Sesquiterpene lactones and lactone glycosides from Hymenoxys species

Psilotropin

“…Atomic scattering factors (O, Cval and nbonded ) and anomalous-dispersion corrections were from International Tables for X-ray Crystallography (1974). The absolute configuration herein reported is that which Herz, Aota, Holub & Samek (1970) determined by chemical methods; the R values calculated for the two enantiomers did not differ sufficiently for this work to determine the absolute configuration.…”

“…& Samek (1970) reported the isolation of floribundin from both Hymenoxys richardsonii and H. anthemoides. Floribundin and psilotropin were shortly thereafter shown to be the same compound by Mabry (see Herz, Aota, Holub & Samek, 1970, footnote 22a). The structure and stereochemistry of psilotropin has been related to a large number of similar sesquiterpenes by chemical methods, CD and ORD studies (St6cklin, WaddeU & Geissman, 1970).…”

Antitumor Agents XXXVIII: Isolation and Structural Elucidation of Novel Germacranolides and Triterpenes from Elephantopus mollis

“…Further studies on the structureactivity relationships and mechanism of action among compounds related to molephantinin and phantomolin are in progress (17). The presence of an ethyl ether is novel and appears to represent the first example in naturally occurring germacranolides and the second instance of the sesquiterpene lactone lactal hymenolide (14). 8 Unless otherwise specified, melting points were determined on a ThomasHoover melting-point apparatus and are uncorrected.…”

“…an ethyl ether is novel and appears to represent the first example in naturally occurring germacranolides and the second instance of the sesquiterpene lactone lactal hymenolide(14) 8. Unless otherwise specified, melting points were determined on a Thomas-Hoover melting-point apparatus and are uncorrected.…”

Terpenoids from Amazonian Icacinaceae

“…The isopropyl unit at C-3 is represented either by the alkane, alcohol or alkene function as usually observed in eudesmane sesquiterpenoids. The O-ethyl-derivatives of emmotin-D and -S could even be considered artifacts, but ethoxylated naturally occurring terpenoids are known (26,27). The isolation of the non-lactonized forms of emmotin-D and -M, which have been named emmotin-J and -Q, respectively, is quite surprising.…”