Solanum torvum SWARTZ (Solanaceae) is a small shrub, of which fruits are commonly available in the markets and are used as a vegetable regarded as an essential ingredient in Thai cuisine. Previously, we reported seven steroidal glycosides from the aerial parts and the roots of this plant.1) As regard with the former reports of the constituents in this plant, neochlorogenin, 2,3) chlorogenin, 3,4) paniculogenin, 2,5) solaspigenin, 5,6) neosolaspigenin, 5,6) and torvonin-B 7) were known. Recently, an additional steroidal glycoside, torvoside H 8) was reported. In this time, three unusual 22-b-O-spirostanol glycosides have been isolated from the fruits of this plant.The methanolic extract (33.4 g) of fresh fruits (600 g) of Solanum torvum was subjected to high-porous polystyrene gel (Diaion) to elute gradually with H 2 O→50% MeOH→ MeOH→acetone. The MeOH eluate was subsequently separated by using silica gel chromatography and HPLC to afford torvoside J (1, 5.4 mg), torvoside K (2, 8.3 mg), and torvoside L (3, 4.2 mg) together with known steroidal glycosides, torvosides A 1) (2.54 g) and H 8) (29.2 mg). Torvoside J (1), obtained as an amorphous powder, [a] D ϩ53.1°(MeOH) showed a quasimolecular ion peak at m/z 763 due to [MϩNa] ϩ in the positive FAB-MS. The Table 1. The absolute configurations of the respective sugars were determined by using HPLC equipped optical rotatory instrument after acid hydrolysis of 1. The remaining 27 carbons originating from the sapogenol moiety were constituted of eight methylene carbons at d 21. 1, 32.3, 32.5, 33.2, 37.8, 37.9, 39.9, 41.4, seven methine carbons at d 24.6, 34.4, 41.4, 51.4, 54.0, 56.5, 64.9, two Since signals due to H-3 and H-6 were overlapped to other sugar signals, their coupling constants could not be discriminated. However, the 13 C-NMR signals due to C-3, C-6 and their surrounding carbons at C-2, C-4, C-5, and C-7 were coincident with those of 1, 1) so that the configuration at C-3 and C-6 were conceivable to be identical with those of 1. Usually, the configuration at C-25 is determined by the signal pattern of H 2 -26. However, the signals due to H 2 -26 appeared around at d 3.70, which were overlapped with the other signals of H-3 and H-6 in the sapogenol and of the quinovosyl H-4 and H-5, so that they could not be discriminated. When the methyl group at C-25 is axial, it would show a remarkable lower shift due to 1,3-diaxial correlation with the hydroxyl group at C-23. But, the signal due to H 3 -27 practically appeared at d 0.73, suggesting it to be equatorial. Next, as for the configuration at C-22, the H 3 -21 signals in other C-23-hydroxyl spirostanol derivatives were referred. The H 3 -21 appeared at
NotesIn previous papers, [1][2][3][4] we reported the isolation and structural elucidation of a steroidal alkaloid glycoside, esculeoside A, from a ripe pink color-type tomato (Lycopersicon esculentum, Momotaro, Solanaceae), a solanocapsine-type glycoside, esculeoside B, from a ripe red color-type tomato (Lycopersicon esculentum, Italian San Marzano), esculeosides A, B, C, and D and lycoperoside G from a ripe cherry tomato [Lycopersicon esculentum var. cerasiforme (DUNAL) ALEF.], and a pregnane glycoside, tomato-pregnane, from an overripe cherry tomato. As part of our ongoing study on the chemical constituents of tomatoes, the present study deals with the isolation and structural characterization of a new steroidal glycoside and a new phenyl glycoside along with two known steroidal alkaloid glycosides and five known aromatic compounds from ripe cherry tomatoes.A ripe cherry tomato was crushed and extracted with MeOH. The MeOH extract was successively subjected to Diaion HP-20, Sephadex LH-20, Chromatorex ODS, and silica gel column chromatography, as well as HPLC on C18, C8, and polyamine to yield three steroidal glycosides (1, 3, 4) and six aromatic compounds (2, 5-9).Compounds 3-9 were identified as esculeoside A (3), 1,2) esculeoside B (4), 2) zizibeoside I (5), 5) benzyl alcohol b-gentiobioside (6), 6) rutin (7), methyl caffeate (8), and phenylalanine (9), respectively, based on the comparison of their physical and spectral data with authentic or previously reported samples (Fig. 1).Compound 1 was obtained as an amorphous powder, and its positive FAB-MS exhibited an [MϩNa] ϩ ion peak at m/z 1367. The molecular formula of 1 was determined to be C 61 H 100 O 32 by using high-resolution (HR)-positive FAB-MS. (d 105.0, 104.6, 104.6, 104.5, 104.3, 102.4). From