Crude Extracts and Secondary Metabolites of Epichloë bromicola against Phytophthora infestans.

Potato late blight caused by Phytophthora infestans is still one of the main factors limiting potato production. Epichloë spp. can provide host plants with various resistances, which makes them show great potential in the biological control of diseases. In this study, we explored the potential biological activity of crude extracts of 20 strains of Epichloë bromicola to control P. infestans. The crude extracts of strains 1 and 8 showed significant antifungal activity with an inhibition rate of 88 % and 81 %, respectively, and showed different effects on the mycelium morphology of P. infestans observed by scanning electron microscopy. Moreover, the two crude extracts demonstrated an interesting therapeutic and protective effect on potato late blight, and none of the extracts had an adverse effect against zebrafish embryos. A total of 13 metabolites were isolated from the crude extract of strain 8, and these tested compounds showed a weak antifungal effect and the inhibition rate was less than 80 %. These findings suggested that strains 1 and 8 have potential for biocontrol of late potato blight.

Terpenoids with anti-inflammatory activity from Abies chensiensis.

The phytochemical investigation of Abies chensiensis led to the isolation and identification of nine new compounds including eight triterpenoids (1-8) and a new abietane-type diterpene (9), along with three known compounds (10-12). The absolute configuration of 9 was assigned by X-ray diffraction analysis. Compounds 1-11 were evaluated for the anti-inflammatory activity. Among the tested compounds, 1, 2, 5 and 6 exhibited potent inhibitory activity with IC50 values of 15.97, 18.73, 20.18 and 10.97µM, respectively.

Highly oxygenated triterpenoids from the roots of Schisandra chinensis and their anti-inflammatory activities.

A new highly oxygenated triterpenoid, schinchinenlactone D (1), and three known compounds (2-4) were isolated from the roots of Schisandra chinensis. Their structures were determined by combining the spectroscopic analysis with the theoretical computations. The anti-inflammatory activities of compounds 1-4 were evaluated, and compound 3 exhibits the most significant activity in the inhibition of NO production with an IC50 value of 10.6 µM.

New lignans from the roots of Schisandra sphenanthera.

Nine new lignans (1-8, 13) and five known ones (9-12, 14) have been isolated from the roots of Schisandra sphenanthera and were tested for their capacity to scavenge 2,2-diphenyl-1-Picryl-hydrazyl (DPPH). Of these lignans tested, compounds 1, 7, 8 and 13 exhibited noteworthy antioxidant activity with IC50 values of 92, 115, 35 and 48 µg/mL, respectively. The anti-oxidative haemolysis of human red blood cells (RBCs) activity of the most active compound 8, which is similar to that of vitamin C, was evaluated.

Lycodine-type alkaloids from Lycopodiastrum casuarinoides and their acetylcholinesterase inhibitory activity.

Four new lycodine-type alkaloids, namely 16-hydroxyhuperzine B (1), N-methyl-11-acetoxyhuperzine B (2), 8,15-dihydrolycoparin A (3) and (7S,12S,13R)-huperzine D-16-O-ß-d-glucopyranoside (4), along with ten known analogues 5-14, were isolated from the whole plant of Lycopodiastrum casuarinoides. The structures of the new compounds were elucidated by means of spectroscopic techniques (IR, MS, NMR, and CD) and chemical methods. Compounds 1 and 2 possessed four connected six-membered rings, while compounds 3 and 4 were piperidine ring cleavage products. In particular, compound 4 was a lycopodium alkaloidal glycoside which is reported for the first time. Among the isolated compounds N-demethylhuperzinine (7), huperzine C (8), huperzine B (9) and lycoparin C (13) possessed significant inhibitory activity against acetylcholinesterase, and the new compound 1 showed moderate inhibitory activity. The structure activity relationships were discussed.

Antifungal activities of triterpenoids from the roots of Astilbe myriantha Diels.

During a search for plant extracts that possess activity against the fungi that cause diseases in plants, a 95% ethanol extract from the roots of Astilbe myriantha Diels showed inhibitory activity against Colletotrichum gloeosporioides. Bioassay-guided fractionation of the 95% ethanol extract led to the isolation of seven triterpenoids (1-7). Their structures were elucidated by spectroscopy and by a comparison with literature data. Among these compounds, 3ß,6ß,24-trihydroxyurs-12-en-27-oic acid (7) was the most active inhibitor of C. gloeosporioides, with >68.0% inhibition at 100mg/ml after 72h. Moreover, compound 7 displayed broad-spectrum inhibitory activity against Rhizoctonia solani, Fusarium oxysporum f. sp. Niveum, Fusarium oxysporum f. sp. Cubens, C. gloeosporioides, Penicillium citrinum, Colletotrichum lagenarium, and Penicillium digitatum, with EC50 values ranging from 13.9 to 34.0µg/ml. The potential of compound 7 as a fungicide is therefore promising. In addition, compound 1 was found to be a new triterpenoid, 3ß,6ß-dihydroxyurs-12-en-7α,27α-olide, which possesses six rings.