Hai-Ying Yang

Xanthone derivatives from the fermentation products of an endophytic fungus Phomopsis sp.

Three new xanthones, 1,5-dihydroxy-3-hydroxyethyl-6-methoxycarbonylxanthone (1), 1-hydroxy-5- methoxy-3-hydroxyethyl-6-methoxycarbonylxanthone (2), and 1-hydroxy-3-hydroxyethyl- 8-ethoxycarbonylxanthone (3), along with seven known xanthones (4-10) were isolated from the fermentation products of an endophytic fungus Phomopsis sp.. Their structures were elucidated by spectroscopic methods including extensive 1D- and 2D-NMR techniques. Compounds 1-10 were also tested for their cytotoxicity against five human tumor cell lines (NB4, A549, SHSY5Y, PC3, and MCF7) by MTT method using paclitaxel as positive control. Compounds 1 and 3 showed cytotoxicity against A549 cell lines with IC50 values of 3.6 and 2.5 μM, respectively. In addition, 1 was cytotoxic to MCF7 cells with IC50 value of 2.7 μM.

Antiviral butyrolactones from the endophytic fungus Aspergillus versicolor.

Versicolactones A-D (1-4), four new butyrolactones, along with four known butyrolactones (5-8) were isolated from the fermentation products of the endophytic fungus Aspergillus versicolor. The structures of compounds 1-4, including absolute configuration, were elucidated by interpretation of the NMR and CD data. Compound 2 was further confirmed by single-crystal X-ray diffraction analysis. In particular, compound 1 is the first naturally occurring butyrolactone possessing an unusual 2-oxopropyl group. More importantly, compounds 1 and 8 displayed significant antitobacco mosaic virus activities with inhibition rates of 46.4 % and 35.4 %, even more potent than the positive control ningnanmycin (30.8 %). Compound 1 also showed moderate cytotoxicity against A549 and MCF7 cells with IC50 values of 3.2 and 2.5 µM, respectively.

Antiviral and Cytotoxic Isocoumarin Derivatives from an Endophytic Fungus Aspergillus oryzae.

Oryzaeins A-D (1-4), four new isocoumarin derivatives, along with five known ones (5-9) were isolated from solid cultures of an endophytic fungus Aspergillus oryzae. Their structures were elucidated by detailed spectroscopic analysis and by comparison with reported data of related derivatives. Among them, compounds 1 and 2 represent the first examples of isocoumarins possessing an unusual 2-oxopropyl group and a rare 3-hydroxypropyl group. Compounds 1 and 2 displayed moderate anti-tobacco mosaic virus activities with inhibition rates of 28.4% and 30.6%, respectively, at the concentration of 20 µM. The new compounds showed moderate inhibitory activities against several human tumor cell lines with IC50 values in the range of 2.8-8.8 µM. Supporting information available online at http://www.thieme-connect.de/products.

Isolation of Xanthones from the Fermentation Products of the Endophytic Fungus of Phomopsis amygdali

Two new xanthones, 4,5-dihydroxy-3-(2-hydroxyethyl)-1-methoxy-8-methoxycarbonylxanthone (1) and 1,8-dihydroxy-4-(2-hydroxyethyl)-3-methoxyxanthone (2), and seven known xanthones (3–9) were isolated from the fermentation products of a Phomopsis species fungus. Compounds 1, 2, and 7 were tested for their cytotoxicity against five human tumor cell lines. Compound 1 showed cytotoxicity against A549 and PC3 cells with IC50 values of 2.6 and 2.4 μM, respectively. The other compounds also showed moderate cytotoxicity for some tested cell lines with IC50 values between 5.2–9.2 μM.

Isocoumarins from the fermentation products of a plant entophytic fungus Penicillium oxalicum

Three new isocoumarins, terrecoumarins A–C (1–3), together with six known isocoumarins (4–9) were isolated from the fermentation products of the fungus Penicillium oxalicum 0403. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. The anti-tobacco mosaic virus (anti-TMV) activities of 1–9 were evaluated. The results revealed that compound 1 showed high anti-TMV activity with inhibition rate 25.4 ± 3.5%. Other compounds also showed weak activity with inhibition rate in the range of 11.3–18.9%.

Dihydroxanthenones from the fermentation product of an endophytic fungus Gliomastix murorum

Three new dihydroxanthones, muroxanthenones A–C (1–3), together with three known dihydroxanthones (4–6) were isolated from the fermentation products of an endophytic fungus Gliomastix murorum. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compound 3 showed high cytotoxicities against NB4 and PC3 cell with IC50 values of 2.2 and 2.8 μM. The other compounds also showed moderate cytotoxicities for some tested cell lines with IC50 values between 4.1 and 9.5 μM.

Isopentylated diphenyl ether derivatives from the fermentation products of an endophytic fungus Phomopsis fukushii

Three new isopentylated diphenyl ethers, (1–3), together with two known isopentylated diphenyl ethers derivatives (4 and 5) were isolated from the fermentation products of an endophytic fungus Phomopsis fukushii. Their structures were elucidated by spectroscopic methods, including extensive 1D- and 2D NMR techniques. Compounds 1–3 were evaluated for their anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity. The results showed that compounds 1–3 showed strong activity with diameter of inhibition zone (IZD) of 21.8 ± 2.4 mm, 16.8 ± 2.2 mm, and 15.6 ± 2.0 mm, respectively.

Three new diphenyl ether derivatives from the fermentation products of an endophytic fungus Phomopsis fukushii

Abstract Three new diphenyl ethers (1-3), together with four known isopentylated diphenyl ethers derivatives (4-7), were isolated from the fermentation products of an endophytic fungus Phomopsis fukushii. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1-3 were evaluated for their anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity. The results revealed that compounds 1 and 2 showed strong inhibitions with inhibition zone diameters (IZD) of 20.2 ± 2.5 mm and 17.9 ± 2.2 mm, respectively. Compound 3 also showed good inhibition with IZD 15.2 ± 1.8 mm. The IZD data of compound 1 is close to that of positive control with IZD 21.9 ± 2.1 mm.