Max wrote...
One way ..

Assuming data is in col A, A1 down

Try in say, B1:

=LEFT(TRIM(A1),SEARCH(" ",TRIM(A1),SEARCH(".",TRIM(A1))))
....

Could fail when there's more than one period in the text.

If the ending substring could be variable length but always preceded by
a space, it's possible to use

=LEFT(TRIM(A1),LOOKUP(2,1/(MID(TRIM(A1),ROW(INDIRECT("1:256")),1)=" "),
ROW(INDIRECT("1:256")))-1)

This relies on the functionality of the LOOKUP formula as it's worked
from Excel 97 through Excel 2003 (and probably in earlier versions as
well).