Separation of Leucas aspera, a medicinal plant of Bangladesh, guided by prostaglandin inhibitory and antioxidant activities.
According to the traditional usage of the plant for antiinflammation and analgesia, Leucas aspera was tested for its prostaglandin (PG) inhibitory and antioxidant activities. The extract showed both activities, i.e., inhibition at 3 x 10(-4) g/ml against PGE(1)- and PGE(2)-induced contractions in guinea pig ileum and a 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effect. The separation guided by the activities in these dual assay methods provided eight lignans and four flavonoids, LA-1- -12, among which LA-1- -7 and LA-10- -12 were identified as nectandrin B, meso-dihydroguaiaretic acid, macelignan, acacetin, apigenin 7-O-[6"-O-(p-coumaroyl)-beta-D-glucoside], chrysoeriol, apigenin, erythro-2-(4-allyl-2, 6-dimethoxyphenoxy)-1-(4-hydroxy-3-methoxyphenyl)propan-1-ol, myristargenol B, and machilin C, respectively. LA-8 was determined to be (-)-chicanine, the new antipode of the (+) compound, by spectroscopic methods including CD and ORD. Chiral-HPLC analysis of LA-9 showed that it was a mixture of two enantiomers, (7R, 8R)- and (7S, 8S)-licarin A. All of these components were first isolated from L. aspera. PG inhibition was observed in LA-1, LA-2, and LA-5, and antioxidant activity in LA-1- -3 and LA-8- -12.
Graduate School of Pharmaceutical Sciences, Chiba University, Japan.
Samir Kumar
SK
Sadhu
Emi
E
Okuyama
Haruhiro
H
Fujimoto
Masami
M
Ishibashi
D000527:Alprostadil / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification; D001459:Bangladesh; D001713:Biphenyl Compounds; D002855:Chromatography, Thin Layer; D002942:Circular Dichroism; D015232:Dinoprostone / Q000037:antagonists & inhibitors / Q000494:pharmacology; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D011048:Polarography; D011448:Prostaglandin Antagonists / Q000737:chemistry* / Q000302:isolation & purification
D000975:Antioxidants; D001713:Biphenyl Compounds; D010851:Picrates; D010936:Plant Extracts; D011448:Prostaglandin Antagonists; C004931:1,1-diphenyl-2-picrylhydrazyl; D000527:Alprostadil; D015232:Dinoprostone