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Showing papers by "Tom J. Mabry published in 1971"


Journal ArticleDOI
TL;DR: The sesquiterpene lactone chemistry is summarized for seventeen taxa of Parthenium including new detailed data for four species and new preliminary results for P. fruticosum , P. hispidum and P. rollinsianum .

68 citations


Journal ArticleDOI
TL;DR: In this article, it was shown that the van der Waal's proximity effect of the C8-α-hydroxyl group on sesquiterpene lactones can be used for making certain stereochemical and conformational assignments.

44 citations


Journal ArticleDOI
TL;DR: Three flavonoids have been identified from the frond exudate of P. calomelanos: rhamnocitrin, apigenin 7-methyl ether and genkwanin this article.

40 citations


Journal ArticleDOI
TL;DR: Betalamic acid, the probable key intermediate in the biogenesis of all betalains, has been detected for the first time as a natural product in numerous species of plants belonging to families of the Order Centrospermae.
Abstract: Betalamic acid, the probable key intermediate in the biogenesis of all betalains, has been detected for the first time as a natural product in numerous species of plants belonging to families of the Order Centrospermae, has been obtained directly from the cleavage of the red beet pigment betanin, and has been characterized by the formation of betanidin when mixed with synthetic cyclodopa, and indicaxanthin on reaction with L-proline.

33 citations


Journal ArticleDOI
TL;DR: Two new flavonols were isolated from Centaurea jacea flowers and they have been shown to be 4′,5,7-trihydroxy-3,6-dimethoxyflavone and its 7-O-β- d -glucoside.

25 citations


Journal ArticleDOI
TL;DR: The distribution of four new sesquiterpene lactones in 21 North American taxa of the genus Vernonia and the preliminary chemical characterization of three of the new compounds are reported.

20 citations


Journal ArticleDOI
TL;DR: The C-glycosylflavonoids of the leaves and stems of more than 30 anthocyanin-distinguishable genetic lines of Linum usitatissimum are all identical.

14 citations


Journal ArticleDOI
TL;DR: A mixture of two new cyanogenetic lipids from the seeds of Ungnadia speciosa have been structurally characterized in this paper, and two new lipids have been shown to be useful for plant growth.

14 citations


Journal ArticleDOI
TL;DR: The sesquiterpene lactone constituents of 25 new plant collections from the Southwestern United States, Mexico and Jamaica, representing 16 different taxa belonging to the genus Ambrosia, are described.

11 citations


Journal ArticleDOI
TL;DR: O -Rhamnosyl-6-C -Xylosyl derivatives of apigenin and luteolin were found to be the two major flavonoids of the flowers of Phlox drummondii as discussed by the authors.

10 citations


Journal ArticleDOI
TL;DR: The structure previously advanced for the flavonol tambuletin isolated in 1947 from the seeds of Xanthoxylum acanthopodium (Rutaceae) has been shown to be incorrect as mentioned in this paper.

Journal ArticleDOI
TL;DR: The structure of apachin (2a), a new xanthanolide isolated from an Arizona collection of Iva ambrosiaefolia Gray, has been established as mentioned in this paper.

Journal ArticleDOI
TL;DR: Flavonoids found in leaf extracts of Leucophysalis nana and L. grandiflora contained kaempferol 3,7-diglucoside, which is related to rutin and quercetin 3-rutinoside-7-glucosid.

Journal ArticleDOI
TL;DR: The conformations of the two conformational isomers of isabelin (1), a germacranolide dilactone isolated from Ambrosia psilostachya DC. (Compositae), have been determined in chloroform solution by use of the intramolecular nuclear Overhauser effect; and further, the configuration of the endocyclic double-bond in its ten-membered ring has been confirmed as mentioned in this paper.
Abstract: The conformations of the two conformational isomers of isabelin (1), a germacranolide dilactone isolated from Ambrosia psilostachya DC. (Compositae), have been determined in chloroform solution by use of the intramolecular nuclear Overhauser effect; and further, the configuration of the endocyclic double-bond in its ten-membered ring has been confirmed. It has been concluded that the major and minor isomers of isabelin mainly adopt the conformations (A) and (B), respectively, which have a trans-orientation of the endocyclic double-bond. Since isabelin has been correlated with artemisiifolin (3), salonitenolide (4), and cnicin (5), the results obtained here have also established a trans configuration for these three germacranolide monolactones. In addition, isoisabelin (2), a geometrical isomer of isabelin, has been examined to determine the configuration of its C(9)–C(10) double-bond and its conformation.