engleski

Isothiocyanates as acetylcholinesterase inhibitors and their sources from croatian wild-growing plants

Glucosinolates (GLs) stand as molecular tags of the plant order Brassicales. Via their hydrolysis products, mostly isothiocyanates (ITCs) and nitriles, GLs are known to be responsible for diverse biological activities such as anticarcinogenic, antimicrobial, and others. Those strikingly bio-relevant thiosaccharidic secondary metabolites are found without exception in all 16 families of the order Brassicales. All known GLs (ca. 130 molecules) display a remarkable structural homogeneity based on a hydrophilic β-D-glucopyrano unit, which bears a O-sulfated anomeric (Z)-thiohydroximate function connected to a rather hydrophobic side chain. Depending on plant species, the constitution of R is the sole structural variant, in which diversified aliphatic, arylaliphatic or indolic arrangements can be found. Extraction and purification of fair amounts of GLs from suitable plant species that contain high concentrations of a single or a small number of GLs represent one of the most used sources of these compounds. Thus, the GL quantitative and qualitative investigation including mostly GC-MS, HPLC-DAD and HPLC-MS techniques is an ongoing research activity and new structures are documented. Our group investigated plants wild-growing in Croatia which included many edible, medicinal and endemic ones, such as Alyssoides utriculata (L.) Medik., Arabis turrita L., Aurinia leucadea (Guss.) K. Koch, Aurinia sinuata (L.) Grieseb, Brassica botteri Vis., Capsella rubella Reut., Degenia velebitica Degen Hayek, Diplotaxis erucoides (L.) DC, Fibigia triquetra (DC.) Boiss. ex Prantl, Lunaria annua L., Peltaria alliacea Jacq. These plants represent sources of various GLs which include aliphatic ones, mostly thiofunctionalized (glucoerucin, glucoraphanin, glucoberteroin, glucoalyssin, glucocamelinin, glucoarabin, 9-methylsulfonylnonyl GL), olefinic (sinigrin, gluconapin, glucobrassicanapin) and branched (glucoputranjivin) ones, while D. erucoides contained arylaliphatic gluconasturtiin. One of the most common forms of neurodegenerative disorders, affecting many elderly people, is Alzheimer disease (AD). Inhibition of acetylcholinesterase (AChE) serves as a strategy for the treatment of AD (as well as some other neurological diseases), and various natural products, such as alkaloids, flavonoids, terpenes, etc. have long been recognized as such inhibitors. Informations on ITCs, the main degradation products of GLs, as AChE inhibitors are rare to non-existent. AChE inhibitory activity measurements were carried out by using the slightly modified Ellman method. Nine pure aliphatic and aromatic ITCs were tested and six of them showed very good inhibition from 60% to 99% at concentrations of 136 µg/mL, showing a potential for treatment of AD.

glucosinolates ; isothiocyanates ; cholinesterase inhibition

Rad izrađen i u okviru hrvatsko-francuskog znanstveno-istraživačkog projekta po nazivom "Glukozinolati - novi izvori i biološki potencijal" (2013.-2014.), voditelj doc. dr. sc.Ivica Blažević