Sapogenins of Yucca glauca seeds

From the seeds of Yucca glauca Nutt., sarsasapogenin. markogenin. tigogenin. neo-tigogenin. neo-gitogenin, hecogenin and gloriogenin have been isolated and identified. Sarsasapogenin was the predominant sapogenin. Markogenin and gloriogenin have not been reported in leaves, roots or rhizomes of this species before. Small amounts of a sapogenin believed to be either diosgenin or yamogenin were also detected.     

Saponins in Tribulus terrestris – Chemistry and Bioactivity

Tribulus terrestris is a valuable herb known for its application in the folk medicine in many parts of the world. Furostanol and spirostanol saponins of tigogenin, neotigogenin, gitogenin, neogitogenin, hecogenin, neohecogenin, diosgenin, chlorogenin, ruscogenin and sarsasapogenin type are frequently found in this plant. Four sulphated saponins of tigogenin and diosgenin type are also isolated. Extracts and steroidal saponins have been found to possess various pharmacological activities. Preparations based on the saponin fraction of T. terrestris are used for treatment of infertility and libido disorders in men and women, as well as for treatment of cardiac diseases. Food supplements containing T. terrestris extracts are on sale in USA and Europe with claim of a general stimulating action. In this review the steroidal saponins found in T. terrestris are presented, covering the literature up to 2004. The data reveal clear difference in the saponin composition of samples from this plant species collected from different geographical regions. A comprehensive account on the biological activity of extracts and individual saponins is also included.     

Steroidal sapogenins from leaves of some species of Agave and Furcraea

The steroidal sapogenins yielded by the leaves of Agave aurea, A. avellanidens, A. cerulata, A. cerulata ssp. subcerulata, A. cocui, A. goldmaniana, A. shawii and Furcraeamacrophylla are recorded. In all these species, hecogenin and tigogenin were the major sapogenins isolated. Gitogenin was found in the extracts of all the leaf samples, except that of A. shawii, and manogenin and 9-dehydromanogenin in all but that of A. cocui. Chlorogenin was isolated from A. cocui, but was not detected in any of the other species examined. Qualitative and quantitative variations were found in the sapogenin contents of extracts of different regions of the same leaves of A. cocui and F. macrophylla. In particular, hecogenin predominated in the basal regions and tigogenin in the apical.     

Sapogenins of Yucca glauca seed pods

From the fruiting pods of Yucca glauca Nutt. devoid of seeds the following sapogenins have been isolated and identified: neo-tigogenin, hecogenin, gitogenin, manogenin, Δ⁹-manogenin and sarsasapogenin. A small amount of a material believed to be Δ²-desoxysarsasapogenin was also isolated and is apparently an artifact arising from the hydrolysis and extraction procedure. Manogenin and Δ⁹-manogenin have not been previously detected in Y. glauca, and Δ⁹-manogenin has not been reported in any Yucca species.     

Screening seed of Trigonella and three related genera for diosgenin

Seed of 45 species of Leguminosae were analyzed for diosgenin by GLC. Since the method did not separate yamogenin and tigogenin from diosgenin, results indicate maximum limits rather than the actual amounts of diosgenin present. Among 27 species of Trigonella tested, only 6 have as much as 0·27% diosgenin; the highest was 0·8% in 1 sample of T. foenum-graecum. Among 7 species of Medicago, 6 species of Melilotus and 5 species of Trifolium, none contained more than 0·1% diosgenin.     

蒺藜甾体皂甙元化学成分研究

从蒺藜(Tribulus terrestris)的氯仿部位分离得到8个已知的甾体皂甙元类化合物,运用光谱分析方法鉴定分别为：tigogenin(1),hecogenin(2),pregna 4,16 diene-3,12,20-trione(3),hecogenin acetate(4),25(R)-spirostan-4-ene-3,12-dione(5),25(R)-spirostan-3,12-dione(6),25(R)-spirostan-3,6,12-trione(7),gitogenin(8)。其中化合物3,5,6为首次从该植物中分得。     

Steroidal sapogenins. LVIII. Steroidal sapogenins from the Joshua tree

The Joshua tree,Yucca brevifolia, is distributed over parts of Arizona, California, Nevada, and Utah. A study of its steroidal sapogenins showed that the leaves contain practically none; the wood, small amounts of smilagenin; the seeds high amounts of hecogenin and tigogenin.     

