Synthesis and evaluation of diterpenic Mannich bases as antiviral agents against influenza A and SARS-CoV-2.

A chemical library was constructed based on the resin acids (abietic, dehydroabietic, and 12-formylabietic) and its diene adducts (maleopimaric and quinopimaric acid derivatives). The one-pot three-component CuCl-catalyzed aminomethylation of the abietane diterpenoid propargyl derivatives was carried out by formaldehyde and secondary amines (diethylamine, pyrrolidine, morpholine, and homopiperazine). All compounds were tested for cytotoxicity and antiviral activity against influenza virus A/Puerto Rico/8/34 (H1N1) in MDCK cells and SARS-CoV-2 pseudovirus in BHK-21-hACE2 cells.

Synthetic modifications of abietane diterpene acids to potent antimicrobial agents.

Among abietane type semisynthetic diterpenoids, a series of quinopimaric and maleopimaric acid derivatives modified at the carboxyl and carbonyl groups, and in ring were synthesised to obtain new compounds with antimicrobial potency against HRv and key ESKAPE pathogens. It was found that compound exhibited low toxicity to human embryonic kidney cell line HEK-293 (> 32 μg/mL) and showed significant bacteriostatic activity against methicillin-resistant (MRSA) (MIC ≤ 0.25 µg/mL) and excellent antifungal activity against (MICs ≤0.

Synthesis, structure, and antitumor activity of 2,9-disubstituted perhydro 2,3a,7b,9,10a,14b-hexaazadibenzotetracenes.

Catalytic methods for the synthesis of previously unknown 2,9-disubstituted 3b*,7a*,10b*,14a*--14c,14d-perhydro-2,3a,7b,9,10a,14b-hexaazadibenzotetracenes have been developed. The structures were established by 1D (H, C) and 2D (COSY, HSQC, HMBC) NMR spectroscopy, MALDI TOF/TOF mass spectrometry, and X-ray diffraction analysis. Primary screening of the synthesized perhydro hexaazadibenzotetracenes for antitumor activity was carried out.

Synthesis, modification, and biological activity of propargylated methyl dihydroquinopimarates.

The introduction of the alkynyl moiety to the abietane diterpenic core by modification of the cycle of methyl dihydroquinopimarate is described. The arylpropargyl, aminopropargyl, and 1,2,3-triazole derivatives are synthesized Sonogashira reaction, Mannich reaction and click-chemistry, correspondingly. The antitumor effect towards the NCI-60 cancer cell line panel and antimicrobial activity against key ESKAPE pathogens of the synthesized compounds were studied .