Ionone Is More than a Violet’s Fragrance: A Review

Abstract

The term ionone is derived from “iona” (Greek for violet) which refers to the violet scent and “ketone” due to its structure. Ionones can either be chemically synthesized or endogenously produced via asymmetric cleavage of β-carotene by β-carotene oxygenase 2 (BCO2). We recently proposed a possible metabolic pathway for the conversion of α-and β-pinene into α-and β-ionone. The differences between BCO1 and BCO2 suggest a unique physiological role of BCO2; implying that β-ionone (one of BCO2 products) is involved in a prospective biological function. This review focuses on the effects of ionones and the postulated mechanisms or signaling cascades involved mediating these effects. β-Ionone, whether of an endogenous or exogenous origin possesses a range of pharmacological effects including anticancer, chemopreventive, cancer promoting, melanogenesis, anti-inflammatory and antimicrobial actions. β-Ionone mediates these effects via activation of olfactory receptor (OR51E2) and regulation of the activity or expression of cell cycle regulatory proteins, pro-apoptotic and anti-apoptotic proteins, HMG-CoA reductase and pro-inflammatory mediators. α-Ionone and β-ionone derivatives exhibit anti-inflammatory, antimicrobial and anticancer effects, however the corresponding structure activity relationships are still inconclusive. Overall, data demonstrates that ionone is a promising scaffold for cancer, inflammation and infectious disease research and thus is more than simply a violet’s fragrance.

Remedia Sternutatoria over the Centuries: TRP Mediation

“…Sneezing occurs because of the activation of these sensory fibers (expressing TRPA1 and TRPV1) in the vagal sensory nerve terminals by noxious stimulants [ 4 ]. Signal transduction occurs by augmenting intracellular calcium concentrations and/or depolarizing membrane potentials [ 137 , 138 ]. It was found that there is an overexpression of TRPV1 in the nasal mucosa and augmented substance P levels in nasal secretions in idiopathic rhinitis patients [ 139 ].…”

β-Ionone: Its Occurrence and Biological Function and Metabolic Engineering

“…The specific oxidative cleavage of carotenoids at (9,10 and 9',10') leads to the production of β-ionone and is catalyzed by a carotenoid cleavage dioxygenase (CCD1) (Figure 1) [13][14][15]. The biosynthesis of β-ionone in general in the plant kingdom has been recently intensively reviewed by Shi et al [57] and Aloum et al [58].…”

“…Plant apocarotenoids, including β-ionone, comprise flavors, aromas, pigments, growth regulators, and defense compounds. They serve as ecological cues, have roles as insect attractants or repellants, and possess antibacterial and fungicidal properties [57,58,70]. β-Ionone and other apocarotenoid pigments are also economically important because they show extremely potent odor thresholds, at a level of 0.007 ppb.…”

“…β-Ionone and other apocarotenoid pigments are also economically important because they show extremely potent odor thresholds, at a level of 0.007 ppb. Therefore, apocarotenoids, including β-ionone, although generally present at relatively low levels in fruits, often exert strong effects on the aroma's overall human appreciation [11,57,58,71]. The synthesis and accumulation of β-ionone and its derivatives can also occur when plants are exposed to photooxidative stress through reactive oxygen species (ROS) oxidation of β-carotene [2,57,58].…”

“…The synthesis and accumulation of β-ionone and its derivatives can also occur when plants are exposed to photooxidative stress through reactive oxygen species (ROS) oxidation of β-carotene [2,57,58].…”