Design, synthesis and triglyceride-lowering activity of tricyclic matrine derivatives for the intervention of non-alcoholic fatty liver disease.

Thirty new tricyclicmatrinic derivatives were successively synthesized and evaluated for their inhibitory activity on the accumulation of triglycerides (TG) in AML12 cells, using 12 N-m-trifluoromethylbenzenesulfonyl matrine (1) as the hit compound. Among the analogues, compound 7n possessing 11-trimethylbutylamine quaternary exerted the highest in vitro TG-lowering potency, as well as a good safety profile. 7n significantly attenuated the hepatic injury and steatosis, and ameliorated dyslipidemia and dysglycemia in the mice with non-alcoholic fatty liver disease (NAFLD) induced by a high-fat diet. Primary mechanism study revealed that upregulation of peroxisome proliferator-activated receptors α (PPARα)-carnitine palmitoyltransferase 1A (CPT1A) pathway mediated the efficacy of 7n. Our study provides powerful information for developing this kind of compound into a new class of anti-NAFLD candidates, and compound 7n is worthy of further investigation as an ideal lead compound.

Structure-activity relationship and biological evaluation of 12 N-substituted aloperine derivatives as PD-L1 down-regulatory agents through proteasome pathway.

Twenty-nine 12 N-substituted aloperine derivatives were synthesized and screened for suppression on PD-L1 expression in H460 cells, as a continuation of our work. Systematic structural modifications led to the identification of compound 6b as the most active PD-L1 modulator. Compound 6b could significantly down-regulate both constitutive and inductive PD-L1 expression in NSCLC cells, and successively enhance the cytotoxicity of co-cultured T cells against tumor cells at the concentration of 20 µM. Also, it exhibited a moderate in vivo anticancer efficacy against Lewis tumor xenograft with a stable PK and safety profile. The mechanism study indicated that 6b mediated the degradation of PD-L1 through a proteasome pathway, rather than a lysosome route. These results provided the powerful information for cancer immunotherapy of aloperine derivatives with unique endocyclic skeleton by targeting PD-L1 to activate immune cells to kill cancer cells.

Discovery and evolution of 12N-substituted aloperine derivatives as anti-SARS-CoV-2 agents through targeting late entry stage.

So far, there is still no specific drug against COVID-19. Taking compound 1 with anti-EBOV activity as the lead, fifty-four 12N-substituted aloperine derivatives were synthesized and evaluated for the anti-SARS-CoV-2 activities using pseudotyped virus model. Among them, 8a exhibited the most potential effects against both pseudotyped and authentic SARS-CoV-2, as well as SARS-CoV and MERS-CoV, indicating a broad-spectrum anti-coronavirus profile. The mechanism study disclosed that 8a might block a late stage of viral entry, mainly via inhibiting host cathepsin B activity rather than directly targeting cathepsin B protein. Also, 8a could significantly reduce the release of multiple inflammatory cytokines in a time- and dose-dependent manner, such as IL-6, IL-1ß, IL-8 and MCP-1, the major contributors to cytokine storm. Therefore, 8a is a promising agent with the advantages of broad-spectrum anti-coronavirus and anti-cytokine effects, thus worthy of further investigation.

Structure-activity relationship and biological evaluation of berberine derivatives as PCSK9 down-regulating agents.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a secreted protein and its deficiency markedly enhanced the survival rate of patient with cardiovascular diseases (CVDs). Forty berberine (BBR) derivatives were synthesized and evaluated for their activities on down-regulating the transcription of PCSK9 in HepG2 cells, taking BBR as the lead. Structure-activity relationship (SAR) analysis revealed that 2,3-dimethoxy moiety might be beneficial for activity. Among them, 9k displayed the most potent activity with IC50 value of 9.5 ± 0.5 µM, better than that of BBR. Also, it significantly decreased PCSK9 protein level at cellular level, as well as in the liver and serum of mice in vivo. Furthermore, 9k markedly increased LDLR expression and LDL-C clearance via down-regulating PCSK9 protein. The mechanism of action of 9k is targeting HNF1α and/or Sp1 cluster modulation upstream of PCSK9, a different one from BBR. Therefore, 9k might have the potential to be a novel PCSK9 transcriptional inhibitor for the treatment of atherosclerosis, worthy for further investigation.

Aloperine inhibits hepatitis C virus entry into cells by disturbing internalisation from endocytosis to the membrane fusion process.

