Alkaloid-metabolites from the mangrove-derived fungus Penicillium robsamsonii HNNU0006.

Nine metabolites, including three undescribed alkaloids pyripyropenes VW (1-2), penicioxa A (4), two previously reported pyripyropene A (3), oxaline (5), three grisephenone-type xanthone derivatives (6-8), and a diphenyl ether derivative 4-chloro-7,4'-dihydroxy-5,2'-dimethoxy-2-methylformate-6'-methybenzophone (9), were isolated from cultures of the mangrove-derived fungus Penicillium robsamsonii HNNU0006. Their structures were determined by spectroscopic analysis, ECD calculations, together with DP4+ probability analysis. Furthermore, all the isolated compounds were tested for cytotoxicity and anti-phytopathogenic fungal activities. Compounds 6-8 showed moderate cytotoxicity against tumor cell lines A549, with IC50 values ranging from 5.68 ± 0.21 to 9.71 ± 0.34 µg/mL, respectively.

Rare isotachin-derived from the Dasymaschalon rostratum fungus Penicillium tanzanicum ZY-5.

Four rare isotachin-derived, isotachins E-H (1-4), together with two known biogenetically related isotachin derivatives (5 and 6) were isolated from the solid rice fermentation of a fungus Penicillium tanzanicum ZY-5 obtained from a medicinal plant Dasymaschalon rostratum collected from the Changjiang County, Hainan Province, China. Their structures were elucidated using comprehensive spectroscopic methods. The single-crystal X-ray diffraction of compound 5 was determined. Compounds 1-4 have a trans-3-(methylthio)-acrylic acid fragment, which are rare in nature. The inhibitory activities of all compounds against the nitric oxide (NO) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells in vitro were evaluated.

Two novel aporphine-derived alkaloids from the stems of Fissistigma glaucescens.

Two novel aporphine-derived alkaloids, aporaloids A and B (1 and 2), together with eight known biogenetically related alkaloids (3-10), two known isoquinoline alkaloids (3 and 4), and six known aporphinoid alkaloids (5-10) were isolated from the stems of Fissistigma glaucescens. Their structures were elucidated using comprehensive spectroscopic methods. Compounds 1 and 2 represent the rare example of a six-membered lactone ring aporphine-derived alkaloids from natural products. The inhibitory activities of all compounds against four cancer cell lines were evaluated. Aporaloids A and B (1 and 2) showed broad spectrum cytotoxic activities.

Bioactive cyclohexene derivatives from a mangrove-derived fungus Cladosporium sp. JJM22.

Four new cyclohexene derivatives cladoscyclitols A-D (1-4) and one new ribofuranose phenol derivative 4-O-α-D-ribofuranose-2-pentyl-3-phemethylol (5) were obtained from the EtOAC extract of the mangrove-derived endophytic fungus Cladosporium sp. JJM22. The structures were elucidated by extensive NMR and MS analysis, while the absolute configurations of the stereogenic carbons were established based on quantum-chemical electronic circular dichroism calculations or comparison of the optical rotations with those of related compounds. Compounds 2 and 5 displayed potent inhibitory activity against α-glucosidase with the IC50 values of 2.95 and 2.05 µM, respectively.

Three new methylated Δ8-pregnene steroids from the Polyalthia laui-derived fungus Stemphylium sp. AZGP4-2.

Three new methylated Δ8-pregnene steroids, stemphylisteroids A-C (1-3) were isolated from the medicinal plant Polyalthia laui-derived fungus Stemphylium sp. AZGP4-2. Their structures were elucidated by the detailed analysis of comprehensive spectroscopic data. The absolute configuration of 1 was determined by X-ray crystallographic analysis. Compound 1 show antibacterial activity against Escherichia coli with the MIC value of 6.25 µg/mL, and 2 exhibited a broad spectrum of antibacterial activities against six pathogenic bacteria with the MIC values ranging from 12.5 to 50 µg/mL. The discovery of three methylated Δ8-pregnene steroids 1-3 are a further addition to diverse and complex array of methylated steroids.

