Quality of herbal remedies from Allium sativum: differences between alliinase fr

May 17, 2006

Quality of herbal remedies from Allium sativum: differences between

alliinase from garlic powder and fresh garlic.

Krest I, Keusgen M.

cmd=Retrieve & db=PubMed & list_uids=10193205 & dopt=Abstract & holding=f1000

,f1000m

Institut fur Pharmazeutische Biologie, Universitat Bonn, Germany.

Alliinase (EC 4.4.1.4) has been isolated from commercially available

garlic (Allium sativum L., Alliaceae) powder and was investigated

with respect to its use as ingredient of herbal remedies. The enzyme

was purified to apparent homogeneity and results were compared with

those obtained from a sample of fresh A. sativum var. pekinense. The

purification of the enzyme involved a gel filtration step as well as

affinity chromatography on concanavalin-A agarose. Vmax using L-(+)-

alliin as substrate (252 mumol min-1 mg-1) was at the lower range of

data given in the literature (214-390 mumol min-1 mg-1). L-(-)-

Alliin was also accepted as substrate (54 mumol min-1 mg-1). Vmax

for alliinase from A. sativum var. pekinense was at 332 mumol min-1

mg-1 and 90 mumol min-1 mg-1 for L-(+)- and L-(-)-alliin,

respectively. The Km values for alliinase from garlic powder were

estimated to be 1.6 mM for L-(+)-alliin and 2.8 mM for L-(-)-alliin.

In contrast to literature values, both temperature and pH optima

were somewhat higher (36 degrees C and pH 7.0 versus 33 degrees C

and pH 6.5, respectively). The enzyme was found to be active in a

range from pH 5 to pH 10. Gel electrophoresis gave evidence that the

alliinase obtained from garlic powder consisted of two slightly

different subunits with molecular weights of 53 and 54 kDa whereas

alliinase obtained from fresh garlic consists of two identical

subunits. It is assumed that the alliinase gets significantly

altered during the drying process of garlic powder but is still

capable to convert alliin to allicin.

PMID: 10193205 [PubMed - indexed for MEDLINE]

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