New Phloroglucinol Derivatives fromHypericum papuanum

Abstract

Bioactivity-guided fractionation of the petroleum ether extract of the aerial parts of Hypericum papuanum led to the isolation of five new tricyclic phloroglucinol derivatives. On the basis of extensive 1D and 2D NMR experiments as well as MS studies, their structures were elucidated as the C-3 epimers of 8-hydroxy-4,4, 7-trimethyl-9-(2-methylpropionyl)-3-(1-methylvinyl)-5beta -H-tricyclo[ 5.3.1.0(1,5)]undec-8-ene-10,11-dione (1,2); the C-3 epimers of 8-hydroxy-4,4, 7-trimethyl-9-(2-methylbutyryl)-3-(1-methylvinyl)-5beta-H-++ +tricyclo[5. 3.1.0(1,5)]undec-8-ene-10,11-dione (3, 4), and 8-hydroxy-4,4, 7-trimethyl-9-(2-methylpropionyl)-5beta-H-tricyclo[5.3 .1.0(1, 5)]undec-8-ene-10,11-dione (5), and their corresponding tautomers (1a, 2a, 3a, 4a, 5a). Compounds 1/1a-5/5a were named ialibinones A-E, respectively. Compounds 1/1a-4/4a showed antibacterial activity against Bacillus cereus, Staphylococcus epidermidis, and Micrococcus luteus.

Bi-, Tri-, and Polycyclic Acylphloroglucinols from Hypericum empetrifolium

“…The 1 H NMR-guided fractionation of a petroleum ether extract afforded four new bicyclic acylphloroglucinol derivatives, empetrikarinens A (1) and B (2) and empetrikarinols A (3) and B (4), and three new tricyclic acylphloroglucinol derivatives, empetriferdinans A (9) and B (10) and empetriferdinol (11). Three new polycyclic acylphloroglucinols containing a monoterpenoid citran moiety were named empetrifranzinans A/B (12/13) and C (14).…”

Novel Antileukemic Sterol Glycosides from Ajuga salicifolia

“…The remaining oxygenated C-resonances for the aglycone indicated the presence of three oxymethine groups (d(C) 82. In the HMBC spectrum (measured in (D 6 )DMSO), the long-range correlations observed between C(13)/C(17)/C (16) and OHÀC(17) and between C(16)/C (15) and OHÀC (16) confirmed the hydroxylation at C(16) and C(17), respectively. The HMBC correlation observed between HÀC(22) and C(25) (d(C) 84.1) indicated the presence of an epoxy group.…”

Cytotoxic and antioxidant constituents from Garcinia subelliptica

“…The NOESY cross-peaks between H b -7/H-8, H b -17/Me-11, Me-11/H-2 and Me-19, Me-14/Me-10, and H a -21/H-22 suggested that H-8, H-2, Me-11, and the 1-oxo-3-methylbutyl group linked to C-3, and 2-hydroxy-2-methyl-propionyl group linked to C-8, H-22, and OH-3 are b-and a-oriented, respectively. The relative configurations at C-1 and C-2, and C-1 and C-6 were established from the fact that the bridge between these carbons can only exist in the cis form (Winkelmann, Heilmann, Zerbe, Rali, & Sticher, 2000). Thus, the chemical bonds between C-1/C-2 and C-1/C-6, and hydroxy group located on C-6, must be a-and b-oriented, respectively, and the structure of garcinielliptone R (2) could be characterized as 1b,2,4a-trihydroxy-7a-(2-hydroxy-2-methyl-propionyl)-3-(2-isopropenyl-5-methyl-hex-4-enyl)-6,6-dimethyl-4b-(3-methyl-butyryl)-bicyclo[3.3.1]non-2-en-9-one.…”