16β-Hydroxycholestanol als biogenetische vorstufe der steroidsapogenine

It has been shown that 5,6-³H,16β-hydroxycholestanol is used in the biogenesis of the steroid sapogenins, tigogenin and gitogenin, by plants of Digitalis lanata but not for the formation of tomatidine by Solanum lycopersicum.     

Effect of chemical mutagens on steroidal sapogenins in Trigonella species

A two- to four-fold increase in the steroidal sapogenins (diosgenin and tigogenin) was observed in the plants and seeds obtained from seeds of T. corniculata and T. foenum-graecum treated with low concentrations of chemical mutagens (EMS, MMS and NaN₃). However, a decrease in their levels was recorded at high concentrations of the mutagens.     

Structure-function relationship for saponin effects on cell cycle arrest and apoptosis in the human 1547 osteosarcoma cells: a molecular modelling approach of natural molecules structurally close to diosgenin

In this paper, eight natural molecules structurally close to diosgenin (five saponins: diosgenin, hecogenin, tigogenin, sarsasapogenin, smilagenin; two steroidal alkaloids: solasodine, solanidine; one sterol: stigmasterol) have been tested for their biological activities on human 1547 osteosarcoma cells. Differences in activity were studied in term of proliferation rate, cell cycle distribution and apoptosis induction. By using molecular modelling, two structural characteristics were calculated: spatial conformation and electron transfer capacity. The second property has been investigated by the HOMO repartition and the corresponding energy. Correlation between the experimental and the theoretical data permit us to highlight the importance of the hetero-sugar moiety and the 5,6-double bond in the biological activity (apoptosis and cell cycle arrest) on the human 1547 cell line. The importance of conformation at C-5 and C-25 carbon atoms was also discussed.     

Deacylation reactions of 20-acetyl dinorcholanic lactones and 20,23-diacetyl furost-22-enes

We report the deacylation of (20R)-20-acetyl-23,24-dinorcholanic lactones by hydrazine hydrate, under microwave irradiation in high yields. The elimination of the 20-acetyl group proceeded with retention of configuration which contrast with other proved deacylation methods that yield a mixture of diastereoisomers. In this way, unnatural (20R)-23,24-dinorcholanic lactones can be produced rapidly on a large scale. Both (20R)- and (20S)-lactones were prepared starting from diosgenin, hecogenin and sarsasapogenin, in 72-80% overall yields.     

Investigations on the content of steroidal alkaloids and sapogenins withinSolanum sect.Solanum ( = sect.Morella) (Solanaceae)

Plant material of 55 strains from 32 species ofSolanum sect.Solanum ( = sect.Morella) has been investigated for the content of steroidal alkaloids and sapogenins. The leaf-extracts of all species contain diosgenin resp. tigogenin or both together in considerable amount. On the contrary the characteristic steroidal alkaloid solasodine was absent in these samples. For 29 species the presence of steroidal sapogenins has been proved for the first time. In unripe fruits, however, solasodine could be detected in most of the species examined. New occurences of solasodine are reported for seven further species. These chemical results may contribute to a better comprehension of the difficult genusSolanum.—Ontogenetic studies on different organs ofS. atriplicifolium show the relationship between accumulation of steroidal compounds and plant maturity.     

A quantitative gas-liquid chromatographic method for the estimation of hecogenin and tigogenin in the leaves, juice and sapogenin concentrates of Agave sisalana

A gas-liquid chromatographic method has been devised for the routine estimation of the hecogenin [3beta-hydroxy-(25R)-5beta-spirostan-12-one] and tigogenin [ (25R)-5beta-spirostan-3beta-ol] contents of Agave sisalana leaf and juice samples and of the crude sapogenin concentrates known as "coffee grounds". Because of partial degradation of the sapogenins in the GLC system it was found necessary to acetylate the compounds prior to their estimation. In East African samples the tigogenin proportion of the total sapogenin content is usually about 10%. At this level, the 95% inverse tolerance limits on predicted tigogenin weights are approximately +/- 7%.     

