Jiangyu Zhao

1,2,3-Triazole-containing derivatives of rupestonic acid: Click-chemical synthesis and antiviral activities against influenza viruses

Two series of rupestonic acid derivatives, (1-substituted-1H-1,2,3-triazol-4-yl)methyl 2-((5R,8S,8aS)-3,8-dimethyl-2-oxo-1,2,4,5,6,7,8,8a-octahydroazulen-5-yl)acrylate and N-(1-substituted-1H-1,2,3-triazol-4-yl)methyl 2-((5R,8S,8aS)-3,8-dimethyl-2-oxo-1,2,4,5,6,7,8,8a-octahydroazulen-5-yl)acrylamide were easily and efficiently synthesized via click chemistry. These compounds were tested for their in vitro activities against various strains of influenza A virus (H1N1, oseltamivir resistant H1N1, H3N2) and influenza B virus. The results showed that nine compounds were active against the H1N1 strain of influenza A virus and among them the best one 14a, was as active as the reference drugs, Oseltamivir and Ribavirin. Some of them were also active on the Oseltamivir resistant H1N1 strain. In regards to influenza B virus, twenty-one compounds over thirty were active and seven of them 7b, 8b, 9b, 10a, 11b, 12b, 13b showed better activity than Ribavirin. The structure-activity relationship of these compounds is discussed on the basis of each type of the viruses studied. Furthermore, four best representative compounds 7b, 10a, 12b and 14a were evaluated in a plaque assay experiment using MDCK cells and RBV as control compound and the results showed that 7b, 10a and 12b were better than RBV in inhibiting plaque formation, in good accordance with their anti-influenza B activities.

Synthesis and anti-influenza activity of aminoalkyl rupestonates

A series of aminoalkyl rupestonates were designed and synthesized by reacting rupestonic acid with 1,ω-dibromoalkanes, followed by amination. All of the new compounds were bioassayed in vitro to determine their activities against influenza A (H3N2, H1N1) and B viruses. The results showed that compounds 5a-5g, which each contain a 1H-1,2,4-triazolyl moiety, were found to be the most potent set of compounds. Compound 5g was demonstrated to possess the highest inhibitory activity against influenza H3N2 and H1N1, with IC(50) values of 0.97 and 0.42 μM, respectively. Our results also indicated that compounds 2g, 3g, 4g and 5g, which contain ten-CH(2)-unit spacers between the rupestonic acid and amino functional groups, were the most potent inhibitors of influenza H1N1 among the synthesized compounds. Unfortunately, most of the synthesized compounds did not show an obvious activity against influenza B; the only exceptions were compounds 5d and 5f, which had IC(50) values of 17.3 and 3.2 μM, respectively. Compounds 4g and 5g were potent inhibitors of influenza H1N1, and they might be potentially developed as new lead anti-influenza virus compounds. Further studies of the mechanism of action are underway.

Rupestonic acid derivative YZH-106 suppresses influenza virus replication by activation of heme oxygenase-1-mediated interferon response

Given the limitation of available antiviral drugs and vaccines, there remains to be a pressing need for novel anti-influenza drugs. Rupestonic acid derivatives were reported to have an anti-influenza virus activity, but their mechanism remains to be elucidated. Herein, we aim to evaluate the antiviral activity of YZH-106, a rupestonic acid derivative, against a broad-spectrum of influenza viruses and to dissect its antiviral mechanisms. Our results demonstrated that YZH-106 exhibited a broad-spectrum antiviral activity against influenza viruses, including drug-resistant strains in vitro. Furthermore, YZH-106 provided partial protection of the mice to Influenza A virus (IAV) infection, as judged by decreased viral load in lungs, improved lung pathology, reduced body weight loss and partial survival benefits. Mechanistically, YZH-106 induced p38 MAPK and ERK1/2 phosphorylation, which led to the activation of erythroid 2-related factor 2 (Nrf2) that up-regulated heme oxygenase-1 (HO-1) expression in addition to other genes. HO-1 inhibited IAV replication by activation of type I IFN expression and subsequent induction of IFN-stimulated genes (ISGs), possibly in a HO-1 enzymatic activity-independent manner. These results suggest that YZH-106 inhibits IAV by up-regulating HO-1-mediated IFN response. HO-1 is thus a promising host target for antiviral therapeutics against influenza and other viral infectious diseases.

Discovery of diethyl 2,5-diaminothiophene-3,4-dicarboxylate derivatives as potent anticancer and antimicrobial agents and screening of anti-diabetic activity: synthesis and in vitro biological evaluation. Part 1.

Series of diethyl 2,5-diaminothiophene-3,4-dicarboxylate (DDTD) derivatives: azomethines of DDTD (2a-l) have been synthesized and screened for their anticancer, antimicrobial and anti-diabetic activities. The novel synthesized compounds were characterized by (1)H, (13)C NMR, MS and FT-IR analyses. All compounds were evaluated for their antiproliferative activity against three types of cancer cell line such as T47D and MCF-7 (human breast cancer), Hela (human cervical cancer) and Ishikawa (human endometrial cancer) lines. The results showed that most compounds exhibited significant antiproliferative activity against breast cancer cells. The majority of azomethines DDTD influenced strongly against breast cancer cells T47D and MCF-7, among them compounds 2b (2.3 μM), 2c (12.1 μM), 2e (13.2 μM), 2i (14.9 μM), 2j (16.0 μM), 2k (7.1 μM), 2l (8.6 μM) manifest potent anticancer activity against cancer cell T47D than Doxorubicin (DOX, 15.5 μM). Compound 2j has shown potent activity on all three types of cancer cells concurrently and IC50 values were considerably low in comparison with positive control DOX. In addition, all compounds were tested for antimicrobial activity against Staphylococcus aureus ATCC 6538 (Gram positive bacteria), Escherichia coli ATCC 11229 (Gram negative bacteria) and Candida albicans ATCC 10231 (Fungi) strains and 2j which contains in the ring nitrofurfural fragment, showed the highest effect on the three species of microbial pathogens simultaneously. Some compounds induced enzymatic inhibition in a concentration-dependent manner on PTP-1B inhibitor.

