Peculiar steroidal saponins with opened E-ring from Solanum genera plants

Zhu, Xing‐Hua; Tsumagari, Hidetsugu; Honbu, Takehiko; Ikeda, Tsuyoshi; Ono, M.; Nohara, Toshihiro

doi:10.1016/s0040-4039(01)01711-7

Cited by 35 publications

(22 citation statements)

References 7 publications

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“…7) We have also isolated nigrosides A (d), 8) B (e) and tuberoside C ( f ) 9) along with the usual major components, furostanol (a) and spirostanol (b) glycosides. The occurrence of a 20,22-dicarbonyl cholestane glycoside skeleton in 16-O-acylpregnane glycoside (c) strongly suggests a biogenetic pathway of oxidation between C-20 and C-22 via C-20(22)-pseudomerization in furostanol glycoside.…”

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confidence: 93%

Metabolism of Tomato Steroidal Glycosides in Humans

Noguchi

Fujiwara

Matsushita

et al. 2006

CHEMICAL & PHARMACEUTICAL BULLETIN

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Pregnane glycoside was first isolated from Paris polyphylla (Liliaceae) by Nohara et al. 1) Recently, pregnane (g in Chart 1) and 16-O-acylpregnane glycosides (c) have been occasionally isolated from various plants of various genera such as Dioscoreacee, [2][3][4][5] Taccaceae,6) and Solanaceae. 7) We have also isolated nigrosides A (d), 8) B (e) and tuberoside C ( f ) 9) along with the usual major components, furostanol (a) and spirostanol (b) glycosides. The occurrence of a 20,22-dicarbonyl cholestane glycoside skeleton in 16-O-acylpregnane glycoside (c) strongly suggests a biogenetic pathway of oxidation between C-20 and C-22 via C-20(22)-pseudomerization in furostanol glycoside. Therefore, we have hypothesized that pregnane glycoside (g) might be biosynthesized from furostanol (a) and/or spirostanol (b) glycosides as shown in Chart 1. Recently, natural foods containing diosgenin, a constituent of Mexican yam (Dioscorea mexicana), are marketed in Japan and promoted as being effective in treating diseases such as osteoporosis and premenstrual syndrome in women. This indicates that diosgenin may be metabolized into a type of steroidal hormone. Therefore, we have speculated that when steroidal glycoside is administered, it might be partially metabolized into a steroidal hormone. However, this has not yet been proven.For the metabolic experiment, we isolated the tomato glycoside, esculeoside A (h in Chart 2), (5a,22R,23R,25S)-, at a yield of 0.025% from the fruit of Cherry tomato, Lycopersicon esculentum var. cerasiforme (DUNAL) ALEF.10,11) Moreover, a pregnane glycoside, 3-O-b-lycoteraosyl 5a-pregn-16-ene-20-one, was isolated from over-ripe tomatoes that showed decreasing amounts of esculeoside A. This fact suggests that esculeoside A could be converted to pregnane derivatives as the tomatoes mature, suggesting that pregnane derivatives are biosynthesized from spirosolane glycoside. Furthermore, we have observed that esculeogenin A (i) corresponding to the sapogenol moiety of esculeoside A (h) can be easily converted to a pregnane derivative, 3b,16b-dihydroxy-5a-pregna-20-one, by merely refluxing with water and pyridine.12) The presence of the hydroxy group at C-23 may cause the E and F-rings of the steroidal nucleus to be fragile. So that we have designed metabolic experiment of tomato glycoside.Eight males consumed Cherry tomatoes at the rate of 2 kg per adult person over a period of 2 d: their urine samples were collected for 48 h and passed through a polystyrene gel . The first eluate with water was discarded, Pregnane glycosides have been isolated in small amounts, along with the major components furostanol and spirostanol glycosides, from Dioscoreaceae, Taccaceae, and Solanaceae, suggesting that pregnane glycosides might be biosynthesized from furostanol and spirostanol glycosides. Recently, commercial natural foods composed of diosgenin have been used for the treatment of diseases such as osteoporosis and premenstrual syndrome in women. It is anticipated that diosgenin would be metabolized into a type of...

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confidence: 93%

Metabolism of Tomato Steroidal Glycosides in Humans

Noguchi

Fujiwara

Matsushita

et al. 2006

CHEMICAL & PHARMACEUTICAL BULLETIN

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“…That is to say, we have discovered a precursor of furostanol, polyhydroxy-cholestane glycoside (3) [6], the conjugated cholesterol glycoside with acetyl Co-A or maronyl Co-A that forms an aromatic E-ring (4) [7], 16,22-dicarbonyl-cholesterol glycosides (5) [6,8], lactone glycosides (6) at the E-ring and pregnane and 16-acyl-pregnane glycosides (7,8) [8]. The most attractive compounds for us are pregnane [9] and 16-acyl-pregnane [6,8] glycosides. This is because the occurrence of the pregnane compounds suggests that they might be biosynthesized in the plant internally from furostanol glycosides by a reaction similar to Marker degradation.…”

