| 单词 | phaeophorbide a |
| 释义 | > as lemmasphaeophorbide a A greyish-green compound formed by the degradation of chlorophyll or phaeophytin (e.g. by strong acid or by enzymes), having the structure of phaeophytin with the phytyl group replaced by a hydrogen atom; (more fully phaeophorbide a, phaeophorbide b) either of two forms of this, derived from chlorophyll a and chlorophyll b respectively. ΘΚΠ the world > life > biology > substance > pigment > [noun] > pigment derivatives phaeophorbide1911 porphyrinogen1913 1911 Chem. Abstr. 5 873 The following nomenclature is now adopted: for the free tricarboxylic acid, the basis of chlorophyll, the name chlorophyllin is retained, the monomethyl ester is called chlorophyllide and the deriv. free from Mg, pheophorbide. 1929 Science 9 Aug. 149/1 Phaeophorbide a and b and phytochlorin e yield substances that appear to be porphyrins. 1963 R. P. Dales Annelids ii. 56 The colour is due to phæophorbides—breakdown products of chlorophylls presumably derived from the food. 1975 Nature 24 Jan. 241/1 Sudden heating [of leaf juice] inactivates chlorophyllase and so prevents the formation of phaeophorbide. 1988 New Scientist 5 Nov. 40/1 Less than fresh vegetables sometimes take on the grey-green colour of phaeophorbide. 1998 Jrnl. Exper. Bot. 49 503 In the senescent mutant leaves, accumulations of chlorophyllide a and chlorophyllide b were detected, but no phaeophorbide a was found. < as lemmas |
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