1544
N , beta - D - glucopyranosyl vincosamide ( GPV ) , a major alkaloid of Psychotria leiocarpa , constitutes up to 2 . 5 % of the dry weight in leaves .
 N , beta - D - glucopyranosyl vincosamide, GPV
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 N , beta - D - glucopyranosyl vincosamide, GPV