Colonization Characteristics of Poplar Fungal Disease Biocontrol Bacteria N6-34 and the Inhibitory Effect on Pathogenic Fungi by Real-Time Fluorescence Quantitative PCR Detection.

Botryosphaeria dothidea is one of the most important diseases which can cause poplar canker. In our previous study, the endophytic Bacillus subtilis N6-34 screened from poplar tissue was found to be an antagonistic strain against B. dothidea. In order to ascertain the colonization rule of B. subtilis N6-34 in poplar plants, colonization of B. subtilis N6-34 labeled with a green fluorescent protein (GFP) was investigated in poplar plants and the rhizosphere soil. To confirm the inhibitory effect of the strain N6-34 on pathogenic fungi, real-time fluorescent quantitative PCR experiment with Fusarium oxysporum as the target strain was carried out. Firstly, a plasmid (pHT01-P43GFPmut3a) containing gfp gene was successfully transformed into wild B. subtilis N6-34, which has the similar characteristics with the strain N6-34 in cell growth and antifungal activity. The poplar pot experiments were carried out to examine the colonization rules and colonization quantity in poplar plants and rhizosphere soil. Observation with a confocal laser scanning microscope showed that GFP-labeled B. subtilis N6-34 (N6-34-GFP) could colonize in primary root, lateral root and adventitious root. With the extension of inoculation time, the colonization quantity of N6-34-GFP in the rhizosphere soil and poplar plants showed a trend of first increasing, then stabilizing for a period of time and then decreasing. The real-time fluorescent quantitative PCR result showed a gradual decrease in the number of F. oxysporum with increasing inoculation time. Therefore, N6-34-GFP exhibited colonization in the rhizosphere soil and different parts of poplar plants. In addition, the strain N6-34 could inhibit the growth of pathogenic fungi. The ability of B. subtilis N6-34 to colonize in the rhizosphere soil and poplar plants and to inhibit fungal growth in vitro suggest a potential application of this strain as a biological control agent.

Synthesis and evaluation of coumarin/1,2,4-oxadiazole hybrids as selective BChE inhibitors with neuroprotective activity.

A series of new coumarin/1,2,4-oxadiazole hybrids were synthesized and evaluated for cholinesterase inhibitory and neuroprotective activities. Among them, enantiomers 5u and 5v showed potent hBChE inhibitory activity with IC50 values of 8.17 and 9.56 µM, respectively, and also exhibited good selectivity for hBChE over hAChE by 9.49- and 7.58-fold, respectively. In addition, both compounds could protect SH-SY5Y cells against Aß25-35-induced neurotoxicity. The preliminary bioassay results provided a new chemotype for multifunctional anti-Alzheimer's disease agents and continuing investigation into compounds 5u and 5v is warranted.

Acanthiline A, a pyrido[1,2-a]indole alkaloid from Chinese mangrove Acanthus ilicifolius.

Chemical investigation of the leaves and stems of the Chinese mangrove Acanthus ilicifolius Linn. led to the isolation and structure elucidation of one new pyrido[1,2-a]indole alkaloid named acanthiline A (1), together with one known compound aurantiamide acetate (2). Compound 1 has a previously unreported natural product skeleton. The structure elucidation of 1 was based on the analysis of its 1D and 2D NMR and mass spectroscopic data.

Fasciospyrinadine, a novel sesquiterpene pyridine alkaloid from a Guangxi sponge Fasciospongia sp.

Fasciospyrinadine (1), a novel sesquiterpene pyridine alkaloid with a previously unreported skeleton featuring a monocyclicfarnesane moiety attached to a 3-methylenepyridine residue, was isolated from the sponge Fasciospongia sp. from Weizhou Island, Guangxi Autonomous Region. The structure and the relative stereochemistry of 1 were elucidated on the basis of extensive analysis of its 1D and 2D NMR spectroscopic techniques.

A new kalihinol diterpene from the Hainan sponge Acanthella sp.

A new kalihinol diterpene, 10-epi-kalihinol X (1), together with two known related diterpenes (2 and 3), and two sesquiterpenes (4 and 5) were isolated from the Hainan sponge Acanthella sp. The structure of the new compound was elucidated on the basis of the detailed analysis of its spectroscopic data and by comparison of its NMR data with those of structurally related compounds. Compounds 1 and 3-5 exhibited in vitro moderate cytotoxicities against human lung adenocarcinoma cell line A549, with IC50 values of 9.30, 3.17, 2.44, and 1.98 microg/mL, respectively.