In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Erdosteine administration with VCM injections caused significantly decreased renal MDA and urinary NAG excretion , and increased SOD activity , but not CAT activity in renal tissue when compared with VCM alone .
### Output Text:
<span class="chemical">Erdosteine</span> administration with <span class="chemical">VCM</span> injections caused significantly decreased renal <span class="chemical">MDA</span> and urinary NAG excretion , and increased SOD activity , but not CAT activity in renal tissue when compared with <span class="chemical">VCM</span> alone . 