Betulinic Acid-Azaprostanoid Hybrids: Synthesis and Pharmacological Evaluation as Anti-inflammatory Agents.

BACKGROUND: Prevention and treatment of chronic inflammatory diseases require effective and low-toxic medicines. Molecular hybridization is an effective strategy to enhance the biological activity of new compounds. Triterpenoid scaffolds are in the focus of attention owing to their anti-inflammatory, antiviral, antiproliferative, and immunomodulatory activities. Heteroprostanoids have different pleiotropic effects in acute and chronic inflammatory processes. OBJECTIVE: The study aimed to develop structurally new and low toxic anti-inflammatory agents via hybridization of betulinic acid with azaprostanoic acids. METHODS: A series of betulinic acid-azaprostanoid hybrids was synthesized. The synthetic pathway included the transformation of betulin via Jones' oxidation into betulonic acid, reductive amination of the latter and coupling obtained by 3ß-amino-3-deoxybetulinic acid with the 7- or 13-azaprostanoic acids and their homo analogues. The hybrids 1-9 were investigated in vivo on histamine-, formalin- and concanavalin A-induced mouse paw edema models and two models of pain - the acetic acid-induced abdominal writhing and the hotplate test. The hybrids were in vitro evaluated for cytotoxic activity on cancer (MCF7, U- 87 MG) and non-cancer humane cell lines. RESULTS: In the immunogenic inflammation model, the substances showed a pronounced anti-inflammatory effect, which was comparable to that of indomethacin. In the models of the exudative inflammation, none of the compounds displayed a statistically significant effect. The hybrids produced weak or moderate analgesic effects. All the agents revealed low cytotoxicity on human immortalized fibroblasts and cancer cell lines compared with 3ß- amino-3-deoxybetulinic acid and doxorubicin. CONCLUSION: The results indicate that the principal anti-inflammatory effect of hybrids is substantially provided with the triterpenoid scaffold and in some cases with the azaprostanoid scaffold, but the latter makes a significant contribution to reducing the toxicity of hybrids. Hybrid 1 is of interest as a potent low toxic agent against immune-mediated inflammation.

Genotoxic activity of 1,2,3-triazolyl modified furocoumarins and 2,3-dihydrofurocoumarins.

The furocoumarin backbone is a promising platform for chemical modifications aimed at creating new pharmaceutical agents. However, the high level of biological activity of furocoumarins is associated with a number of negative effects. For example, some of the naturally occurring ones and their derivatives can show genotoxic and mutagenic properties as a result of their forming crosslinks with DNA molecules. Therefore, a particularly important area for the chemical modification of natural furocoumarins is to reduce the negative aspects of their bioactivity. By studying a group of 21 compounds-1,2,3-triazolyl modified derivatives of furocoumarin and peucedanin-using the SOS chromotest, the Ames test, and DNA-comet assays, we revealed modifications that can neutralize the structure's genotoxic properties. Theoretical aspects of the interaction of the compound library were studied using molecular modeling and this identified the leading role of the polyaromatic molecular core that takes part in stacking-interactions with the pi-systems of the nitrogenous bases of DNA.

Rapid Access to Oxazine Fused Furocoumarins and in vivo and in silico Studies of theirs Biological Activity.

BACKGROUND: The synthesis of 1,2-oxazine-fused linear furocoumarins was performed involving the transition metal catalysis reaction of plant coumarin oreoselone derivatives. OBJECTIVE AND METHOD: The Pd-catalyzed desulfonative cross-coupling reactions of 2-(tosyl)oreoselone with terminal alkynes and the successive treatment of the obtained 2-(arylethynyl)furocoumarins with an excess of hydroxylamine gave the expected (Z,E)-3-(hydroxyimino)-2-(arylethynyl)furocoumarins with an (Z:E) ratio of about 1:0.5. The gold(III)-catalyzed cycloisomerization of furocoumarin ß,γ-acetylenic (Z)-oximes led to a new group of heterocyclic compounds - chromeno[6',7':4,5]furo[3,2-c][1,2]oxazine. The (E)-isomer in this condition was transformed into (E)-3-(hydroxyimino)-2-(propan-2-ylidene) furocoumarin. RESULTS: Pharmacological screening of the synthesized 1,2-oxazine-fused linear furocoumarins for anti-inflammatory and analgesic activity in vivo revealed that this compounds possessed high activity which was depend on the substitution in the aromatic ring of the oxazine unit. The results of experimental studies were found to be in accordance with that of the in silico docking results. CONCLUSION: The moderate toxicity of compounds (LD50 value was more than 2000 mg/kg) encouraged the further design of therapeutically relevant analogues based on this novel type of fused linear furocoumarins.