified 9α-hydroxy-17-oxo-1,2,3,4,10,19-hexanorandrost-6-en-5-oic acid as an intermediate compound in the β-oxidation of this compound.

The first isolation of furanoeremophilane from Ligularia nelumbifolia.

Ligularol (1), a furanoeremophilane, was isolated together with eremophil-l(10)-en-11-ol (2) from one of eight collected samples of Ligularia nelumbifolia and L. kongkalingensis, a closely related species. It is proposed that the ability to produce the furanoeremophilane has been acquired through hybridization.

Terpendole E and its derivative inhibit STLC- and GSK-1-resistant Eg5.

Terpendole E is first natural product found to inhibit mitotic kinesin Eg5, but its inhibitory mechanism remains to be revealed. Here, we report the effects of terpendole E and 11ketopaspaline (a new natural terpendole E analogue) on the Eg5-microtubule interaction and in several Eg5 mutants. 11-Ketopaspaline is a shunt product from terpendole E, and it shows potent inhibitory activity against the microtubule-stimulated ATPase activity of Eg5.

Boseongazepines A-C, pyrrolobenzodiazepine derivatives from a Streptomyces sp. 11A057.

Three new pyrrolobenzodiazepine derivatives, boseongazepines A-C (1-3), were isolated from a culture broth of Streptomyces sp. 11A057, together with the known compound usabamycin B (4). The structures of 1-4 were determined through the analysis of spectroscopic data including extensive 1D-, 2D-NMR, and MS techniques.

Application of plug-plug technique to ACE experiments for discovery of peptides binding to a larger target protein: a model study of calmodulin-binding fragments selected from a digested mixture of reduced BSA.

To discover peptide ligands that bind to a target protein with a higher molecular mass, a concise screening methodology has been established, by applying a "plug-plug" technique to ACE experiments. Exploratory experiments using three mixed peptides, mastoparan-X, β-endorphin, and oxytocin, as candidates for calmodulin-binding ligands, revealed that the technique not only reduces the consumption of the protein sample, but also increases the flexibility of the experimental conditions, by allowing the use of MS detection in the ACE experiments. With the plug-plug technique, the ACE-MS screening methodology successfully selected calmodulin-binding peptides from a random library with diverse constituents, such as protease digests of BSA.

Terpendole E, a kinesin Eg5 inhibitor, is a key biosynthetic intermediate of indole-diterpenes in the producing fungus Chaunopycnis alba.

Terpendole E is the first natural product inhibitor of kinesin Eg5. Because terpendole E production is unstable, we isolated and analyzed the terpendole E biosynthetic gene cluster, which consists of seven genes encoding three P450 monooxygenases (TerP, TerQ, and TerK), an FAD-dependent monooxygenase (TerM), a terpene cyclase (TerB), and two prenyltransferases (TerC and TerF). Gene knockout and feeding experiments revealed that terpendole E is a key intermediate in terpendole biosynthesis and is produced by the action of the key enzyme TerQ from paspaline, a common biosynthetic intermediate of indole-diterpenes.

Possible molecular mechanisms of species recognition by barnacle larvae inferred from multi-specific sequencing analysis of proteinaceous settlement-inducing pheromone.

Gregarious settlement is essential for reproduction and survival of many barnacles. A glycoprotein, settlement-inducing protein complex (SIPC) has been recognized as a signal for settlement and it is expressed in both conspecific adults and larvae. Although the settlement-inducing activities of SIPC are species-specific, the molecular-based mechanism by which larvae distinguish conspecific SIPC from the SIPC of other species is still unknown.

Four new bisabolane-type sesquiterpenes from Ligularia lankongensis.

The chemical constituents of the roots of two Ligularia lankongensis samples collected in Yunnan and Sichuan Provinces, China, were investigated, together with the DNA sequence of the atpB-rbcL and ITS regions. Four new highly oxygenated bisabolane-type sesquiterpenes (1 - 4) were obtained. Intraspecific diversity in the DNA sequence was found to be limited.