Sesquiterpene lactones from the pericarps of Illicium majus; 2-oxy derivatives of neomajucin and 3,4-dehydroxyneomajucin.

Secoprezizaane Sesquiterpene Lactones from Illicium micranthum

“…Tables 1 and 2, resp.) with those of neomajucin (5) [6] indicated a close structural analogy, except for C(1) and C(2). Compared to 5, the NMR spectrum of 1 suggested an oxygenated methine (HÀC(1)) and an oxygenated quaternary C-atom (C(1)) instead of a non-oxygenated CH and a CH 2 group, respectively.…”

“…The NMR data of 2 (Tables 1 and 2) also indicated a secoprezizaane skeleton [6]. The only difference between 2 and neomajucin (5) was that a CH 2 signal in the latter was replaced by an oxygenated CH in 2.…”

“…C-NMR spectra of 3 (Tables 1 and 2, resp.) also indicated a secoprezizaane sesquiterpene [6]. Two characteristic lactone C=O signals at d(C) 178.0 and 174.8 were observed in the 13 C-NMR spectrum.…”

“…Herein, we describe the isolation and structure elucidation of three new sesquiterpene lactones (1 -3) from I. micranthum, which were obtained together with the known sesquiterpene lactones pseudomajucin (4) [5], neomajucin (5) [6], majucin (6) [6], (2S)-2-hydroxyneomajucin (7) [6], 3,4-dehydro-2-oxoneomajucin (8) [6], and 2-oxoneomajucin (9) [6].…”

Phytoquinoids and Secoprezizaane‐Type Sesquiterpenes from Illicium arborescens

“…Analyses of the 1D-and 2D-NMR data of 4 and comparison of the Compound 5 has a molecular formula C 22 [24], which differ in the lactone-ring type (at the C(11), C(7) or the C(11), C(3) position). The NMR data of compound 5 indicated that it is an analog of 3, i.e., the signals of the cyclopentane ring and benzoyloxy moiety, as well as the connection of the d-lactone ring between C(7) and C(11), have similarities to each other as shown in Tables 2 and 1, resp.) indicated a secoprezizaane sesquiterpene [25]. A characteristic lactone signal at d(C) 170.2 was observed in the 13 C-NMR spectrum.…”