[Synthesis of A-secomethylenamino- and substituted amidoximotriterpenoids]

Azepanodipterocarpol is potential candidate for inhibits influenza H1N1 type among other lupane, oleanane, and dammarane A-ring amino-triterpenoids

A series of lupane-, oleanane- and dammarane-based triterpenoids with 3β-amino, A-ring azepano- and 3,4-seco-fragments has been synthesized and evaluated for antiviral activity against influenza A(H1N1) virus. It was found that azepanodipterocarpol 8 and 3β-amino-28-oxoallobetulin 11 showed antiviral activity with IC50 1.1 and 2.6 μg ml-1, and selectivity index of 19 and 10, respectively.

From Marine Metabolites to the Drugs of the Future: Squalamine, Trodusquemine, Their Steroid and Triterpene Analogues

This review comprehensively describes the recent advances in the synthesis and pharmacological evaluation of steroid polyamines squalamine, trodusquemine, ceragenins, claramine, and their diverse analogs and derivatives, with a special focus on their complete synthesis from cholic acids, as well as an antibacterial and antiviral, neuroprotective, antiangiogenic, antitumor, antiobesity and weight-loss activity, antiatherogenic, regenerative, and anxiolytic properties. Trodusquemine is the most-studied small-molecule allosteric PTP1B inhibitor. The discovery of squalamine as the first representative of a previously unknown class of natural antibiotics of animal origin stimulated extensive research of terpenoids (especially triterpenoids) comprising polyamine fragments. During the last decade, this new class of biologically active semisynthetic natural product derivatives demonstrated the possibility to form supramolecular networks, which opens up many possibilities for the use of such structures for drug delivery systems in serum or other body fluids.

Anti-SARS-CoV-2 Natural Products as Potentially Therapeutic Agents

Severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2), a β-coronavirus, is the cause of the recently emerged pandemic and worldwide outbreak of respiratory disease. Researchers exchange information on COVID-19 to enable collaborative searches. Although there is as yet no effective antiviral agent, like tamiflu against influenza, to block SARS-CoV-2 infection to its host cells, various candidates to mitigate or treat the disease are currently being investigated. Several drugs are being screened for the ability to block virus entry on cell surfaces and/or block intracellular replication in host cells. Vaccine development is being pursued, invoking a better elucidation of the life cycle of the virus. SARS-CoV-2 recognizes O-acetylated neuraminic acids and also several membrane proteins, such as ACE2, as the result of evolutionary switches of O-Ac SA recognition specificities. To provide information related to the current development of possible anti-SARS-COV-2 viral agents, the current review deals with the known inhibitory compounds with low molecular weight. The molecules are mainly derived from natural products of plant sources by screening or chemical synthesis via molecular simulations. Artificial intelligence-based computational simulation for drug designation and large-scale inhibitor screening have recently been performed. Structure-activity relationship of the anti-SARS-CoV-2 natural compounds is discussed.

Evaluation of Cytotoxicity and α-Glucosidase Inhibitory Activity of Amide and Polyamino-Derivatives of Lupane Triterpenoids

A series of two new and twenty earlier synthesized branched extra-amino-triterpenoids obtained by the direct coupling of betulinic/betulonic acids with polymethylenpolyamines, or by the cyanoethylation of lupane type alcohols, oximes, amines, and amides with the following reduction were evaluated for cytotoxicity toward the NCI-60 cancer cell line panel, α-glucosidase inhibitory, and antimicrobial activities. Lupane carboxamides, conjugates with diaminopropane, triethylenetetramine, and branched C3-cyanoethylated polyamine methyl betulonate showed high cytotoxic activity against most of the tested cancer cell lines with GI50 that ranged from 1.09 to 54.40 µM. Betulonic acid C28-conjugate with triethylenetetramine and C3,C28-bis-aminopropoxy-betulin were found to be potent micromolar inhibitors of yeast α-glucosidase and to simultaneously inhibit the endosomal reticulum α-glucosidase, rendering them as potentially capable to suppress tumor invasiveness and neovascularization, in addition to the direct cytotoxicity. Plausible mechanisms of cytotoxic action and underlying disrupted molecular pathways were elucidated with CellMinner pattern analysis and Gene Ontology enrichment analysis, according to which the lead compounds exert multi-target antiproliferative activity associated with oxidative stress induction and chromatin structure alteration. The betulonic acid diethylentriamine conjugate showed partial activity against methicillin-resistant S. aureus and the fungi C. neoformans. These results show that triterpenic polyamines, being analogs of steroidal squalamine and trodusquemine, are important substances for the search of new drugs with anticancer, antidiabetic, and antimicrobial activities.

Inhibition of Alpha-Glucosidase by Synthetic Derivatives of Lupane, Oleanane, Ursane and Dammarane Triterpenoids

A variety of new and earlier synthesized lupane, oleanane, ursane and dammarane triterpenoids have been investigated for their inhibitory activity against α-glucosidase. 2,3-Indole-21β-acetyl-20β,28-epoxy-18α,19βH-ursane and 3-oxo-3A-homo-3a-aza-20( S)-hydroxydammar-24(25)-ene were synthesized for the first time. The compounds 3, 4, 8–11 and 14 demonstrated strong in vitro inhibitory activity towards α-glucosidase with IC50 values of 37.5–115.1 μM. 3-Deoxy-3a-homo-3a-aza-28-cinnamoyloxy-20(29)-lupene, with an IC50 of 6.67 μM was 60-fold more active than the market drug acarbose.

[Synthesis and cytotoxicity of triterpenoid seven members cyclic amines]

Synthesis of 3-deoxy-3a-homo-3a-aza-derivatives of betulin and erythrodiol from betulonic and oleanonic acids was carried out. The most antineoplastic activity with a wide range of action at in vitro testing showed 3-deoxy-3a-homo-3a-aza-28-hydroxy-12(13)-oleanene, which by results of profound studying could be recommended for in vivo investigation. Its modification in the C28 position by introduction of amethoxycinnamoyl fragment led to a loss of antineoplastic activity. 3-Deoxy-3a-homo-3a-aza-derivatives of betulin (3-(aminopropyl)-, 28-(2-carboxyethyl)carboxy-, and 28-cinnamoyloxy-) showed moderate antineoplastic activity in the case of Colon Cancer, Breast Cancer and Leukemia cell lines.