7332. Phorbol

Nomenclature

CAS number: 17673-25-5
[1aR-(1aα,1bβ,4aβ,7aα,7bα,8α,9β,9aα)]-1,1a,1b,4,4a,7a,7b,8,9,9a-Decahydro-4a,7b,9,9a-tetrahydroxy-3-(hydroxymethyl)-1,1,6,8-tetramethyl-5H-cyclopropa[3,4]benz[1,2-e]azulen-5-one.
C20H28O6; mol wt 364.43.
C 65.91%, H 7.74%, O 26.34%.

Description and references

Parent alcohol of the tumor promoting compounds in croton oil, q.v., the oil expressed from the seeds of Croton tiglium L., Euphorbiaceae. Phorbol has a structural skeleton based on cyclopropabenzazulene. Isoln: Flaschentr"ager, Wigner, Helv. Chim. Acta 25, 569 (1942); Kauffmann, Neumann, Ber. 92, 1715 (1959); S. Tseng et al., J. Org. Chem. 42, 3645 (1977). Structure and stereochemistry: Hecker et al., Tetrahedron Lett. 1967, 3165; Pettersen, Ferguson, Chem. Commun. 1967, 716. Unlike its diesters, phorbol does not appear to be co-carcinogenic or enhance chemically-induced mutagenesis: C. J. Soper, F. J. Evans, Cancer Res. 37, 2487 (1977). Mechanism of action study on phorbol esters: A. S. Kraft, W. B. Anderson, Nature 301, 621 (1983). Comprehensive review of phorbol and its esters: Hecker, Schmidt, Fortschr. Chem. Org. Naturst. 31, 377-467 (1974); P. M. Blumberg, Crit. Rev. Toxicol. 8, 199-234 (1981).

Chemical structure

Properties

Anhydr crystals, dec 250-251°. Two forms of solvated crystals from ethyl acetate: mp 162-163° and 233-234°. Solvated crystals from methanol or ethanol; mp 249-250°. [α]D24 +102° (water). [α]D20 +118° (c = 0.4 in dioxane). uv max (ethanol): 235, 334 nm (ε 5200, 70). Quite sol in polar solvents, including water.

Derivative

12-Myristate 13-acetate diester.

Nomenclature

12-O-Tetradecanoylphorbol-13-acetate; TPA; croton oil factor A1.
C36H56O8; mol wt 616.83.
C 70.10%, H 9.15%, O 20.75%.

Properties

uv max (ethanol): 232, 333 nm (ε 5400, 73). Differentiation of human leukemia cells: J. B. Weinberg, Science 213, 655 (1981).