Aloperine, a natural alkaloid isolated from the Chinese traditional herb Sophora alopecuroides, is a broad-spectrum antiviral agent with anti-inflammatory activity. Here, we found that aloperine effectively inhibited hepatitis C virus (HCV) propagation in Huh7.5 cells and primary human hepatocytes without cytotoxicity, and it blocked HCV cell-to-cell viral transmission. The antiviral mechanism evidence demonstrated that aloperine inhibits HCV internalisation from endocytosis to the membrane fusion process, and the target may be associated with host factors. Aloperine additively inhibited HCV propagation with direct-acting antivirals (DAAs) and was effective against HCV variants resistant to known DAAs. Therefore, aloperine might be a natural lead compound for the development of innovative antivirals, and the combined use of aloperine with DAAs might contribute to eliminating liver diseases caused by HCV infection.

Structure-activity relationship and hypoglycemic activity of tricyclic matrines with advantage of treating diabetic nephropathy.

Forty-three tricyclic matrinic derivatives with a unique scaffold were prepared and evaluated for their stimulation effects on glucose consumption in HepG2 cells. The structure-activity relationship was systematically elucidated for the first time. Among them, compound 17a exhibited the most promising potency, and dose-dependently increased glucose consumption in L6 myotubes. It significantly lowered blood glucose, glucosylated haemoglobin and AGE level, and improved glucose tolerance and insulin resistance in KK-Ay mice as well. More importantly, 17a effectively ameliorated diabetic nephropathy (DN), as indicated by the improvement of renal function and pathological changes, and decrease of urinary protein. Furthermore, 17a could induce glycolysis but suppressed aerobic oxidation of glucose, in a similar mechanism to Metform. Our results indicated that in addition to hyperglycemia, 17a may be developed to treat diabetic complication such as DN.

The novel quinolizidine derivate IMB-HDC inhibits STAT5a phosphorylation at 694 and 780 and promotes DNA breakage and cell apoptosis via blocking STAT5a nuclear translocation.

Sophoridine is a quinolizidine natural product and the exploration of its derivatives has been carried out, and the potent anticancer compound IMB-HDC was acquired. Although previous studies have revealed that some sophoridine derivatives could induce DNA breakage, the underlying mechanisms of inhibition of DNA damage repair (ATR inactivation) and the apoptosis independent of p53, have not been elucidated. Our research reveals a novel DNA response mechanism different from general DNA-damaging agents, and that sophoridine derivate inhibits the phosphorylation of Tyr694 and Ser780 of STAT5a to induce the lessened shuttle from the cytoplasm to the nucleus, and leads to the decreased nuclear STAT5a and subsequently inhibits the expression of STAT5a target gene RAD51 that contributes to the checkpoint activation, thus inhibiting ATR activation. Meanwhile, IMB-HDC that induced the diminished expression of STAT5a target gene contributes to proliferation and leads to apoptosis. More importantly, we give the first evidence that promoting the effect of Tyr694 phosphorylation on nuclear location and subsequent STAT5a target gene transcription depends on Ser780 increased or unchanged phosphorylation and was not correlated with Ser726 phosphorylation.

Synthesis and antibacterial evaluation against resistant Gram-negative bacteria of monobactams bearing various substituents on oxime residue.

Based on the structural characteristics of aztreonam (AZN) and its target PBP3, a series of new monobactam derivatives bearing various substituents on oxime residue were prepared and evaluated for their antibacterial activities against susceptible and resistant Gram-negative bacteria. Among them, compounds 8p and 8r displayed moderate potency with MIC values of 0.125-32 µg/mL against most tested Gram-negative strains, comparable to AZN. Meanwhile, the combination of 8p and 8r with avibactam as a ß-lactamases inhibitor, in a ratio of 1:16, showed a promising synergistic effect against both ESBLs- and NDM-1-producing K. pneumoniae, with significantly reduced MIC values up to 8-fold and >256-fold respectively. Furthermore, both of them demonstrated excellent safety profiles both in vitro and in vivo. The results provided powerful information for further structural optimization of monobactam antibiotics to fight ß-lactamase-producing resistant Gram-negative bacteria.

Synthesis and biological evaluation of berberine derivatives as a new class of broad-spectrum antiviral agents against Coxsackievirus B.

