Nomenclature
CAS number: 121-79-9
3,4,5-Trihydroxybenzoic acid propyl ester;
n-propyl gallate; gallic acid propyl ester; PG; Progallin P (Nipa); Tenox PG (Eastman).
C
10H
12O
5; mol wt 212.20.
C 56.60%, H 5.70%, O 37.70%.
Description and 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.).Use
Antioxidant for cosmetics, foods, fats, oils, ethers,
emulsions, waxes, transformer oils.