Polyoxometalates as Potential Next‐Generation Metallodrugs in the melanogenesis inhibitor

Abstract

Melanogenesis is a process to synthesize melanin, which is a primary responsibility for the pigmentation of human skin, eye and hair. In order to study the effect of polyoxometalates on tyrosinase activity and melanin content in mouse melanocytes, four polyoxometalates with Dawson structure were synthesized. Intracellular and docking studies have shown that the two transition metal phosphomolybdic acids (H8[P2Mo17Fe(OH2)61] and H8[P2Mo17Ni(OH2)61]) are highly effective melanogenesis inhibitors with 22.4 % and 24.1 % inhibitory activities at a concentration of 200 μM. Among the four POMs synthesized, the three phosphomolybdic acids showed extremely significant inhibitory effects on the tyrosinase activity in B16 cells (p<0.0001), and the inhibitory activities were 77.5 %, 79.3 % and 44.4 % at a concentration of 200 Μm, respectively. MTT reduction experiments show that the three polyacids (H6[P2Mo18O62], H8[P2Mo17Co(OH2)61] and H8[P2Mo17Ni(OH2)61]) have basically no effect on the viability of B16 cells. Molecular dynamics simulation studies also show that H8[P2Mo17Ni(OH2)61] forms a stable complex with tyrosinase, with a docking fraction of −51.54 kcal/mol. Based on intracellular and docking studies, we believe that H8[P2Mo17Ni(OH2)61] is a promising candidate for safe cosmetic development.

Study on the Antioxidant Properties of Polyoxometalates α-Glucosidase Inhibitors

“…多酸能与 1,1-二苯基-2-三硝基苯肼(DPPH)自由基 产生反应, 可通过其降低 517 nm 处的吸收值体现出来; 吸收值越低, 抗氧化活性越好 [54] . 如图 1b, P [56] 向 100 mL 水中分别加入 0.01 mol 可溶性过渡元素 化合物(硫酸镍、硫酸钴、硫酸铬、硫酸铁和氯化铜), 充 分溶解后加入 25 mL 0.02 mol 的磷酸二氢钠溶液, 在 pH 计监测下, 缓慢滴加 1∶1 硫酸使得溶液体系 pH＝4, 之 后加入 75 mL 0.17 mol 的钼酸钠溶液, 缓慢滴加 1∶1 硫 酸使得溶液体系 pH＝3.6, 80 ℃回流 8 h, 冷却后, 移至 分液漏斗中, 用乙醚萃取法制得杂多酸醚合物, 风干后 重结晶两次即得到样品. [48] 在磁力搅拌器和 pH 计的严格监测下合成 1～5 个钒 原子取代的磷钼酸.…”