2-Aminothiophene scaffolds: Diverse biological and pharmacological attributes in medicinal chemistry

2-Aminothiophenes are important five-membered heterocyclic building blocks in organic synthesis, and the chemistry of these small molecules is still developing based on the discovery of cyclization by Gewald. Another attractive feature of 2-aminothiophene scaffolds is their ability to act as synthons for the synthesis of biological active thiophene-containing heterocycles, conjugates and hybrids. Currently, the biological actions of 2-aminothiophenes or their 2-N-substituted analogues are still being investigated because of their various mechanisms of action (e.g., pharmacophore and pharmacokinetic properties). Likewise, the 2-aminothiophene family is used as diverse promising selective inhibitors, receptors, and modulators in medicinal chemistry, and these compounds even exhibit effective pharmacological properties in the various clinical phases of appropriate diseases. In this review, major biological and pharmacological reports on 2-aminothiophenes and related compounds have been highlighted; most perspective drug-candidate hits were selected for discussion and described, along with additional synthetic pathways. In addition, we focused on the literature dedicated to 2-aminothiophenes and 2-N-substituted derivatives, which have been published from 2010 to 2017.

Identification of metabolites of rupestonic acid in rat urine by liquid chromatography combined with electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry

Rupestonic acid, a potential anti-influenza agent, is an important and characteristic compound in Artemisia rupestris L., a well-known traditional Uighur medicine for the treatment of colds. In the present study, high-performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight tandem mass spectrometry was used to detect and identify the metabolites in rat urine after oral administration of rupestonic acid. A total of 10 metabolites were identified or partially characterized. The structure elucidations of the metabolites were performed by comparing the changes in accurate molecular masses and fragment ions with those of the parent compound. The results showed that the main metabolites of rupestonic acid in rat urine were formed by oxidation, hydrogenation and glucuronidation. A metabolism pathway was proposed for the first time based on the characterized structures. This metabolism study can provide essential information for drug discovery, design and clinical application of rupestonic acid.

Synthesis and In Vitro Anti-Influenza Evaluation of Rupestonic AcidAnalogues: Effect of Configuration and Substitution at C (3)

Rupestonic acid is the main active compound in Artemisia rupestris L, which mainly grows in Xinjiang of China. To find its active group, a series of novel rupestonic acid 3-carbonyl analogues were prepared. The structures of the compounds were confirmed by spectral and high resolution mass spectrum. All compounds were evaluated for antiviral activity against influenza A (H3N2 and H1N1) and B viruses in MDCK cell cultures. The compounds displayed a confined structure-activity relationship. Compound 13 with allyl group was the most potent inhibitor against influenza A/H1N1 virus with an IC50 value of 4.27 μM and a SI value of 27.04. Dihydrogen amide 3 possesses the good potency against influenza B virus with an IC50 value of 5.5 μM and a SI value of 13.

Diversity-oriented synthesis of amide derivatives of tricyclic thieno[2,3-d]pyrimidin-4(3H)-ones and evaluation of their influence on melanin synthesis in murine B16 cells

Abstract A diversity-oriented synthesis of amide-containing thieno[2,3-d]pyrimidin-4(3H)-ones is reported. All compounds were tested for their influence on melanin synthesis in murine B16 cells. The azepine fragment in thieno[2,3-d]pyrimidin-4(3H)-one skeleton significantly increases the melanin content.

Synthesis of Rupestonic Acid Derivatives with Antiviral Activity

A series of 23 new rupestonic acid derivatives were synthesized. Their activities against influenza viruses A (H3N2, H1N1) and B were studied. Compounds 2d and 2g demonstrated potent activity against influenza virus A (H3N2) with IC50 values of 0.35 and 0.21 μM, respectively. Compound 5g (n = 10) was the most potent compound of this series against influenza viruses H3N2 and H1N1 with IC50 values of 2.89 and 0.38 μM. Several of the synthesized compounds were weakly active against influenza virus B and were more toxic than starting rupestonic acid.

Total synthesis of rupestine G and its epimers

Rupestine G is a guaipyridine sesquiterpene alkaloid isolated from Artemisia rupestris L. The total synthesis of rupestine G and its epimers was accomplished employing a Suzuki reaction to build a terminal diene moiety. The diene was further elaborated into the desired guaipyridine structure by a ring-closing metathesis reaction. Over all, rupestine G and its three epimers were obtained as a mixture in a sequence of nine linear steps with 18.9% yield. Rupestine G and its optically pure isomers were isolated by chiral preparative HPLC and fully characterized by 1H ,13C NMR, HRMS, optical rotation value, and experimental and calculated electronic circular dichroism spectroscopy.