[Flavonoids from leaves of Psidum littorale].

We investigated the chemical constituents of the leaves of Psidum littorale, which include 16 flavonoids, including seven flavonols, six flavonoid glycosides and three flavonones. The compounds were isolated by silica gel column chromatography. Their structures were elucidated on the basis of spectral analysis and by comparison with published data. Seven flavonols were kaempferol (1), isorhamnetin (2), myricetin- 3,7,3'-trimethyl ether(3), laricitrin (4), quercetin (5), myricetin (6) and quercein-3,4'-dimethyl ether (7), six flavonoid glycosides were guaijaverin (8), hyperoside (9), 5,4'-dyhydroxy-3,7,5'-methoxyflavone-3'-O-ß-D- glucoside (10), laricitrin-3-O-xyloside (11), myricetin-3-O-α-L-rhamnopyranoside (12) and myricetin-3-O-ß-D- xyloside (13). Three flavonones were 4'-O-methyldihydroquercetin (14), dihydroapigenin (15) and ampelopsin 4'-O-ß-D-glucopyranoside (16). Compound 10 is a new chemical, compounds 2-4, 7, 10-16 were first isolated from this plant. (1)H NMR and (13)C NMR data of compound 11 were not reported in literature.

A new alkaloid from the fruit of Nandina domestica Thunb.

A new steroidal alkaloid, (20S,22R,24R)-24-ethyl-3-oxocholest-4-en-22-amino, named as nandsterine (1), together with 10 known alkaloids, palmatine (2), O-methylbulbocapnine (3), nantenine (4), dehydronantenine (5), glaucine (6), didehydroglaucine (7), dehydrocorydaline (8), jatrorrhizine (9), magnoflorine (10) and berberine (11), was isolated from the fruit of Nandina domestica Thunb. Their structures were elucidated by using spectroscopic methods as well as by comparing with the published data. Compound 1 was a new class of steroidal alkaloid isolated from the family Berberidaceae, meanwhile compounds 2, 3, 6-8 and 10 were obtained from N. domestica for the first time. Compound 1 exhibited cytotoxicity against HL-60 cells (human leukaemia) with IC50 values of 52.1 µM.

[Study on Megastigmane Glycosides and Lignan Constituents from Leaves of Psidium littorale].

OBJECTIVE: To study the chemical constituents of the leaves of Psidium littorale. METHODS: The constituents were isolated with silica gel column chromatography and the structures of these compounds were elucidated on the basis of spectral analysis. RESULTS: Four megastigmane glycosides and three lignans were isolated and their structures were identified as Bridelionoside B(1), Euodinoside E(2), (3S,5R,6R,7E,9S)-Megastignan-7-ene-3,5,6,9-tetrol 9-O-ß-D-glucopyranoside (3), Bridelionoside C(4), (--)-Isolaricires-inol 3-α-O-ß-D-glucopyranoside (5), (--)-5'-methoxy-Isolariciresinol 3-α-O-ß-D-glucopyranoside (6) and dihydrodehydrodiconiferyl alcohol 4-O-ß-D-glucopyranoside(7). CONCLUSION: Compounds 1-7 are isolated from this plant for the first time. The results have provided the scientific basis for further exploitation of Psidium littoratle.