Preface to the series

There is increasing interest in industry, academia and the health sciences in medicinal and aromatic plants. In passing from plant production to the eventual product used by the public, many sciences are involved. This series brings together information which is currently scattered through an ever increasing number ofjournals. Each volume gives an in-depth look at one plant genus, about which an area specialist has assembled information ranging from the production of the plant to market trends...

Rubusoside and related glycosides from Rubus suavissimus

In a continuation oftheir search for natural sweeteners,Tanaka et al. (1981) isolated rubusoside (7 steviol 13,19-di-O- -D-glucoside) from the leaves of a type of the Chinese raspberry, R. suavissimus S.Lee (Rosaceae). Although Rubus is taxonomically distinct from Stevia (Compositae), the structure of 7 was identical with the intermediate obtained from the synthesis of rebaudioside A (2) from stevioside (1) (see Figure 7.2). Rubusoside (7) tastes sweet, but the magnitude of sweetness is not...

Sweetness quality

Figure 9.3 shows the sweetness-taste profiles of stevioside, rebaudioside A, and other sweeteners including saccharin, sucrose, and glycyrrhizin. When placed in the mouth, stevioside gives a slightly latent sweet sensation with an aftertaste. Nevertheless, the taste profile of stevioside more closely resembles that of sucrose compared with the triterpene glycoside sweetener, glycyrrhizin, and the sweetness quality of stevioside is superior to that of sucrose in mildness and freshness. The...

Info

A Table modified and expanded from Kinghorn and Soejarto (1985). b In cases of multiple citations for a compound, the first reference containing the correct structure is given. c Obtained from feeding cut stems of S. rebaudiana with DL-sodium mevalonate-2-14C. d Not stated in original publication, e Thought to be an artifact of extraction, f Weight fresh weight, g Chemical structures not determined. preparation of the -sophorosyl ester of ent-kaur-16-en-19-oic acid, and subsequent comparison of...

Relationship Between Stevia And

Through the ages, a relationship between man and Stevia plants has developed. Such a relationship took the form of recognition of the plants as expressed in their common names and the discovery of their utility in various ways.The knowledge discovered became part of the folklore of a culture or a population and, occasionally, came to the attention of botanists, explorers, or even casual travelers, who recorded it and communicated it in a written form. Some of the older records are not easy to...

References

Amaro, J.M., Adrian, M., Cerda, C.M. and Joseph-Nathan, P. (1988) Longipinene derivatives from Stevia lucida and S. triflora. Photochemistry 27, 1409 1412. Amaro-Luis, J.M. (1993) An ent-kaurenolide from Stevia lucida. Phytochemistry 32, 1611 1613. Amaro-Luis, J.M. and Adrian, R.M. (1988) Terpenoids and steroids from Stevia triflora. Fitoterapia 59, 512. Amaro-Luis, J.M. and Adrian, R.M. (1997) A new caryophyllane derivative from Stevia triflora. Pharmazie 52, 162-163. Amaro-Luis, J.M. and...

Total synthesis of hibaene

Ireland and coworkers converted ketoacetal 149 to the hydroxy olefin 156, a model for the C D ring system of steviol (1) (Bell et al. 1966b). Acid-catalyzed rearrangement of 156 provided entry to the hibaene-stachene system, and the synthesis of racemic hibaene 158 was achieved (Scheme 15). Introduction of the C-13 acetyl grouping was accomplished through hydroboration-oxidation of the C-13 ethylene derivative 150 which in turn was obtained from the C-13 keto acetal 149 with...

Evaluation Of The Safety Of Stevioside In Korea

While there has been considerable doubt expressed on the safety of stevioside in Korea, as in several other countries, a recent report of the Korean Food and Hygienic Consideration Committee of the Ministry of Health and Welfare concluded provisionally that consumption of stevioside is regarded as safe for human health (Korea National Institute of Health 1996). In addition to stevioside, steviol, the aglycone of stevioside, has also been reported to have toxic effects (Pezzuto et al. 1985...

