Chang K.-C.,National Sun Yat - sen University |
Lee C.-L.,National Sun Yat - sen University |
Lee C.-L.,Kaohsiung Medical University |
Lee C.-L.,Asia Pacific Ocean Research Center |
And 3 more authors.
Environmental Science and Pollution Research | Year: 2015
Polycyclic aromatic compounds (PACs) are widespread environmental pollutants with a high potential to act as human carcinogens and mutagens. The behavior of PACs is significantly affected by their interactions with dissolved organic matter (DOM), such as their transport, solubility, bioavailability, and bioaccumulation in the aquatic environment. Being a basic PAC, benzo(h)quinoline (BQ) is the dominant species, as the solution’s pH value is higher than BQ’s pKa (pKa of BQ = 4.2). In contrast, benzo(h)quinolinium (BQH+) is the major species, as the solution’s pH value is lower than its pKa. The binding constant (KDOC), measured by fluorescence quenching, between BQ/BQH+ and Leonardite humic acid (LHA) would decrease 70 to 95 % and 20 to 90 % when increasing the ionic strength in acidic and neutral to basic conditions, respectively. The results can be attributed to the added cation (Na+ and Mg2+), which forms a bridge with LHA and enhances the intramolecular reaction among these functional groups, therefore inducing the coiling up within the LHA molecule. In addition, the decrease of the KDOC with added MgCl2/MgSO4 (75–95 %) is higher than that with added NaCl/Na2SO4 (20–75 %), indicating that the KDOC was affected by the charge density of cations. The fluorescence intensity of BQH+ in the absence of LHA (F0) was found to decay only in the acidic solution with Cl−, suggesting that Cl− might be a heavy atom serving as a quencher in an acidic solution. © 2015, Springer-Verlag Berlin Heidelberg.
Cheng S.-Y.,National Sun Yat - sen University |
Cheng S.-Y.,Asia Pacific Ocean Research Center |
Chuang C.-T.,National Sun Yat - sen University |
Wang S.-K.,Kaohsiung Medical University |
And 6 more authors.
Journal of Natural Products | Year: 2010
Chemical investigation of the soft coral Sinularia gyrosa led to the purification of three new diterpenoids, designated as gyrosanols A-C (1-3). The structures of 1-3 were elucidated through extensive spectroscopic analyses. Compounds 1 and 2 exhibited antiviral activity against HCMV with IC 50's of 2.6 and 3.7 μM, respectively. In addition, compounds 1 and 2 showed significant anti-inflammatory activity by reducing the levels of the COX-2 protein (19.6 ± 3.9% and 29.1 ± 9.6%, respectively) in RAW 264.7 macrophages. © 2010 The American Chemical Society and American Society of Pharmacognosy.
Tsai C.-W.,Asia Pacific Ocean Research Center |
Lin C.-S.,Asia Pacific Ocean Research Center |
Wang W.-H.,Asia Pacific Ocean Research Center
Journal of Food and Drug Analysis | Year: 2012
A LC-MS/MS method was validated for the simultaneous quantification of 4 quinolones (oxolinic acid, enrofloxacine, ciprofloxacine, norfloxacine) and 4 sulfonamides (sulfamethoxypyridazine, sulfadoxine, sulfadimidine, sulfamerazine) on fish muscle following the European Union's (EU) criteria for the analysis of veterinary drug residues in foods. One gram of sample was extracted by acidic acetonitrile (0.5 mL of 0.1% formic acid in 7 mL of ACN), followed by LC-MS/MS analysis using an electrospray ionization interface. Typical recoveries of the 4 quinolones in the fish tissues ranged from 85 to 104%. While those of the sulfonamides ranged from 75 to 94% at the fortification level of 5.0 μg/kg. The decision limits (CCα) and detection capabilities (CCβ) of the quinolones were 1.35 to 2.10 μg/kg and 1.67 to 2.75 μg/kg, respectively. Meanwhile, the CCα and CCβ of the sulfonamides ranged from 1.62 μg/kg to 2.53μg/kg and 2.01μg/kg to 3.13 μg/kg, respectively.