Identification of Secondary Metabolites in Tunisian Tilia platyphyllos Scop.Using MALDI-TOF and GC-MS

This study is the first to evaluate the phytochemical content and biological properties of Tunisian T.platyphyllos Scop.A total of 23 compounds of essential oils were identified by gas chromatography-mass spectrometry(GC-MS)analysis of bracts and fruit extracts.The results show that oxygenated monoterpenes were the dominant class of essential oils.The phenolic composition was investigated by matrix-assisted laser desorption/ionizationtime of flight(MALDI-TOF).The analysis showed that the chemical profiles of the ethanolic extracts of bracts and fruits are substantially similar.The highest polyphenol content was found in the ethanolic extracts of the fruits(7.65 mg gallic acid equivalents(GAE).g−1 on dry weight(DW).As for the antioxidant capacity,it was recorded in the essential oils of the fruits(IC_(50)=0.91 mg.mL^(−1)).The results obtained showed that the antioxidant activity of the fruit essential oil was higher than that of the ethanol extract.The fruit essential oil was also found to have the highest reducing power(IC_(50)=0.67 mg.mL^(−1)).In terms of iron-chelating power,fruit essential oil has the highest chelating power(IC_(50)=2.03 mg.mL^(−1)).Compared to the ethanolic extract,the essential oil had the maximum antioxidant capacity.The enzymatic activity of acetylcholinesterase(AChE)inhibition of the essential oil from T.platyphyllos bracts had the most potent inhibitory effect(IC_(50)=0.77 mg.mL^(−1)),followed by the essential oil from the fruits(IC_(50)=0.95 mg.mL^(−1)).The results suggest that T.platyphyllos can be used as a potential source of naturally occurring bioactive compounds and antioxidants.

Acetylcholinesterase inhibitory activities of 48 traditional Chinese medicinal herbs

Inhibition of acetylcholinesterase （ACHE） is one of the approaches for the treatment of Alzheimer＇s disease （AD）. In this paper the AChE inhibitory activities of ethanolic and aqueous extracts of 48 traditional Chinese medicinal herbs were evaluated. These traditional Chinese medicines have intelligence-promoting, anti-insomnia, sedative, neurotonic or tonic effects. Microplate assay indicated that ethanolic extracts of 28 traditional Chinese medicinal herbs and water extracts of 11 herbs showed AChE inhibitory activities. Among them, ethanolic extracts of Herba Moslae, Fructus Alpiniae Oxyphyllae, Radix Rehmanniae and Folium Nelumbinis showed most potent AChE inhibitory activities at the concentration of 0.1 mg/mL, with （68.63±1.12）%, （44.49±3.66）%, （43.78±4.76）%, and （42.63±8.31）% inhibition, respectively. The AChE inhibitory activities were also confirmed by TLC bioautographic assay. These results partially validate the traditional uses of some medicinal herbs for cognitive improvement.

Acetylcholinesterase inhibitors and antioxidants mining from marine fungi:bioassays,bioactivity coupled LC-MS/MS analyses and molecular networking

Marine fungi are potentially important resources for bioactive lead compounds for discovering new drugs for diseases such as Alzheimer's disease.In this paper,the combined bioassay model of acetylcholinesterase(AChE)inhibition,1,1-diphenyl-2-picrylhydrazyl(DPPH)free radical scavenging,and Artemi ci larval lethality was used to evaluate the activity and toxicity of 35 n narine fun gal strains from seas around China.Their bioactive constitue nfs were revealed by thin layer chromatography(TLC)autography,bioactivity coupled LC-MS/MS and Global Natural Products Social Molecular Networking(GNPS).The results show that the extracts of five strains exhibited higher AChE inhibition ratios than the positive control compound,'tacrine;for which the ratio was 89.8%at 200 pig/ml.Six strains displayed both AChE inhibition(inhibition ratios>20%at 200 pg/ml)and DPPH scavenging activity(scavenging ratios>30%at 200 pg/ml)together with low Artemia larval toxicity(lethal rates<12%).TLC autography showed that the fractioned extracts of four strains contained highly diverse and different bioactive constituents,includi ng strains Talaromyces sp.C2\-\,Aspergillus ter re us C23-3,Trichoderma harzianum DLEN2008005,and Penicillium corylophilum TBG1-17.From the most potent sample F-l 1-1-b(derived from Aspergillus tern us C23-3),five AChE inhibitors and seven antioxida nts were recognized as bioactive molecules by AChE coupled ultrafiltration followed by LC-MS/MS,and LC-MS/MS coupled with DPPH incubation.Furthermore,with the aid of GNPS,the AChE inhibitors were plausibly annotated as territrem analogues including territrems A-C/D,arisugacin A and an unknown compound 4,and the seven antioxidants were assigned as butyrolactone I.aspernolide E,a phenolic derivative and possibly unknown compounds 8-10 and 12.