Title: Alternative Sweeteners

Less Common High-Potency Sweeteners 213
tracts from S. grosvenorii and other Siraitia species as a sweet juice (19). It was
estimated that the domestic demand for lo han kuo fruits containing mogroside
V for food, beverages, and medicinal products in Japan in 1987 was 2 metric
tons, representing a sales volume of 40 million yen (2).
Safety studies on mogroside V have not been extensive to date. The compound
has been found to be nonmutagenic when tested in a forward mutation
azaguanine assay with Salmonella typhimurium strain TM677 (2). Mogroside V
produced no mortalities when administered by oral intubation at doses up to 2
g/kg body weight in acute toxicity studies in mice, and an aqueous extract of lo
han kuo fruits exhibited an LD 50 in mice of 10 g/kg body weight (2). There
appear to have been no adverse reactions among human populations who have
ingested aqueous extracts of lo han kuo, which would be expected to contain
substantial quantities of mogroside V. Therefore, lo han kuo extracts containing
mogroside V are worthy of wider application for sweetening purposes in the
future because of their apparent safety in addition to favorable sensory, stability,
solubility, and economic aspects.
C. Phyllodulcin
Phyllodulcin is produced from its naturally occurring glycosidic form by enzymatic
hydrolysis when the leaves of Hydrangea macrophylla Seringe var. thunbergii
(Seibold) Makino (Saxifragaceae) and other species in this genus are
crushed or fermented. Phyllodulcin (Fig. 3) is a dihydroisocoumarin and was
isolated initially in 1916 and structurally characterized in the 1920s. In 1959,
this sweet compound was found to have 3R stereochemistry (2). In recent work,
phyllodulcin from the unprocessed leaves of its plant of origin has been found
to be a 5:1 mixture of the R and S forms (20). Phyllodulcin has been detected
in the leaves of H. macrophylla subsp. serrata var. thunbergii at levels as high
as 2.36% w/w (2). Several patented methods are available for the purification of
phyllodulcin. In one such procedure, after initial extraction from the plant with
methanol or ethanol, hydrangenol (a nonsweet analog of phyllodulcin) and pigment
impurities were removed after pH manipulations and extraction with chloro-
Figure 3 Structure of phyllodulcin.