Identification of Unknown Microcontaminants in Dutch River Water by Liquid Chromatography-High Resolution Mass Spectrometry and Nuclear Magnetic Resonance Spectroscopy

2014 ◽  
Vol 48 (21) ◽  
pp. 12791-12799 ◽  
Author(s):  
J.A. van Leerdam ◽  
J. Vervoort ◽  
G. Stroomberg ◽  
P. de Voogt
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Liquid Chromatography ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Magnetic Resonance Spectroscopy ◽  
River Water ◽  
High Resolution Mass Spectrometry ◽  
Resonance Spectroscopy ◽  
Resolution Mass

scholarly journals Five New Ent-Atisene Glycosides From Stevia rebaudiana

2019 ◽  
Vol 14 (7) ◽  
pp. 1934578X1986265
Author(s):  
Krishna P. Devkota ◽  
Romila D. Charan ◽  
Christopher Priedemann ◽  
Ryan Donovan ◽  
Tara M. Snyder ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Magnetic Resonance Spectroscopy ◽  
High Resolution Mass Spectrometry ◽  
Stevia Rebaudiana ◽  
Resonance Spectroscopy ◽  
Stevia Rebaudiana Bertoni ◽  
Resolution Mass

Five new ent-atisene diterpene glycosides (1-5) have been isolated from Stevia rebaudiana Bertoni. This adds to a list of only 2 new ent-atisene diterpene glycosides isolated previously from S. rebaudiana. Diterpene glycosides isolated from S. rebaudiana, such as the rebaudiosides, are typically associated with the ent-kaurene core and glycosylation at the C-13 and C-19 positions. Extensive application of nuclear magnetic resonance spectroscopy techniques (1H, 13C, 1D-TOCSY, COSY, HSQC-DEPT, HMBC, and ROESY) as well as high-resolution mass spectrometry demonstrated that the ent-atisenes 1 to 5 had glycosylation patterns identical to rebaudiosides J, N, O, K, and T, respectively. We have named these compounds stevatisene J, N, O, K, and T, respectively.

scholarly journals Synthesis of spiro[benzo[4,5]imidazo[2,1-b][1,3]thiazole-2,3-thiolane]s via sulfa-Michael/aldol cascade reactions

2019 ◽  
Vol 43 (1-2) ◽  
pp. 63-66 ◽  
Author(s):  
Jiaying Lei ◽  
Xinliang Fu ◽  
Yulin Huang ◽  
Xiaofang Li
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Resolution ◽  
High Resolution Mass Spectrometry ◽  
Cascade Reactions ◽  
Cascade Reaction ◽  
Crystallographic Analysis ◽  
X Ray ◽  
Resolution Mass

The sulfa-Michael/aldol cascade reaction of ( Z)-2-arylmethylidene-benzo[4,5]imidazo[2,1- b]thiazol-3(2H)-ones and 1,4-dithiane-2,5-diol afforded novel 2-aryl-4-hydroxy-spiro[benzo[4,5]imidazo[2,1- b][1,3]thiazole-2,3-thiolan]-3-ones in moderate yields. The structures of all the products were characterized thoroughly by nuclear magnetic resonance, infrared and high-resolution mass spectrometry together with X-ray crystallographic analysis.

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