Phospholipid hydroperoxide (photoactivated singlet oxygen-mediated oxidation)

Phospholipid hydroperoxidation via singlet oxygen generation (photoactivated) refers to the chemical process in which unsaturated phospholipids within biological membranes are oxidized to form phospholipid hydroperoxides, primarily through the action of singlet molecular oxygen (\( ^1O_2 \)). This process is typically initiated by photosensitization, where light energy absorbed by endogenous or exogenous chromophores leads to the formation of excited-state photosensitizers. These then transfer energy to ground-state molecular oxygen, generating highly reactive singlet oxygen[3][5][8]. Singlet oxygen reacts with double bonds in unsaturated fatty acyl chains of membrane lipids via an "ene" reaction, producing lipid hydroperoxides as primary products[5][8]. The accumulation of these oxidized lipids alters membrane structure and function—hydroperoxide groups migrate toward the polar head region, introducing bends into fatty acid chains and increasing membrane permeability[3]. Phospholipid hydroperoxides can act as signaling molecules but also contribute to cellular damage under oxidative stress. They are implicated in cell death pathways such as apoptosis and necrosis and play roles in inflammation, atherogenesis, neurodegeneration, and cancer progression[7][9]. Enzymes like phospholipid hydroperoxide glutathione peroxidase (GPx4/PHGPx) reduce these peroxides to less reactive alcohols as part of cellular antioxidant defenses[6][9]. This entry does not represent a single protein or classical drug target but rather describes a biochemical process or modification. Therefore, it is not considered a therapeutic target itself; instead, enzymes that metabolize these species—such as GPx4—are recognized targets for drug development. In summary: "Phospholipid hydroperoxidation via singlet oxygen generation" is an important oxidative modification relevant for cell signaling and pathology but does not correspond to a discrete molecule or receptor suitable for direct pharmacological targeting.

Other names

Photooxidized phospholipidSinglet oxygen-induced phospholipid hydroperoxideOxidized phospholipid (via singlet oxygen)Lipid hydroperoxide (photoactivated)