Does it come from the UIC code?
Yes, it comes from the UIC Code, but the Thurbo writes only the last three numbers + the error checking number.
The real UIC Number from your two pictures are:
526 777 - 8
526 742 - 2
Have a look here: http://en.wikipedia.org/wiki/THURBO
And with the calculator from AC his link, you can calculate the error checking number