Chemical constituents from the leaves of Ilex paraguariensis inhibit human neutrophil elastase.
Human neutrophil elastase (HNE), a serine protease with broad target specificity, is the only enzyme responsible for the degradation of elastin which is an insoluble elastic fibrous protein in animal connective tissue. Biologically, elastase activity significantly increased with age, which results in a reduced skin elasticity and in the appearance of wrinkles or stretchmarks. In the course of our screening program for HNE inhibitors from natural source, the MeOH extract of Ilex paraguariensis leaves showed strong HNE inhibitory effect. Bioassay-guided fractionation led to the isolation of a new pyrrole alkaloid (1), along with seventeen known compounds (2-18) from the MeOH extract of Ilex paraguariensis leaves, and their chemical structures were elucidated on the basis of spectroscopic analysis. All isolated compounds were evaluated for HNE inhibitory activity, and the result demonstrated that dicaffeoylquinic acid derivatives (12, 13, 14, 15 and 16) and flavonoids (8 and 17) exhibited potent HNE inhibitory activity with IC50 values ranging from 1.4 to 7.3 microM.
Xu
Guang-Hua
GH
Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Korea.
Kim
Young-Hee
YH
Choo
Soo-Jin
SJ
Ryoo
In-Ja
IJ
Yoo
Jae-Kuk
JK
Ahn
Jong-Seog
JS
Yoo
Ick-Dong
ID
D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D006801:Humans; D030019:Ilex paraguariensis / Q000737:chemistry*; D019272:Leukocyte Elastase / Q000037:antagonists & inhibitors*; D018515:Plant Leaves / Q000737:chemistry; D015842:Serine Proteinase Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D013329:Structure-Activity Relationship
D000470:Alkaloids; D015842:Serine Proteinase Inhibitors; D019272:Leukocyte Elastase