New paeonol derivative C302 reduces hypertension in spontaneously hypertensive rats through endothelium-dependent and endothelium-independent vasodilation.

Hypertension is a major risk factor for cardiovascular disease and Chinese herb monomers could provide new structural skeletons for anti-hypertension new drug development. Paeonol is a Chinese herbal monomer extracted from Cortex moutan, exhibited some anti-hypertensive activity. The study focused on the structural optimization of paeonol to provide promising lead compounds for anti-hypertension new drug development. Herein, twelve new paeonol derivatives (PD) were designed and synthesized and their vasodilation activity was evaluated by in vitro vasodilation drug screening platform based on Myograph. Its anti-hypertension activity, PD-C302 (2-hydroxy-4-methoxyvalerophenone) as a representative with the optimal vasodilation activity, was determined by its response to blood pressure in spontaneously hypertensive rats (SHR) in vivo. Moreover, its molecular mechanism was probed by the vasodilation activity of rat superior mesenteric artery rings with or without endothelium pre-contracted by potassium chloride (KCl) or phenylephrine hydrochloride (PE). It was indicated that PD-C302 significantly reduced the blood pressure in SHR, which would involve in PD-C302-induced vasodilation. Furthermore, endothelium-dependent pathways and endothelium-independent pathways both contributed importantly to PD-C302-induced vasodilation at low concentration of PD-C302. Endothelium-independent pathways (vascular smooth muscle cell-mediated vasodilation), were mainly responsible for the PD-C302-induced vasodilation at high concentration of PD-C302, which involved in opening multiple K+ channels to restrain Ca2+ channels, and then triggered vasodilation to reduce blood pressure. PD-C302 has a simple structure and favorable anti-hypertensive activity in vivo, which could be a promising lead compound for anti-hypertension new drug development.

[Synthesis and anti-tumor activity of paeonol and its derivatives].

A series of paeonol derivatives have been synthesized by simple acylation and etherification of the paeonol. Anti-tumor activities of the synthesized compounds were evaluated against HeLa and MCF-7 cells lines in vitro by the standard MTT assay. It was found that the derivatives were more active against HeLa than MCF-7. The results also indicated that 4-methoxy group is the synergistic group of paeonol's anti-tumor activity and ketone carbonyl side chain is essential functional group of paeonol's anti-tumor activity. Compound 2d had stronger antiproliferative activities than paeonol against HeLa and MCF-7 cell lines with IC50 values of 2.67 and 4.74 micromol x L(-1) respectively. The results showed that paeonol derivatives were worth to be intensively studied further.