Bioactive acetaminophen derivatives from Penicillum herquei JX4.

Two novel epimer pairs of acetaminophen derivatives penicilquei A-D (1-4) were isolated from Penicillium herquei JX4. Their structures were elucidated using comprehensive spectroscopic methods. The absolute configurations of penicilquei A-D (1-4) were determined by modifified Mosher's method, and comparing their experimental and calculated electronic circular dichroism (ECD) spectra. Penicilquei A-D (1-4) are the first example of acetaminophen derivatives featuring an unprecedented carbon skeleton. The inhibitory activities of all compounds against nine phytopathogenic fungi and α-glucosidase were evaluated. Penicilquei A-D (1-4) showed strong inhibitory activities against at least eight phytopathogenic fungus.

Two new benzophenones and one new natural amide alkaloid isolated from a mangrove-derived Fungus Penicillium citrinum.

Two new compounds penibenzophenones A-B (1-2), and the synthetic α,ß-unsaturated amide alkaloid (E)-tert-butyl(3-cinnamamidopropyl)carbamate (4), newly identified as a natural product, alone with three known ones (3, 5-6) were isolated from the EtOAc extract of the endophytic fungus Penicillium citrinum HL-5126 isolated from the mangrove Bruguiera sexangula var. rhynchopetala collected in the South China Sea. Compound 1 was a chlorinated benzophenone. The structures of 1-6 were elucidated by extensive NMR spectral interpretation, MS data and X-ray analysis. The new compound 2 displayed cytotoxic activity against human A549 cell lines with an IC50 value of 15.7 µg/mL, and 1 showed antibacterial activity against Staphylococcus aureus with a MIC value of 20 µg/mL.

A new norisoprenoid from the leaves of Ficus pumila.

One new norisoprenoid 3,9-dihydroxy dihydro actinidiolide (1), together with eleven known compounds (2-12), were isolated from ethanol extract of the leaves of Ficus pumila collected in Hainan Province, China. Their structures were elucidated by the detailed analysis of comprehensive spectroscopic data. Compounds 1, 2, 4, 5, 8 and 10-12 were isolated from the F. pumila for the first time. All compounds were evaluated for their cytotoxic activity. Compounds 3 and 9 showed weak cytotoxic activity against Hela, MCF-7 and A549 cell lines.

One new Lignan derivative from the fruiting bodies of Ganoderma lipsiense.

One new lignan derivative 2,3-dimethyl-4-(4'-hydroxy-3',5'-dimethoxyphenyl)-6-hydroxy-7-methoxy-naphthalene (1), together with four known analogues (2-5), were isolated from acetone extract of the fruiting bodies of Ganoderma lipsiense collected in the Hainan Province, China. Their structures were elucidated by the detailed analysis of comprehensive spectroscopic data. Compound 1 showed insecticidal activity against newly hatched karvae of Helicoverpa armigera Hubner. Compounds 1-5 showed moderate antibacterial activity against Staphylococcus aureus with the same MIC value of 1.25 µg/mL.

New phenylpropanoid and 6H-dibenzo[b,d]pyran-6-one derivatives from the stems of Dasymaschalon rostratum.

Three new phenylpropanoid derivatives, dasymaroacid A (1), dasymaroesters B and C (2 and 3), and one new polyoxygenated 6H-dibenzo[b,d]pyran-6-one derivative dasymarolactone D (4), together with seven known compounds (5-11), were isolated from the stems of Dasymaschalon rostratum Merr. Compounds 1 and 2 are unusual phenylpropanoid derivatives with a polymethyl substituted cyclopentene conjugated diketone as a substituent, and 3 is a unique cinnamic acid detective with a polymethyl substituted cyclohexene conjugated triketone as a substituent. Their structures were elucidated by extensive spectroscopic methods and chemical method, and 4 was further confirmed by the single crystal X-ray diffraction method. Compounds 1-4 and 7 showed weak anti-HIV-1 activities with EC50 values ranged from 16.44 to 25.91µM.

