KEYS TO ANTIBIOTICS 161 



Valine — continued D-Valine — continued 

 phytoactin valinomyein 



phytostreptin L- Valine 

 thiostrepton valinomyein 



D-Valine L-Valine (N-methyl-) 

 actinomyeins aetinomycins 



amidomyein echinomycin 



