Rapid estimation of corynetoxins in bacterial galls from annual ryegrass (Lolium rigidum Gaudin) by high-performance liquid chromatography

1985 ◽  
Vol 36 (1) ◽  
pp. 35 ◽  
Author(s):  
PA Cockrum ◽  
JA Edgar

A rapid and sensitive method is described for the extraction, detection and measurement of corynetoxins in ryegrass seed galls colonized by Corynebucterium rathayi. Excised galls are extracted with aqueous methanol and the extract analysed, without further purification, by reversed-phase high-performance liquid chromatography with detection by uItraviolet absorption. The method is applicable down to the level of a single gall or part of a gall with a minimum level of detection of about 0.25 �g using the equipment described. The corynetoxin content of the individual galls examined varied from below the detection limit to 10.6 �g. The highest level of corynetoxin in a single gall was 1.15% of gall weight. The corynetoxin composition of galls collected during outbreaks of annual ryegrass toxicity in South Australia, Western Australia and South Africa during a 19-year period were found to be similar.

2005 ◽  
Vol 10 (5) ◽  
pp. 427-436 ◽  
Author(s):  
Jeroen Kool ◽  
Sebastiaan M. van Liempd ◽  
Rawi Ramautar ◽  
Tim Schenk ◽  
John H. N. Meerman ◽  
...  

A high-resolution screening platform, coupling online affinity detection for mammalian cytochrome P450s (Cyt P450s) to gradient reversed-phase high-performance liquid chromatography (HPLC), is described. To this end, the onlineCyt P450 enzyme affinity detection (EAD) system was optimized for enzyme (β-NF-induced rat liver microsomes), probe substrate (ethoxyresorufine), and organic modifier (methanol or acetonitrile). The optimized Cyt P450 EAD system has first been evaluated in a flow injection analysis (FIA) mode with 7 known ligands of Cyt P450 1A1/1A2 (β-naphthoflavone, ßnaphthoflavone, ellipticine, 9-hydroxy-ellipticine, fluvoxamine, caffein, and phenacetin). Subsequently, IC 50 valueswere online in FIA-mode determined and compared with those obtained with standardmicrosomal assay conditions. The IC 50 values obtained with the online Cyt P450 EAD system agreed well with the IC 50 values obtained in the standard assays. For highaffinity ligands ofCyt P450 1A1/1A2, detection limits of 1 to 3 pmol injected ( n= 3; signal to noise [S/N] = 3) were obtained. The individual inhibitory properties of ligands in mixtures of the ligands were subsequently investigated using an optimized Cyt P450 EAD system online coupled to gradient HPLC. Using the integrated online gradient HPLC Cyt P450 EAD platform, detection limits of 10 to 25 pmol injected ( n= 1; S/N= 3) were obtained for high-affinity ligands. It is concluded that this novel screening technology offers new perspectives for rapid and sensitive screening of individual compounds in mixtures exhibiting affinity for liver microsomal Cyt P450s.


Author(s):  
Raju Chandra ◽  
Manisha Pant ◽  
Harchan Singh ◽  
Deepak Kumar ◽  
Ashwani Sanghi

A reliable and reproducible reversed-phase high performance liquid chromatography (RP-HPLC) was developed for the quantitative determination of Remipril drug content from marketed bulk tablets. The active ingredient of Remipril separation achieved with C18 column using the methanol water mobile phase in the ratio of 40:60 (v/v). The active ingredient of the drug content quantify with UV detector at 215 nm. The retention time of Remipril is 5.63 min. A good linearity relation (R2=0.999) was obtained between drug concentration and average peak areas. The limit of detection and limit of quantification of the instrument were calculated 0.03 and 0.09 µg/mL, respectively. The accuracy of the method validation was determined 102.72% by recoveries method.


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