Amides,Isoquinoline Alkaloids and Dipeptides from the Aerial Parts of Piper mullesua

One undescribedamide,pipermullesine A,twoundescribed isoquinoline alkaloids,pipermullesinesBand C,and six undescribed dipeptides,pipermullamides A–F,along with 28 known compounds,were isolated from the aerial parts of Piper mullesua.The structures of the undescribed compounds were elucidated based on the analysis of 1D and 2D NMR and MS data.Furthermore,the structures of pipermullesines A–Cwere confirmed by single crystal X-ray diffraction analysis.All isolates were evaluated for inhibitory activity against platelet aggregation induced by thrombin(IIa)or platelet-activating factor(PAF).(-)-Mangochinine,pellitorine,and(2E,4E)-N-isobutyl-2,4-dodecadienamide showed weak inhibitory activity against rabbit platelet aggregation induced by PAF,with IC_(50)values of 470.3μg/mL,614.9μg/mL,and 579.7μg/mL,respectively.

New Amides and Phenylpropanoid Glucosides from the Fruits of Piper retrofractum

Two new amides(E)-N-cinnamoyl-2-methoxypiperidine(1)and(R)-1-(2-oxopyrrolidin-3-yl)-5,6-dihydropyridin-2(1H)-one(2),four new amide glucosides,retrofractosides A-D(3-6),and two new phenylpropanoid glucosides,retrofractosides E(7)and F(8),together with 24 known compounds(9-32)were isolated from the fruits of Piper retrofractum.The chemical structures of these new compounds were elucidated based on extensive spectroscopic analysis.All of these isolates(1-32)were evaluated for inhibitory activity against mouse platelet aggregation induced by the peptide AYPGKF-NH2.(E)-N-(Tetrahydro-2H-pyran-2-yl)cinnamamide(9)showed a weak inhibitory efect,with an inhibition ratio of 52.0%at a concentration of 150μM.

Chemical Constituents from the Whole Plant of Cuscuta reflexa

Two new 2H-pyran-2-one glucosides,cuscutarosides A(1)and B(2),and one new steroidal glucoside,7β-methoxy-β-sitosterol 3-O-β-glucopyranoside(3),together with 12 known compounds(4-15)were isolated from the whole plant of Cuscuta reflexa(Convolvulaceae)collected from Myanmar.The chemical structures of these new compounds were elucidated based on extensive spectroscopic analysis.The antiobesity activity of these isolates was evaluated using porcine pancreatic lipase(PPL),and the antiplatelet aggregation activity was screened using rabbit platelets induced by thrombin,platelet-activating factor(PAF),arachidonate(AA),or collagen.7β-Methoxy-β-sitosterol 3-O-β-glucopyranoside(3)showed weak PPL inhibitory activity.Cuscutaroside A(1),its acetylated derivative(1a),and scrophenoside B(8)showed weak inhibitory activity against rabbit platelet aggregation induced by collagen.Compound 1a also showed inhibitory activity against rabbit platelet aggregation induced by AA.

Chemical Constituents from Ethanoic Extracts of the Aerial Parts of Leea aequata L.,a Traditional Folk Medicine of Myanmar

We aimed at reporting the chemical constituents and antimicrobial activities of Leea aequata L.,a traditional folk medicine used in Myanmar for the treatment of wounds and skin diseases.A new neolignan,(7S,8R)-9′-O-acetylcedrusin(1),a new lactam,(3S,4S)-4-chloro-3-hydroxypiperidin-2-one(2),along with 21 known compounds,including fve lignans(3-7),four favonoid glycosides(8-11),and others(12-23),were isolated from the ethanoic extract of the aerial parts of L.aequata.The structures of the new compounds were determined by NMR,MS,and ECD spectra.For all the antimicrobial tests of the 23 compounds,only 3,4,5-trihydroxybenzoic acid ethyl ester(17)showed weak inhibitory activities against Escherichia coli and Salmonella enterica subsp.enterica.