A novel in vitro assay for the discovery of anticancer agents was used to examine aqueous and organic extracts from 1847 plants collected mainly in the U.S. Southwest and West. The assay results were separated into 5 categories: inactive (62%), equally active (36%), equally active and potent (0.5%), solid tumor selective (1.4%), and human selective (0.8%). Extracts from the latter three categories were fractionated using the in vitro assay to biodirect each step. Psorothamnus emoryi extracts were solid tumor selective and yielded two active compounds upon fractionation: dalrubone and 5-methoxydalrubone. Calocedrus decurrens was equally active and potent and yielded deoxypodophyllotoxin as the active compound. Linanthus floribundus was human selective and yielded strophanthidin as the active compound. The potential of this assay to discover novel anticancer agents from the active extracts is discussed.
Eremocarpus setigerus (Hook) Benth, a member of the spurge family, commonly known as "dove weed" and T h e ability to quantitatively analyze vicinal dideuteriated systems for erythro/ threo2s3 (e.g., 1) and m e s~/ d l *~~ (e.g., 2) ratios have been useful in many " 0
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As part of our continuing search for plants containing tumor inhibitory constituents, we isolated and determined the constitution of the antitumor agent uvaricin (1) (1). We now report that it is accompanied in this extract by a free diol (2), which we term desacetyluvaricin, and that we have determined the C(36) configuration of these substances to be S.4.94 in 1 to the 3.8-4.0 envelope [where HC(16), HC(19), HC(20), and HC(23) also absorbed] in 2, and HC(25) shifted from 1.55 to 1.28. Confirmation came
An activity-guided fractionation of a methanol-dichloromethane extract obtained from the aerial parts of Eysenhardtia texana led to the isolation of two novel antibacterial and antifungal flavanones together with a known flavanone. Their structures were established as 4',5,7-trihydroxy-8-methyl-6-(3-methyl-[2-butenyl])-(2S)-flavanone, 4',5,7-trihydroxy-6-methyl-8-(3-methyl-[2-butenyl])-(2S)-flavanone and 4',5-dihydroxy-7-methoxy-6-(3-methyl-[2-butenyl])-(2S)-flavanone on the basis of their UV, 1D and 2D-NMR spectra.
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