Tadayuki Shimanuki

Four fungitoxic C-18 hydroxy unsaturated fatty acids from stromata of epichloe typhina

Abstract Four fungitoxic C-18 hydroxy unsaturated fatty acids ( 1 )–( 4 ) have been isolated from stromata of Epichloe typhina . Their structures including the absolute configuration have been elucidated from spectral data.

Three phenolic acid derivatives from stromata of Epichloe typhina on Phleum pratense

Abstract Three new phenolic acid derivatives, 1,3- O -di- trans - p -coumaroylglycerol, 1,2- O -di- trans - p -coumaroylglycerol and chokorin were isolated from stromata of Epichloe typhina on timothy plants Phleum pratense . Their structures were established by spectroscopic and chemical means.

A ring B aromatic sterol from stromata of Epichloe typhina

Abstract A sterol with an aromatized B ring was isolated from stromata of Epichloe typhina growing on Phleum pratense . The structure was established as 1(10→6) abeo -ergosta-5,7,9,22-tetraen-3α-ol by spectral analysis and synthesis.

Gamahonolides A, B, and Gamahorin, Novel Antifungal Compounds from Stromata of Epichloe typhina on Phleum pratense

Four novel antifungal compounds, gamahonolides A and B, gamahorin, and 5-hydroxyl-4-phenyl-2(5H)-furanone, were isolated from stromata of Epichloe typhina on Phleum pratense. Their structures were determined by spectroscopic methods. The absolute configuration of gamahonolide A was determined by its ORD spectrum and (1)H-NMR shift difference between the diastereomeric pair of its O-methylmandelates. The stereochemistry of gamahorin was determined by NOE difference spectra and its CD spectrum.

Three fungitoxic cyclopentanoid sesquiterpenes from stromata of epichloe typhina

New fungitoxic sesquiterpenes, chokol A (1), B (2), and C (3), have been isolated from stromata of Epichloe typhina. Their structures and the relative configuration of 3 have been also elucidated from spectral data.

Production of phleichrome by Cladosporium phlei as stimulated by diketopiperadines of Epichloe typhina

Epichloe typhina is an endophytic fungus, while Cladosporium phlei is a pathogenic fungus of the timothy plant (Phleum pretense L.). We found two activities in the culture filtrate of E. typhina: one stimulated the pathogenic fungus, C. phlei, to produce phleichrome and the other inhibited its growth. The active ingredients that stimulated the production of phleichrome and inhibited the growth of C. phlei were isolated and characterized. The isolated compounds were identified as cyclo-(L-Pro-L-Leu) and cyclo-(L-Pro-L-Phe), which were stimulatory compounds, and p-hydroxybenzaldehyde, which was the growth inhibitory compound, based on an analysis of their spectral data. Of the two stimulatory compounds, cyclo-(L-Pro-L-Phe) showed higher activity. However, when 500 μg of cyclo-(L-Pro-L-Phe) was spotted on the TLC plate for bio-autography, a growth inhibitory zone was identified in the central red region, which contained phleichrome. On the other hand, phleichrome showed antifungal activity against E. typhina in the light, so it is assumed that there might be antagonism between the endophytic fungus, E. typhina, and the pathogenic fungus, C. phlei.

Two sphingoid derivatives from stromata of Epichloe typhin A on Phleum pratense

Abstract Two novel sphingoid derivatives were isolated from stromata of Epichloe typhina on timothy grass, Phleum pratense . Their structures were determined as 3-hydroxy-9-oxo-4-tetradecyl-5-oxa-1-azabicyclo[4.3.0]nonane-2-methanol and 3-hydroxy-9-oxo-4-(4 E -tetradecenyl)-5-oxa-1-azabicyclo[4.3.0]nonane-2-methanol by spectroscopic methods.