Pigment molecule

Pigment molecules, or biochromes, are a diverse class of biological compounds that selectively absorb and reflect light, serving critical roles across all domains of life. In humans, the most significant pigment is melanin, which provides essential photoprotection against ultraviolet radiation and determines the coloration of skin, hair, and eyes [12, 16]. In the context of infectious diseases, many pathogens produce specialized pigments, such as staphyloxanthin in Staphylococcus aureus and pyocyanin in Pseudomonas aeruginosa, which function as potent virulence factors by neutralizing reactive oxygen species and aiding in immune evasion [1, 14]. These molecules are increasingly viewed as therapeutic targets; for example, anti-virulence strategies aim to inhibit pigment biosynthesis to weaken pathogens without exerting the selective pressure of traditional antibiotics [1, 2]. Furthermore, the high affinity of certain drugs, such as chloroquine and thioridazine, for melanin can lead to tissue-specific accumulation and associated toxicities, such as retinopathy [11, 16]. Emerging therapies also utilize the intrinsic photosensitivity of these molecules for targeted photoinactivation in both antimicrobial and oncological applications [1, 13]. Overall, pigment molecules represent a unique intersection of biological function, disease pathology, and pharmacological interaction.

Other names

BiochromesBiological pigmentsChromophoresNatural pigments

Inhibition of pigment biosynthesis (e.g., staphyloxanthin or melanin), high-affinity binding and sequestration in pigmented tissues (e.g., chloroquine binding to melanin), and photoinactivation through light absorption in phototherapy.