Fractionation of Lycopodiaceae Alkaloids and Evaluation of Their Anticholinesterase and Cytotoxic Activities

Abstract

In view of the abundant evidence that Lycopodiaceae alkaloids, including the well-known huperzine A (HupA), are among the potent acetylcholinesterase (AChE) inhibitors, an attempt was made to search for new compounds responsible for this property. For this purpose, three plant species belonging to the Lycopodiaceae family, commonly found in the Euro-Asia region, were subjected to the isolation of bioactive compounds, their identification and subsequent evaluation of their anticholinesterase and cytotoxic activities. Methanolic extracts of two Lycopodium and one Hupezia species were obtained via optimized pressurized liquid extraction (PLE) and then pre-purified using innovative gradient vacuum liquid chromatography (gVLC). For the first time, three sorbents of different porosity packed in polypropylene cartridges and mobile phase systems of different polarity were used to elute the target compounds. This technique proved to be a rapid tool for the obtainment of alkaloid fractions and allowed one to select the appropriate process conditions to yield potent AChE inhibitors in each of the species studied. More than 100 collected fractions were analyzed via HPLC/ESI-QTOF-MS, which enabled one to detect more than 50 compounds, including several new ones previously unreported. Some of them were present in high purity fractions (60–90% of the established purity). TLC bioautography assays proved that the analyzed species are rich sources of AChE inhibitors, but H. selago showed the highest anti-AChE activity. Additionally, the modified silanized silica gel sorbent used allowed one to isolate L. clavatum alkaloids more efficiently using an aqueous reversed-phase solvent system. Furthermore, the tested extracts from the three plant extracts were found to be safe, as they did not exhibit cytotoxicity to skin fibroblasts.

Amaryllidaceae, Lycopodiaceae Alkaloids and Coumarins—A Comparative Assessment of Safety and Pharmacological Activity

“…Many of the studies on the Lycopodiaceae alkaloids were carried out in the second half of the 20th century. They led to the isolation of more than 200 alkaloids, which were then divided by Canadian scientists in the 1990s into four major classes based on similarities in structure and pharmacological activity, including lycopodine, lycodine, fawcettimine and miscellaneous [ 34 ]. Alkaloids belonging to the lycopodine type with a single nitrogen atom in their structure constitute the largest group with more than 100 compounds.…”

“…Over time, researchers have proven that the alkaloid huperzine A (HupA), isolated from the Huperzia species (the Lycopodiaceae family), penetrates better the blood–brain barrier, has higher bioavailability and is less toxic compared to known AChE inhibitors (e.g., galantamine). Furthermore, recent studies in Huperzia , as well as Lycopodium species , confirmed the presence of novel potent AChE inhibitors in vitro assays [ 34 ]. Angelica dahurica (Hoffm.)…”

Antifungal Sesquiterpenoids from Michelia formosana Leaf Essential Oil against Wood-Rotting Fungi

“…Pure compounds were obtained from active fractions by high-performance liquid chromatography (HPLC, L-2130, Hitachi, Tokyo, Japan) with a preparative 9.4 × 250 mm Zorbax Sil column (5 μm). The isocratic mobile phase consisted of n -hexane (90%) and ethyl acetate (10%), at a flow rate of 2 mL/min; elution peaks were detected by the refractive index (RI) detector [ 34 , 35 , 36 ].…”

Differentiation Effect of Two Alkaloid Fractions from Vietnamese Lycopodiaceae on Mouse Neural Stem Cells

“…L. clavatum is a rich source of alkaloids and triterpenoids. Recently, Dymek et al (2021) developed a technique to extract L. clavatum, L. annotinum, and H. selago active ingredients by using the pressurized liquid extraction method. These methanolic extracts showed bioactivity as anti-AChE (Dymek et al 2021).…”

“…Recently, Dymek et al (2021) developed a technique to extract L. clavatum, L. annotinum, and H. selago active ingredients by using the pressurized liquid extraction method. These methanolic extracts showed bioactivity as anti-AChE (Dymek et al 2021). Three new triterpenoids of L. clavatum were isolated from the methanol extract via combined chromatographic separation techniques.…”