Abstract
In this chapter, we focus on the UV absorption characteristics of MAAs and
describe the application examples. UV rays that pass through the ozone layer and the
atmosphere and reach the surface of the Earth consist of UV-A and UV-B. Because
these rays are harmful to biomolecules, MAAs, which can efficiently absorb these
wavelength regions and detoxify their by-products, are promising natural organic
compounds such as sunscreens. Products containing MAAs extracted from red algae
are already on the market. With a focus on Helioguard 365 and HELINORI, the
biological effects of MAAs against UV irradiation will be described.