Standard Lemma guide

isoleucine

noun · 2 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

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  • /ˌaɪ.səˈluː.siːn/
  • UK: Recorded audio is listed in the source snapshot.
  • rhymes with -uːsiːn

1

noun

Meaning 1

An essential amino acid, C6H13NO2, isomeric with leucine, found in most animal proteins.

Definition source: English Wiktionary via Wiktextract

Usage: countable, uncountable

Topics: biochemistry, biology, chemistry, microbiology, natural-sciences, physical-sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

an essential amino acid found in proteins; isomeric with leucine

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: essential amino acid

History

Etymology

From iso- + leucine.

Across languages

Translations

19 source translations are retained for this English entry.

  • Bulgarian: изолевцин (izolevcin) — essential amino acid; C6H13NO2
  • Chinese Mandarin: 異亮氨酸 /异亮氨酸 (yìliàng'ānsuān) — essential amino acid; C6H13NO2
  • Czech: isoleucin — essential amino acid; C6H13NO2
  • Esperanto: izoleŭcino — essential amino acid; C6H13NO2
  • Finnish: isoleusiini — essential amino acid; C6H13NO2
  • French: isoleucine — essential amino acid; C6H13NO2
  • Galician: isoleucina — essential amino acid; C6H13NO2
  • German: Isoleucin — essential amino acid; C6H13NO2
  • Greek: ισολευκίνη (isolefkíni) — essential amino acid; C6H13NO2
  • Hungarian: izoleucin — essential amino acid; C6H13NO2
  • Italian: isoleucina — essential amino acid; C6H13NO2
  • Japanese: イソロイシン (isoroishin) — essential amino acid; C6H13NO2
  • Latvian: izoleicīns — essential amino acid; C6H13NO2
  • Portuguese: isoleucina — essential amino acid; C6H13NO2
  • Romanian: izoleucină — essential amino acid; C6H13NO2
  • Russian: изолейцин (izolejcin) — essential amino acid; C6H13NO2
  • Slovak: izoleucín — essential amino acid; C6H13NO2
  • Spanish: isoleucina — essential amino acid; C6H13NO2
  • Swedish: isoleucin — essential amino acid; C6H13NO2