grapefruit seed extract --- analysis

because of a recent lecture and discussions with friends/other midwives I did some research on grapefruit seed extract. There are some abstracts that show efficacy -- but I think that the different analysis of content to be revealing and also unsettling . Triclosan alone would put this out side the purpose of many folks who are using this to avoid the use of such chemicals in other products/forms, especially since it's presence may account for efficacy

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J Agric Food Chem. 2005 Sep 21;53(19):7630-6.

Identification of benzalkonium chloride in commercial grapefruit seed extracts.

Takeoka GR, Dao LT, Wong RY, Harden LA.

Western Regional Research Center, Agricultural Research Service, US Department
of Agriculture, Albany, California 94710, USA. [email protected]

Commercial grapefruit seed extracts (GSE) were extracted with chloroform. The
solvent was evaporated, and the resulting solid was subsequently analyzed by
high-performance liquid chromatography (HPLC), electrospray ionization mass
spectrometry (ESI/MS), tandem mass spectrometry (ESI/MS/MS), and elemental
analysis (by proton-induced X-ray emission analysis). Three major constituents
were observed by HPLC and were identified as benzyldimethyldodecylammonium
chloride, benzyldimethyltetradecylammonium chloride, and
benzyldimethylhexadecylammonium chloride. This mixture of homologues is commonly
known as benzalkonium chloride, a widely used synthetic antimicrobial ingredient
used in cleaning and disinfection agents.
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J Agric Food Chem. 2001 Jul;49(7):3316-20.

Identification of benzethonium chloride in commercial grapefruit seed extracts.

Takeoka G, Dao L, Wong RY, Lundin R, Mahoney N.

Western Regional Research Center, Agricultural Research Service, U.S. Department
of Agriculture, 800 Buchanan Street, Albany, California 94710, USA.
[email protected]

Commercial grapefruit seed extracts (GSE) were extracted with chloroform. The
solvent was evaporated, and the resulting solid was subsequently analyzed by
high-performance liquid chromatography, electrospray ionization mass
spectrometry, nuclear magnetic resonance (NMR) spectroscopy, and elemental
analysis (by proton-induced X-ray emission [PIXE] analysis). The main
constituent was identified as benzethonium chloride, a synthetic antimicrobial
agent commonly used in cosmetics and other topical applications. This compound
comprised 8.03% (n = 2) of the liquid GSE sample. Higher amounts of benzethonium
chloride were found in powder GSE samples.

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Pharmazie. 1999 Jun;54(6):452-6.

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.

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Eisei Shikenjo Hokoku. 1996;(114):38-42.

[Analysis of components in natural food additive "grapefruit seed extract" by
HPLC and LC/MS]

[Article in Japanese]

Sakamoto S, Sato K, Maitani T, Yamada T.

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.

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