I want to prevent that Google indexes the contents of one
I want to prevent that Google indexes the contents of one on my page
Then I think you shouldn't put that content on the page, period.
You could try using the googleon/googleoff tags, per this article:
Tell Google to Not Index Certain Parts of Your Page
don't index this content
Then again, I find this article which states that it isn't possible:
http://productforums.google.com/forum/#!topic/webmasters/qrBI_v-N4N0
How to tell Google not to? =============
You don't!
If it is content, If it is part of that page, then it Will be Crawled, and may be Indexed and Ranked
You cannot use a Meta-Tag, or a HTML tag to tell Google to ignore, discount, not use, refer or touch part of your content.