138. Actinobolin

Nomenclature

CAS number: 24397-89-5
(2S)-2-Amino-N-[(3R,4R,4aR,5R,6R)-3,4,4a,5,6,7-hexahydro-5,6,8-trihydroxy-3-methyl-1-oxo-1H-2-benzopyran-4-yl]propanamide; 4-(2-aminopropionamido)-3,4,4a,5,6,7-hexahydro-5,6,8-trihydroxy-3-methylisocoumarin.
C13H20N2O6; mol wt 300.31.
C 51.99%, H 6.71%, N 9.33%, O 31.97%.

Description and references

Antibiotic produced by Streptomyces griseoviridus var atrofaciens; (+)-form is naturally occurring. Isoln and characterization: T. H. Haskell, Q. R. Bartz, Antibiot. Annu. 1958-1959, 505; T. H. Haskell et al., US 3043830 (1962 to Parke, Davis). Structural studies: Struck et al., Tetrahedron Lett. 1967, 1589; Munk et al., J. Am. Chem. Soc. 89, 4158 (1967). Structure: eidem, ibid. 90, 1087 (1968). Absolute configuration and chemistry: Antosz et al., ibid. 92, 4933 (1970). Crystal structure: J. B. Wetherington, J. W. Moncrief, Acta Crystallogr. B31, 501 (1975). Total synthesis: M. Yoshioka et al., J. Am. Chem. Soc. 106, 1133 (1984); eidem, Heterocycles 21, 151 (1984); R. S. Garigipati et al., J. Am. Chem. Soc. 107, 7790 (1985). Antibacterial activity and toxicity: R. F. Pittillo et al., Antibiot. Annu. 1958-1959, 497. Series of articles on antineoplastic activity: ibid. 515-532. Inhibition of protein synthesis: D. Smithers et al., Mol. Pharmacol. 5, 433 (1969). Experimental use as cariostat: D. E. Hunt et al., J. Dent. Res. 50, 371 (1971). Reduction of periodontal syndrome in mice, rats: J. H. Shaw, J. K. Ivimey, Arch. Oral Biol. 18, 357 (1973).

Chemical structure

Properties

Amorphous, fluffy, very hygroscopic powder. [α]D28 +59° (c = 0.5 in pH 7 phosphate buffer). pKa: 7.5, 8.8. Freely sol in water; mod sol in methanol, ethanol. Unstable in aqueous solns pH >7. uv max: 262 nm (0.1N HCl); 288 nm (0.1N NaOH). LD50 in mice, rats (mg/kg): 800 ±27, 1550 ±26 i.v. (Pittillo).

Derivative

Acetate.
C13H20N2O6.C2H4O2; mol wt 360.36.
C 49.99%, H 6.71%, N 7.77%, O 35.52%.

Properties

Needles from ethanol; softens at 130°, resolidifies at 145°, mp 263-266°. [α]D26 +58°. pKa: 4.6, 7.5, 8.8. Very sol in water; sol in warm methanol, ethanol, acetone; sparingly sol in ethyl acetate. uv max: 264 nm (pH 7 phosphate buffer).

Derivative

Hydrochloride.
C13H20N2O6.HCl; mol wt 336.77.
C 46.36%, H 6.29%, N 8.32%, O 28.51%, Cl 10.53%.

Properties

Hygroscopic. [α]D22 +59° (c = 0.41) (natural); [α]D22 +55° (c = 0.47) (synthetic).