Pfizer Handbook of Microbial Metabolites 432 



Yeast 



K. Lohmann and Ph. Schuster, Biochem. Z. 294 188 (1937). 

 (Isolation) 



Kurt G. Stern and Jesse W. Hofer, Science 85 483 (1937). 

 (Synthesis) 



905 Synnematin-B (Cephalosporin N, Salmotin), C14H21O6N3S, bar- 



ium salt, [xW° +187° (c 0.6 in water). 



HOOC— CH N— C=0 



CH3 

 \ 



C CH— CH— NH— CO— CH2— CH2— CH2— CH— COOH 



/ \c/ 1 



CHs ^ NH2 



Cephalosporium salmosynnematum 



E. P. Abraham, "CIBA Lectures in Microbiol. Biochemistry," 

 Biochemistry of some peptide and steroid antibiotics, John 

 Wiley and Sons, New York, 1957. (A review) 



Natural Penicillins. General formula: 



HOOC— CH N C=0 



CH3 I II O 



C CH CH— NH— C— R 



CHs ^ 



906 Penicillin G, Ci„Hi804N2S, colorless prisms, m.p. (Na salt) 215° 



(dec), [aW'-' +305° (c 0.821 in water). 



R = Benzyl <f \-CH2 



907 Penicillin K, C16H26O4N2S, colorless prisms (Na salt), [aln"'^ 



+258° (c 0.43 in water). 



R = n-Heptyl CHslCHzle" 



908 Penicillin X, CkjHisOjNsS, colorless crystals, m.p. (Na salt) 



228-235° (dec), [a]v +267° (c 0.525 in water). 



R = p-Hydroxybenzyl HO— f y-CH2- 



909 Gigantic Acid (Dihydro F), C14H20O4N2S (Na salt), colorless 

 crystals, m.p. 188° (dec), [czId'' +319° (c 1 in water). 



R = n-Amyl CH3(CH2)4~ 



