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Differential effects of quercetin and its two derivatives (isorhamnetin and isorhamnetin-3-glucuronide) in inhibiting proliferation of human breast cancer MCF-7 cells

Pristimerin and celastrol isolated from the roots of Celastrus hypoleucus (Oliv) Warb f argutior Loes exhibited inhibitory effects against diverse phytopathogenic fungi. Pristimerin and celastrol were found to inhibit the mycelial growth of Rhizoctonia solani Kuhn and Glomerella cingulata (Stonem) Spauld & Schrenk in vitro by 83.6 and 62.6%, respectively, at 10 microg ml(-1). Pristimerin showed good preventive effect (96.7% at 100 microg ml(-1)) and curative effect (66.5% at 100 microg ml(-1)) against wheat powdery mildew in vivo. For celastrol, the preventive and curative effects against wheat powdery mildew were 80.5 and 45.4%, respectively, at 100 microg ml(-1).

A fungal pigment, hypocrellin D (1), together with three known perylenequinone derivatives hypocrellin A (2), B (3) and C (4), was isolated from the fruiting bodies of Shiraia bambusicola. Its structure was elucidated on the basis of spectral data including 2D NMR experiments. Hypocrellin D (1) significantly inhibited the growth of tumor cell lines Bel-7721, A-549 and Anip-973 with IC 50 values of 1.8, 8.8, 38.4 mg/ml, respectively.

Six new sesquiterpenes having the botryane carbon skeleton (1ϳ6), together with known compounds (7ϳ10) were induced and isolated from the ascomycete Daldinia concentrica (strain S 0318). Structures elucidation was accomplished by NMR spectroscopic and X-ray crystallographic studies.

Daldinin A, B, C with a new skeleton, together with four known compounds, were induced and isolated from cultures of the ascomycete Daldinia concentrica. Their structures were elucidated by spectroscopic analysis, and that of daldinin A was confirmed by single-crystal X-ray diffraction.