[R] Add qoutation marks and combine values in a vector

[Jerry Pressnell]

I wish to place quotation marks around each element of the following 
list;

             X1
1  Label 1
2  Label 2
3  Label 3
4  Label 4

and combine the values in the following format for use in another 
function;

c("Label 1","Label 2","Label 3","Label 4")

Many thanks,

Jerry