Novel trans-Resveratrol Derivatives: Design, Synthesis, Antibacterial Activity, and Mechanisms.

Rice bacterial leaf blight and rice bacterial leaf streak have induced tremendous damage to production of rice worldwide. To discover an effective novel antibacterial agent, a series of novel trans-resveratrol (RSV) derivatives containing 1,3,4-oxadiazole and amide moieties were designed and synthesized for the first time. Most of them showed excellent antibacterial activities against Xanthomonas oryzae pv oryzicola and Xanthomonas oryzae pv oryzae. Especially, compound J12 had the best inhibitory with the half-maximal effective concentration values of 4.2 and 5.0 mg/L, respectively, which were better than that of RSV (63.7 and 75.4 mg/L), bismerthiazol (79.5 and 89.6 mg/L), and thiodiazole copper (105.4 and 112.8 mg/L). Furthermore, compound J12 had an excellent control effect against rice bacterial leaf streak and rice bacterial leaf blight, with protective activities of 46.2 and 42.1% and curative activities of 44.5 and 41.7%, respectively. Preliminary mechanisms indicated that compound J12 could not only remarkably decrease biofilm formation, extracellular polysaccharide production, and the synthesis of extracellular enzymes but also destroy bacterial cell surface morphology, thereby reducing the pathogenicity of bacteria. In addition, compound J12 could increase the activity of defense-related enzymes and affect the expression of multiple pathogenic-related genes including plant-pathogen interaction, the MAPK signaling pathway, and phenylpropanoid biosynthesis, and this could improve the defense of rice against rice bacterial leaf streak infection. The present work indicates that the RSV derivatives can be used as promising candidates for the development of antibacterial agents.

[T-SPOT.TB in the diagnosis of tuberculous peritonitis].

OBJECTIVE: To evaluate the value of T-SPOT.TB in the diagnosis of tuberculous peritonitis (TBP). METHODS: A total of 50 patients with clinically suspected TBP admitted from August 2011 to July 2012 from the Third Xiangya Hospital were enrolled in this prospective cohort study. Peripheral blood T-SPOT.TB, purified protein derivatives of tuberculin (PPD) skin test, serum tuberculosis antibody (TB-Ab) and ascitic adenosine deaminase (ADA) were measured in the 50 patients and we compared the diagnostic value of the 4 methods. RESULTS: According to the standard of diagnosis of TBP and grouping, 24 patients were diagnosed with TBP, 17 non-TBP and 9 undiagnosed in the end. The sensitivity of T-SPOT.TB for the diagnosis of TBP was 91.7% (22/24), with statistical significance when compared with PPD skin test 37.5% (9/24), serum TB-Ab 16.7% (4/24), and ascitic ADA 36.4% (8/22) (P<0.01). The specificity of T-SPOT.TB for the identification of non-TBP was 76.5% (13/17), without statistical significance when compared with PPD skin test 70.0% (7/10), serum TB-Ab 78.6% (11/14), and ascitic ADA 100% (14/14) (P>0.05). The positive prediction value of T-SPOT.TB for the diagnosis of TBP was 84.6% (22/26), without statistical significance when compared with PPD skin test 75.0% (9/12), serum TB-Ab 57.1% (4/7), and ascitic ADA 100%(8/8) (P>0.05). The negative prediction value of T-SPOT.TB for the identification of non-TBP was 86.7% (13/15), with statistical significance when compared with PPD skin test 31.8% (7/22), serum TB-Ab 35.5% (11/31), and ascitic ADA 50.0% (14/28) (P<0.05). CONCLUSION: Peripheral blood T-SPOT.TB for the diagnosis of TBP is highly sensitive, which is better than PPD skin test, serum TB-Ab, and ascitic ADA. T-SPOT.TB has an important reference for diagnosing suspected TBP quickly and accurately.