Design,Synthesis And Evaluation Of Anti-Coxsackie Activity Virus For Tricyclic Matrinic Derivatives

Sophocarpine (SC) is a monomer of quinolizidine alkaloid extracted from sophora plants. As a hospital preparation, injection of SC was effectively active against the Coxsackie B3 virus and was applied in the treatment of viral myocarditis. Because of its unique chemical scaffold and biological activity, SC was applied as the lead compound in our earlier study, its inner amide ring was opened and a simplified tricyclic scaffold was form, with several newly introduced modifiable sites on the 11-and 12-side chains. The novel representative compound 12-N-/m-cynanobenzensulfonyl matrinic butane (DB-3) was active against CVB3 with an IC50 value as low as 1.26 μM, and the activity was promoted for over 1000 times compared to the lead SC. At the meantime, DB-3 displayed a broad-spectrum anti-CVBs activity as well as reasonable pharmacokinetic properties (.Future Med Chem.,2016). However, in the acute toxicity experiment, mice were in panic at the dosage of 500 mg/kg by oral route, thus indicating a safety issue.Based on these works, DB-3 was taken as the lead compound, systematic modifications and optimizations were carried out focusing on the 12-N-substitution fragments and the 11-side chain, directed by the anti-CVB3 activity. By the following in vitro anticancer assay against HepG2 hepatoma cells, the anti-CVB3 SAR of tricyclic matrinic derivatives was further completed by the synthesis and biological assay of 96 new compounds, and summarized as follows (Figure 2):1. The activities of different substitutions on the 12-N atom followed the order: benzenesulfonyl≥benzeneformyl>benzyl>aliphatic formyl. Strong electron-withdrawing groups like cynano or trifluoromethyl on the benzenesulfonyl and benzeneformyl were the most favorable for activity.2. The activity disappeared in the case that the 11-butane chain was converted to butylamine or butyric acid. The activity sustained when The converting of 11-butane chain to the butyl methyl ether maintained the activity, while converting to ethyl methyl ether cause the decrease of activity. The longer chain corresponded to higher activity in the case of ether analogues.3. The introduction of halide atom (chlorine or fluorine) onto the end of 11-butane chain led to the maintaining of activity. While the bytyl chain was shortened to ethyl chain, the chlorine substitution caused the increase of activity, while the fluorine substitution caused the decrease of activity.15 compounds with diverse structure types and IC50 values lower than 10 μM, including DHC-1, DB-11, DB-1-03, DXC-9, DXC-10, DXC-17, CK-2, CK-3, CK-5, JM-2, CF-4, CF-5, CF-6, CF-9 and 3408 were screened out to carry out the mice acute toxicity experiment,6 of them, such as DB-11, DB-1-03, JM-2, CF-5, CF-6 and CF-9 gave the LD50 values of over 500 mg/kg. And the summarized STR was as follows (Figure 2):1. When the 11-side chain was fixed as butane, the toxicity of 12-N-substitution gave an order of benzene sulfonyl< heterocyclic sulfonyl< benzoyl.2. When the substitution on the 12-N atom was fixed as benzenesulfonyl group, the toxicity order was as follows:butylamine< butane, butyl fluoride, butylmethyl ether< butyl chloride and ethyl chloride.Next, four compounds including DB-11, DHC-1, DXC-9 and DXC-10 with diverse structure types as well as reasonable activity and safety characters were screened out, and showed good broad-spectrum anti-coxsackie virus against CVB1 、 CVB2、CVB4、CVB5、 CVB6 and CVA16 with IC50 ranges of 0.6-16.0 μM, indicating a broad anti-coxsackie virus spectra of these tricyclic matrinc compounds.The in vivo pharmacokinetic experiment showed that DB-11 and DXC-10 had ideal pharmacokinetic profiles with Cmax:2.8 and 1.8 μM, Tmax 1.3 and 1.8 h, AUC 28.1 and 7.5 μM·h respectively, indicating that DB-11 had good drugability and had promising prospect for further study.Totally 96 novel compounds were synthesized, whose structures were confirmed by 1H NMR,13C NMR and HRMS.36 derivatives gave anti-CVB3 IC50 values less than 10 μM, and among them, DB-11(IC50=1.58 μM) were equipped with a broad-spectrum anti-CVBs activity as well as good PK profiles and safety in vivo.. These results indicated that tricyclic matrinic derivatives were a class of broad-spectrum anti-CVB compounds with novel skeleton, and were thus very promising. Intensive mechanism of action of related candidates is in progress. Some of these works were published in Acta Pharmaceutica Sinica (2016).Besides, the anti-influenza screening of the synthesized compounds highlighted DHC-13 as a good lead compound with the IC50 value of 10.8 μM against Influenza A95-359.