No, you can't, sorry. There's no Print (to PDF) command in ADE (Adobe Digital Editions) nor in any eReaders, nor is there an Export to PDF command. (If you find an eReader device or app that does this, please tell us!)
I'm guessing you want to grab the formatting, otherwise you'd just copy and paste the text into a text frame in Powerpoint. The only way to get the formatting would be to take a screen shot of the paragraphs in ADE and then import the screen shot as a picture into Powerpoint.
I think the people who make ebooks use Digital Editions specifically so you CANNOT do this.