ChemInform Abstract: AMMONOLYSIS OF CEPHAMYCINS: CARBON-13 NMR CHARACTERIZATION OF THE INTERMEDIATES FROM β-LACTAM RING CLEAVAGE PRIOR TO LOSS OF THE 3′-GROUP

1985 ◽  
Vol 16 (19) ◽  
Author(s):  
E. J. J. GRABOWSKI ◽  
A. W. DOUGLAS ◽  
G. B. SMITH
Keyword(s):  
Ring Cleavage ◽  
Nmr Characterization ◽  
Lactam Ring

NMR characterization of complex natural products: Assigning novel, proton-deficient alkaloid scaffolds

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
KR Gustafson ◽  
STS Chan ◽  
D Milanowski
Keyword(s):  
Natural Products ◽  
Nmr Characterization

Synthesis and 31 P NMR characterization of new low toxic highly sensitive pH probes designed for in vivo acidic pH studies

2002 ◽  
Vol 10 (5) ◽  
pp. 1451-1458 ◽  
Author(s):  
Sophie Martel ◽  
Jean-Louis Clément ◽  
Agnès Muller ◽  
Marcel Culcasi ◽  
Sylvia Pietri
Keyword(s):  
Acidic Ph ◽  
Highly Sensitive ◽  
Nmr Characterization ◽  
Low Toxic ◽  
Ph Probes

scholarly journals Characterization of the Gallate Dioxygenase Gene: Three Distinct Ring Cleavage Dioxygenases Are Involved in Syringate Degradation by Sphingomonas paucimobilis SYK-6

2005 ◽  
Vol 187 (15) ◽  
pp. 5067-5074 ◽  
Author(s):  
Daisuke Kasai ◽  
Eiji Masai ◽  
Keisuke Miyauchi ◽  
Yoshihiro Katayama ◽  
Masao Fukuda
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Terminal Region ◽  
Ring Cleavage ◽  
Sphingomonas Paucimobilis ◽  
Acid Protein ◽  
Demethylation Pathway ◽  
Dioxygenase Gene ◽  
Amino Acid Protein

ABSTRACT Sphingomonas paucimobilis SYK-6 converts vanillate and syringate to protocatechuate (PCA) and 3-O-methylgallate (3MGA) in reactions with the tetrahydrofolate-dependent O-demethylases LigM and DesA, respectively. PCA is further degraded via the PCA 4,5-cleavage pathway, whereas 3MGA is metabolized via three distinct pathways in which PCA 4,5-dioxygenase (LigAB), 3MGA 3,4-dioxygenase (DesZ), and 3MGA O-demethylase (LigM) are involved. In the 3MGA O-demethylation pathway, LigM converts 3MGA to gallate, and the resulting gallate appears to be degraded by a dioxygenase other than LigAB or DesZ. Here, we isolated the gallate dioxygenase gene, desB, which encodes a 418-amino-acid protein with a molecular mass of 46,843 Da. The amino acid sequences of the N-terminal region (residues 1 to 285) and the C-terminal region (residues 286 to 418) of DesB exhibited ca. 40% and 27% identity with the sequences of the PCA 4,5-dioxygenase β and α subunits, respectively. DesB produced in Escherichia coli was purified and was estimated to be a homodimer (86 kDa). DesB specifically attacked gallate to generate 4-oxalomesaconate as the reaction product. The Km for gallate and the V max were determined to be 66.9 ± 9.3 μM and 42.7 ± 2.4 U/mg, respectively. On the basis of the analysis of various SYK-6 mutants lacking the genes involved in syringate degradation, we concluded that (i) all of the three-ring cleavage dioxygenases are involved in syringate catabolism, (ii) the pathway involving LigM and DesB plays an especially important role in the growth of SYK-6 on syringate, and (iii) DesB and LigAB are involved in gallate degradation.

NMR characterization of isomers of C78, C82 and C84 fullerenes

Nature ◽  
1992 ◽  
Vol 357 (6374) ◽  
pp. 142-145 ◽  
Author(s):  
Koichi Kikuchi ◽  
Nobuo Nakahara ◽  
Tomonari Wakabayashi ◽  
Shinzo Suzuki ◽  
Haruo Shiromaru ◽  
...  
Keyword(s):  
Nmr Characterization
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