Bioactive components of marine species have received great attention in recent years, especially phlorotannins isolated from brown algae. This paper summarized progress in the structures and bioactivities of phlorotannins including antibacterial, antioxidant, anticoagulant, anti-diabetic, anti-hypertensive, inhibiting HIV, anti-tumor, anti-allergic, anti-inflammatory, defense activity, and deodorant activities.
In recent years, marine natural products isolated from associated microorganisms have become a hot topic in medicine. It has been reported that secondary metabolites produced by sponge-associated fungi are of great importance for the discovery of active substances with novel structures and they own broad prospects for clinical medicine and the development of drugs. Herein, we summarize the structures of marine sponge-associated fungi including lactones, anthraquinones, pyrenes, chromones and others, as well as the bioactivities of polyketides from marine sponge-associated fungi.
Iron (Fe), an essential micro-nutrient for marine organisms, is a necessary element for many biochemical processes such as photosynthesis, respiration, synthesis of DNA and chlorophyll, and reduction of nitrate. However, the iron for life is in water under natural pH conditions in the main form of Fe(OH)3. The concentration of soluble iron is very low in seawater due to its insolubility. While iron is the fourth most abundant transition metal in the Earth's crust, the insolubility of iron(III) [KSp of Fe(OH)3 = 10-39] at physiological pH in aerobic environments limits the availability of this essential nutrient severely. Marine microbes face similar challenges for obtaining iron because they live in the environments with very low iron concentrations. In this paper, we summarize the detection methods of siderophores from marine microbials and their structures.