The Quantitative Analysis and Identification of Steroidal Sapogenins of the Dioscorea Plant

The results for the quantitative analysis and identification of steroidal sapo-genins of 16 species of Dioscorea rhizomes are given in Table 1. The amount of steroidal sapogenin varies from 0.073%–5.93%, its highest content of diosgenin is 5.93% in D. zingiberensis C. H. Wright. 2. The results observed from paper chromatography, thin layer chromatography and gas-liquid chromatography revealed that except the sapogenin of D. chingii Pr. and Br. is similar to tokorogenin, all other sapogenins after recrystallization yield a spot identical to diosgenin or yamogenin. Meanwhile, in most Dioscorea sample, a spot identical to △ 3, 5-diene-25D-spirostane was shown by using thin layer chromatography and gas-liquid chromatography. (Table 2). 3. The results observed from infrared spectrum and gas-liquid chromatography revealed that the sapogenins of D. collettii, Hook. f; D. collettii. Hook, f. var. hypoglauca, Pei and Ting. and D. tokoro Makino. contained 25L-spirostane. (A900≤ A920 cm-1).     

Regioselective cleavage of rings E and F in sarsasapogenin

Sapogenins from the 25R and 25S series show a marked difference on the E/F regioselectivity of the spiroketal cleavage with BF(3)/Ac(2)O. In contrast to the high yield of single E-ring cleavage products from diosgenin (3) and hecogenin (5), sapogenins of the 25R series (equatorial C-27 methyl), sarsasapogenin (1, 25S series, axial C-27 methyl) yields the corresponding acetyldihydropyran, (25S)-23-acetyl-22,26-epoxy-5beta-cholest-22-ene-3beta,16beta-diyl diacetate (8), two isomeric furostenes: (E)- and (Z)-(25S)-23-acetyl-5beta-furost-22-ene-3beta,26-diyl diacetate (9 and 10) and a third one bearing an additional acetyl group: (E)-(20S,25S)-20,23-diacetyl-5beta-furost-22-ene-3beta, 26-diyl diacetate (11). The structures of the compounds were unambiguously established using two dimensional NMR techniques. The lower E/F selectivity in the cleavage of 1 is attributed to steric hindrance resulting from the axial methyl in F ring on a beta elimination forming the dihydropyran double bond in the major product 8.     

Regioselective cleavage of 22-oxo-23-spiroketals. Novel cholestanic frameworks with pyranone and cyclopentenone E rings on the side chain

The regioselective opening of the F ring of 22-oxo-23-spiroketals using a saturated solution of HCl in acetic anhydride yielded novel cholestanic frameworks with pyranone or cyclopentenone E rings. The structures of the new derivatives of sarsasapogenin, diosgenin and hecogenin thus obtained were established using one and two dimensional (1)H, (13)C experiments (DEPT, COSY, HETCOR, HMBC, ROESY, and NOESY). The X-ray analysis for compound 11b confirmed the 23R configuration for the new stereogenic center.     

One unique steroidal sapogenin obtained through the microbial transformation of ruscogenin by Phytophthora cactorum ATCC 32134 and its potential inhibitory effect on tissue factor (TF) procoagulant activity

With the aim to obtain more effective tissue factor (TF) inhibitors, the microbial transformation of three steroidal sapogenins, ruscogenin (1), diosgenin (2) and sarsasapogenin (3), was carried out and only ruscogenin was selectivity converted to 1-hydroxy-spirost-4-en-3-one (4) by Phytophthora cactorum ATCC 32134. The in vitro anti-TF procoagulant activity of this metabolite was enhanced almost 10 times to an IC₅₀ value of 0.29 μM. The chemical assignments of compound 4 were made unambiguously using ESI-MS, IR and 2D NMR spectroscopy.     