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confidence: 99%

Physiological functions of solanaceous and tomato steroidal glycosides

et al. 2006

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Solanaceous plants are widely distributed. They are used as food and in folk medicine. Our studies focused on these plants, starting with Solanum lyratum and S. nigrum, which are used as anti-cancer and anti-herpes agents. Extensive investigations in 45 Solanum plant species revealed that a considerable amount of glycosides such as spirosolane, solanidane, spirostane and furostane is in these plants, and some of the isolated glycosides showed strong anti-proliferative activity against various cancer cell lines and anti-herpes activity. Furthermore, we have discovered a few new hypothetical biosynthetic routes in which the pathways for the biosynthesis of 16-acyl-pregnane and pregnane glycosides were the most interesting. The occurrence of these pregnane compounds indicates that they might be internally biosynthesized in the plant from furostanol glycosides by a reaction that is similar to Marker degradation. Furthermore, this may imply that the administration of steroidal glycosides may result in their metabolization into pregnane derivatives possessing various activities. In order to perform metabolic experiments using the steroidal glycosides, we recently isolated tomato glycosides from ripe tomato fruits for the first time. For this experiment, we examined the metabolites in urine obtained from persons that consumed tomatoes. We obtained androstane derivatives that were probably metabolized via pregnane derivatives from tomato glycoside. Hence, when a steroidal glycoside is administered, it may be metabolized into a type of steroidal hormone with various physiological activities.

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“…Our recent studies on the constituents of Solanum plants have revealed that pregnane glycosides are accompanied by normal spirostanol and furostanol glycosides [4][5][6][7][8][9][10][11][12] ; esculeogenin A is easily converted into a pregnane derivative by refluxing with aqueous pyridine, 13) and pregnane glycoside has been obtained from the over-ripe tomato fruit. 14) These facts strongly suggest that orally administered steroidal glycosides can be metabolized into pregnane derivatives, which are a type of steroidal hormone.…”

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Saponins Esculeosides B-1 and B-2 in Italian Canned Tomatoes

et al. 2013

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Italian canned tomatoes contain the tomato glycosides esculeosides B-1 (1, 0.0052%) and B-2 (2, 0.0068%) without esculeoside A. Herein, the structure of esculeoside B-1 (1) is characterized to be 3-O-β-lycotetraosyl (5S,22R,23S,25S)-22,26-epimino-16β,23-epoxy-3β,23,27-trihydroxycholestane 27-O-β-d-glucopyranoside. We hypothesized that these substances might be derived from esculeoside A when the cans are prepared with treatment in boiling water. To confirm that hypothesis, we refluxed esculeoside A with water for 6.5 h, providing esculeosides B-1 (1) and B-2 (2) in yields of 25.8% and 31.0%, respectively. Key words Solanum lycopersicum; canned tomato; tomato saponin; esculeoside A; esculeoside B-1; esculeoside B-2In 2003, Nohara and colleagues 1,2) isolated a tomato saponin, called esculeoside A, from the ripe fruits of tomato, Solanum lycopersicum L. and determined its structure ( Fig. 1). Tomato saponin is a significant component of ripened tomatoes and occurs at levels approximately 4-fold higher than those of lycopene. Thus far, the bioactivity of tomato has been attributed solely to lycopene. Therefore, carrying out pharmacological examinations of esculeoside A in the near future is important.Recently, Fujiwara et al. 3) have revealed that oral administration of esculeoside A to apolipoprotein E-deficient mice significantly reduces levels of serum cholesterol glycerides, low-density lipoprotein-cholesterol and the areas of atherosclerotic lesions without any detectable side effects. Our recent studies on the constituents of Solanum plants have revealed that pregnane glycosides are accompanied by normal spirostanol and furostanol glycosides [4][5][6][7][8][9][10][11][12] ; esculeogenin A is easily converted into a pregnane derivative by refluxing with aqueous pyridine, 13) and pregnane glycoside has been obtained from the over-ripe tomato fruit. 14) These facts strongly suggest that orally administered steroidal glycosides can be metabolized into pregnane derivatives, which are a type of steroidal hormone.Therefore, in further experiments, men consumed tomatoes and their urine was collected and separated with various column chromatographies to afford 3 androstane derivatives. 15)These androsterone analogs are normally excreted; however, because no excretions were detected in the control samples, the occurrence of androsterone analogs indicated excretion via the production of progesterone by subjects that had consumed tomatoes. The tomato steroidal glycoside might stimulate the hormone secretor or perhaps is itself metabolized into the pregnane. We hypothesize that orally administered steroidal glycosides such as spirostanol, furostanol and spirosolane glycosides are metabolized, introducing a hydroxyl group at C-23. These intermediates may then be metabolized into pregnane derivatives.Thus, we conclude that the tomato saponin esculeoside A

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Peculiar steroidal saponins with opened E-ring from Solanum genera plants

Cited by 35 publications

References 7 publications

Metabolism of Tomato Steroidal Glycosides in Humans

Metabolism of Tomato Steroidal Glycosides in Humans

Physiological functions of solanaceous and tomato steroidal glycosides

Saponins Esculeosides B-1 and B-2 in Italian Canned Tomatoes

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