<!-- entities -->

<!-- the top level element -->
<!ELEMENT amino-acid (name,abbreviation,symbol,molecular-formula,molecular-weight,isoelectric-point,CAS-registry-number)>

<!-- elements -->
<!ELEMENT name                      (#PCDATA)>
<!ELEMENT abbreviation              (#PCDATA)>
<!ELEMENT symbol                    (#PCDATA)>
<!ELEMENT molecular-formula         (#PCDATA)>
<!ELEMENT molecular-weight		(#PCDATA)>
<!ELEMENT isoelectric-point         (#PCDATA)>
<!ELEMENT CAS-registry-number		(#PCDATA)>
