Title: Alternative Sweeteners

Less Common High-Potency Sweeteners 221
Figure 8 Structures of pterocaryosides A and B. (Qui d-quinovopyranosyl; ara
l-arabinopyranosyl.)
caryosides A and B, in being the first sweet-tasting secodammarane sweeteners
to have been discovered, represent a new sweet-tasting chemotype and may serve
as useful lead compounds in the future for synthetic optimization (55). Additional
work on Pterocarpa (Cyclocarya) paliurus carried out in the People’s Republic
of China has led to the isolation of several sweet dammarane glycosides (56).
III. SYNTHETIC COMPOUNDS
In addition to the well-known synthetic sweeteners described in other chapters
of this book, activity in this area has yielded some of the most intensely sweet
compounds known to mankind and has improved our understanding of the structural
requirements for the sweet-tasting response.
A. Oximes
Perillartine (Fig. 9), the α-syn-oxime of perillaldehyde, has been known to be
highly sweet since 1920 and is reported to be up to 2000 times sweeter than
sucrose (1, 2). In contrast, perillaldehyde itself (Fig. 9), the major constituent of
the volatile oil of Perilla frutescens (L.) Britton (Labiatae), is only slightly sweet.
Perillartine is used commercially in Japan as a replacement for maple syrup or
licorice for the sweetening of tobacco, but more widespread use of this compound
for sweetening has been restricted by a limited solubility in water, an appreciably
bitter taste, as well as a menthol-licorice off-taste that accompanies sweetness
(1, 2).