Studies On Chemical Constituents Of Paris Polyphylla Var. Latifolia

Plants belonging genus Paris possess high medicinal value, and their rhizomes are often used as folk medicine to treat nameless tumor, snake bites, mumps, tonsillitis, throat swelling and pain, mastitis, and traumatic injury. Modern studies have showed that they exhibited anti-tumor, anti-bacteria and hemostatic activities. Paris polyphylla var. latifolia, a new variety of Paris polyphylla included in Chinese Pharmacopoeia, is mainly distributed in Shanxi, Anhui, Henan, Hubei and Shaanxi Provinces. However, no studies on the chemical constituents of the variety has been reported so far. Therefore, the rhizome of Paris polyphylla var. latifolia was chosen as the research objective in this thesis. The chemical consitituents were extracted and isolated systematically, their stuctures were elucidated by modern spectral analysis and their antitumor activity was evaluated, in order to clarify the main constituents of the plant, obtain novel compounds and anti-tumor components, and provide theoretical and experimental basis for the development of the medicinal resource.The 70% Et OH extract of the rhizome of Paris polyphylla var. latifolia collected from Taibai Conty, Shaanxi Province was sep Arated by the silica gel, Sephadex LH-20, and HPLC chromatographies to obtain 18 compounds. Their structures were identified by spectroscopic methods(1H-NMR, 13C-NMR, 2D NMR and MS) and comparison with the literatures’ data. They are two steroidal glycosides: β-sitosterol(1)and daucosterol(2); six steroidal saponins, pennogenin-3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside(polyphyllin VI, 6), pennogenin-3-O-α-L-rhamnopyranosyl-(1→4)-[α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranoside(7), pennogenin-3-O-α-L-rhamnopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→4)-[α-L-rhamnopyranos yl-(1→2]-β-D-glucopyranoside(polyphyllin VII, 8), diosgenin-3-O-α-L-rhamnopyran osyl-(1→4)-α-L-rhamnopyranosyl-(1→4)-[α-L-rhamnopyranosyl-(1→2)]-β-D-glucop yranoside(polyphyllin II, 9),(25R)-26-O-β-D-Glc-22-hydroxy-5-ene-furost-3β,26-diol-3-O-α-L-Rha-(1→3)-α-L-Rha-(1→3)-[β-D-Glc-(1→4)]-α-L-rhamnopyranoside(10),(25R)-26-O-β-D-Glc-22-methoxy-5-ene-furost-3β,26-diol-3-O-α-L-Rha-(1→3)-α-L-rh a-(1→3)-[β-D-Glc-(1→4)]-α-L-rhamnopyranoside(11); seven lignan glycosides,(–)-isolariciresinol-3α-O-β-D-glucopyranoside(15),(–)-isolariciresinol-6-O-β-D-glucopy ranoside(16),(–)-lyoniresinol-3α-O-β-D-gluco- pyranoside(17),(+)-lyoniresinol-3α-O-β-D-glucopyranoside(18),(+)-pinoresinol- 4,4′-O-bisglucopyranoside(12),(+)-medioresinol-di-O-β-D-glucopyranoside(13) and liriodendrin(14); one flavonoid glycoside, quercetin-3-O-rutinoside(5); one phenylethanoid glycoside, 2-phenylethyl-β-D-glucopyranoside(3); one polyphenolic compound, Gallic acid(4). All the compounds were obtained from Paris polyphylla var. latifolia for the first time. And among them, saponins 10 and 11 are new compounds, and compounds 3,4 and 10–18 were firstly isolated from genus Paris.The previous studies on the chemical constituents of genus Paris have found that steroidal saponins were the main bioactive consitituens. The first discovery of these seven lignans from this genus might possess a significant chemotaxonomic value, and enriched the types of chemical constituents from genus Paris. Meanwhile, new scientific problems come into being: according to literatures, the lignans exhibited a wide range of biological activities, such as lower the levels of blood pressure and blood lipid which have been seldom found in genus Paris. Then, can P. polyphylla var. latifolia exhibit these activities, differing from other plants of genus Paris? Do other remarkable bioactive constituents exsit in genus Paris, besides steroidal saponins which were generally regarded as material foundation of efficacy of the genus? Our studies may provide the possibility of solving these problem.The cytotoxic activities of several steroidal saponins and lignans against several human tumor cell lines were evaluated by MTT colorimetric assay. The results showed that compound 6 and compounds 12-18 have weak inhibition effect in two tumor cell lines. Compounds 7-9 showed well inhibition effect compared with positive drugs of Doxorubicin for Hep G2, and compound 8 showed better inhibition effect than Compound 7 and compound 9.Compounds 7-9 showed better inhibition effect than positive drugs of ACNU for U87 MG, and compound 7 and compound 9 showed better inhibition effect than compound 8 for U87 MG. Both compound 10 and compound 11 showed well inhibition effect compared with their positive drugs respectivily.Innovations and significance:1. The systematic study of the chemical constituents of Paris polyphylla var. latifolia was carried out for the first time, and 18 compounds were isolated and identified, including six steroidal saponins, seven lignans, two steroidal glycosides, one flavonoid glycoside, one phenylethanoid glycoside and one polyphenolic compound. The preliminary constituents of the plant were explicited by and large through the studies.2. Chemical novelty: Two steroidal saponins were elucidated as new compounds whose structures of the 3-O-sugar moieties were very rare and encountered in saponins of genus Paris for the first time. Nine compounds were firstly obtained from this genus. All the eighteen compounds were identified from the plant for the first time.3. Lignans were found from genus Paris for the first time, which might possess a significant chemotaxonomic value. The finding provided new type of constituents as material foundation of efficacy of genus Paris, and enriched the research data for clarifying the constituents of the genus.4. On the basis of the in vitro anti-tumor experiments, several steroidal saponins with significant cytotoxic activities against two tumor cell lines were found.5. Our studies focused on bioactive constituents of the rhizome of P. polyphylla var. latifolia have established a homebase for the further rational utilization anddevelopment of the plant resources. The studies also provided new data for the further studies of genus Paris, accumulated research materials for the further studies on the active substances of the plant, and provided valuable leads for pursuing new antitumor drugs.