I have a column in a dataframe that looks as such:

```
>head(df$col, 10)

"glut.AN02737.1.1" "glut.AN02737.1.2" "glut.AN02737.1.15" "glut.AN02737.2.1" "glut.AN02737.1.1" "gad.AN17896.1.9" "gad.AN17896.1.9" "gad.AN17896.1.9" "gad.AN17896.1.9" "gad.AN17896.1.9" "gad.AN17896.1.9"

```

I want to extract all characters after the first ".", and before the second ".".

So I want:

`"AN02737" "AN02737" "AN17896"`

How can I achieve this?