Chrodrimanins O-S from the fungus Penicillium sp. SCS-KFD09 isolated from a marine worm, Sipunculusnudus.

Five new meroterpenoids, chrodrimanins O-S (1-5), as well as a known one (6), were isolated from the fermentation broth of Penicillium sp. SCS-KFD09 isolated from a marine worm, Sipunculusnudus, from Haikou Bay, China. The structures including the absolute configurations of the new compounds were unambiguously elucidated by spectroscopic data and ECD spectra analysis along with quantum ECD calculations. Among them, compound 1 represents the first example of an unusual trichlorinated meroterpenoid with an unique dichlorine functionality. Compounds 1 and 4-6 displayed inhibitory activity of protein tyrosine phosphatase 1B (PTP1B) with IC50 values of 71.6, 62.5, 63.1, and 39.6µM, respectively, and showed no apparent activity against three tumor cell lines (A549, HepG2, and Hela) and human umbilical vein endothelial cells (HUVEC) at 10µM.

Cytotoxic activity of a synthetic deoxypodophyllotoxin derivative with an opened D-ring.

Podophyllotoxin and its synthetic derivatives are valuable medicinal agents that have antitumor, insecticidal, and antifungal properties. We previously synthesized a deoxypodophyllotoxin derivative with an opened D-ring (DPD) exhibiting potent insecticidal activity. This article was firstly performed to identify the cytotoxicity of DPD toward human cancer cell lines (SGC7901, HeLa, and A549) and normal cell line (HEK293T) using MTT assay. DPD showed potent cytotoxicity against human cancer lines (HeLa and A549) and less cytotoxicity against normal cell lines HEK293T. DPD could also induce the cell cycle arrest at G2/M phase in HeLa cells and significantly increase the phosphorylation (Tyr 15) of CDC2 leading to inactivation of CDC2. The effects of DPD on cellular microtubule networks were detected using immunofluorescence technique in HeLa cells. The immunofluorescence results showed DPD influenced the arrangement and organization of cellular microtubule networks in HeLa cells. Microtubules are long, hollow cylinders made up of polymerized tubulin dimers. Total microtubules were separated after DPD treatment. Western blot results showed that the free polymerized tubulin dimers were obviously increased after DPD treatment. DPD may be a good drug candidate with the therapeutic potential to human cancer by affecting microtubule polymerization.

Dihydroberkleasmin A: a new eremophilane sesquiterpenoid from the fermentation broth of the plant endophytic fungus Pestalotiopsis photiniae.

Dihydroberkleasmin A (1), a new ester-substituted sesquiterpenoid related to the eremophilane class, together with the known compound berkleasmin C (2), were isolated from the fermentation broth of the plant endophytic fungus Pestalotiopsis photiniae. The structure of dihydroberkleasmin A (1) was elucidated by extensive spectroscopic analysis. The stereochemistry was assigned by comparison of the NMR spectroscopic data with those of berkleasmin A.

Insecticidal compounds from Tripterygium wilfordii active against Mythimna separata.

In the course of screening for novel naturally occurring insecticides from plants, the ethanol extract of the root bark of Tripterygium wilfordii Hook f. was found to show insecticidal activity against larvae of Mythimna separata Walker. Three active compounds were isolated by bioassay-guided fractionation of the extract and characterized as triptolide (1), triptonide (2) and euonine (3) by IR, 1H and 13C NMR and mass spectral analysis. Compounds 1 and 2 showed strong contact activity against 3rd or 5th larvae of M. separata (LD50 1.6 microg/insect for 1, 2.9 microg/insect for 2, no contact activity for 3; LD50 is the lethal dose for 50% mortality). The antifeedant activity against the 3rd larvae of M. separata after a 24-h treatment was demonstrated; 1, 2 and 3 gave EC50 (effective concentration causing 50% antifeedance) values of 0.25, 0.35 and 0.02 mM, respectively. 1 and 2 were inferior to the positive control represented by toosendanin (12a-acetoxyamoorastatin), 3 was superior to toosendanin. For the ingested toxicity against M. separata, 1 had the more potent activity with an KD50 value of 13.5 microg/g (insect body weight) than toosendanin. This is the first report on insecticidal activity of these three compounds.