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Chemical Studies in the Genus Lobaria and the Occurrence of a New Tridepside, 4-O-Methylgyrophoric Acid

Chicita F. Culberson
The Bryologist
Vol. 72, No. 1 (Spring, 1969), pp. 19-27
DOI: 10.2307/3241351
Stable URL: http://www.jstor.org/stable/3241351
Page Count: 9
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Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Chemical Studies in the Genus Lobaria and the Occurrence of a New Tridepside, 4-O-Methylgyrophoric Acid
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Abstract

A new tridepside, 4-O-methylgyrophoric acid, was extracted from a Jamaican collection of Lobaria cfr. dissecta that also contained gyrophoric acid. The structure of the new product was proven by identification of its methyl ester as tenuiorin by direct comparison with a sample of the latter extracted from L. linita. Microchemical studies on 177 herbarium specimens of 18 taxa of Lobaria showed the presence of 4-O-methylgyrophoric acid, either as a constant component or as an accessory but always accompanying gyrophoric acid in L. crassior, L. dentata, L. cfr. dissecta, L. erosa, and L. quercizans. In addition to the tridepsides gyrophoric acid, 4-O-methylgyrophoric acid, and tenuiorin, the following substances were detected: atranorin, constictic acid, norstictic acid, scrobiculin, stictic acid, usnic acid, thelephoric acid, and several unidentified substances.

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