Jinghua Xue

β-Resorcylic Acid Lactones from a Paecilomyces Fungus

Six new beta-resorcylic acid lactones (1-6), named paecilomycins A-F, and five known compounds, aigilomycin B (7), zeaenol (8), aigialomycin D (9), aigialomycin F (10), and aigialospirol, were isolated from the mycelial solid culture of Paecilomyces sp. SC0924. Their structures were elucidated by extensive NMR analysis, single-crystal X-ray study, and chemical correlations. Compounds 5 and 10 exhibited antiplasmodial activity against Plasmodium falciparum line 3D7 with IC(50) values of 20.0 and 10.9 nM, respectively, and compounds 5-7 showed moderate activity against the P. falciparum line Dd2.

Three New Isochromans from the Mycelial Culture of a Cylindrocarpon Fungus

Three new isochroman derivatives, l-acetonyl-7-carboxyl-6,8-dihydroxy-3,4,5-trimethylisochroman (1), 7-carboxyl-6,8-dihydroxy-1,1,3,4,5-pentamethylisochroman (2), and 6,8-dihydroxy-3,4,5-trimethylisochroman (3), together with decarboxydihydrocitrinone (4), were isolated from mycelial solid culture of a Cylindrocarpon fungus. Their structures were established by spectroscopic methods.

Penicillitone, a Potent in Vitro Anti-inflammatory and Cytotoxic Rearranged Sterol with an Unusual Tetracycle Core Produced by Penicillium purpurogenum

A rearranged sterol with an unusual tetracycle core skeleton, penicillitone (1), and a new sterol, penicillisterol (2), were obtained from the culture of the fungus Penicillium purpurogenum SC0070. Their structures were characterized by spectroscopic analysis, DFT/TDDFT compuations, and X-ray diffraction. Compound 1 demonstrated potent inhibitory effects on tumor cell growth and key pro-inflammatory cytokine production in macrophages. A biogenetic pathway with oxidative cleavage and vinylogous aldol addition as key reactions is proposed for 1.

Cytotoxic and Antibacterial Quinone Sesquiterpenes from a Myrothecium Fungus

Six new quinone sesquiterpenes, myrothecols A-F (1-6), and hymenopsin B (7) were isolated from cultures of Myrothecium sp. SC0265 by bioassay-guided fractionation. Their structures were elucidated on the basis of 1D and 2D NMR and MS data. The absolute configurations of the new compounds were assigned by CD/TDDFT calculations, and that of and hymenopsin B was confirmed by X-ray diffraction analysis. Compounds 1-5 and hymenopsin demonstrated cytotoxic activity against human carcinoma A549, HeLa, and HepG2 cells. Compounds 1-5 also exhibited antibacterial activity against Staphylococcus aureus and Bacillus cereus.

Polyoxygenated methyl cyclohexanoids from a terrestrial ampelomyces fungus.

Seven structurally related new polyoxygenated methyl cyclohexanoids, ampelomins A-G (1-7), were isolated from the mycelial solid culture of a soil-derived Ampelomyces fungus. Their structures were determined by spectroscopic and chemical means. Ampelomins A (1), C (3), E (5), and G (7) exhibited weak activity against alpha-glucosidase with IC(50) values of 1.74-5.93 mM, and ampelomin A (1) showed moderate antibacterial activity with MIC(90) values ranging from 202.4 to 1015.9 microM. A plausible polyketide biogenetic pathway is postulated for these compounds.

Antifungal Activity of Hypothemycin against Peronophythora Litchii In Vitro And In Vivo

The antifungal activity of a natural resorcylic acid lactone, hypothemycin (HPM), against Peronophythora litchii in vitro and in vivo was investigated. HPM treatment substantially suppressed spore germination of P. litchi, with the inhibition rate of 100% when 0.78 μg/mL HPM was applied. Similarly, mycelial growth of P. litchii was efficiently inhibited. Furthermore, HPM caused the ultrastructural modifications of P. litchii, including the disruption of the cell wall and the endomembrane system, especially the plasma membrane, mitochondria, and vacuoles, which led to the destruction of the cellular integrity. Moreover, application of HPM significantly reduced decay and suppressed peel browning of postharvest litchi fruit inoculated with P. litchii during storage at 28 °C. Overall, these findings suggested that HPM exhibited excellent antifungal activity against P. litchii both in vitro and in vivo, which could be helpful for the storage of harvest litchi fruit.

Cyclopeptides from Amanita exitialis

A new cyclic nonapeptide, amanexitide (1), along with the known cyclopeptides, α- and β-amanitins, was isolated from the fruiting bodies of Amanita exitialis, a newly described poisonous mushroom endemic to Guangzhou, Guangdong Province, China. Its amino acid composition and absolute configuration were determined by chemical degradation and derivatization followed by chiral GC analysis. Its amino acid sequence was elucidated by extensive analysis of ESIMS/MS and FTICRMS data. The occurrence of 1 in this mushroom is interesting because it has a structure closely related to antamanide, a cyclic decapeptide with antidote activity against amatoxins and phallotoxins, occurring in A. phalloides.

Bisacremines E–G, Three Polycyclic Dimeric Acremines Produced by Acremonium persicinum SC0105

Three dimeric acremines, bisacremines E-G (1-3), with an unusual carbon skeleton were isolated from cultures of the soil-derived fungus Acremonium persicinum SC0105. Their structures were elucidated by spectroscopic analysis, X-ray diffraction, and ECD/TDDFT computations. Compound 3 exhibited inhibitory effects on the production of TNF-α, IL-6, and NO in LPS-stimulated macrophages. A biogenetic pathway with a [4 + 2] cycloaddition as the key reaction is proposed for 1-3.

Versicorin, a new lovastatin analogue from the fungus Aspergillus versicolor SC0156

A new lovastatin analogue versicorin (1), together with three related compounds, decumbenones A (2) and B (3) and versiol (4), were isolated from mycelial solid cultures of Aspergillus versicolor SC0156. Their structures were elucidated on the basis of MS data and NMR spectroscopic analysis. The new compound versicorin (1) possesses a hexahydro-2H-naphtho[1,8-bc]furan moiety, which is a rare type of the lovastatin-analogous compounds. A hypothetical biosynthetic pathway for compounds 1–4 was proposed.

Bisacremines A-D, Dimeric Acremines Produced by a Soil-Derived Acremonium persicinum Strain.

Four dimeric acremines, bisacremines A-D (1-4), with a novel carbon skeleton and a new monomer, acremine T (5), were obtained from cultures of the soil-derived fungus Acremonium persicinum SC0105. Their structures were characterized by analysis of spectroscopic data, ECD/TDDFT computations, and X-ray diffraction. Compounds 1 and 2 exhibited weak cytotoxicity against HeLa cells, and 2 also showed modest activity against A549 and HepG2 cells.