Title:  Propyl Gallate 
CAS Registry Number:  121-79-9 
CAS Name:  3,4,5-Trihydroxybenzoic acid propyl ester 
Additional Names:  n-propyl gallate;  gallic acid propyl ester;  PG 
Trademarks:  Progallin P (Nipa);  Tenox PG (Eastman) 
Molecular Formula:  C10H12O5 
Molecular Weight:  212.20 
Percent Composition:  C 56.60%, H 5.70%, O 37.70% 
Literature References:  Spectrophotometric determn:  C. S. Sastry et al., Talanta 29, 917 (1982).  Effects on survival of Saccharomyces cerevisiae:  V. L. Eubanks, L. R. Beuchat, J. Food Prot. 46, 29 (1983).  Antioxidant effectiveness:  M. A. Augustin, S. K. Berry, J. Am. Oil Chem. Soc. 60, 105 (1983).  Comprehensive review of biological effects and toxicology:  J. Am. Coll. Toxicol. 4, 23-64 (1985). 
Properties:  Crystals, mp 150°.  Soly at 25° in water = 0.35 g/100 ml; in alcohol = 103 g/100 g; in ether = 83 g/100 g.  Soly in cottonseed oil at 30° = 1.23 g/100 g; in lard at 45° = 1.14 g/100 g.  Darkens in the presence of iron and iron salts.  Synergic with acids, BHA, BHT.  pKa 8.11.  Partition coefficient (oleyl alcohol:water) 17.  Partition coefficient (octanol:water) 32.  pH (0.05% aq soln) 6.3; (0.1% aq soln) 5.9; (0.2% aq soln) 5.7.  LD50 in mice, rats, hamsters, rabbits (g/kg):  1.70-3.50, 2.1-7, 2.48, 2.75 orally; LD50 i.p. in rats:  0.38 g/kg (J. Am. Coll. Toxicol.). 
Melting point:  mp 150° 
pKa:  pKa 8.11 
Log P:  Partition coefficient (oleyl alcohol:water) 17; Partition coefficient (octanol:water) 32 
Toxicity data:  LD50 in mice, rats, hamsters, rabbits (g/kg):  1.70-3.50, 2.1-7, 2.48, 2.75 orally; LD50 i.p. in rats:  0.38 g/kg (J. Am. Coll. Toxicol.) 
Use:  Antioxidant for cosmetics, foods, fats, oils, ethers, emulsions, waxes, transformer oils.   |