Two new cholinesterase inhibitors asiatoates A and B from Buddleja asiatica

A Recent Look into Natural Products that have Potential to Inhibit Cholinesterases and Monoamine Oxidase B: Update for 2010-2019

With respect to the unknowns of pathophysiology of Alzheimer's Disease (AD)-, and Parkinson's Disease (PD)-like neurodegenerative disorders, natural product research is still one of the valid tools in order to provide alternative and/or better treatment options. At one hand, various extracts of herbals provide a combination of actions targeting multiple receptors, on the other hand, the discovery of active natural products (i.e., secondary metabolites) generally offers alternative chemical structures either ready to be employed in clinical studies or available to be utilized as important scaffolds for the design of novel agents. Regarding the importance of certain enzymes (e.g. cholinesterase and monoamine oxidase B), for the treatment of AD and PD, we have surveyed the natural product research within this area in the last decade. Particularly novel natural agents discovered within this period, concomitant to novel biological activities displayed for known natural products, are harmonized within the present study.

Iridoid Glycosides and Phenolic Glycosides from Buddleja asiatica with Anti-inflammatory and Cytoprotective Activities

Chemical investigation of the methanol extract of the aerial parts of Buddleja asiatica resulted in the isolation of a new iridoid glycoside, buddlejasiaside A (1) and 11 known compounds: 6- O -[α-L-(4-isoferuloyl)-rhamnopyranosylcatalpol (2), specioside (3), verminoside (4), minecoside (5), 6- O -( p -hydroxybenzoyl)-ajugol (6), 6- O -caffeoyl ajugol (7), litanthosalin 8), eurostoside (9), 10- O -caffeoylaucubin (10), phlorizin (11), and garashangin (12). Their chemical structures were identified based on the MS and NMR spectroscopic analyses and comparing with the data reported in the literature. Compounds 1, 2, and 8-10 showed the modest inhibitory effects against nitrite production in LPS-stimulated BV2 microglia, with IC50 values ranging from 43.5-79.6 μM. Compounds 6, 7, and 11 protected HT22 hippocampal cells from glutamate-induced cell death, with EC50 values of 38.9, 14.8, and 27.1 μM, respectively.