Is there a method to determine the zwitterion

Hi, I checked API and did not find a straight method to determine if a molecule is a zwitterion or not. Otherwise I have to traverse all atoms to count their formal charge, and decide. Is there a short cut to do that?

Thanks

Dong

Hi,

 

The   isoelectricpoint which based on the pKa values is  a good indicator of the  zwitterionic property.

http://www.chemaxon.com/marvin/help/developer/beans/api/chemaxon/marvin/calculations/IsoelectricPointPlugin.html

For example : isolectric point of alanine is 5.98

 

Jozsi