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.
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.
As cancer is one of humanity’s biggest killers in the world, scientists have been looking for different drugs as agents to treat cancer. However, current chemotherapeutics is not sufficiently effective. Thiosemicarbazone complexes of transition metals have attracted wide attention due to a great effect of anticancer activity with different mechanisms including ribonucleotide reductase inhibition, metal dependent radical damage, DNA binding, and inhibition of protein synthesis, and so on. In this minireview, we summarize different metal chelators of thiosemicarbazones and their anticancer mechanisms, which are useful for the development of thiosemicarbazone as anticancer drugs.
The walnut kernel has appeared on dining tables as a non-staple food and gained much popularity for centuries owing to its flavor as well as the function of food therapy, while the green husk or hard shells enwrapped are always discarded or processed into low value-added products. The waste of walnut green husk and shell can cause environment pollution and the waste of resources. As medicinal food, lots of researches on walnut have been carried out during the past decades, including the walnut kernel, the green husk and the hard shell. The researches on the green husk and hard shell showed the mass of chemical compounds isolated from both green husk and hard shell possesses various bioactivities such as antimicrobial, antioxidant, antitumor, and other effects. In this paper, we summarized phytochemical compositions of green husk and hard shell of walnut (Junglans regia) as well as their bioactivities.
Ultrasound-mediated gene delivery is a kind of new method of gene delivery because ultrasound given a certain dose of irradiation can reversibly change the morphology of the cell membrane. Thus, a gene carrier material is obtained through a positive liposome filled with CO2 gas and absorbed by DNA molecule, in which ultrasound-mediated gene delivery is established. Furthermore, the kind of new method of gene delivery is helpful for the dissociation of DNA molecules from liposome (LIP)/DNA complex and the cellular membrane permeability, which can increase SPCA-1 cell viability. Furthermore, the transfection efficiencies of LIP/DNA complex to cells are performed and the effect of ultrasonic time and intensity is further estimated.