Yamogenin in fenugreek inhibits lipid accumulation through the suppression of gene expression in fatty acid synthesis in hepatocytes

Yamogenin is a diastereomer of diosgenin, which we have identified as the compound responsible for the anti-hyperlipidemic effect of fenugreek. Here, we examined the effects of yamogenin on the accumulation of triacylglyceride (TG) in hepatocytes, because yamogenin is also contained in fenugreek. It was demonstrated that yamogenin also inhibited TG accumulation in HepG2 hepatocytes and suppressed the mRNA expression of fatty acid synthesis-related genes such as fatty acid synthase and sterol response element-binding protein-1c. Indeed, yamogenin also antagonized the activation of the liver X receptor (LXR) in luciferase ligand assay similar to diosgenin. However, yamogenin could not exert such effects in the presence of T0901713, a potent agonist of LXR. These findings indicate that the effects of yamogenin on TG accumulation would be weaker than those of diosgenin, suggesting that the structural difference between yamogenin and diosgenin would be important for the inhibition of LXR activation.     

Phospholipids modulate the substrate specificity of soluble UDP-glucose:steroid glucosyltransferase from eggplant leaves.

UDP-glucose-dependent glucosylation of solasodine and diosgenin by a soluble, partially purified enzyme fraction from eggplant leaves is affected in a markedly different way by some phospholipids. While glucosylation of diosgenin and some closely related spirostanols, e.g. tigogenin or yamogenin, is strongly inhibited by relatively low concentrations of several phospholipids, the glucosylation of solasodine is unaffected or even slightly stimulated. These effects depend both on the structure of the polar head group and the nature of the acyl chains present in the phospholipid. The most potent inhibitors of diosgenin glucosylation are choline-containing lipids: phosphatidylcholine (PC) and sphingomyelin (SM) but the removal of phosphocholine moiety from these phospholipids by treatment with phospholipase C results in an almost complete recovery of the diosgenin glucoside formation by the enzyme. Significant inhibition of diosgenin glucoside synthesis and stimulation of solasodine glucosylation was found only with PC molecular species containing fatty acids with chain length of 12-18 carbon atoms. PC with shorter or longer acyl chains had little effect on glucosylation of either diosgenin or solasodine. Our results indicate that interaction between the investigated glucosyltransferase and lipids are quite specific and suggest that modulation of the enzyme activity by the nature of the lipid environment may be of importance for regulation of in vivo synthesis of steroidal saponins and glycoalkaloids in eggplant.     

In vitro propagation and biosynthesis of steroidal sapogenins from various morphogenetic stages of Moringa oleifera Lam., and their antioxidant potential

Moringa oleifera is a highly valued medicinal plant. The present research reports callus cultures of M. oleifera Lam., established from seeds and nodal segments on Murashige and Skoog’s (MS) medium using different concentrations and combinations of auxins and cytokinins. Best induction of callus was observed at BAP:IBA (3 mg l^?1 each). Shooting and rooting from callus in terms of morphogenesis were observed in MS media supplemented with BAP:KN (2:0.2 mg l^?1) and IBA:NAA (3:0.5 mg l^?1), respectively. Multiple shooting was observed at treatment dose of BAP:NAA:IAA (1:1:0.2 mg l^?1). Regenerated shoots were rooted and mature plants were established, acclimatized, and thrived in greenhouse conditions. Over 95 % of plantlets survived after transplanting plantlets into trays with a mixture of sand and perlite (2:1) for 20 days. The regeneration protocol developed in this study provides a basis for germplasm conservation and for further investigation of bioactive constituents of this medicinal plant. Further qualitative and quantitative production of steroidal sapogenins (diosgenin and tigogenin) from various morphogenetic stages was studied using TLC, PTLC, IR spectra, HPLC and GC–MS analysis. Steroidal sapogenins were maximum in the callus associated with rooting. Various stages were further analyzed for their antioxidant potential.