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L A Mitscher

Publications and source records attributed to L A Mitscher.

113 records · Page 7Linked to original sources
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Antimicrobial agents from higher plants. The antimicrobially inactive components of Ptelea trifoliata L.

From the weakly antibacterial non-quaternary alkaloidal fractions from Ptelea trifoliata L. (Rutaceae), ten tertiary quinol-2-one and quinol-4-one alkaloids were isolated and identified. In addition, beta-sitosterol, beta-sitosteryl-beta-D-glucoside and bergapten were isolated. None of these compounds possessed perceptible antimicrobial activity. The weak antimicrobial activity of the neutral and alkaloidal fractions was traced to small amounts of pteleatinium chloride which had not been completely separated by bulk processes. Alkaloids previously known to be present in P. trifoliata which were found in this study ptelefoline methyl ether, pteleine and skimmianine. Alkaloids previously known but new to this plant were lunidoine and isomaculasidine. Alkaloids newly found in nature were neohydroxylunine, hydroxylunidonine, 6-methoxylunidoine, 6-methoxylunineand 6-methoxy-hydroxylunidine. The structure of the latter three bases is proposed tentatively.

Alkaloids↗
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Antimicrobial agents from higher plants. An investigation of Hunnemannia fumariaefolia pseudoalcoholates of sanguinarine and chelerythrine.

The antimicrobial activity seen in extracts of Hunnemmania fumariaefolia S. resides in the alkaloids. The activity seen in the non-polar fractions had been shown by chromatography, physicochemical measurements, and comparisons with authentic samples to be due to apparently artifactual formation of the pseudomethanolates and pseudoethanolates of the alkaloids sanguinarine and chelerythrine, which are abundant in the plant. The enhanced potency of the pseudoalcoholates of sanguinarine over the parent benzophenanthridine is discussed in comparison with the in vitro biopotencies of other analogs prepared for the purpose. It appears that the pseudoalcoholates may be useful prodrugs.

Alcohols↗
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Antimicrobial agents from higher plants. Additional alkaloids and antimicrobial agents from Thalictrum rugosum.

Further study of mother-liquors from ethanolic extracts of Thalictrum rugosum resulted in the identification or partial characterization of 10 alkaloids, bringing the total to 17 characterized in our work on this plant. Five of the new alkaloids were active in vitro against microorganisms. Structures, based upon spectroscopic properties and chemical transformations, are proposed for a new bisbenzylisoquinoline alkaloid named thalrugosaminine, and a protopine alkaloid named protothalipine. A phenanthrene base (thaliglucinone), an aporphine (thalphenine), and three protoberberine bases (columbamine, thalifendine and deoxythalidastine) were identified; three very minor bases of unknown identify were partially characterized.

Alkaloids↗
PubMedDate not supplied

Alkaloids of Thalictrum. XV. Isolation and identification of the hypotensive alkaloids of the root of Thalictrum lucidum.

Sixteen alkaloids, namely homoaromoline, obaberine, O-methyl-thalicberine, oxyberberine, thalidasine, thaliglucinone, thalrugosine, obamegine, oxyacanthine, berberine, columbamine, jatrorrhizine, magnoflorine, palmatine, thalifendine and base A chloride, plus the artifact, 8-trichloromethyldihydroberberine, were isolated from the alkaloid fraction of the roots of Thalictrum lucidum L. Of these, obamegine, thalrugosine, O-methylthalicberine, thaliglucinone, obaberine and homoaromoline were found to possess hypotensive activity in normotensive dogs. Thalidasine, homoaromoline, thalrugosine, thaliglucinone, obamegine, jatrorrhizine, and columbamine were found to possess antimicrobial activity against Mycobacterium smegmatis at a concentration of 100 mug/ml or less.

Alkaloids↗