Biomaterial Database

Conversion of 5-(1,2-epoxy-2,6,6-trimethylcyclohexyl)-3-methylpenta-cis-2-trans-4-dienoic acid into abscisic acid in plants. 1970

B V Milborrow, and R C Noddle

(+/-)-5-(1,2-Epoxy-2,6,6-trimethylcyclohexyl) -3-methyl[2-(14)C]penta-cis-2-trans-4-dienoic acid is converted into abscisic acid by tomato fruit in 1.8% yield (or 3.6% of one enantiomer if only one is utilized) and 15% of the abscisic acid is derived from the precursor. The 2-trans-isomer is not converted. The amounts of [2-(3)H]mevalonate incorporated into abscisic acid have shown that the 40-times higher concentration of (+)-abscisic acid in wilted wheat leaves in comparison with unwilted ones reported by Wright & Hiron (1969) arises by synthesis. The conversion of (+/-)-5-(1,2-epoxy-2,6,6-trimethylcyclohexyl) -3-methyl-[2-(14)C]penta-cis-2-trans-4-dienoic acid into abscisic acid by wheat leaves is also affected in the same way by wilting and it is concluded from this that the epoxide or a closely related compound derived from it is on the biosynthetic pathway leading to abscisic acid. The oxygen of the epoxy group was shown, by (18)O-labelling, to become the oxygen of the tertiary hydroxyl group of abscisic acid.

UI	MeSH Term	Description	Entries
D008798	Mevalonic Acid	A dihydroxy monocarboxylic acid and precursor in the biosynthetic pathway known as the mevalonate pathway, which produces terpenes and steroids that are vital for diverse cellular functions.	Mevalonate,Acid, Mevalonic
D010103	Oxygen Isotopes	Stable oxygen atoms that have the same atomic number as the element oxygen, but differ in atomic weight. O-17 and 18 are stable oxygen isotopes.	Oxygen Isotope,Isotope, Oxygen,Isotopes, Oxygen
D010937	Plant Growth Regulators	Any of the hormones produced naturally in plants and active in controlling growth and other functions. There are three primary classes: auxins, cytokinins, and gibberellins.	Phytohormone,Phytohormones,Plant Growth Regulator,Plant Hormone,Plant Hormones,Growth Regulators, Plant,Regulators, Plant Growth,Growth Regulator, Plant,Hormone, Plant,Hormones, Plant,Regulator, Plant Growth
D010944	Plants	Multicellular, eukaryotic life forms of kingdom Plantae. Plants acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations. It is a non-taxonomical term most often referring to LAND PLANTS. In broad sense it includes RHODOPHYTA and GLAUCOPHYTA along with VIRIDIPLANTAE.	Plant
D002247	Carbon Isotopes	Stable carbon atoms that have the same atomic number as the element carbon but differ in atomic weight. C-13 is a stable carbon isotope.	Carbon Isotope,Isotope, Carbon,Isotopes, Carbon
D002845	Chromatography	Techniques used to separate mixtures of substances based on differences in the relative affinities of the substances for mobile and stationary phases. A mobile phase (fluid or gas) passes through a column containing a stationary phase of porous solid or liquid coated on a solid support. Usage is both analytical for small amounts and preparative for bulk amounts.	Chromatographies
D004988	Ethers, Cyclic	Compounds of the general formula R-O-R arranged in a ring or crown formation.	Cyclic Ether,Cyclic Ethers,Ether, Cyclic
D014316	Tritium	The radioactive isotope of hydrogen also known as hydrogen-3. It contains two NEUTRONS and one PROTON in its nucleus and decays to produce low energy BETA PARTICLES.	Hydrogen-3,Hydrogen 3
D014675	Vegetables	A food group comprised of EDIBLE PLANTS or their parts.	Vegetable