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[thee-uh-fil-een, -in] /ˌθi əˈfɪl in, -ɪn/
noun, Pharmacology.
a white, crystalline, poisonous alkaloid, C 7 H 8 N 4 O 2 , an isomer of theobromine, extracted from tea leaves or produced synthetically: used to relieve bronchial spasms, in the treatment of certain heart conditions, and as a diuretic.
Origin of theophylline
1890-95; theo-, irregular combining form representing New Latin thea tea + -phyll + -ine2 Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
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Examples from the Web for theophylline
Historical Examples
  • Caffeine, theophylline, and theobromine are not found in animal tissues, but are fairly widely distributed in plants.

    The Chemistry of Plant Life Roscoe Wilfred Thatcher
British Dictionary definitions for theophylline


/ˌθɪəˈfɪliːn; -ɪn; θɪˈɒfɪlɪn/
a white crystalline slightly water-soluble alkaloid that is an isomer of theobromine: it occurs in plants, such as tea, and is used to treat asthma. Formula: C7H8N4O2 See also xanthine (sense 2)
Word Origin
C19: from theo(bromine) + phyllo- + -ine²
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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theophylline in Medicine

theophylline the·oph·yl·line (thē-ŏf'ə-lĭn, thē'ō-fĭl'ēn')
A colorless crystalline alkaloid derived from tea leaves or made synthetically, used as a cardiac stimulant and diuretic.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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theophylline in Science
A colorless, crystalline alkaloid derived from tea leaves or made synthetically. It is used in medicine especially as a bronchial dilator. Theophylline is a xanthine that is similar in structure to caffeine and is a structural isomer of theobromine. Chemical formula: C7H8N4O2.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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