11. Abscisic Acid

Nomenclature

CAS number: 21293-29-8
(2Z,4E)-5-[(1S)-1-Hydroxy-2,6,6-trimethyl-4-oxo-2-cyclohexen-1-yl]-3-methyl-2,4-pentadienoic acid; abscisin II; dormin; ABA.
C15H20O4; mol wt 264.32.
C 68.16%, H 7.63%, O 24.21%.

Description and references

Abscission-accelerating plant hormone; naturally occurring as the (+)-cis,trans-form. Regulates seed maturation and germination and mediates the plant response to environmental stress. Isoln from young cotton fruit: K. Ohkuma et al., Science 142, 1592 (1963) DOI PubMed; from sycamore leaves: J. W. Cornforth et al., Nature 205, 1269 (1965) DOI. Identification in sycamore, birch, rose, cabbage, potato, lemon, avocado: eidem, ibid. 210, 627 (1966) DOI. Structure and synthesis of (±)-cis,trans-form: eidem, ibid. 206, 715 (1965) DOI; and enantiomers: F. Kienzle et al., Helv. Chim. Acta 61, 2616 (1978) DOI. Absolute configuration of naturally occurring form: G. Ryback, Chem. Commun. 1972, 1190. Crystal and molecular structure: H. W. Schmalle et al., Acta Crystallogr. B33, 2218 (1977) DOI. Review: F. T. Addicott, J. L. Lyon, Annu. Rev. Plant Physiol. 20, 139 (1969) DOI. Review of role in root growth regulation: P. E. Pilet, P. W. Barlow, Plant Growth Regul. 6, 217-265 (1987) DOI; of metabolism: J. A. D. Zeevaart, R. A. Creelman, Annu. Rev. Plant Physiol. Plant Mol. Biol. 39, 439-473 (1988) DOI; of signal transduction: J. Leung, J. Giraudat, ibid. 49, 199-222 (1998) DOI PubMed.

Chemical structure

Properties

Crystals from ethyl acetate + hexane, mp 161-163°. Sublimes at 120°. [α]D20 +411.1° (c = 1 in ethanol). [α]D20 +426.5° (c = 1 in 0.005N methanolic H2SO4). Sol in aq NaHCO3, chloroform, acetone, ethyl acetate, ether; slightly sol in benzene, water; sparingly sol in petr ether. uv max (methanol): 252 nm (ε 25200).

Derivative

()-cis,trans-Form.

Nomenclature

CAS number: 14398-53-9
(R)-()-Abscisic acid.

Properties

mp 162-163°. [α]D20 426.2° (c = 1 in 0.005N H2SO4).

Derivative

(±)-cis,trans-Form.

Nomenclature

CAS number: 14375-45-2

Properties

Crystals, mp 188-190°.