Stevia rebaudiana Rebaudioside

The plant Stevia rebaudiana bertoni has been studied in depth because it was discovered that this plant is the source of six sweet-tasting diterpene glycosides. They are stevioside, rebaudiosides A, C, D, E and dulcoside A. (Table 1). These sweet diterpene glycosides, as well as a complex mixture of organic compounds of which more than a hundred compounds have been identified, are found mainly in the leaves of the plant. The leaves contain a complex mixture of labdane diterpenes, triterpenes, stigmasterol, tannins and volatile oils. There is an abundance of reviews and patents relating to these sweet diterpene glycosides. 

The leaves of Stevia rebaudiana (Compositae) are a source of several sweet glycosides of steviol (26) (Fig. 15) [1, 61]. The major glycoside, stevioside (27), is used in oriental countries as a food sweetener and the second major glycoside named rebaudioside (28), which is sweeter and more delicious than stevioside, is utilized in beverages. 

Stevia rebaudiana (Bertoni) Hemsl. Tian Jiu (Stevia) (stem, leaf) Stevioside, steviolbioside, rebaudiosides, austroinulin.57 Treat diabetes, tonic, lower blood pressure. 

Stevia sweeteners are extracted from the leaves of Stevia rebaudiana Bertoni (Compositae), an herb native to Paraguay but cultivated in Southeast Asia, Japan, Paraguay, Brazil, Israel, and the United States. The sweet constituents of stevia include eight diterpene glycosides stevioside, ste-violbioside, rebaudiosides A, B, C, D, E, and dulcoside A, which collectively are 100-300 times... 

MS Ahmed, RH Dobberstein. Stevia rebaudiana. II. High-performance liquid chromatographic separation and quantitation of stevioside, rebaudioside A and rebaudioside C. J Chromatogr 236(2) 523-526, 1982. 

Stevia species are members of the family of Asteraceae. Stevia rebaudiana contains steviol glycosides, such as stevioside and rebaudioside A, used as artificial sweeteners and 100-300 times sweeter than sucrose [72, 73 ]. Their clinical pharmacology and therapeutic actions have been reviewed [74, 75 ]. 

Figure 4A.21 Steviarebaudiana. (a) Stevia plant (b) Stevia field (Picture (a) and (b) Foundation of Humanity and Development "F.H.D." Guido Herrera, with kind permission) (c) Dry leaves of Stevia rebaudiana (d) chemical structure Stevioside (e) chemical structure Steviol (f) chemical structure Rebaudioside A.

Stevioside is an ent-kaurene type diteipenoid glycoside isolated from leaves of Stevia rebaudiana Bertoni. Leaves of this plant produce zero-calorie diterpene glycosides (stevioside and rebaudioside), a nmi-nutiitive, high-potency sweetener. Stevioside content in leaves will vary in field grown plants and is also influenced by agroclimatic conditions. Stevia leaves are also in use for their medicinal benefits. In this chapter, natural distribution and cultivation of Stevia,... 

Potential widespread use of steviosides requires an easy and effective extraction method. Enzymatic extraction of stevioside from Stevia rebaudiana leaves with cellulase, pectinase, and hemicellulase, using various parameters, such as concentration of enzyme, incubation time, and temperature, has been reported [33]. Purification is achieved through adsorption, colunm chromatography, and ion-exchange electrolytic technique for rebaudioside A, rebaudioside C, and dulcoside A [34]. An ultrafiltration (UF) process was reported for recovery of 45 % steviosides from an extract of leaves. Final purification was achieved by two consecutive mixed bed ion-exchange processes. The ion exchangers improved purity of the final product to 90 % [35]. 

Sakamoto, I., K. Yamasaki, and O. Tanaka Application of NMR spectroscopy to chemistry of plant glycosides rebaudiosides-D and -E, new sweet diterpene-glucosides of Stevia rebaudiana Bertoni. Chem. Pharm. Bull. 25, 3437 (1977). 

Extraction of stevia sweeteners from dried leaves can be accomplished with acetonitrile in the presence of calcium carbonate solution (116) or with boiling water adjusted to pH 9.0 (107). Ahmed and Dobberstein (117) extracted stevioside and rebaudioside A and C from dried leaves of S. rebaudiana in a micro-Soxhlet apparatus. They observed that chloroform/methanol provided the best results, compared to chloroform or to chloroform/methanol/water. Extraction of stevioside, rebaudioside A and C, and dulcoside A can also be performed by subcritical fluid extraction using C02 and methanol as a modifier. Such an extraction technique has been gaining popularity as an analytical tool because it is rapid, simple, and less expensive in terms of solvent cost (110). Beverages, tabletop sweeteners, beverages containing pulp, and candies are prepared as indicated in Sec. I.C (110,115,118). 

In Japan, the largest market for the S. rebaudiana sweeteners to date, three different forms of stevia sweetener products are commercially available, namely, stevia extract , sugar-transferred stevia extract , and rebaudioside A-enriched stevia extract . Stevia extract is a powder or granule made by several industrial steps and standardized so as to contain more than 80% of steviol glycosides, inclusive of dulcoside A (3-5%), rebaudioside A (20-25%), rebaudioside C (5-10%), and stevioside (50-55%) [31]. Sugar-transferred stevia extract is made by... 

The full paper on the C n.m.r. of the glycosides derived from Stevia panF culata LAG has appeared (see Vol. 10, p. 182), and the structures of two sweet glucosides from S. rebaudiana Bertoni, rebaudioside-D and -E, have been studied by means of C n.m.r. and enzymic and chemical hydrolysis. A report of a study of C n.m.r. spectra of a wide range of pyranoside epoxides has confirmed that the presence of the epoxide ring leads to an upheld... 

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