Grapefruit seed extract

Pharmazie 1999 Jun;54(6):452-6
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                       Aspects of the antimicrobial efficacy of grapefruit seed extract and its
                       relation to preservative substances contained.

                       von Woedtke T, Schluter B, Pflegel P, Lindequist U, Julich WD.

                       Institute of Pharmacy, Ernst Moritz Arndt University, Greifswald, Germany.

                       The antimicrobial efficacy as well as the content of preservative agents of six commercially
                       available grapefruit seed extracts were examined. Five of the six extracts showed a high
                       growth inhibiting activity against the test germs Bacillus subtilis SBUG 14, Micrococcus
                       flavus SBUG 16, Staphylococcus aureus SBUG 11, Serratia marcescens SBUG 9,
                       Escherichia coli SBUG 17, Proteus mirabilis SBUG 47, and Candida maltosa SBUG 700.
                       In all of the antimicrobial active grapefruit seed extracts, the preservative benzethonium
                       chloride was detected by thin layer chromatography. Additionally, three extracts contained
                       the preserving substances triclosan and methyl parabene. In only one of the grapefruit seed
                       extracts tested no preservative agent was found. However, with this extract as well as with
                       several self-made extracts from seed and juiceless pulp of grapefruits (Citrus paradisi) no
                       antimicrobial activity could be detected (standard serial broth dilution assay, agar diffusion
                       test). Thus, it is concluded that the potent as well as nearly universal antimicrobial activity
                       being attributed to grapefruit seed extract is merely due to the synthetic preservative agents
                       contained within. Natural products with antimicrobial activity do not appear to be present.

                       PMID: 10399191 [PubMed - indexed for MEDLINE]

Author(s): Sakamoto S ; Sato K ; Maitani T ; Yamada T
Title: [Analysis of components in natural food additive "grapefruit seed extract" by HPLC and LC/MS]
Source: Eisei Shikenjo Hokoku (Eisei Shikenjo hokoku. Bulletin of National Institute of Hygienic Sciences.) 1996(114): 38-42 Journal Code: BQ8
Additional Info: JAPAN
Standard No: ISSN: 0077-4715; NLM Unique Identifier: 0421152
Language: Japanese
Abstract: The components in a commercial natural food additive "Grapefruit seed extract" and the ethanol extract of
grapefruit seeds were analyzed by HPLC and LC/MS. The HPLC chromatogram of the commercial grapefruit seed extract was quite different from that of the ethanol extract of grapefruit seeds. Three main peaks were observed in the chromatogram of the commercial grapefruit seed extract. By comparison of the retention times and the absorption spectra with those of authentic samples, two peaks were ascribed to methyl-p-hydroxybenzoate and 2,4,4'-trichloro-2'-hydroxydiphenylether (triclosan). Triclosan was also identified by LC/MS by using the negative electrospray ionization method.
MESH Subject(s) below:
Descriptor: (Minor): Chromatography, High Pressure Liquid
Citrus -- chemistry
Ethanol
Food Additives -- chemistry
Food Additives -- isolation & purification
Parabens -- analysis
Seeds -- chemistry
Spectrum Analysis, Mass
Triclosan -- analysis
Chemical Subst: Food Additives [0]
Parabens [0]
Triclosan [3380-34-5]
Ethanol [64-17-5]
methylparaben [99-76-3]
Record Type: Index Medicus
Article Type: Journal Article
Entry: 19970515
Update: 20001218
Accession No: PMID: 9037863; Medline: 97189748