A series of novel berberine (BBR) analogues were prepared and tested for their antiviral potencies against six different genotype Coxsackievirus B (CVB1-6) strains, taking BBR core for structural modification. Structure-activity relationship (SAR) research revealed that introduction of a primary amine through a linker at position 3 might be beneficial for both antiviral activity and safety. Compound 14c displayed most promising inhibitory potency with IC50 values of 3.08-9.94 µM against tested CVBs 2-6 strains and satisfactory SI value of 34.3 on CVB3, better than that of BBR. Also, 14c could inhibit CVB3 replication through down-regulating the expression of VP1 protein and VP1 RNA. The mechanism revealed that 14c could suppress host components JNK-MAPK, ERK-MAPK and p38-MAPK activation. Therefore, BBR derivatives were considered to be a new class of anti-CVB agents with an advantage of broad-spectrum anti-CVB potency.

Evolution and Antibacterial Evaluation of 8-Hydroxy-cycloberberine Derivatives as a Novel Family of Antibacterial Agents Against MRSA.

Twenty-five new derivatives of 8-hydroxycycloberberine (1) were synthesized and evaluated for their activities against Gram-positive bacteria, taking 1 as the lead. Part of them displayed satisfactory antibacterial activities against methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA), as well as vancomycin-intermediate Staphylococcus aureus (VISA). Especially, compound 15a displayed an excellent anti-MRSA activity with MICs (minimum inhibitory concentrations) of 0.25⁻0.5 µg/mL, better than that of 1. It also displayed high stability in liver microsomes and whole blood, and the LD50 value of over 65.6 mg·kg-1 in mice via intravenous route, suggesting a good druglike feature. The mode of action showed that 15a could effectively suppress topo IV-mediated decatenation activity at the concentration of 7.5 µg/mL, through binding a different active pocket of bacterial topo IV from quinolones. Taken together, the derivatives of 1 constituted a promising kind of anti-MRSA agents with a unique chemical scaffold and a specific biological mechanism, and compound 15a has been chosen for the next investigation.

Synthesis and biological evaluation of 7-substituted cycloberberine derivatives as potent antibacterial agents against MRSA.

A series of new 7-substituted cycloberberine (CBBR) derivatives were synthesized and evaluated for their antibacterial activities against Gram-positive pathogens, taking CBBR as the lead. The SAR revealed that the introduction of a substituent at the C7 position resulted in a potency against both the reference Gram-positive bacteria and MDR clinical isolates, much higher than that of CBBR. Compound 1f with a 7-phenyl group exhibited higher activities against MRSA and VRE than that of vancomycin, with MIC values of 1-8 µg/mL. Its rapid bactericidal action against MRSA was further confirmed in time-kill study. The preliminary mechanism study indicated that 1f might target bacterial DNA Topo IV ParE subunit, indicating a mode of action distinct from the currently used antibacterial drugs such as quinolones. These results supplemented and enriched the SAR of its kind, and provided powerful information for developing these compounds into a novel class of antibacterial candidates against MRSA.

Synthesis and Biological Evaluation of Quinoline Derivatives as a Novel Class of Broad-Spectrum Antibacterial Agents.

Nineteen new quinoline derivatives were prepared via the Mannich reaction and evaluated for their antibacterial activities against both Gram-positive (G⁺) and Gram-negative (G-) bacteria, taking compound 1 as the lead. Among the target compounds, quinolone coupled hybrid 5d exerted the potential effect against most of the tested G⁺ and G- strains with MIC values of 0.125⁻8 µg/mL, much better than those of 1. Molecular-docking assay showed that compound 5d might target both bacterial LptA and Top IV proteins, thereby displaying a broad-spectrum antibacterial effect. This hybridization strategy was an efficient way to promote the antibacterial activity of this kind, and compound 5d was selected for the further investigation, with an advantage of a dual-target mechanism of action.

Synthesis and Evolution of Berberine Derivatives as a New Class of Antiviral Agents against Enterovirus 71 through the MEK/ERK Pathway and Autophagy.

