Hi Igor,
Finally got around to looking into this in detail, and below changes will
be in the upcoming release (hopefully by the end of this week).
You can now export peak lists without assignments: just depress the 'Write
assignments' button in the 'Additional options' when exporting a peak
list.
Next, the problem with the HB2/HB3/QB discrepancy between the shift and
peak file for XEASY. The issue here was that some prochiral methylenes
(I'll use HB2 and HB3 from now on as example) were stereospecifically
assigned, *and* had the same chemical shift value. When writing out the
chemical shift file with the 'Compress resonances' option on, these
resonances were merged by an extra bit of code that checks whether
prochiral atoms have the same chemical shift (so it ended up as QB in the
.prot file). For the peaks, I was always assuming that stereospecifically
assigned resonances had to be written out separately, even with the
'Compress resonances' option on.
This behaviour has now been changed, so stereospecifically assigned
resonances will be 'compressed' in the peak list if the 'Compress
resonances' option is on. This might still create problems if you have
stereospecifically assigned resonances with shifts that are very close but
not the same: they will be written as separate atoms in the .prot file and
as joint (QB-type) in the .peaks file.
In general, for complete consistency (and if you can use ambiguous XEASY
lists), it's best to toggle off the 'Compress resonances' option when
exporting.
Hope that helps,
Wim
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