scholarly journals Identification of ecdysonoic acid and 20-hydroxyecdysonoic acid isolated from developing eggs of Schistocerca gregaria and pupae of Spodoptera littoralis

1983 ◽  
Vol 213 (1) ◽  
pp. 261-265 ◽  
Author(s):  
R E Isaac ◽  
N P Milner ◽  
H H Rees
Keyword(s):  
Mass Spectrometry ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Methyl Ester ◽  
Spodoptera Littoralis ◽  
High Performance ◽  
Fast Atom Bombardment ◽  
Schistocerca Gregaria ◽  
Methyl Esters ◽  
Desert Locust

Ecdysonoic acid and 20-hydroxyecdysonoic acid have been purified from developing eggs of the desert locust, Schistocerca gregaria, by high performance liquid chromatography (h.p.l.c.), and their structures were determined by p.m.r. spectroscopy and fast atom bombardment mass spectrometry of the free and methyl ester derivatives. 20-Hydroxyecdysonoic acid was also characterized from Spodoptera littoralis pupae. The occurrence of both 20-hydroxyecdysonoic acid and ecdysonoic acid in Sp. littoralis pupae was also established by h.p.l.c. comparison of the 3H-labelled acids formed from [3H]ecdysone and of their methyl esters with the corresponding substances from Sch. gregaria. The significance of ecdysteroid acids as products of ecdysteroid inactivation is discussed.

scholarly journals Identification of the 22-phosphate esters of ecdysone, 2-deoxyecdysone, 20-hydroxyecdysone and 2-deoxy-20-hydroxyecdysone from newly laid eggs of the desert locust, Schistocerca gregaria

1983 ◽  
Vol 213 (2) ◽  
pp. 533-541 ◽  
Author(s):  
R E Isaac ◽  
M E Rose ◽  
H H Rees ◽  
T W Goodwin
Keyword(s):  
Mass Spectrometry ◽  
High Performance Liquid Chromatography ◽  
High Performance ◽  
Fast Atom Bombardment ◽  
Schistocerca Gregaria ◽  
Reversed Phase ◽  
Phosphate Esters ◽  
Desert Locust ◽  
Phosphate Analysis ◽  
Moulting Hormone

The four major ecdysteroid (insect moulting hormone) conjugates present in the newly laid eggs of the desert locust, Schistocera gregaria, have been purified by reversed-phase and anion-exchange high-performance liquid chromatography. The steroid moieties were identified as ecdysone, 2-deoxyecdysone, 20-hydroxyecdysone and 2-deoxy-20-hydroxyecdysone. Phosphate analysis of acid-hydrolysed samples showed a steroid:phosphate ratio of approx. 1:1 for all four compounds. The intact conjugates were identified as ecdysone 22-phosphate, 2-deoxyecdysone 22-phosphate, 20-hydroxyecdysone 22-phosphate and 2-deoxy-20-hydroxyecdysone 22-phosphate by fast atom bombardment mass spectrometry and 1H, 13C and 31P n.m.r. The significance of ecdysteroid phosphates as a source of free hormone during embryogenesis is discussed.

scholarly journals Altered peptidoglycan composition in vancomycin-resistant Enterococcus faecalis.

1996 ◽  
Vol 40 (4) ◽  
pp. 863-869 ◽  
Author(s):  
B L de Jonge ◽  
S Handwerger ◽  
D Gage
Keyword(s):  
Mass Spectrometry ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Enterococcus Faecalis ◽  
Resistant Strain ◽  
High Performance ◽  
Fast Atom Bombardment ◽  
Vancomycin Resistant Enterococcus ◽  
Reverse Phase ◽  
Vancomycin Resistant

The muropeptide compositions of isogenic vancomycin-resistant and -susceptible Enterococcus faecalis strains were analyzed by reverse-phase high-performance liquid chromatography combined with amino acid analysis and fast atom bombardment mass spectrometry. Peptidoglycan of the susceptible strain contained pentapeptides as stem peptides, whereas peptidoglycan of the isogenic resistant strain was composed of muropeptides with tetrapeptide stem peptides. Despite the synthesis of lactate-terminating peptidoglycan precursors, no lactate-containing muropeptides were detected in peptidoglycan of the resistant strain. These findings indicate that either lactate-terminating precursors are not incorporated into peptidoglycan of the resistant strain or that the lactate residues are removed from peptidoglycan during synthesis.

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