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|Section2= }} Pyrogallol is an organic compound with the formula C6H3(OH)3. It is a white solid although because of its sensitivity toward oxygen, samples are typically brownish. It is one of three isomeric benzenetriols. == Production, occurrence, reactions== It is produced in the manner it was first prepared by Scheele (1786): heating gallic acid. Presently gallic acid is obtained from tannin. Heating induces decarboxylation: : : Because tannin is expensive, many alternative routes have been devised. An alternate preparation involves treating para-chlorophenoldisulphonic acid with potassium hydroxide, a variant on the time-honored route to phenols from sulfonic acids. The aquatic plant ''Myriophyllum spicatum'' produces pyrogallic acid.〔Myriophyllum spicatum-released allelopathic polyphenols inhibiting growth of blue-green algae Microcystis aeruginosa. Satoshi Nakai, Yutaka Inoue, Masaaki Hosomi and Akihiko Murakami, Water Research, Volume 34, Issue 11, 1 August 2000, Pages 3026–3032, 〕 When in alkaline solution, it absorbs oxygen from the air, turning brown from a colourless solution. It can be used in this way to calculate the amount of oxygen in air, notably via the use of the Orsat apparatus. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「pyrogallol」の詳細全文を読む スポンサード リンク
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