Matrix_assisted laser desorption ionization_time of flight tandem mass spectrometry ( MALDI_TOF/TOF MS) and electrospray ionization_quadrupole_time of flight mass spectrometry ( ESI_Q_TOF MS) were used to confirm the structure of cyclic lipopeptide daptomycin fastly. First, the relative molecular weight 1916. 7107 of daptomycin was measured by ESI with error 0. 0007. The sample’s doubly charged peak m/z 809. 848 was selected as precursor ion for ESI_MS/MS analysis, and the exocyclic amino acid sequence C9 H19 CO_Trp_Asn_Asp was successfully matched. Second, the experimental conditions of cleaving daptomycin by lithium hydroxide ( LiOH) were optimized and the ring_opened process was monitored by MALDI_TOF/TOF MS. After obtaining ring_opened product with purity of above 95%, the MS/MS measurements by MALDI and ESI were carried out. The b+and y+of ring_opened product were completely matched, which confirmed the amino acid sequence of daptomycin. Finally, ESI_MS/MS conditions of ring_opened product were further optimized to obtain more low mass fragment ions for analyzing the structure of fatty acid chain and the cleavage pattern of fat chain in mass spectrometry was proposed. The method was fast, convenient, accurate and reliable for identifying cyclic lipopeptide compounds.

Objective:To investigate the effects of Apelin-13 regulatory peptide on neuronal cell pyroptosis in mice modeled with cerebral ischemia-reperfusion(I/R).Methods:We prepared a mouse cerebral I/R model using middle cerebral artery embolization and Reperfusion(MCAO/R).The HT22 cell injury model was prepared by the oxygen glu-cose deprivation/reoxygenation(OGD/R),and Apelin-13 treatment was also given.Neurological function was assessed by neurological deficit score;hematoxylin-eosin(HE)staining and Nissl staining were used to observe the morphologic changes of the infarcted area of the mice;and 2,3,5triphenyltetrazolium chloride(TTC)staining was used to observe the volume of cerebral infarcts;The expression of NOD-like receptor thermoprotein structural domain-related protein 3(NLRP3),gasdermin D(GSDMD),caspase-1,apoptosis-associated speck-like protein(ASC),interleukin 1β(IL-1β),and interleukin 18(IL-18)in brain tissues from infarcted areas or HT22 cells was detected by Western Blot,and IL-1β and IL-18 were detected by enzyme-linked immunosorbent assay(ELISA)in serum of mice and culture supema-tants;The cell viability and cell damage of HT22 were detected by CCK-8 kit and lactate dehydrogenase(LDH)assay kit,respectively;caspase-1 activity was measured by caspase-1 activity kit in HT22 cells;and the expression of caspase-1 and GSDMD was observed by immunofluorescence staining in HT22 cells.Results:Apelin-13 significantly improved neurological function and cerebral infarct volume in I/R mice,and attenuated pathological damage in the in-farcted area.It also reduced the serum levels of IL-1β and IL-18.In addition,Apelin-13 reduced the expression of mol-ecules such as NLRP3,GSDMD,caspase-1,IL-1β,and IL-18 in the cerebral infarct area of mice.In vitro experiments showed that Apelin-13 significantly increased the viability of OGD/R-treated HT22 cells,decreased caspase-1 activity,and reduced the LDH content,as well as decreased the expression of molecules such as NLRP3,GSDMD,caspase-1,IL-1β,IL-18,and so on,in OGD/R-treated HT22 cells.Conclusion:Apelin-13 inhibits pyroptosis through the NL-RP3/caspase-1/GSDMD pathway in cerebral ischemia/reperfusion mice and thus exerts neuroprotective effects.

Objective: To investigate the clinical effect and safety of long-acting pegylated interferon-α-2b (Peg-IFN-α-2b) (Y shape, 40 kD) injection (180 μg/week) in the treatment of HBeAg-positive chronic hepatitis B (CHB) patients, with standard-dose Peg-IFN-α-2a as positive control. Methods: This study was a multicenter, randomized, open-label, and positive-controlled phase III clinical trial. Eligible HBeAg-positive CHB patients were screened out and randomized to Peg-IFN-α-2b (Y shape, 40 kD) trial group and Peg-IFN-α-2a control group at a ratio of 2:1. The course of treatment was 48 weeks and the patients were followed up for 24 weeks after drug withdrawal. Plasma samples were collected at screening, baseline, and 12, 24, 36, 48, 60, and 72 weeks for centralized detection. COBAS® Ampliprep/COBAS® TaqMan® HBV Test was used to measure HBV DNA level by quantitative real-time PCR. Electrochemiluminescence immunoassay with Elecsys kit was used to measure HBV markers (HBsAg, anti-HBs, HBeAg, anti-HBe). Adverse events were recorded in detail. The primary outcome measure was HBeAg seroconversion rate after the 24-week follow-up, and non-inferiority was also tested. The difference in HBeAg seroconversion rate after treatment between the trial group and the control group and two-sided confidence interval (CI) were calculated, and non-inferiority was demonstrated if the lower limit of 95% CI was > -10%. The t-test, chi-square test, or rank sum test was used according to the types and features of data. Results: A total of 855 HBeAg-positive CHB patients were enrolled and 820 of them received treatment (538 in the trial group and 282 in the control group). The data of the full analysis set showed that HBeAg seroconversion rate at week 72 was 27.32% in the trial group and 22.70% in the control group with a rate difference of 4.63% (95% CI -1.54% to 10.80%, P = 0.1493). The data of the per-protocol set showed that HBeAg seroconversion rate at week 72 was 30.75% in the trial group and 27.14% in the control group with a rate difference of 3.61% (95% CI -3.87% to 11.09%, P = 0.3436). 95% CI met the non-inferiority criteria, and the trial group was non-inferior to the control group. The two groups had similar incidence rates of adverse events, serious adverse events, and common adverse events. Conclusion In Peg-IFN-α regimen for HBeAg-positive CHB patients, the new drug Peg-IFN-α-2b (Y shape, 40 kD) has comparable effect and safety to the control drug Peg-IFN-α-2a.