Emerging applications of cyanobacterial ultraviolet protecting compound scytonemin

Abstract

Cyanobacteria are one of the most ancient life forms present today. This phylum of organisms is capable of photosynthesis, and they depend on solar radiation for their survival. They are found under diverse climatic conditions where ultraviolet (UV) radiation can damage cellular machinery. In order to be protected from harmful radiation, many cyanobacteria produce the UV radiation-absorbing compound, scytonemin in the extracellular sheath. In this review, characteristic features of seven sheath-forming cyanobacteria are shown and genes involved in scytonemin biosynthesis are discussed. Scytonemin as a sunscreen compound and its biomedical applications are also summarized. Recent advances on the application of scytonemin as a biosignature for extraterrestrial life on Mars are also discussed.

Raman spectroscopic search for scytonemin and gloeocapsin in endolithic colonizations in large gypsum crystals

“…The cyanobacterial colonies were visually observed as regions of dark yellow‐brown or black in colour which could be tentatively linked to species of Nostoc or Gloeocapsa (Figure 2). From our previous study [ 55 ] and the supporting microbiological analysis, Nostoc sp. and Gloeocapsa compacta are the most abundant species in the black‐coloured zones of gypsum.…”

“…Scytonemin is produced by cyanobacteria from diverse lineages and interestingly has been also detected in the gelatinous envelopes of yellow‐coloured Gloeocapsa species. [ 55 ] On the other hand, gloeocapsin has been found only in certain Gloeocapsa species exhibiting blackish‐blue or violet pigmentation of mucilaginous envelopes such as G. compacta . [ 56 ]…”

Marine Pharmacology in 2014–2015: Marine Compounds with Antibacterial, Antidiabetic, Antifungal, Anti-Inflammatory, Antiprotozoal, Antituberculosis, Antiviral, and Anthelmintic Activities; Affecting the Immune and Nervous Systems, and Other Miscellaneous Mechanisms of Action

“…(g) Nervous system marine pharmacology: astaxanthin as a potential neuroprotective agent [342]; origin, distribution, toxicity, and therapeutic uses of the marine neurotoxin tetrodotoxin [343]; marine natural products with neuroprotective activity [344]; marine-terpenoid gracilins as promising compounds for Alzheimer's disease [345]; new marine drugs for Alzheimer's disease treatment [346]. (h) Miscellaneous molecular targets and uses: matrix metalloproteinase inhibitors isolated from edible marine algae [347]; marine natural products that targeting apoptosis signaling pathways [348]; scytonemin and emerging biomedical applications [349]; antiobesity effects of the carotenoid fucoxanthin [350]; therapeutic potential of astaxanthin [351]; pharmacological properties of marine coumarins [352].…”

On the photostability of scytonemin, analogues thereof and their monomeric counterparts

“…13 Scytonemin is characterized by a homodimeric core structure that is unique among natural products, and is composed of two cyclopenta[b]indol-2(1H)-one moieties linked at the 1 and 1′ positions. 9,15 This interest has certainly been nurtured by the reported stability of the pigment. The parent skeleton com-prising the eight rings has been given the trivial name scytoneman by Proteau et al who in 1993 were the first to elucidate the chemical structure of the scytonemin pigment.…”

“…14 The ascertained role as a "natural UV-sunscreen" has sparked the interest of using scytonemin as a UV-absorbing agent (UVA)/sunscreen agent in consumer products or as a starting point for the development of new UVAs. 9,15 This interest has certainly been nurtured by the reported stability of the pigment.…”