Manabu Nukina

A new fungal morphogenic substance, pyrenolide a from Pyrenophora teres

Abstract A new ten-membered lactone, pyrenolide A, was identified as a new fungal morphogenic substance and its structure including absolute stereochemistry was elucidated.

Fumiquinones A and B, Nematicidal Quinones Produced by Aspergillus fumigatus

New nematicides named fumiquinones A (1) and B (2), together with spinulosin (3), LL-S490β (4), and pseurotin A (5), were isolated from Aspergillus fumigatus and their structures were established by spectroscopic methods including 2D-NMR. Compound 1 showed effective nematicidal activities against Bursaphelenchus xylophilus and Pratylenchus penetrans without inhibiting plant growth except for lettuce seedlings. Compound 2 showed effective nematicidal activity against B. xylophilus, but had no inhibitory activity against P. penetrans. Compounds 3–5 showed effective nematicidal activities against B. xylophilus without any plant growth inhibition. Compounds 1–5 had no nematicidal activity against Caenorhabditis elegans. This is the first report of the nematicidal activities of compounds 3–5.

Structural Confirmation of Cotylenin A, a Novel Fusicoccane-diterpene Glycoside with Potent Plant Growth-regulating Activity from Cladosporium Fungus sp. 501-7W

The structure of cotylenin A, a potent plant-growth stimulant with the most complex molecule in cotylenins from Cladosporium fungus sp. 501-7W, was analyzed again by HMBC experiments and X-ray crystallography of its diacetyl-dihydroderivative. The previously proposed stereostructure of cotylenin A was thus completely confirmed.

Salinisporamycin, a novel metabolite from Salinispora arenicora

A new rifamycin antibiotic, salinisporamycin (1), has been isolated from a culture of a marine actinomycete. The producing organism was identified as Salinispora arenicora on the basis of the 16S rRNA sequence. High-resolution FAB-MS established the molecular formula of 1 as C33H43NO9. The planar structure of 1 was elucidated by NMR spectral analysis including COSY, heteronuclear single quantum coherence and heteronuclear multiple bond correlation. The relative stereochemistry of 1 was determined on the basis of rotating frame nuclear Overhauser effect spectroscopy. In addition, the solvatochromic behavior of 1 was investigated by measuring the UV spectra. This compound inhibited the growth of A549 cells, the human lung adenocarcinoma cell line, with an IC50 value of 3 μg ml−1, and also showed antimicrobial activity.

Isolation and Identification of New Antifungal Macrophorins E, F and G as Malonyl Meroterpenes from Botryosphaeria berengeriana

Macrophorins E, F and G were newly isolated from Botryosphaeria berengeriana, each showing potent antifungal activity similar to that of macrophorin A against phytopathogenic fungi B. berengeriana and Gibberella fujikuroi. Macrophorins E and G were identified as novel malonylated derivatives of macrophorin A, and F as a macrophorin E congener with a hydroxy-cyclohexenedione moiety instead of its epoxy-cyclohexenone one.

β-Hydroxyergothioneine, a New Ergothioneine Derivative from the Mushroom Lyophyllum connatum, and Its Protective Activity against Carbon Tetrachloride-Induced Injury in Primary Culture Hepatocytes

A new ergothioneine derivative named β-hydroxyergothioneine was isolated from the mushroom Lyophyllum connatum. Ergothioneine,N-hydroxy-N′,N′-dimethylurea, and connatin (N-hydroxy-N′,N′-dimethylcitrulline) were also isolated. All the compounds displayed the ability to scavenge free radicals, based on a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. Structural determination, including the absolute stereochemistry of β-hydroxyergothioneine, was achieved by spectroscopic analysis and X-ray crystallography. The radical scavenging activity of β-hydroxyergothioneine was almost the same as that of ergothioneine. β-Hydroxyergothioneine showed the greatest protective activity against carbon tetrachloride-induced injury in primary culture hepatocytes.

Novel Fusicoccins R and S, and the Fusicoccin S Aglycon (Phomopsiol) from Phomopsis amygdali Niigata 2-A, and Their Seed Germination-stimulating Activity in the Presence of Abscisic Acid

Our search for new 3-hydroxyfusicoccins structurally related to cotylenin A from a culture of Phomopsis amygdali Niigata 2-A resulted in the isolation of novel 3-hydroxy fusicoccins, called fusicoccins R and S, and the fusicoccin S aglycon, called phomopsiol, together with known 3α-hydroxyfusicoccin J. The structure of phomopsiol was identified as that of O-demethyl-3-epicotylenol based on spectroscopic evidence. The structures of fusicoccins R and S were also determined to be those of 3′-deacetyl-3α-hydroxyfusicoccin A and 3β-hydroxy-3-epifusicoccin H. The lettuce seed germination-stimulating activity of fusicoccins R and S, phomopsiol and 3α-hydroxyfusicoccin J was examined in the presence of ABA; fusicoccin R and 3α-hydroxyfusicoccin J were highly active, while fusicoccin S and phomopsiol were inactive. The possible biosynthetic relationships among these novel fusicoccins having a 3α- or 3β-hydroxy group in their diterpene moiety are briefly discussed.

(1R,6R,9S,10S)-9-Chloro-10-hydroxy-8-methoxycarbonyl-4-methylene-2,5-dioxabicyclo[4.4.0]Dec-3-one-7-ene, a first chlorine-containing shikimate-related metabolite from fungi

Abstract A new chlorine-containing metabolite has been isolated from two fungi, and its structure including absolute stereochemistry was established by spectroscopic and X-ray crystallographic studies.

5-(2,2-Dimethyl-4H-1,3-benzodioxin)methanol: the synthetic precursor to o-formyl-m-hydroxycinnamic acid, the most oxidized salicylaldehyde-type phytotoxin isolated from rice blast fungus, Magnaporthe grisea

Abstract o-Formyl-m-hydroxycinnamic acid, the most oxidized salicylaldehyde-type phytotoxin isolated from rice blast fungus, Magnaporthe grisea, was synthesized for the first time using 5-(2,2-dimethyl-4H-1,3-benzodioxin)methanol as the starting material, and the proposed structure was confirmed.

Erratum: Salinisporamycin, a novel metabolite from Salinispora arenicora

Correction to: The Journal of Antibiotics (2009) 62, 519–526; doi:10.1038/ja.2009.75 The authors of the above article noted an error in the publication of this paper (AOP and in this issue) in the spelling of the bacterium Salinispora arenicora in the title and throughout the text. The correct spelling of this bacterium is Salinispora arenicola.