Study On The Chemical Constituents And Bioactivities From The Roots Of Piper Longum L.

Piper longum L.is a medicinally valuable perennial climbing fujimoto belongs to Piper of Piperaceae.It is mainly produced in the Philippines and Indonesia.In China,it is mainly distributed in Yunnan.The commonly medicinal parts are dried near-ripe or mature fruits of Piper longum L.,it is usually used in Chinese medicine to treat diarrhea,migraine and toothache.Uygur medicine is different from traditional Chinese medicine,and mainly uses its roots as common medicinal materials for the diseases of the digestive system.However,the domestic researches on Piper longum L.mainly focus on the chemical composition of the fruits of Piper longum L.,extraction technology and determination of piperine.There are very few studies on the chemical compositions of the roots of Piper longum L..In order to explore its effective chemical constituents and make the medicinal value of Piper longum L.better developed,this paper systematically studied the chemical constituents and their biological activities in the roots of Piper longum L.from Gengma,Yunnan.4.5 kg of the roots of Piper longum L.were leached with 95%industrial alcohol and concentrated several times to obtain the crude extract.The crude extract was subdivided by separation means such as silica gel column chromatography,Sephadex LH-20,and recrystallization.Finally,15 compounds were obtained.These compounds were identified by their physical and chemical properties,various chromatographic techniques as:xxivacid(1),onadecanoic acid(2),hexadcanoyl cholesterol easter(3),succinic acid(4),?-sitosterol(5),stigmast-4-ene-3,6-dione(6),N-isobutyl-(2E,4E,12Z)-octadecatrienamide(7),3,4-(methylenedioxy)benzoic acid(8),piperine(9),piperolactam D(10),piperlongumine(11),3,4-(methylenedioxy)cinnamic acid(12),1-[11-(ferulyloxy)undecanoyl]glycerol(13),piperolactam A(14),daucosterol(15).Compounds 3,6,7,10,12,13 were isolated from the roots of Piper longum L.for the first time.Inhibitory activity of 7 compounds against bacteria and fungi was determined.The results showed:the amide alkaloid compounds piperine(9)and piperlongumine(11)showed a satisfied antibacterial activity.Moreover,9 and 11 showed a good inhibitory effect especially on plant pathogenic fungi.This study further clarified the components with antibacterial effects of the roots of Piper longum L..7 compounds were tested for antioxidant activity using the DPPH radical scavenging rate as a criterion.The results showed:none of the compounds revealed significant antioxidant effects.Antioxidant active ingredients in the roots of Piper longum L.need to be further studied.Compounds 9 and 11 were tested for their antitumor activity against three human tumor cell lines(PC3,A549,MCF7).The results showed:two compounds was found showing significant cytotoxicity against three tumor cell lines.In particular,compound 11 showed excellent tumor cell-inhibiting activity.From the study of apoptosis signals,it was found that the mechanism of the two compounds inhibiting tumor cells is to induce apoptosis to tumor cells.