Guaiane-Type Sesquiterpenoids from Fissistigma oldhamii Inhibit the Proliferation of Synoviocytes.

Three guaiane-type sesquiterpenoids, dysodensiols G-I (1-3), together with five known sesquiterpenoids (4-8) were isolated from the stems of Fissistigma oldhamii (Hemsl.) Merr. Compound 1 represents the first example of an ene(6 → 5)-abeo-14-norguaiane sesquiterpenoid derived from natural products. Their structures were elucidated by a combination of 1D and 2D NMR and MS spectra. The absolute configuration of 2 was determined by an X-ray crystallographic analysis. The inhibitory effect of all compounds on the proliferation of primary synovial cells was evaluated. Compound 3 showed a potent inhibitory effect on the proliferation of synoviocytes with an IC50 value of 1.0 µM.

One new lignan derivative from the Combretum alfredii Hance.

One new lignan derivative 2,3-dimethyl-4-(4-methoxyphenyl)-6,7-dihydroxynaphthalene (1), together with five known compounds (2-6), were isolated from ethanol extract of the branches and leaves of Combretum alfredii Hance collected in Hainan Province, China. Their structures were elucidated by the detailed analysis of comprehensive spectroscopic data. Compounds 1, 2, 5 and 6 were isolated from the genus of Combretum for the first time. All compounds were evaluated for their antibacterial activities. Compounds 1 and 2 showed significant antibacterial activities against six pathogenic bacteria.

Five new lactone derivatives from the stems of Dendrobium nobile.

Five new lactone derivatives decumbic acids A and B (1 and 2), (-)-decumbic acid (3a), (-)- and (+)-dendrolactone (4a and 4b) together with four known compounds (3b and 5-7) were isolated from the stems of Dendrobium nobile. Their structures were elucidated using comprehensive spectroscopic methods. Compounds 3a and 3b, 4a and 4b were isolated as two pair of enantiomers by chiral HPLC. The absolute configurations of 1, 2, 3a, 4a and 4b were determined by optical rotation and X-ray crystallographic analysis. The inhibitory activities of all compounds against nine phytopathogenic fungi and three cancer cell lines were evaluated.

Bioactive Phenanthrene and Bibenzyl Derivatives from the Stems of Dendrobium nobile.

A new enantiomeric pair of spirodiketones, (+)- and (-)-denobilone A (1 and 2), three new phenanthrene derivatives (3-5), and three new biphenanthrenes (22-24), along with 11 known phenanthrene derivatives (6-16), five known bibenzyl derivatives (17-21), and four known biphenanthrenes (25-28), were isolated from Dendrobium nobile. The structures of 1-5 and 22-24 were elucidated using comprehensive spectroscopic methods. (+)-Denobilone and (-)-denobilone A (1 and 2) were isolated as a pair of enantiomers by chiral HPLC. The absolute configurations of (+)- and (-)-denobilone A (1 and 2) were determined by comparing their experimental and calculated electronic circular dichroism spectra. The absolute configuration of denobilone B (3) was determined by X-ray crystallographic analysis. The inhibitory activities of all compounds against nine phytopathogenic fungi and three cancer cell lines were evaluated.

One new berberine from the branches and leaves of Polyalthia obliqua Hook.f. & Thomson.

One new alkaloid consanguine B (1), together with 10 known alkaloids (2-11), were isolated from ethanol extract of the branches and leaves of Polyalthia obliqua Hook.f. & Thomson collected in the Hainan Province, China. Their structures were elucidated by the detailed analysis of comprehensive spectroscopic data. All compounds were evaluated for their cytotoxic activities. Compound 1 showed weak cytotoxic activities against Hela and MCF-7 human cancer cell lines.