these data, 1 was concluded to be a steroidal hexaglycoside. Acidic hydrolysis of 1 yielded D-glucose, D-galactose, D-xylose, and L-arabinose, which were identified by using optical rotation chiral detection in the HPLC analysis, along with several unidentified artificial aglycones. A detailed analysis of the 1 H-and 13 C-NMR signals of 1 using the 1 H-1 H correlation spectroscopy (COSY), heteronuclear multiple-quantum coherence (HMQC), heteronuclear multiple-bond correlation (HMBC), and total correlation spectroscopy (TOCSY) indicated that the planar structure of 1 was a 3,26-bisdesmoside of 3,26-dihydroxy cholestan-16,22-dione, as shown in Fig. 2. Further, the 13 C-NMR data of C-1-C-11 and C-19 of the aglycone (Ag) moiety and sugar chain attached to C-3 of Ag were superimposable on those of 3 2); on the other hand, those of C-12-C-18 and C-20-C-27 of the Ag moiety were quite similar to those of anguivioside XV (10).7) The remaining sugar chain, which was attached to C-26, was determined to be an a-L-arabinopyranosyl-(1→6)-b-D-glucopyranosyl group based on the following evidence. The 13 C-NMR spectrum of 1 exhibited signals due to a terminal a-L-arabinopyranosyl group (d 105.0, 72.0, 74.0, 68.8, 66.3) 8) and a b-D-glucopyranosyl group (d 104.5, 74.8, ...
It has been revealed that the absolute configurations at C-22 of 23-hydroxyspirostane and 23-hydroxyspirosolane could be unambiguouly judged by the 1 H-and 13 C-NMR spectroscopies.
The steroidal hormones are mainly derivatized from Dioscoreacea plants to produce birth controllable medicine, the pill. The raw material bearing steroidal hormones are strongly disired. The aerial parts of tomatoes are discarded after picking the fruits of tomatoes. Taking into the consideration of an effective utilization for tomato rejectings, we tried an efficient conversion of tomatidine (1) into a pregnane derivative, possessing the NGF-like neurite extension capability being available for dementia.Tomatidine (1) is the sapogenol of tomatine which is contained in ca. 0.1% in the aerial parts of tomato. Effective application of the aerial parts after picking the fruits is strongly desired. Previously, Sato et al. reported that refluxing of tomatidine with anhydrous acetic acid produced a hydrogenable triaetate, d20(22) -pseudo compound, which was subsequently oxidized with chromic acid to give 5a-pregn-16-en3b-ol-20-one in an overall ca. 27.3% yield. 1) We have now developed a new conventional method into a pregnane derivative from tomatidine. In addition, we have revealed that the product of the pregnane derivative possesses neuritogenic and NGF-enhancing activities.Tomatidine (1) was acetylated with anhydrous acetic acid and pyridine for 20 h at r.t. After the reaction mixture was poured into ice-water and left to stand overnight, the deposited white precipitate was collected by filtration. The product was purified by using silica gel column chromatography to provide a homogeneous acetate (2) in a 62.1% yield, whose EI-MS exhibited a molecular ion at m/z 499 corresponding to C 31 H 49 NO 4 . The Next, to a solution of 2 in MeOH, ozone gas was introduced for 10 min at Ϫ40°C. The solution was evaporated to give a residue, which was then refluxed with 3% KOH dioxane-water (1 : 1) and neutralized. The product was purified by silica gel column chromatography to give the pregnane derivative (3), which was obtained in a 87.0% yield as colorless needles, mp 203-205°C, [a] D ϩ48.2°(EtOH). Compound 3 showed a peak due to a molecular ion at m/z 316, corresponding C 21 H 32 O 2 in the EI-MS. The 1 H-NMR spectrum showed signals due to three tertiary methyls at d 0.82 (3H, s, H 3 -19), 0.94 (3H, s, H 3 -18), 2.26 (3H, s, H 3 -21), along with one oxygen bearing a methine proton at d 3.85 (1H, m, H-3) and one olefinic proton at d 6.62 (1H, dd, Jϭ1.8, 3.1 Hz,, of which assignments were made by the 2D-NMR measurements. The 13 C-NMR signals were also assigned as follows: C-1-21, 32.5, 32.2, 70.6, 37.3, 45.5 Chikusa-ku, Nagoya 464-8601, Japan. Received February 1, 2007; accepted March 26, 2007; published online April 19, 2007 Moderate acetylation of tomatidine with anhydrous acetic acid and pyridine for 20 h at r.t., followed by pseudomerization in ice-water, gave a d d 20(22) -pseudo compound, which was then subjected to ozonolysis to provide a pregnane derivative in a total 54% yield showing neuritogenic and NGF-enhancing activities.
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