Separation And Identification Of The Phytochemical Constituents And Dynamic Changes Of Main Ones From Plantago Maxima

The genus Plantago L.?Plantaginaceae?comprises more than 190 species distributed in wide areas from the tropics to temperate zones of the world.Plantaginis Herba was firstly recorded in"Shennong Ben Cao Jing",with a long history of medicinal use.The seeds and whole plant were used as herbawith the functions of antifebrile and detoxifying,promoting diuresis,clearing liver to brithten eye,to treat diarrhea due to summer heat,heat toxin and painful swelling,dysuria,edema,etc.The whole plant of Plantago maxima was washed,dried,and extracted with 80%ethanol under reflux.Various column chromatography techniques such as macroporous resin,silica gel,Sephadex LH-20 and ODS were used to separate and purify the phytochemical components.The structures of these compounds were established through modern spectroscopic methods such as ¹H NMR,¹³C NMR,etc.A total of 26 compounds were obtained,including one new compound and 25 known ones,which were identified as plantomoside?1?,geniposidic acid?2?,cistanoside F?3?,eurycorymboside A?4?,dihydrophaseic acid?5?,roseoside?6?,syringic acid?7?,p-hydroxybenzoic acid?8?,plantamajoside?9?,vanillic acid 4-O-?-D-glucopyranoside?10?,10-deoxygeniposidic acid?11?,nepitrin?12?,3'-hydroxyscutellarein7-O-?6''-O-trans-feruloyl?-?-D-glucopyranoside?13?,homoplantaginin?14?,6-hydroxy luteolin-7-O-glucose glycoside?15?,luteolin3'-methoxy-6-hydroxy-7-O-?-D-glucopyranoside?16?,syringaresinol-4'-O-?-D-glucopyranos-ide?17?,baicalein 7-O-?-D-glucopyranoside?18?,luteolin-7-O-?-D-glucopyranoside?19?,4-methoxycinnamic acid?20?,methyl caffeate?21?,methyl ferulate?22?,acteoside?23?,isoacteoside?24?,pedalitia?25?,viteoid??26?.Except for luteolin-7-O-?-D-glucopyranos-ide?19?and acteoside?23?,all the other ones were isolated from P.maxima for the first time.The contents of three components of acteoside,isoverbascoside and luteolin-7-O-?-D-glucopyranoside in P.maxima were determined by high performance liquid chromatography,and the dynamic changes of these three components in 12 different harvest periods were investigated.This method is stable and repeatable.It can be used to determine the content of acteoside,isoverbascoside and luteolin-7-O-?-D-glucopyranoside in P.maxima.The results indicated that the contents of acteoside,isoverbascoside and luteolin-7-O-?-D-glucopyranos-ide changed significantly during different harvest periods.These three compounds were main components and can be used as the basis for evaluating the harvesting time of P.maxima.According to the changes in the contents of these three compounds,the best harvest time is June.