TY - JOUR

T1 - Oximes

T2 - unrecognized chameleons in general and specialized plant metabolism

AU - Sørensen, Mette

AU - Neilson, Elizabeth Heather Jakobsen

AU - Møller, Birger Lindberg

PY - 2018

Y1 - 2018

N2 - Oximes (R 1R 2C=NOH) are nitrogen-containing chemical constituents that are formed in species representing all kingdoms of life. In plants, oximes are positioned at important metabolic bifurcation points between general and specialized metabolism. The majority of plant oximes are amino acid-derived metabolites formed by the action of a cytochrome P450 from the CYP79 family. Auxin, cyanogenic glucosides, glucosinolates, and a number of other bioactive specialized metabolites including volatiles are produced from oximes. Oximes with the E configuration have high biological activity compared with Z-oximes. Oximes or their derivatives have been demonstrated or proposed to play roles in growth regulation, plant defense, pollinator attraction, and plant communication with the surrounding environment. In addition, oxime-derived products may serve as quenchers of reactive oxygen species and storage compounds for reduced nitrogen that may be released on demand by the activation of endogenous turnover pathways. As highly bioactive molecules, chemically synthesized oximes have found versatile uses in many sectors of society, especially in the agro- and medical sectors. This review provides an update on the structural diversity, occurrence, and biosynthesis of oximes in plants and discusses their role as key players in plant general and specialized metabolism. Oximes are highly bioactive compounds playing a major role bridging general and specialized plant metabolism. In general metabolism, oximes are nitrogen precursors for further metabolism, e.g., to the phytohormone auxin. In specialized metabolism, oximes act either as the final product or as key intermediates in pathways of several classes of defense compounds.

AB - Oximes (R 1R 2C=NOH) are nitrogen-containing chemical constituents that are formed in species representing all kingdoms of life. In plants, oximes are positioned at important metabolic bifurcation points between general and specialized metabolism. The majority of plant oximes are amino acid-derived metabolites formed by the action of a cytochrome P450 from the CYP79 family. Auxin, cyanogenic glucosides, glucosinolates, and a number of other bioactive specialized metabolites including volatiles are produced from oximes. Oximes with the E configuration have high biological activity compared with Z-oximes. Oximes or their derivatives have been demonstrated or proposed to play roles in growth regulation, plant defense, pollinator attraction, and plant communication with the surrounding environment. In addition, oxime-derived products may serve as quenchers of reactive oxygen species and storage compounds for reduced nitrogen that may be released on demand by the activation of endogenous turnover pathways. As highly bioactive molecules, chemically synthesized oximes have found versatile uses in many sectors of society, especially in the agro- and medical sectors. This review provides an update on the structural diversity, occurrence, and biosynthesis of oximes in plants and discusses their role as key players in plant general and specialized metabolism. Oximes are highly bioactive compounds playing a major role bridging general and specialized plant metabolism. In general metabolism, oximes are nitrogen precursors for further metabolism, e.g., to the phytohormone auxin. In specialized metabolism, oximes act either as the final product or as key intermediates in pathways of several classes of defense compounds.

KW - structural diversity

KW - CYP79

KW - auxin

KW - cyanogenic glucosides

KW - volatile organic compounds

KW - E-oxime

KW - Z-oxime

KW - Volatile Organic Compounds/metabolism

KW - Animals

KW - Oximes/metabolism

KW - Lizards/metabolism

KW - Plants/metabolism

U2 - 10.1016/j.molp.2017.12.014

DO - 10.1016/j.molp.2017.12.014

M3 - Review

C2 - 29275165

VL - 11

SP - 95

EP - 117

JO - Molecular Plant

JF - Molecular Plant

SN - 1674-2052

IS - 1

ER -