Drewes SE, van Vuuren SF. Antimicrobial acylphloroglucinols and dibenzyloxy flavonoids from flowers of Helichrysum gymnocomum.
PHYTOCHEMISTRY 2008;
69:1745-1749. [PMID:
18406436 DOI:
10.1016/j.phytochem.2008.02.022]
[Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2008] [Revised: 02/27/2008] [Accepted: 02/28/2008] [Indexed: 05/26/2023]
Abstract
From the dichloromethane extract of the flowers of Helichrysum gymnocomum (Asteraceae) two known flavonoids, 4 and 5, and a known acylphloroglucinol, 3B, were isolated. In addition to 1 and 2, the 4',6'-dibenzyloxy-2'-hydroxy derivative of 2',4',6'-trihydroxychalcone and 5,7-dibenzyloxy derivative of pinocembrin, respectively, are reported in Nature for the first time. A compound 3A, related to 3B has the structure 2-methyl-1-[2,4,6-trihydroxy-3-(2-hydroxy-3-methyl-3-butenyl)phenyl]-1-propanone. Compounds 1, 2, 3A, 3B, 4 and 5 have MIC values below 64microg/ml against a selection of pathogens, with 3B having the highest sensitivity (6.3-45microg/ml) for eight of the ten pathogens tested, including Staphylococcus aureus (6.3microg/ml) and methicillin and gentamycin resistant strain of S. aureus (7.8microg/ml). With the exception of 2, the other compounds had notable activity (45-63microg/ml) towards Pseudomonas aeruginosa.
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