<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31374466</termId><termName>xanthine</termName><termType>PT</termType><termNote><![CDATA[ A feebly basic compound (C5H4N4O2) allied to uric acid, found in various organs and secretions of the animal body and from plants, that forms a lemon-yellow compound with nitric acid. It is derived from guanine and hypoxanthine, and yields uric acid on oxidation. ]]></termNote><termCreatedDate>2026-03-30 20:40:59</termCreatedDate><relation><relationType>UF</relationType><termId>31374467</termId><termName>xanthic oxide</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31344370</termId><termName>processed animal material</termName><termType>PT</termType></relation></term>  </Zthes>