Total synthesis of kaurene and atisirene

The synthesis of ( )-kaurene (159) from the olefinic aldehyde 163 via hydroboration of the double bond and aldol-type cyclization of the C-14 ketoacetal 165 to form a bridged system has been reported (Bell et al. 1966a) (Scheme 17). The route makes available as well the substituted bicyclo 2.2.2 octane derivatives through similar cyclization of the isomeric C-13 ketoacetal 149 from the hydroboration and leads to ( )-atisirene (169). (i) ethylene glycol, TsOH, C6H6, reflux (II) BH3-THF, H202,0H_...

Introduction

Stevia rebaudiana has been studied in depth because this plant is the source of several well-known sweet-tasting compounds. Interest in using S. rebaudiana as a commercial sweetener, especially by the Japanese food industry, has led to extensive phytochemical investigations of the herb's constituents. To date more than 100 compounds have been identified from this species. The best known of these are the sweet-tasting ent-kaurene diterpenoid glycosides, particularly stevioside and rebaudioside...

Chemical Constituents

Despite the fact that Stevia is one of the largest and most easily recognized genus in the tribe Eupatorieae (Robinson and King 1977), this morphologically well-delineated taxon in the Piqueria group is surprisingly diverse in its chemical composition. However, the chemical profile for Stevia does not differ widely from that described for other members of the Eupatorieae (Dom nguez 1977). To our knowledge, phytochemical information is available to date on only 58 species, with some of the...

Synthesis of radiolabeled gibberellic acids from steviol

Radiolabeled gibberellic acids from steviol have been prepared by feeding chemically synthesized radiolabeled steviol acetate (133) to the fungus Gibberella fujikuroi (Gianfagna et al. 1983) (Scheme 13). Steviol (1) was obtained by enzymatic hydrolysis ofstevioside (2) and the product was acetylated with acetic anhydride-pyridine under reflux.The resulting acetate 133 was oxidized with OsO4-NaIO4 to acid, 134. Labeled steviol acetate (135) was produced by theWittig reaction from 134 using 2H...

Recent Trnd In Cancer Madicine Of Stevioside

Akashi, H. (1975) Safety of dried-leaves extracts of stevia (report of toxicological test). Shokuhin Kogyo (Food Industry) 18, 1 4. Akashi, H. andYokoyama,Y. (1975) Dried-leaf extracts of Stevia. Toxicology tests. Shokuhin Kogyo (Food Industry) 18, 34-43. Alvarez, M., Bazzote, R.B., Godoy, G.L., Cury, R. and Espinoza, A.D. (1981) Hypoglycemic effect of Stevia rebaudiana Bertoni. Arquivos Biologia eTecnologia 24, 178. Bakal, A.I. and O'Brien Nabors, L. (1986) Stevioside. In Alternative...

Cultivation And Cell Culture Of Stevia Rebaudiana

There is now a considerable body of literature on methods for the cultivation of S. rebaudiana leaves leading to the optimization of levels of their sweet ent-kaurene glycoside constituents. The native habitat of S. rebaudiana is at a latitude of25 S in a subtropical region ofnortheastern Paraguay between 500 1,500 m above sea level, on soil having a low phosphate content, with an annual average temperature of75 F, and an average rainfall of about 55 in. per year (Sumida 1973 Shock 1982). This...

Moris approach toward the total synthesis of steviol

The total synthesis of steviol (1) by Mori (Mori and Matsui 1965 1966 1970 Mori et al 1970a 1970b Nakahara et al. 1971 Nakahara 1982) is described in Scheme 1.The synthesis involves the annelation of 6-methoxy-1-methyl-2-tetralone (4) with methyl acroylacetate (3) to afford 5. Compound 5 was methylated and converted to thioketal 6. Desulfurization of 6, followed by Birch reduction afforded an a, -unsaturated ketone (7). Compound 7 was selectively reduced with lithium tri-t-butoxyaluminum...

The Genus Stevia

Stevia is a New World genus distributed from the southern United States to Argentina and the Brazilian highlands, through Mexico, the Central American States, and the South American Andes. It is one of five large genera of the Eupatorieae, of which none has been fully monographed in recent years. These five genera are Ageratina, Chromolaena, Koanophyllon, Mikania, and Stevia (Robinson and King 1977 King and Robinson 1987). Members of Stevia comprise herbs and shrubs, found mostly at altitudes...

