Activity-Guided Isolation and Identification of Azadirachta indica Bark Extract Constituents which Specifically Inhibit Chemiluminescence Production by Activated Human Polymorphonuclear Leukocytes

J. M. van der Nat; W. G. van der Sluis; L. A. 'tHart; H. Van Dijk; K. T. D. de Silva; R. P. Labadie

doi:10.1055/s-2006-960021

Planta Medica, Table of Contents

Planta Med 1991; 57(1): 65-68
DOI: 10.1055/s-2006-960021

Papers

Activity-Guided Isolation and Identification of Azadirachta indica Bark Extract Constituents which Specifically Inhibit Chemiluminescence Production by Activated Human Polymorphonuclear Leukocytes

J. M. van der Nat¹ , W. G. van der Sluis¹ , L. A. 'tHart¹ , H. Van Dijk² , K. T. D. de Silva³ , R. P. Labadie¹

¹Section of Pharmacognosy, Faculty of Pharmacy, State University of Utrecht, Catharijnesingel 60, 3511 GH Utrecht, The Netherlands
²Section of Experimental Immunology, Laboratory for Microbiology, Medical Faculty, State University of Utrecht, Utrecht, The Netherlands
³Department of Chemistry, University of Sri Jayewardenepura, Nugegoda, Sri Lanka

Abstract

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Abstract

The A. indica crude aqueous bark extract inhibits the generation of chemiluminescence by activated human polymorphonuclear leukocytes (PMN). Guided by this activity the responsible compounds were purified by extraction with different organic solvents and HPLC. Gallic acid, (+)-gallocatechin, (-)-epicatechin, and (as a 2:1 mixture) (+)-catechin and epigallocatechin were isolated and identified by means of HPLC, TLC, MS, ¹H-NMR, UV, and CD data. Commercial samples of gallic acid, (+)-catechin and (-)-epicatechin showed the same effects. To our knowledge the identified catechins have never been described as constituents of A indica.

Key words

Azadirachta indica - activity-guided isolation - inhibition of chemiluminescence - human polymorphonuclear leukocytes

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