14625
While the literature states that the naturally occurring form of this alkaloid is the R - enantiomer and that its S - antipode is usually not found in nature , we confirmed the hypothesis of Govindachari and Nagarajan that natural levorotatory tylophorine is indeed a nearly racemic mixture with a slight excess of the R - enantiomer .
 levorotatory tylophorine
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 levorotatory tylophorine