Bao-Min Feng

Polyketide butenolide, diphenyl ether, and benzophenone derivatives from the fungus Aspergillus flavipes PJ03-11

Five new polyketides including three new butenolides (1-3), one new diphenyl ether (4), and one new benzophenone (5), together with eleven known compounds (6-16) were isolated from a wetland fungus Aspergillus flavipes PJ03-11. Their structures were elucidated on the basis of detailed spectroscopic analysis. All the isolated compounds were tested for their α-glucosidase inhibitory activities. The results showed that compounds 1-3, 6, 7, 11, 15 and 16 exhibited stronger inhibitory activities than acarbose. And the preliminary structure-activity relationships of aspulvinone and diphenyl ether compounds on the α-glucosidase inhibitory activity were reported.

Sporulaminals A and B: a pair of unusual epimeric spiroaminal derivatives from a marine-derived fungus Paraconiothyrium sporulosum YK-03

Sporulaminals A (1) and B (2), a pair of unusual epimeric spiroaminal derivatives, bearing a 6/4/5/5 tetracyclic ring system derived from bergamotane sesquiterpenoid, were isolated from a marine-derived fungus Paraconiothyrium sporulosum YK-03. Their structures including the absolute configurations were elucidated by extensive NMR experiments, crystal X-ray diffraction and computational electronic circular dichroism (ECD) method. Furthermore, the epimerization induced by pH, temperature and H2O was revealed, together with the hypothetical biosynthetic pathway.

Three new compounds from the marine fungus Penicillium sp.

Continuous research on the ethyl acetate extract of the fermentation broth of the marine fungus Y26-02 (Penicillium sp.) led to the purification of one known and three new compounds. Their structures were elucidated, respectively, as butyl 2-(4-oxo-5,6-dihydro-2H-pyran-3-yl) acetate (1), 4-hydroxyphenethyl 2-(4-oxo-5,6-dihydro-2H-pyran-3-yl) acetate (2), 3-hydroxybenzyl 2-(4-oxo-5,6-dihydro-2H-pyran-3-yl) acetate (3), and desoxypatulinic acid (4) on the basis of their spectroscopic and physico-chemical properties.

Aldose Reductase Inhibitors from Stellera chamaejasme

Abstract Six biflavonoids (chamaejasmin, 7-methoxyneochamaejasmin, 7-methoxychamaejasmin, chamaejasmenin B, chamaechromone, wikstrol A) from Stellera chamaejasme. L. have been assayed to show good aldose reductase inhibiting activity. These compounds may be useful to improve diabetic complications such as neuropathy, cataract formation, neophropathy, and retinopathy.

A new acylated flavonoid glycoside from the flowers of Camellia nitidissima and its effect on the induction of apoptosis in human lymphoma U937 cells

From the EtOH extract of the flowers of Camellia nitidissima Chi, a new acylated flavonoid glycoside, quercetin 7-O-(6″-O-E-caffeoyl)-β-d-glucopyranoside (1), has been isolated, together with three known flavonoids: quercetin (2), quercetin 3-O-β-d-glucopyranoside (3), and quercetin 7-O-β-d-glucopyranoside (4). Their structures were elucidated on the basis of spectroscopic analysis. Compound 1 was shown to inhibit proliferation and to induce apoptosis of human lymphoma U937 cells.

Two diketopiperazines from Acanthopanax senticosus Harms

From the dried aerial parts of Acanthopanax senticosus, two new diketopiperazines, eleutherazines A (1) and B (2), were isolated. Their structures were elucidated on the basis of chemical and spectroscopic methods.

Three new steroid glycosides from the starfish Asterina pectinifera.

Three new steroid glycosides, pectiniosides H–J (1–3), were isolated along with three known compounds (4–6) including a steroid glycoside and two polyhydroxysteroids, from the alcoholic extract of the starfish Asterina pectinifera. The structures of 1–3 were determined by extensive NMR and HR-ESI-MS experiments. Compounds 1–4 did not show cytostatic activity on HL-60 cells below 100 μM, while compounds 5–6 showed moderate cytostatic activity, with IG50 values of 80.3 and 40.5 μM, respectively.

Three new secolignan glycosides from Urtica fissa E. Pritz

Three new secolignan glycosides {3,4-trans-4-[bis(3,4-dimethoxyphenyl)methyl]-2-oxotetrahydrafuran-3-yl}methyl-O-β-glucopyranoside (1), {3,4-trans-4-[(3-methoxy-4-hydroxyphenyl)(3,4-dimethoxyphenyl)methyl]-2-oxotetrahydrafuran-3-yl}methyl-O-β-glucopyranoside (2) and {3,4-cis-4-[(3-methoxy-4-hydroxyphenyl)(3,4-dimethoxyphenyl)methyl]-2-oxotetrahydrafuran-3-yl}methyl-O-β-glucopyranoside (3) were isolated from the roots of Urtica fissa E. Pritz. Their structures were identified by spectral methods including 1D NMR, 2D NMR and HR-EI-MS.

C21 steroidal glycosides from the roots of Cynanchum paniculatum

As a part of our continuing research for bioactive constituents from Cynanchum plants, four new C21 steroidal glycosides, cynapanoside D-G (1-4), together with six known compounds (5-10) were isolated from the roots of Cynanchum paniculatum (Bge.) Kitag. Their structures were elucidated on the basis of 1D- and 2D-NMR spectroscopic data as well as HR-ESI-MS analysis. Compound 8 exhibited potent inhibitory activities against HL-60, HT-29, PC-3 and MCF-7 cell lines with IC50 values of 8.3, 7.5, 34.3 and 19.4μM, respectively and compounds 1-4 and 9 displayed moderate cytotoxicity against the four cell lines. The in vitro antioxidant activities of compounds 1-4, 8 and 9 were assayed by DPPH radical scavenging activity. Antibacterial and antifungal activities of compounds 1-4, 8 and 9 were also tested.

A New Cyclo-thioglucoside from the Seeds of Raphanus sativus L.

A cyclo-thioglucoside named as raphanuside was isolated from the seeds of Raphanus sativus L.. The structure of raphanuside was determined on the basis of extensive spectroscopic means including HR-FAB-MS, ID and 2D NMR experiments.