Germacranolides and a new type of guaianolide from Acanthospermum hispidum.
The aerial parts of an Argentinian collection of Acanthospermum hispidum afforded 26 sesquiterpene lactones, including the two guaianolides (1 and 2) having a novel oxygen bridge between C-4 and C-14, three new cis,cis-germacranolides (4, 7, and 8), and two new melampolides (25 and 26). Guaianolides 1 and 2 seem to derive biosynthetically from the germacranolide 27 having the (1)D(14, 15)D(5) conformation. The structures were elucidated using extensive spectroscopic analysis.
Cartagena
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E
Instituto de Química Orgánica, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 491, S. M. de Tucumán 4000, Argentina.
Bardón
A
A
Catalán
C A
CA
de Hernández
Z N
ZN
Hernández
L R
LR
Joseph-Nathan
P
P
D001118:Argentina; D004952:Esters / Q000737:chemistry / Q000302:isolation & purification*; D005663:Furans / Q000737:chemistry / Q000302:isolation & purification*; D007783:Lactones / Q000737:chemistry / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D019684:Magnoliopsida / Q000737:chemistry*
D004952:Esters; D005663:Furans; D007783:Lactones; C017879:germacanolide; C416425:hispidunolide A; C416426:hispidunolide B