Transglycosylation by other enzyme systems

Trans-a-1,6- and 1,3-glucosylation by biozyme L and glucosyltransferase from Streptococcus mutans Aiming for a more effective transglucosylation system, several commercially available glucosyltransferases were screened.Treatment of stevioside (1) with maltose and 'Biozyme L' (a crude -amylase preparation produced by Aspergillus spp.) afforded three products (i) 1m (6-O-a-glucosylated at the C-19-O-glucose) (ii) 2m (6-O-a-glucosylated at C-13-O-glucose) and (iii) 3m (3-O-a-glucosylated at the...

Comparison Of Stevioside To Other Natural Product Highintensity Sweetening Agents

In 1998, the artificial sweetener market in the United States was worth about 610 million, and this is scheduled to increase 3.4 per year to 720 million by 2003 (Seewald 2000). There remains a strong demand for highly sweet, non-caloric, and non-cariogenic substances to substitute for sucrose in the diet. Such compounds, whether natural or synthetic, should exhibit a sucrose-like taste, and should also lack any offensive odor, exhibit satisfactory water solubility and hydrolytic and thermal...

CGTase and starch

Stevioside (1) was treated with the CGTase with soluble starch as donor, yielding a complex mixture of products which were mono-, di-, tri- and polyglucosylated at the 19-O-glucosyl unit and or the terminal glucosyl unit of the 13-O-sophorosyl moiety (Kasai et al. 1981) (Figure 7.6). Separation and structure identification ofall the mono- (S1a and S1b),di- (S2a, S2b, and S2c) and tri- (S3a, S3b, S3c, and S3d) glucosylated products were achieved by Fukunaga et al. (1989), who also evaluated the...

Conversion of stevioside to rebaudioside A

Rebaudioside A (108) is the sweetest of the ent-kaurene glycosides isolated from S. rebaudiana to date, being approximately 350 450 times sweeter than sucrose (Crammer and Ikan 1986). Stevioside (2) has been synthetically converted to rebaudioside A (108) (Kaneda et al. 1977) (Scheme 9).The synthetic pathway followed a selective removal ofa glucose unit from stevioside (2) at the C-13 position by an enzyme, and systematic reintroduction of two glucose units of different linkage to the remaining...

O

Figure 5.20 Structure of subpubescensoside (174) and the conformation of its aglycone. Figure 5.20 Structure of subpubescensoside (174) and the conformation of its aglycone. bitter-tasting principle was an acetylated ent-atisene diterpene glycoside, stevisalioside A (175). The structure was established by the interpretation ofspectral data, with the NMR assignments of this compound being based on 1H-1H COSY, 1H-13C HETCOR, and selective INEPT experiments. While acidic hydrolysis led to a...

Rubusoside as the starting material

Rubusoside (7), a congener of stevioside (1) with one less sugar unit, was also treated with the CGTase-starch system,to undergo trans-a-1,4-glucosylation. From the reaction mixture, mono- (R1a and R1b), di- (R2a, R2b, and R2c),tri- (R3a, R3b, R3c, and R3d) and three of five tetraglucosylated products (R4a, R4b, and R4e) were separated (Darise et al. 1984) and identified (Figure 7.8) (Ohtani et al. 1991a).Two of the tetraglucosylated products (R4c and R4d) were difficult to purify and were...

Acyclic and bicyclic diterpenoids

The aerial parts of S. myriadenia, the only species in the genus for which acyclic diterpenoids have been reported, were shown to contain geranyl-linalol (152) and 20-hydroxygeranylnerol (153), as well as several kaurene derivatives and bicyclic diterpenoids (Bohlmann et al. 1982). Examples of both enantiomeric series of the labdane skeleton, i.e. the 10-Mea-labdane and the enantiomeric 10-Me -labdane, have been described in Stevia. The normal labdane type has been found in the isolated...