Taking berberine (BBR) as the lead, 23 new BBR derivatives were synthesized and examined for their antiviral activities against four different genotype enterovirus 71 (EV71) strains with a cytopathic effect (CPE) assay. Structure-activity relationship (SAR) studies indicated that introduction of a suitable substituent at the 9-position might be beneficial for potency. Among them, compound 2d exhibited most potent activities with IC50 values of 7.12⁻14.8 µM, similar to that of BBR. The effect of 2d was further confirmed in a dose-dependent manner both in RNA and protein level. The mechanism revealed that 2d could inhibit the activation of MEK/ERK signaling pathway. Meanwhile, it could suppress the EV71-induced autophagy by activating AKT and inhibiting the phosphorylation of JNK and PI3KIII proteins. We consider BBR derivatives to be a new family of anti-EV71 agents through targeting host components, with an advantage of broad-spectrum anti-EV71 potency.

Synthesis and antibacterial evaluation of 13-substituted cycloberberine derivatives as a novel class of anti-MRSA agents.

A series of new 13-substituted cycloberberine (CBBR) derivatives were prepared and evaluated for their antibacterial activities against Gram-positive bacteria taking CBBR as the lead. Structure-activity relationship revealed that the introduction of a suitable electron-donating group at the 13-position in CBBR might be beneficial for the antibacterial potency. Among them, compounds 5b and 5w exhibited high potency against methicillin-sensitive (MSSA) and resistant strains of S. aureus (MRSA) with MIC values of 1-4 µg/mL. Both of them also displayed high stabilities in blood, and good in vivo safety profiles with LD50 values of 65.6 and 41.2 mg kg-1 in intravenous route respectively. Molecular docking analysis indicated that compound 5b might target FtsZ protein that could inhibit cell division, with the advantage of activity against multidrug resistant S. aureus. Therefore, we consider 13-substituted CBBR derivatives to be a novel class of anti-MRSA agents worthy of further investigation.

Discovery and evolution of aloperine derivatives as novel anti-filovirus agents through targeting entry stage.

Preventing filoviruses in the entry stage is an attractive antiviral strategy. Taking aloperine, a Chinese natural herb with an endocyclic skeleton, as the lead, 23 new aloperine derivatives were synthesized and evaluated for their anti-filovirus activities including ebola virus (EBOV) and marburg virus (MARV) using pseudotyped virus model. Structure-activity relationship (SAR) analysis indicated that the introduction of a 12N-dichlorobenzyl group was beneficial for the potency. Compound 2e exhibited the most potent anti-EBOV and anti-MARV effects both in vitro and in vivo. It also displayed a good pharmacokinetic and safety profile in vivo, indicating an ideal druglike feature. The primary mechanism study showed that 2e could block a late stage of viral entry, mainly through inhibiting cysteine cathepsin B activity of host components. We consider compound 2e to be a promising broad-spectrum anti-filovirus agent with the advantages of a unique chemical scaffold and a specific biological mechanism.

Synthesis and Biological Evaluation of 12N-substituted Tricyclic Matrinic Derivatives as a Novel Family of Anti-Influenza Agents.

BACKGROUND: Influenza is still a serious threat to human health with significant morbidity and mortality, so it is desirable to develop novel anti-flu drug agents with novel structures. OBJECTIVE: The main purpose of this research was to explore broad-spectrum anti-flu agents and provide antiviral stockpiles in response to potential future influenza pandemics. METHODS: Fifteen novel 12N-substituted tricyclic matrinic derivatives were synthesized and evaluated for their anti-influenza activities against H1N1 subtype taking 12N-p-cyanobenzenesulfonyl matrinane (1) as the lead. All prepared compounds were characterized by 1H NMR, 13C NMR and ESI-HRMS. The pharmacokinetics (PK) profile of the key compound was also examined in this study. RESULT: The structure-activity relationship study indicated that suitable benzyl groups on 12N atom might be beneficial for the activity. Among them, 12N-p-carboxybenzyl matrinic butane (17g) exhibited the most promising activity with an IC50 value of 16.2 µM and a selective index (SI) value of over 33.4. In addition, compound 17g displayed a good in vivo pharmacokinetic profile with an area under the curve (AUC0-∞) value of 9.89 µM·h. CONCLUSION: We consider tricyclic matrinic butane derivatives to be a new class of anti-influenza agents and this study provided useful information on further optimization.

Discovery and evolution of aloperine derivatives as a new family of HCV inhibitors with novel mechanism.

