Study On Bioactive Constituents Of The Seeds Of Quercus Serrata Thunb.

Quercus serrata Thunb. is a species of Quercus L.(commonly called oak)in family Fagaceae.The genus of Quercus spreads wildly in Asia,Europe,Africa and America.China owes 51 species,14 varieties and 1 variant.Oaks are cultivated as cash crop and esculent in China.Their woods are used for ornamentation in constructions or furniture.The fruits of oaks,known as acorns,could be served as the crude material to brew wine and make processed food owing to their abundant starches.Acorns play a significant role in feeding farm livestock as well.According to Compendium of Materia Medica,the barks,acorns and shells of oak taste bitter and could treat diarrhea,crewels and malignant sore in gastrointestinal systemThe previous studies were mainly focused on the chemical constituents of the barks or leaves of oak,while less on its seeds.The chemical constituents consist of triterpenes,flavones,phenylpropanoids and tannins Meanwhile,the reported studies revealed oaks have multiple pharmacological activities,including anti-inflammatory,antitumor,antibiosis,antivirus and antioxidant activitiesIn this study,the dried seeds of Q.serrata Thunb.(30 kg)were extracted with 95%ethanol and extracted with cyclohexane,chloroform,ethyl acetate and n-butanol successively.On the basis of various chromatographic methods and spectroscopic identification techniques,sixty-one compounds were purified and identified from the chloroform fraction and ethyl acetate fraction,which were(1)triterpenes-(i oleanane type):2?,3?,19?,23-Tetrahydroxyolean-12-en-28,29-dioic acid(1*),2?,3?,19?,23,29-Pentahydroxyolean-12-en-28-oic acid(2*),Oleanolic acid(3),Maslinic acid(4),Hederagenin(5),Arjunolic acid(6),Arjunglucoside ?(7),Arjunic acid(8),Arjunetin(9),Arjungenin(10),Arjunglucoside ?(11),Sericic acid(12),Sericoside(13),2?,3?,19?,23-Tetrahydroxyolean-12-en-28-oic acid(14),Rubuside P(15),3,23-O-Methyl butyrate-2?,3?,19a,23-tetrahydroxyolean-12-en-28-oic acid ?-D-glucopyranoside ester(16),Quadranoside X(17),2?,3?-Dihydroxy-27-norolean-13-en-28-oic acid ?-D-glucopyranoside(18*);(ii ursane type):2?,3?,23-Trihydroxyurs-20-en-28-oic acid ?-D-glucopyranoside(19*),2?,3?,19?,23,30-Pentahydroxyurs-12-en-28-oic acid(20*),Ursolic acid(21),3?,19?,23-Trihydroxyurs-12-en-28-oic acid ?-D-glucopyranoside ester(22),Corosolic acid(23),Asiatic acid(24),Quadranoside IV(25),Tormentic acid ester glucoside(26),2?,3?,19?,23-Tetrahydroxyurs-12-en-28-oic acid(27),Niga-ichigoside F1(28),4-epi-Niga-ichigoside F1(29),3,23-O-Methyl butyrate-2?,3?,19?,23-tetrahydroxyurs-12-en-28-oic acid?-D-glucopyranoside ester(30),Rubuside A(31),Pinfaenoic acid(32),2?,3?,23-Trihydroxyurs-12,18-dien-28-oic acid ?-D-glucopyranoside ester(33),2?,3?,23-Trihydroxyurs-12,19(29)-dien-28-oic acid(34),Quadranoside ?(35),3,23-O-Methyl butyrate-2?,3?,23-trihydroxyurs-12,19(29)-dien-28-oic acid ?-D-glucopyranoside(36*),Rubuside D(37),2?,3?,23-Trihydroxyurs-12,19-dien-28-oic acid ?-D-glucopyranoside ester(38),Actindic acid(39),Rubuside H(40),2?,3?,23-Trihydroxy-19-oxo-18,19-seco-urs-11,13(18)-dien-28-O-?-D-glucopyranoside(41);(2)phenylpropanoids:3,3'-Dimethoxy-4',7-epoxy-8,5'-oxyneligna-4,9,9'-triol(42*),4-[3-Hydroxymethyl-5-(3-hydroxypropyl)-2,3-dihydrobenzofuran-2-yl]-2-methoxyphenol(43),(7S,8R)-Dihydrodehydroconifery alcohol(44),Massonianoside A(45),4-Keto-2,6-bis(3-methoxy-4-hydroxyphenyl)-3,7-dioxabicyclo-[3,3,0]octane(4-ketopinoresinol)(46),(+)-Isolariciresinol(47),Butane-2,3-diol 2-O-(6-O-caffeoyl)-?-D-glucopyraniside(48),4-[(6-O-(E)-Caffeoyl)-?-D-glucopyranosyl]vanillic acid(49);(3)other type compounds:4-(6-O-p-Hydroxybenzoyl)-?-D-glucopyranosyl vanillic acid(50*),4-O-[(6-O-p-Hydroxybenzoyl)-?-D-glucopyranosyl]-3,4-dihydroxyphennethyl alcohol(51*),4-O-[(6-O-Vanilloyl)-?-D-glucopyranosyl]-3,4-dihydroxyphennethyl alcohol(52*),2R-Naringenin 7-O-?-D-glucopyranoside(53),Kaempferol-7-O-?-D-glucopyranoside(54),Tiliroside(55),Phloridzin(56),Gallic acid(57),Ellagic acid 3,3'-dimethyl ether-O-?-D-glucopyranoside(58),3'-O-Methyl-ellagic acid-4-O-?-D-xyloside(59),4-(3‘-O-?-D-Glucopyranosyl-4'-hydroxyphenyl)-butan-2-on(60),(Z)-9-Heptadecenoic(61),3-a-Linolenoylglycerol 1-O-?-D-galactopyranoside(62).These compounds include forty-one triterpenoids(1-41),eight phenylpropanoids(42-49)and thirteen other type compounds(50-62).Among them,there are ten novel compounds(1,2,18,19,20,36,42,50,51and 52).All these compounds(1-62)were isolated for the first time from Q.serrata ThunbSome isolated compounds were evaluated for anti-neuroinflammatory activity.Compounds 1,11,18,20,21,24 and 39 showed remarkable inhibitory effects(IC50 21.67-42.76 ?M)on LPS-induced NO production in BV-2 cells compared with indometacin(IC50 45.86±4.55 ?M)Compounds 1,18 and 36 had potent inhibitory effects on protein and mRNA expression of iNOS and COX-2 in LPS-induced BV-2 cells in a dose-dependent manner.Compounds 1,18,20 and 36 suppressed LPS-induced NF-?B nuclear translocation.These novel triterpenoids(1,18,20,36)demonstrated notable anti-neuroinflammatory activityThis study could afford some guidance for further exploitation and utilization of the seeds of Q.serrata Thunb.