Chemical Constituents Of Piper Wallichii

Piper wallichii (Miq.) Hand.-Mazz belongs to the genus Piper, which mainly distributed in the tropical and subtropical regions of the world. Many plants in genus Piper have been used as traditional herbal medicine for thousands of years. P. wallichii is used as traditional herbal medicine in China for the treatment of rheumatic pain and lumbocrural pain. Phytochemical investigation on plants of this genus has led to the isolation of various compounds. Among them, alkaloids are the predominant constituents. Biological activities of chemical constituents in this genus are diverse, including antifungal, antibacterial, antitumor, antiplatelet, antituberculosis, antiplasmodial and antiinflammatory activities. In this paper, recent developments on the chemical constituents and biological activities of genus Piper since2004were reviewed systematically.Previous investigation found that, the water extract of stem of P. wallichii together with its ethyl estate and n-butanol fraction inhibited the gene transcription and protein expression of p-amyloid precursor protein (β-APP), and its aqueous extract possessed in vivo anti-AD activity, indicating that P. wallichii possessed some constituents which had the potential to treat AD. Therefore, the constituents of P. wallichii were investigated systematically. Compounds were separated by column chromatography of silica gel, ODS-A and Sephadex-LH20. Their structures were elucidated based on spectroscopic analysis.16compounds were isolated and identified as3,4-methylenedioxy-benzoic acid (1), vanillic acid (2), benzoic acid (3), N-p-coumaroyltyramine (4), futoenone (5), futoquinol (6), isofutoquinol A (7),4-hydroxy-3,5-dimethoxy-benzoic acid (8), futoamide (9), dihydropiperlonguminine (10), piperlonguminine (11), goniothalactam (12), aristololactam A Ⅲa (13),1,2-dihydro-6,8-dimethoxy-7-hydroxy-1-(3,5-dimethoxy-4-hydroxyphenyl)-N1,N2- bis-[2-(4-hydroxyphenyl)ethyl]-2,3-naphthalene dicarboxamide (14),13-docosenoic acid (15) and8-C-β-D-glucosylkaempferol-3-O-β-D-glucoside (16). Among them, compound16is a new compound; compound14is isolated from the genus Piper for the first time, and compounds1-6are isolated from P. wallichii for the first time. DPPH radical scavenging activity and acetylcholinesterase (AChE) inhibitory activity were tested. Compound8,14and2showed potent scavenging activity against DPPH radical with EC50of22.99±0.36,31.38±0.97,224.3±29.72μM, respectively. Compound4,10,12,13and14showed week inhibition activity against AChE, while compound1,2,3,8,15and16showed no inhibition activity against AChE.