Abstract
A study of secondary metabolites from the bark of Alnus glutinosa led
to the isolation of fourteen diarylheptanoids: oregonin (1),
platyphylloside (2), rubranoside A (3), rubranoside B
(4), hirsutanonol (5), hirsutenone (6),
hirsutanonol-5-O-β-D-glucopyranoside (7),
platyphyllonol-5-O-β-D-xylopyranoside (8),
aceroside VII (9), alnuside A (10), alnuside B (11),
1,7-bis-(3,4-dihydoxyphenyl)-5-hydroxy-heptane-3-O-β-D-xylopyranoside
(12),
(5S)-1-(4-hydroxyphenyl)-7-(3,4-dihydroxyphenyl)-5-O-β-D-glucopyranosyl-heptan-3-one
(13), and
(5S)-1,7-bis-(3,4-dihydroxyphenyl)-5-O-β-D-[6-(3,4-dimethoxycinnamoylglucopyranosyl)]-heptan-3-one
(14). All of the diarylheptanoids, except 1 and 5,
were found in A. glutinosa for the first time, while 13 and
14 were new compounds. The structures were determined by
spectroscopic techniques: 1D and 2D NMR, HR-ESI-MS, FTIR, UV, and CD. All
isolated compounds were analyzed for an in vitro protective effect on
chromosome aberrations in peripheral human lymphocytes using the
cytokinesis-block micronucleus assay. The majority of them, including the
new compounds 13 and 14, exerted a pronounced effect in
decreasing DNA damage in human lymphocytes. Diarylheptanoids 1, 2, 5,
13, and 14 at a concentration of 1 µg/mL decreased the
frequency of micronuclei by 52.8 %, 43.8 %, 63.6 %, 44.4 %, and 56.0 %,
respectively, exerting a much stronger effect than the synthetic protector
amifostine (17.2 %, c = 1 µg/mL).
Key words
Alnus glutinosa
- Betulaceae - diarylheptanoids - HPLC-DAD - NMR analysis - protective effect - CBMN assay
