New Cytotoxic α-Aminoacylamide and bis-1,5-Disubstituted Tetrazole Adducts From Amino-Diterpene Molecules by Ugi Reaction.

In search for new molecules of diterpene origin with promising anticancer activity, two amino-derivatives (methyl maleopimarate aminoimide and methyl 1β,13-epoxydihydroquinopimarate C4-hydrazone) were involved in the 4-component Ugi reaction (Ugi-4CR) and pseudo-7-component azido-Ugi condensation (azido-Ugi-7CR) to afford a series of adducts holding α-aminoacylamide and bis-1,5-disubstituted tetrazole substituents. The NCI-60 cancer cell panel screening revealed diterpene-type Ugi adducts 2, 5, and 6 with strong antiproliferative potency with GI in range of 1.2-15.

Derivatization of Abietane Acids by Peptide-like Substituents Leads to Submicromolar Cytotoxicity at NCI-60 Panel.

Natural compounds, including diterpenoids, play a critical role in various biological processes and are recognized as valuable components in cancer treatment. Isocyanides multicomponent reactions (IsMCRs) are one of the effective methods to obtain adducts at the carboxyl group with a peptide-like substituent. In this study, dehydroabietic acid and levopimaric acid diene adducts as the starting scaffolds were modified by the multicomponent Passerini (P-3CR) and Ugi (U-4CR) reactions to afford α-acyloxycarboxamides and α-acylaminocarboxamides.

Synthesis and bioevaluation of water-soluble -cyclodextrin-diterpene acid conjugates.

A series of -cyclodextrin (-CD)-conjugates were prepared by combining three abietane-type diterpene acids with two azide-functionalized -CDs via click chemistry, and the antiviral activity against wild-type and omicron SARS-CoV-2 spike pseudovirus as well as the antibacterial activity against were investigated. All the synthesised conjugates exhibited no significant cytotoxicity to BHK-21-hACE2 cells with cell viability over 80% at concentration of 15 M. Among the conjugates, the heptavalent -CD-dehydroabietic acid conjugate exhibited higher anti-SARS-CoV-2 activity against the omicron variant compared to the other conjugates.

Evaluation of A-ring hydroxymethylene-amino- triterpenoids as inhibitors of SARS-CoV-2 spike pseudovirus and influenza H1N1.

A set of triterpene A-ring hydroxymethylene-amino-derivatives was synthesized and their antiviral activity was studied. The synthesized compounds were tested for their potential inhibition of SARS-CoV-2 pseudovirus in BHK-21-hACE2 cells and influenza A/PuertoRico/8/34 (H1N1) virus in MDCK cell culture. Compounds 6, 8 and 19 showed significant anti-SARS-CoV-2 pseudovirus activity with EC value of 3.

Inhibitory properties of quinopimaric acid derivatives towards cholinesterases.

A series of new diterpene quinopimaric acid derivatives modified at the hydroxyl group with different pharmacophore fragments has been synthesised and their (along with previously obtained compounds) inhibitory properties towards cholinesterases were studied. Thereby an indole-3-acetyl derivative and a propargyl substituted compound were shown to be excellent and acetylcholinesterase-selective inhibitors. Both compounds inhibited the enzyme as a mixed type inhibitor, and K values of 0.