r - how can I remove part of a names in one column of a data frame? -

i have data looks

v1                                         v2 phenzine.mo.4213121906560.c02.name  2.376140e-05 dnium.bte.mo.02400072107987.e10.name    2.423254e-05 trene.mo.024213121906564.c09.name       2.438986e-05 tilli.mo.550760072207033.f09.name       2.495574e-05 tnolone.mo..614615111406.name           2.511859e-05 

i want remove part of first column looks below

      v1              v2     phenzine    2.376140e-05     dnium.bte   2.423254e-05     trene       2.438986e-05     tilli       2.495574e-05     tnolone     2.511859e-05 

i know must use grep or sub not

you can try below regex if 'mo' common elements

 df1$v1 <- sub('\\.mo.*', '', df1$v1) 

suppose, want remove strings . followed first capital letter

 sub('\\.[a-z].*', '', df1$v1)  #[1] "phenzine"  "dnium.bte" "trene"     "tilli"     "tnolone"   

or if more specific

sub('\\.(mo|no|nr).*', '', df1$v1) #[1] "phenzine"  "dnium.bte" "trene"     "tilli"     "tnolone"