Study On The Chemical Constituents Of Corydalis Florets

Corydalis racemosa(Thunb.)Pers.is an annual herbaceous plant and primarily distributed in the middle and lower reaches of the pearl and the Yangtze rivers.It is also called huangjin,yeshuiqin,huanghuayudengcao,etc.Its roots or dried whole plants are used in folk medicine,which can clear away heat,damp,and toxins.It is commonly used in the treatment of damp-heat diarrhea,dysentery,jaundice,swelling and pain of eye,purulence,ear pus,scabies,snake bites,etc.Our preliminary research suggested that 95%ethanol extract of C.racemosa could significantly promote the insulin secretion of pancreatic islet HIT-T15 cells in vitro,and has the potential to treat diabetes.Further study indicated that the dichloromethane extract and water extract from 95%ethanol extract are the active fractions.In order to clarify the active components of C.racemosa,we conducted a systematic chemical study on these two active fractions.The purified compounds were tested by using the same cell model.Furthermore,the MS fragematation pathways of the main chemical components in C.racemosa were investigated,and the qualitative characterization of the main components in 95%ethanol extract of C.racemosa was also performed by using LCIT-TOF-MS.The main results are listed as follows:1 Literature reviewThe chemical constituents and pharmacological activities of medicinal plants from Corydalis genus were summaried in detail.Literature research found that Corydalis plants mainly contain alkaloids,phenylpropamide,flavonoids,terpenoids,steroids,phenylpropanoids,and other types of compounds;their pharmacological activities mainly include anti-inflammatory,analgesic,anticancer,anti-insect,cholinesterase inhibitory,and liver protecting activities.2 Study on the chemical constituents of Corydalis racemosa(Thunb.)Pers.Fifty-seven pure compounds were isolated from the CH2Cl2 and water layers of 95%ethanol extract of the whole plants of C.racemosa by using various chromatographic techniques,and spectroscopy and spectroscopy methods.The isolated compounds included 17 alkaloids:racemosine A(1),racemosine B(2),8-oxostylopine(8),stylopine(9),hendersine B(10),magnocurarine(11),pseudoprotopine(12),protopine(13),thalifendine(14),jatrorrhizine(15),sinoacutine(16),(-)-pallidine(17),maclekarpine E(18),(+)-magnoflorine(19),noroxyhydrastinine(20),pyrrolezanthine(21),indole-3-carbaldehyde(22);16 phenylpropanoid amides:N-cis-sinapoyltyramine-4’-O-D-β-glucoside(3),N-cissinapoyl-3-methoxytyramine-4’-O-β-D-glucoside(4),N-trans-cinnamoyltyramine(23),Ntrans-feruloylphenethylamine(24),N-trans-feruloyltyramine(25),N-trans-feruloyl-3methoxydopamine(26),N-trans-sinapoyltyramine(27),N-trans-p-coumaroyltyramine(28),N-trans-p-methoxycinnamoyl-3-hydoxyoctopamine(29),N-trans-feruloyltyramine4-O-β-Dglucopyranoside(30),N-trans-feruloyltyramine-4’-O-β-D-glucopyranoside(31),N-transsinapoyl-7-hydroxytyramine(32),N-cis-sinapoyltyramine(33),N-cis-feruloyl-3methoxytyramine(34),N-cis-feruloyltyramine(35),flavifloramide B(36);12 norsesquiterpenes:3-hydroxy-4,7-megastigmadien-9-one-3-O-α-L-arabinopyranosyl-(1→6)-βD-glucopyranoside(5),3-hydroxy-5α,6α-epoxy-β-ionone-3-O-β-D-xylopyranosyl-(1→6)-βD-glucopyranoside(6),3-hydroxy-5α,6α-epoxy-β-ionone-3-O-α-L-arabinopyranosyl-(1→6)β-D-glucopyranoside(7),(+)-dehydrovomifoliol(37),3-hydroxy-4,7-megastigmadien-9-one(38),9-hydroxy-4,7-megastigmadien-3-one(39),6,9-dihydroxy-4,7-megastigmadien-3-one9-O-β-D-glucoyranoside(40),3-hydroxy-5α,6α-epoxy-β-ionone(41),icariside B2(42),loliolide(43),5β,6α-dihydroxy-7-megastigmen-9-one-3β-O-β-D-glucoyranoside(44),crotolidine(45);12 other types of compounds:kaempferol-3-O-α-L-rhamnopyranosyl(1→6)-β-D-glucopyranoside(46),kaempferol-3-O-α-L-arabinopyranosyl-(1→6)-β-Dglucopyranoside(47),kaempferol-3-O-β-D-glucopyranoside-(1-2)-β-D-glucopyranoside(48),quercetin-3-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside(49),isorhamnetin3-O-β-D-xylopyranosyl-(1→6)-β-D-glucopyranoside(50),quercetin-3-O-β-D-xylopyranosyl(1→6)-β-D-glucopyranoside(51),isorhamnetin-3-O-α-L-rhamnopyranosyl-(1→6)-β-Dglucopyranoside(52),5-O-feruloylquinic acid(53),3-O-feruloylquinic acid(54),4hydroxy-3-methoxyphenylethanol(55),vanillin(56),p-hydroxyphenylethanol(57).Among them,compounds 1-7 are new compounds,compounds 33-41 are firstly isolated from Corydalis genus,and all the isolates are found from C.racemosa for the first time.3 Insulin-secretion-promoting activityThirteen alkaloids were evaluated for their insulin-secretion-promoting effects in HIT-T15 cells.The results showed that racemosine A(1),racemosine B(2),pseudoprotopine(12),maclekarpine E(18),and pyrrolezanthine(21)possess insulinotropic activity.In addition,the influence of the isolates on cell viability was tested by an MTT method.None of these compounds showed cytotoxicity against HIT-T15 cells at a test concentration of 100μM.4 Qualitative characterization of chemical constituents in C.racemosaThe MS fragementation pathways of the main compounds from C.racemosa were clarified by using LC-IT-TOF-MS.Furthermore,an UPLC-IT-TOF-MS method was developed to characterize the main components in the 95%EtOH extract,and forty-two chromatographic peaks were identified on the basis of MS/MS data as well as comparison with the reference substances.