Aloperine (1), a Chinese natural product with a unique endocyclic scaffold, was first identified to be a potent hepatitis C virus (HCV) inhibitor in our laboratory. Thirty-four new aloperine derivatives were designed, synthesized and evaluated for their anti-HCV activities taking 1 as the lead. Among them, compound 7f exhibited the potential potency with EC50 values in a micromolar range against both wild-type and direct-acting antiviral agents (DAAs)-resistant variants, and synergistically inhibited HCV replication with approved DAAs. Furthermore, it also owned a good oral pharmacokinetic and safety profile, suggesting a highly druglike nature. The primary mechanism showed that 7f might target host components, distinctly different from the DAAs currently used in clinic. Therefore, we consider aloperine derivatives to be a novel class of anti-HCV agents, and compound 7f has been selected as a promising antiviral candidate for further investigation.

Synthesis and biological evaluation of new berberine derivatives as cancer immunotherapy agents through targeting IDO1.

To discover small-molecule cancer immunotherapy candidates through targeting Indoleamine 2,3-dioxygenase 1 (IDO1), twenty-five new berberine (BBR) derivatives defined with substituents on position 3 or 9 were synthesized and examined for repression of IFN-γ-induced IDO1 promoter activities. Structure-activity relationship (SAR) indicated that large volume groups at the 9-position might be beneficial for potency. Among them, compounds 2f, 2i, 2n, 2o and 8b exhibited increased activities, with inhibition rate of 71-90% compared with BBR. Their effects on IDO1 expression were further confirmed by protein level as well. Furthermore, compounds 2i and 2n exhibited anticancer activity by enhancing the specific lysis of NK cells to A549 through IDO1, but not cytotoxicity. Preliminary mechanism revealed that both of them inhibited IFN-γ-induced IDO1 expression through activating AMPK and subsequent inhibition of STAT1 phosphorylation. Therefore, compounds 2i and 2n have been selected as IDO1 modulators for small-molecule cancer immunotherapy for next investigation.

Synthesis and biological evaluation of tricyclic matrinic derivatives as a class of novel anti-HCV agents.

BACKGROUND: 12N-benzyl matrinic acid analogues had been identified to be a novel scaffold of anti-HCV agents with a specific mechanism, and the representative compound 1 demonstrated a moderate anti-HCV activity. The intensive structure-activity relationship of this kind of compounds is explored so as to obtain anti-HCV candidates with good druglike nature. RESULTS: Taking compound 1 as the lead, 32 compounds (of which 27 were novel) with diverse structures on the 11-side chain, including methyl matrinate, matrinol, matrinic butane, (Z)-methyl Δßγ-matrinic crotonate derivatives were synthesized and evaluated for their anti-HCV activities. Among all the compounds, matrinol 7a demonstrated potential potency with a greatly improved SI value of 136. Pharmacokinetic studies of 7a showed the potential for oral administration that would allow further in vivo safety studies. The free hydroxyl arm in 7a made it possible to prepare pro-drugs for the potential in the treatment of HCV infection. CONCLUSIONS: 27 novel 12N-substituted matrinol derivatives were prepared. The SAR study indicated that the introduction of electron-donating substitutions on the benzene ring was helpful for the anti-HCV activity, and the unsaturated 11-side chain might not be favorable for the activity. This study provided powerful information on further strategic optimization and development of this kind of compounds into a novel family of anti-HCV agents. Graphical abstract Matrinol derivatives as a class of novel anti-HCV agents.

Synthesis and Identification of Novel Berberine Derivatives as Potent Inhibitors against TNF-α-Induced NF-κB Activation.

Twenty-three new berberine (BBR) analogues defined on substituents of ring D were synthesized and evaluated for their activity for suppression of tumor necrosis factor (TNF)-α-induced nuclear factor (NF)-κB activation. Structure-activity relationship (SAR) analysis indicated that suitable tertiary/quaternary carbon substitutions at the 9-position or rigid fragment at position 10 might be beneficial for enhancing their anti-inflammatory potency. Among them, compounds 2d, 2e, 2i and 2j exhibited satisfactory inhibitory potency against NF-κB activation, with an inhibitory rate of around 90% (5 µM), much better than BBR. A preliminary mechanism study revealed that all of them could inhibit TNF-α-induced NF-κB activation via impairing IκB kinase (IKK) phosphorylation as well as cytokines interleukin (IL)-6 and IL-8 induced by TNF-α. Therefore, the results provided powerful information on further structural modifications and development of BBR derivatives into a new class of anti-inflammatory candidates for the treatment of inflammatory diseases.