Novel hydroxy lignans from the heartwood of gmelina arborea

Chemical constituents and bioactivity of Piper sarmentosum

“…Eight amides, two lignans and four other compounds were isolated from the hexane and methanol extracts of Piper sarmentosum fruits and identified by spectroscopic methods: pellitorine (1) (Likhitwitayawuid et al, 1987), guineensine (2) (Okogun and Ekong, 1974;Koul et al, 1988), brachystamide B (3) (Banerji and Das, 1989), sarmentine (4) (Likhitwitayawuid et al, 1987), brachyamide B (5) (Koul et al, 1988), 1-piperettyl pyrrolidine (6) (Singh et al, 1974), 3 ,4 ,5 -trimethoxycinnamoyl pyrrolidine (7) (Achenbach et al, 1986), sarmentosine (8) (Likhitwitayawuid et al, 1987), (+)-asarinin (9) (Pelter et al, 1976), sesamin (10) (Pelter et al, 1976;Anjaneyulu et al, 1977), 1-(3,4-methylenedioxyphenyl)-1E-tetradecene (11) (Likhitwitayawuid et al, 1987), methyl piperate (12) (Kijjoa et al, 1989) and a mixture of ␤-sitosterol (13) (Pouchert and Behnke, 1993) and stigmasterol (14) (Pouchert and Behnke, 1993). The structures of compounds 1-14 are presented in Fig.…”

The Use of Carbon-13 Nuclear Magnetic Resonance Spectroscopy in Natural Products Chemistry

“…(Table 32). 13C chemical shifts for steroids (577)(578)(579) and four epimers of 20,22-epoxycholesterol (580a-580c) are listed in Table 33. Epoxides (580 a-580 d), which were synthesized and their 13C spectra recorded, exhibit characteristic chemical shifts, permitting unambiguous assignment of sidechain stereochemistry (152,153).…”

Antioxidant Lignans from Machilus thunbergii Protect CCl4-injured Primary Cultures of Rat Hepatocytes

“…In this study, we isolated eleven lignans (1±11) from the CH 2 Cl 2 fraction of the bark of M. thunbergii. The lignans were identi®ed as (À)-acuminatin (1) (El-Feraly et al 1982), (À)-isoguaiacin (2) (King & Wilson 1964), meso-dihydroguaiaretic acid (3) (Shimomura et al 1988), ( )-galbacin (4) (Achenbach et al 1987;Hada et al 1988), (À)sesamin (5) (Ajaneyulu et al 1977), ( )-galbelgin (6) (Holloway & Scheinmann 1974), machilin A (7) (Shimomura et al 1987), machilin G (8) (Shimomura et al 1988), licarin A (9) (Achenbach et al 1987), nectandrin A (10) (Shimomura et al 1988) and B (11) (Shimomura et al 1988). Among the lignans described, (À)-acuminatin and (À)-isoguaiacin are reported as components of Lauraceae for the ®rst time.…”