Species Relationships In Stevia

Although sound phylogenetic relationships can be established only following a thorough systematic study of the genus, a discussion on relationships of species and subgeneric groups based on currently available data, and with emphasis on chemotaxonomic relationships, will provide guidance in continuing and future efforts to search for sweet-tasting molecules within the genus. On the basis of information available to him, Grashoff (1972) postulated two hypotheses for the origin and evolution of...

Tetracyclic diterpenoids

The genus Stevia is well-known as the source of eight important sweet-tasting ent-kaurene glycosides (Figure 5.18), namely, stevioside (161), steviolbioside (162), rebaudiosides A E (163 167), and dulcoside A (168), which are extracted commercially from the South American plant, S. rebaudiana (Ishikawa 1991). However, such sweet glycosides appear to have a very limited distribution in Stevia, since aside from S. rebaudiana, they were only detected in S. phlebophylla, among 108 other Stevia...

Analytical methods for steviol glycosides in stevia sweeteners

According to the Voluntary Specifications of Non-chemically Synthesized Food Additives (Second Edition 1993), the quantitative analysis oftotal steviol glycosides in stevia extracts is performed using high-performance liquid chromatography (HPLC) on an NH2 column (normal-phase mode), in the following manner. About 60 to 120 mg of the sample is accurately weighed and dissolved in 80 (v v) acetonitrile to make 100ml of a test solution. About 50 mg each of stevioside and rebaudioside A, dried...

Classification Of Stevia

Members of Stevia are characterized by the following. Plant habit Annual, perennial or rhizomatous perennial herbs or shrubs. Leaves Simple, opposite, rarely alternate, mostly petiolate, but exstipulate, penninerved or reticulately nerved. Inflorescences Capitula (flower heads) are arranged on a corymbose, paniculate or thyrsoid clusters at tips of branches or stem. Capitulum The capitulum consists of a cylindrical to funnelform involucre of five linear to oblong phyllaries (bracts) arranged in...

Medicinal and Aromatic Plants Industrial Profiles

Individual volumes in this series provide both industry and academia with in-depth coverage of one major medicinal or aromatic plant of industrial importance. Edited by Dr Roland Hardman Volume 1 Valerian, edited by Peter J.Houghton Volume 2 Perilla, edited by He-ci Yu, Kenichi Kosuna and Megumi Haga Volume 3 Poppy, edited by Jen Bernath Volume 4 Cannabis, edited by David T.Brown Volume 5 Ergot, edited by Vladimir Kren and Ladislav Cvak Volume 7 Caraway, edited by Eva Nemeth Volume 8 Saffron,...

Stevia extract

Soon after being introduced to the Japanese market, a simple, concentrated product of an aqueous decoction of S. rebaudiana leaves was employed, namely, 'stevia extract'. At present 'stevia extract' is made through several steps using absorbent resins to produce a white to pale yellowish powder or granule, containing stevioside, rebaudioside A, rebaudioside C, dulcoside A, and minor principles. According to the Voluntary Specifications of Non-chemically Synthesized Food Additives, published by...

Historical Perspective And Introduction

There can have been few botanical discoveries quite so dramatic as the realization that the leaves of Stevia rebaudiana (Bertoni) Bertoni (Compositae) are so highly sweet. It is not clear when this was made originally, but the observation was brought to the attention of the scientific community about a hundred years ago (Gosling 1901 Bertoni 1905 Lewis 1992). The British Consul at Asunci n, Paraguay, Cecil Gosling, attributed the discovery of the sweetness of the plant S. rebaudiana to the...

Practical Applications Of Stevia Sweeteners

Formulations of orange juice and coffee-flavored jelly containing a simple 'stevia extract' known as Marumilon Pure (Maruzen Pharmaceuticals Co. Ltd.), which is 200 times sweeter than sucrose, are shown in Table 9.6. In both examples, the amounts of Marumilon Pure to be added are 0.008 (w v) and 0.0184 (w w), respectively, of the formulations, and the sweetener substitutes for about 20 of the commonly used sugar in these foods. Stevia Table 9.6 Formulation of orange juice, coffee-flavored...

