Hello everyone, I am studying gapmers (antisense oligonucleotides), which have 20 nucleotides formed by DNA and RNA at their wings. I have the sequence with chemical modifications (such as phosphorothioates and 2'-MOE) example:

CCGACcattgtacagAAAGC (phosphorothioates modifications, UPPER LETTER: RNA sequence)

I need to know of a program that allows me to predict if it can cause toxicity and/or off-target the molecule. Based on this, the questions are:

1. Does anyone know of a program (or R or python package) that allows me to predict this?
2. I found a possible candidate but it asks me to draw the chemical formula. Is there something that can draw a chemical formula from a sequence?

I'd need an image like this below but with all my sequence

Any help I very much appreciate