Eremophilenolides from Hertia cheirifolia

Herticins A and B, New Sesquiterpenes from Hertia intermedia

“…The signal for Me attached to C(5) was shifted downfield, which indicated that the A/B ring system could not be trans fused, thus confirming a 10b-OH group [9]. The absence of a NOESY correlation between HÀC(8) and the Me group attached to C(5) and the coupling constant of HÀC (8) and HÀC(9) [1] provided evidence for their relative trans-orientation ( Fig.). Hence, herticin A (1) was assigned the structure (8aH)-10b-hydroxyeremophilenolide, i.e., compound 1 ist the C(8)-epimer of the known natural product 10b-hydroxyeremophilenolide (see Formulae).…”

“…Three Me groups appeared in the C-NMR data were comparable to the eremophilenolide class of sesquiterpenes [5 -7]. A literature search revealed that the data is almost superimposible to 10b-hydroxyeremophilenolide [8]. The optical rotation observed for (1) is a stereoisomer of 10b-hydroxyeremophilenolide.…”

New Sesquiterpenoids from Ligularia duciformis

“…Furthermore, the absence of a homoallylic coupling between Me(13)ÀC (11) and H a ÀC(6) in the 12,8a-olide showed that the MeO group at C(6) was b-oriented, as the angle between H a ÀC(6) and Me(13)ÀC(11) was around 08 [8]. The upfield signal for Me(15) also indicates a ciseremophilane skeleton, supporting a b-orientation of the OH group at C(10) [11] [12], confirmed by the key cross peaks in the NOESY spectrum (Fig. 2).…”

“…The absence of a homoallylic coupling between H a ÀC(6) and Me(13)ÀC (11) showed that the 6-OH group was in b-orientation. The upfield Me(15) also implied a cis-eremophilane, showing the 10-OH group in borientation [11] [12]. Thus, compound 4 was elucidated as 3b-acetoxy-6b,8b,10b-trihydroxyeremophil-7(11)-en-12,8a-olide.…”

Eremophilane Sesquiterpenoids from Farfugium japonicum

“…2 Phytochemical investigations on this plant collected in Japan have resulted in the isolation of sesquiterpenoids, [3][4][5][6][7][8][9][10] triterpenoids, 4 sterols, 8 fatty acids, 8 and pyrrolizidine alkaloids. 11 In the course of searching for antibacterial sesquiterpenes from Compositae plants, a new eremophilane sesquiterpenoid, 3β-angeloyloxy-6α-hydroxy-8β-methoxy-9α-senecioyloxyeremophila-7(11)-en-12,8α-lactone (1), and three known ones, 3β-angeloyloxy-8β,10β-dihydroxyeremophila-7(11)-en-12,8α-lactone (2), 5 3β-angeloyloxy-10β-hydroxy-8β-methoxyeremophila-7(11)-en-12,8α-lactone (3) 10 and 3β-angeloyloxy-10β-hydroxy-8α-methoxyeremophila-7(11)-en-12,8β-lactone (4), 12 were isolated from the roots of F. japonicum. We herein report the isolation and structure characterization of 1.…”