Pharmacological actions Energy metabolism

Steviol inhibits oxidative phosphorylation, with 40 M producing 50 inhibition (Vignais et al. 1966). It is, therefore, more potent than the related aglycones atractyligenin and dihydrosteviol (see Figure 8.1), which produce 50 inhibition at 210 M and 100 M, respectively. Some of the mitochondrial actions of steviol are summarized on Table 8.1. The effects on oxidative phosphorylation are complex, involving at least three components (i) inhibition of adenine nucleotide exchange (ii) inhibition...

Background To Stevia Sweetener Development In Japan

Stevia sweeteners in Japan were originally developed as alternative sweeteners for Japanese seasonings. Used in various Japanese foods for several hundred years, soy sauce is the most popularJapanese seasoning and is generally formulated with high levels ofsalt (sodium chloride) for preservation and flavoring. In the early part of the twentieth century, the suppressing effect of a decoction from roots of Glycyrrhiza species (licorice) on the saline taste of soy sauce was recognized. Since then,...

Essential Oils And Other Volatile Constituents

Although the flowers and leaves of Stevia species could be rich sources of essential oils, as expected for any member of the Asteraceae (Dom nguez 1977), only three studies have been carried out to fully analyze the lower terpenoids and volatile substances by modern techniques. The first study involved the gas chromatographic analysis of the essential oil of S. satureiaefolia, collected in Argentina, which yielded the monoterpenes borneol (1), cineole (2), pulegone (3), geraniol (4), nerol (5),...

Use Of Stevioside In Korea

Stevioside occupies 40 of the sweetener market in Korea (Seon 1995).Table 10.1 shows the increasing consumption of stevioside in Korea over the period 1988 1991. Presently, the majority of the S. rebaudiana leaves for the isolation of stevioside are imported from the People's Republic of China. Five companies in Korea manufacture stevioside from S. rebaudiana leaves and products containing this sweet compound. The total output of stevioside per year in Korea is estimated to be 200 250 metric...

Ethnobotany Of Steviarebaudiana

Although data on the ethnobotany of S. rebaudiana are givenin Table3.1, becauseofthe importance of this species, and because of in its native land, Paraguay (Soejarto et al. 1983a), furthercommentsconcerningthisspecies arejustified. The oldest record that points out the sweet-tastingpropertiesof S. rebaudiana isapaper by Mois s S.Bertoni published in Revista de Agronom ade Asunci n, vol. 1 35, 1899 (notseen by the author), when he described this species under the name of Eupatorium rebaudianaum...

Definition And Standardization Of Stevioside In Korea

Stevioside is defined as those compounds having the skeleton of steviol originating from S. rebaudiana, by the Korean Standard of Food Additives published by the Ministry of Health and Welfare (Ministry of Health and Welfare 1996). In addition to this definition, the product must contain 98.0 of stevioside (C38H60O18) as the major component by quantitative analysis, after being dried for two hours at 100 C. Stevioside is permitted as a food additive in distilled liquors, unrefined rice wines,...

Triterpenoids And Sterols

Besides the widespread sterols, -sitosterol, stigmasterol, and campesterol, Stevia species also produce pentacyclic triterpenoids with the oleanane, lupane, taraxastane and friedelane skeletons Figure 5.22 Selected kaurenoic and beyerenic acids derivatives 177 180 from Stevia species. Figure 5.22 Selected kaurenoic and beyerenic acids derivatives 177 180 from Stevia species. Figure 5.23 . -Amyrin 181, R1 H R2 CH3 , oleanolic acid 181, R1 H, R2 CO2H and their acetyl derivatives have been...

Physical Properties Solubility And Stability Of Stevioside

In pure form, stevioside acid -D-glucopyranosyl ester Chemical Abstracts name is a white crystalline material with a melting point of 198 C, an optical rotation of -39.3 in water, an elemental composition of C38H60O18, and a molecular weight of 804.88 Anonymous 1996 . Stevioside is only sparingly soluble in water 1 g dissolves in 800 ml water , but it is soluble in dioxane and slightly soluble in ethanol Anonymous 1996 . Rebaudioside A mp 242 244 C a D24 Table 1.3 Physical and solubility data...