N-(2-Aminoethyl)-2-(hexylthio) Acetamide-Functionalized Pillar[5]arene for the Selective Detection of l-Trp through Guest-Adaptive Multisupramolecular Interactions.

Tryptophan (Trp) is very necessary for biosystems; therefore, high-efficient detection of Trp is an important subject. Hereof, based on our early research works on fluorescent sensors, we rationally designed and synthesized a fluorescent sensor (SNP5) based on N-(2-aminoethyl)-2-(hexylthio) acetamide-functionalized pillar[5]arene, which showed high selectivity and sensitive recognition for l-Trp (LOD = 2.19 × 10-8 M). Moreover, SNP5 exhibited aggregation-induced emission enhancement fluorescence. Within SNP5, the pillar[5]arene group could act as N-H···π- and C-H···π-interaction sites, as well as a H-bond-interaction site; meanwhile, the N-(2-aminoethyl)-2-(hexylthio) acetamide group also served as a multihydrogen-bonding site. As a result, SNP5 could selectively detect l-Trp through the synergy of the pillar[5]arene group and the N-(2-aminoethyl)-2-(hexylthio) acetamide group. Compared with previous work, the results of this work support the strategy that changing the functionalized group of the pillar[5]arene can adjust the selectivity of the pillar[5]arene-based sensor and achieve the detection of different amino acids. The detection mechanism was specifically researched through experiments and theoretical calculations including frontier orbitals, electrostatic potential, and the independent gradient model approach. Interestingly, these theoretical calculations not only supported the experimental results but also provided a visualized understanding of guest-adaptive multisupramolecular interactions between SNP5 and l-Trp.

A pillar[5]arene-based fluorescent sensor for sensitive detection of L-Met through a dual-site collaborative mechanism.

L-Methionine (L-Met) is one of the essential amino acids in human health, efficiently detect L-Met is a significant issue. Herein, a concept "dual-site collaborative recognition" had been successfully introduced into the design and achieved high selective and sensitive recognition of L-Met. In order to realize the "dual-site collaborative recognition", we rationally designed and synthesized an ester functionalized pillar[5]arene-based fluorescent sensor (SP5). And it shows blue Aggregation-induced emission (AIE) fluorescence. In the SP5, the pillar[5]arene group act as C-H···π interactions site, and ester group serve as multi hydrogen bonding acceptor. Interestingly, the SP5 exhibited high selectivity and sensitivity (2.84 × 10-8 M) towards L-Met based on the collaboration of electron-rich cavernous pillar[5]arene group and ester group through C-H···π and H-bond interactions, respectively. This "dual-site collaborative recognition" mechanism has been investigated by 1H NMR, ESI-MS and theoretical calculation including frontier orbital (HOMO and LUMO), electrostatic potential (ESP) and the noncovalent interaction (NCI). These theoretical calculations not only support the proposed host-guest recognition mechanism, but also provided visualized information on the "dual-site collaborative recognition" mode. Furthermore, the concept "dual-site collaborative recognition" is an effective strategy for easily detecting biological molecules.

2',3'-cyclic nucleotide 3'-phosphodiesterases inhibit hepatitis B virus replication.

2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP) is a member of the interferon-stimulated genes, which includes isoforms CNP1 and CNP2. CNP1 is locally expressed in the myelin sheath but CNP2 is additionally expressed at low levels outside the nervous system. CNPs regulate multiple cellular functions and suppress protein production by association with polyadenylation of mRNA. Polyadenylation of Hepatitis B virus (HBV) RNAs is crucial for HBV replication. Whether CNPs interact with polyadenylation signal of HBV RNAs and interfere HBV replication is unknown. In this study, we evaluated expressions of CNP isoforms in hepatoma cell lines and their effects on HBV replication. We found that CNP2 is moderately expressed and gently responded to interferon treatment in HepG2, but not in Huh7 cells. The CNP1 and CNP2 potently inhibited HBV production by blocking viral proteins synthesis and reducing viral RNAs, respectively. In chronic hepatitis B patients, CNP was expressed in most of HBV-infected hepatocytes of liver specimens. Knockdown of CNP expression moderately improved viral production in the HepG2.2.15 cells treated with IFN-α. In conclusion, CNP might be a mediator of interferon-induced response against HBV.

Evaluation of the performance of the EIAgen HCV test for detection of hepatitis C virus infection.

The EIAgen HCV test (Adaltis Inc., Montreal, Canada) is an enzyme immunoassay (EIA) for the detection of anti-hepatitis C virus (HCV) antibodies. This study compared the performance of this test side-by-side with the current Ortho HCV 3.0 Anti-HCV assay (Ortho-Clinical Diagnostics Inc., Johnson & Johnson Company, Raritan, NY, USA). Among 2559 specimens examined, 178 were true positives, 2376 were true negatives and 5 were indeterminate. The sensitivity of the EIAgen HCV test was 100%, versus 98.3% for the Ortho HCV test, while their respective specificities were 98.1% and 98.2%. The EIAgen HCV test gave a positive predictive value of 79.8% and a negative predictive value of 100%. Overall, the concordance of this test with the Ortho HCV test was 98.2%. Specimens from potentially interfering substances, such as sera from pregnant women, sera from patients with acute non-C hepatitis, autoimmune diseases, lipidemia, or from patients undergoing hemolysis, showed no interference with either EIA. An EIAgen HCV test signal-to-cut-off ratio of >5.9 would be highly predictive of a true-positive finding in these specimens. The EIAgen HCV test is well suited for screening blood and blood products in antibodies to HCV.