Metabolism of trans-resveratrol-3-O-glucoside in vitro in rat tissues / 药学学报

To study the metabolism of trans-resveratrol-3-O-glucoside (TRG) in vitro in rat tissues, the incubation with cell-free extracts from rat stomach, duodenum, jejunum, ileum and liver was performed, separately. After TRG was incubated with the tissue extracts at 37 degrees C for up to 90 min, the deglycosylation of TRG was (3.50 +/- 0.24) % for stomach, (65.7 +/- 5.94)% for duodenum, (83.5 +/- 6.43)% for jejunum, (77.6 +/- 6.26)% for ileum and (9.62 +/- 1.21)% for liver, separately. It was observed that the small intestine extracts were more active in deglycosylation of TRG than the liver extract, which suggested that the small intestine mucosa played an important role in deglycosylation of TRG. It was assumed that the deglycosylation of TRG was catalyzed by beta-glucosidase in small intestine mucosa.

Electrospray ion trap mass spectrometry of eight aminoglycoside antibiotics / 药学学报

<p><b>AIM</b>To study the dissociation pathways of aminoglycoside antibiotics.</p><p><b>METHODS</b>In positive mode, eight aminoglycoside antibiotics were elucidated by use of electrospray ion trap mass spectrometry in the multi-stage MS full scan mode.</p><p><b>RESULTS</b>It was demonstrated that the eight aminoglycoside antibiotics gave abundant product ions at m/z 322 (gentamicin, micronomicin and sisomicin), m/z 350 (etimicin, netilmicin and vetilmicin) and m/z 324 (kanamycin and tobramycin) by loss of the C-ring (amino-alpha-D-glucopyranose) in MS2 full scan mode. In MS3 full scan mode, the prominent fragmentation ions at m/z 163 as well as m/z 191 were formed from the fragmentation ions at m/z 322, m/z 350 and m/z 324 by loss of the A-ring (amino-alpha-D-glucopyranose), separately, while the characteristic fragmentation ions at m/z 160 as well as m/z 162 were formed from m/z 322, m/z 350 and m/z 324 by loss of the B-ring (2-deoxy-D-streptamine), separately.</p><p><b>CONCLUSION</b>The structural information was obtained via collision-activated dissociation and these characteristics are applicable to the structural elucidation and quantitative analysis of aminoglycoside compounds.</p>