The causal fungus of frosty mildew in Quercus acutissima was taxonomically studied. Brown spots with conical white to yellowish tufts of the causal fungus developed on the leaves, followed by successive defoliation. The fungus was regarded as a new species of Mycopappus, M. quercus, from the morphology of the multicellular propagules. The ascogenous stage and true conidia of the fungus were not observed, although sclerotia were formed on the fallen diseased leaves.

Culcitiolides E-J (1-6), six new eremophilane-type sesquiterpenes, were isolated from the stem of Senecio culcitioides Sch. Bip. (Asteraceae). The structures were determined by detailed NMR spectral analysis. The inhibitory activities of these compounds against nuclear factor κB (NF-κB)-dependent gene expression were assessed. Culcitiolides E, H, and I potently inhibited NF-κB-induced gene expression at 20 µm.Key words Senecio culcitioides; eremophilane; culcitiolide; nuclear factor κB Senecio culcitioides Sch. Bip. is distributed throughout the Peruvian Andes in South America at an altitude of 4500-5000 m. S. culcitioides belongs to the family Asteraceae and has been used as a traditional folk medicine to treat cough, bronchitis and asthma.1-3) Nuclear factor κB (NF-κB) is a transcription factor and functions as a key regulatory element in inflammatory and immune responses and in cancer. During our search for new classes of inhibitors of NF-κB derived from natural products, we previously isolated culcitiolides A-D, eremophilane-type sesquiterpenoids from the stem of the previously uninvestigated plant S. culcitioides, and we showed that culcitiolides C and D are potent NF-κB inhibitors. 4) Our continuous effort to identify NF-κB inhibitors in S. culcitioides led to the isolation of six new eremophilane-type sesquiterpenoids exhibiting potent NF-κB inhibitory activity. Herein, we describe the isolation and structural elucidation of culcitiolides E-J and the evaluation of their inhibitory activities against NF-κB-dependent gene expression.

Culcitiolides E (I), H (IIIa) and I (IIIb) potently inhibit NF‐ϰB‐induced gene expression.

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Four new eremophilane-type sesquiterpenes, culcitiolides AD , were isolated from the stem of Senecio culcitioides Sch. Bip (Asteraceae). Their structures were established by detailed 2D NMR spectroscopic and single-crystal X-ray experiments. These compounds were assessed for inhibitory activity against nuclear factor B (NF-B). Culcitiolides C and D at 20 M showed 97 and 100% inhibition of NF-B activity, respectively.