Studies On The Active Components Of Mesua Ferrea L. And Eclipta Prostrata L.

Natural products have always played a leading role in the discovery of antimicrobial therapy.In addition to the high degree of structural diversity,natural products are highly selective in the action of cellular targets compared to synthetic antibiotics and are less likely to develop drug resistance.Medicinal plants are regarded as a natural treasure for the prevention and treatment of human diseases in world culture because of their remarkable antibacterial,anti-inflammatory and immunomodulation effect,which also provides a new way of thinking for this study.Our previous research have found that the extracts of Mesua ferrea flowers and the whole grass of Eclipta prostrata L.had significant antibacterial and anti-T3SS activities.In this paper,we will study the chemical constituents in order to find the active ingredients with excellent activity.The 41 compounds in the two plants were systematically separated by Sephadex LH-20,Silica gel,MPLC column chromatorgraphy,HPLC and identified through MS,NMR,UV,IR and other techniques.From the ethyl acetate extract of M.ferrea L.,11 compounds were elucidated,a new biphenyl compound,5,6,6’-trihydroxy[1.1’-biphenyl]-3,3’-dicarboxylic acid(T11)and ten known compounds including 3 flavonoid glucosides,kaempfero 1-3-O-rhamnoside(T1),quercetin-3-O-rhamnoside(quercitrin)(T2),7-O-methyl quercetin-3-O-rhamnoside(T3);1 flavone,quercetin(T4)and 4 aromatic compounds,3-amino-4-hydroxybenzoic acid(T5),3,4-dihydroxybenzoic acid(T6),phyllemblin(T7),gallic acid(T8)and 2 biflavonoids,rhusflavanone(T9),mesuaferrone B(T10).We found rhusflavanone(T9)and mesuaferrone B(T10)exhibited inhibitory effects on the secretion of SPI-1 effector proteins SipA/B/C/D without effecting the bacterial growth.The petroleum ether extract of M ferrea L.was investigated for its chemical constituents.Seven type B PPAPs(T12-T18)were identified,including 5 new compounds mesuaferroic acid H-L(T13,T15-T18)and 2 known compounds laxifloranone(T12)and mesuaferroic acid C(T14),of which T12 exhibited excellent antibacterial activity against clinic G+ bacteria with MIC of 1-8 μg/mL.The EA extracts of E.prostrata L.exhibited inhibitory activity on the T3SS effector proteins secretion of Salmonella.9 compounds(E1-E9)were identified including 2 flavones,orobol(E1),3’-O-methyl orobol(E2);2 coumarin,wedelolaetone(E3),isodemethyl wedelolactone(E4);3 aromatic compounds,protocatechuic acid(E5),4-hydroxy-3-methoxybenzoic acid(E6),3,4-dihydroxybenzoic acid methyl ester(E7);1 isoflavone,luteolin(E8)and 1 thiophene,5’-(4-hydroxy-1-butyn-1-yl)[2,2’-bithiophene]-5-carboxaldehyde(E9).And luteolin(E8)was proved to be the inhibitor of Salmonella T3SS.14 compounds(E10-E23)were isolated and identified from petroleum ether extract including 12 thiophene compounds,[2,2’:5’,2"-terthiophene]-5-carboxaldehyde(E11),5-hydroxymethyl-(2,2,:5’,2"-terthienyl)(E12),2,2’:5’,2"-terthiophene,5-(methoxymethyl)-(9CI)(E13),5-hydroxymethyl-(2,2’:5’,2")-terthienyl acetate(E14),[2,2’:5’,2"-terthiophen]-5-ylmethyl 2-methylbutanoate(E15),5-hydroxymethyl-(2,2’:5’,2")-terthienyl agelate(E16),5-hydroxymethyl-(2,2’:5’,2")-terthienyl tiglate(E17),[2,2’-bithiophene]-5-methanol,5’-(3-buten-1-ynyl)-,2-methylcrotonate,(Z)-(8CI)(E18),[2,2’-bthiophene]-5-methanol,5’-(3-buten-1-ynyl)-,2-methylcrotonate,(E)-(8CI)(E19),[2,2’-bithiophene]-5-methanol,5’-(3-buten-l-yn-1-yl)-,5-acetate(E20),5’-hydroxymethyl-5-(3-buten-1-ynyl)-2,2’-bithiophene(E21).Compounds E10-E23 did not show antibacterial and anti-T3SS virulence activities.