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From the underground parts of Tupistra chinensis, a novel polyhydroxylated spirostanol sapogenin, tupichigenin A [(20S, 22R)-spirost-25(27)-ene-1beta,2beta,3beta,5beta- tetraol] (1), was isolated and determined structurally on the basis of spectroscopic methods. Also isolated was the known steroidal sapogenin (20S, 22R)-spirost-25(27)-ene-1beta,2beta,3beta,4beta, 5beta, 7alpha-hexaol-6-one (2).
Lyophilized aqueous extracts obtained from Agave americana L (Agavaceae) collected in the north of Sardinia were characterized with regard to their steroidal sapogenin content. Extracts of A. americana and genins isolated from them were evaluated for anti-inflammatory properties by testing their effects on carrageenin-induced edema. The effect of orally administered genins on gastric mucous membranes was also assessed. Lyophilized extracts administered by the intraperitoneal route at doses equivalent to 200 and 300 mg/kg of fresh plant starting material, showed good anti-inflammatory activity. Doses of genins (total steroidal sapogenins, hecogenin and tigogenin) equivalent to the amount in the lyophilized extracts produced an antiedentatous effect which was much stronger and more efficacious than that obtained with an i.p. administration of 5 mg/kg of indomethacin or dexamethasone 21-phosphate at a dose equivalent to the molar content of hecogenin administered. At the doses used to evaluate the anti-inflammatory activity, the genins did not have any harmful effect on the gastric mucous membranes. Lesions occurred when significantly higher doses of hecogenin were given, but gastric damage was still less than that caused by the drugs used for comparative purposes.
Chemical examination of the underground parts of Tupistra chinensis led to the isolation of two new 5beta-spirostane type steroidal sapogenins, tupichigenin B (1) and C (2), together with two known steroidal sapogenins, ranmogenin A (3) and delta25(27)-pentrogenin (4). The structures of 1 and 2 were established as spirost-25(27)-ene-1beta,3beta,4beta,5beta,6b eta-pentaol and 1beta,2beta,3beta,4beta,5beta-pentahydroxyspi rost-25(27)-en-6-one, respectively, on the basis of detailed analysis of their physical and spectral data.
Two new saponins were isolated from Ardisia pusilla and proved to have marked immunological function and antitumor activity. Acidic hydrolysis of saponin I gave five sapogenins and two prosapogenins. The structures of three sapogenins were elucidated as cyclamiretin A, C, D and two prosapogenins as cyclamiretin D-3-O-alpha-L-arabipyranoside and cyclamiretin D-3-O-beta-D-glucopyranosyl-(1-->2)-alpha-L-arabipyranoside.
In order to find alternative protein sources in African regions where protein deficiency in nutrition is prevailing, solubility, in-vitro digestibility, amino acid composition and chemical score of Balanites aegyptiaca Del. kernel proteins were investigated as a function of different processing steps including defatting, air classification, wet sieving and aqueous ethanol treatment. Air classification delivered a fine fraction of 58.1% of the total protein. Applying a wet sieving process, a protein concentrate of 72.9% protein content was achieved but the recovery was very low (35.6%). However, in case of isoelectric precipitation followed by aqueous ethanol treatment both protein content (78.2%) and recovery (53.7%) were high. Data concerning the chemical score revealed, that lysine content of the defatted kernel flour amounted to 74.2% of the recommended FAO/WHO standard level. In-vitro protein digestibility was found to be higher than of legume proteins. The digestible protein of the full fat flour, defatted flour, air classified and wet sieved fine fractions and protein concentrate were 91.9, 93.7, 82.0, 86.4 and 94.2%, respectively. The sapogenin content per 100 g protein of the investigated protein preparations was significantly lower (46% to 62%) than of the initial material (oilcake).
The assumption that complex formation between erythrocyte membrane cholesterol and saponins or sapogenins is the cause for their hemolytic activity, was tested by measuring the susceptibility of cholesterol-depleted erythrocytes towards these hemolysins. For some of the hemolysins cholesterol depletion caused inhibition of hemolysis, for others an augmentation. The results suggest that cholesterol does not serve as a specific binding site for these hemolysins.
A relationship between the 1H NMR chemical shifts of the ring F resonances and orientation of the H3-27 group has been derived for the establishment of 25R- and 25S-stereochemistry in spirostane type of steroidal sapogenins.
The structures of two new monodesmosidic and bisdesmosidic triterpenoid saponins (1 and 2) and the known compound delta 5-stigmasterol-3-O-beta-D-glucopyranoside (3) as well as two new oleanane type triterpene lactone glycosides 4, 5 and a new sapogenin lactone 6 isolated from the stem bark of Albizia gummifera C.A. Smith (Mimosaceae) have been elucidated as 3-O-¿beta-D-glucopyranosyl(1-->2)-[alpha-L-arabinopyranosyl(1-->6) ]-beta-D- glucopyranosyl¿-oleanolic acid (1), beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl 3-O-¿beta-D-glucopyra-nosyl(1-->2)-[alpha-L-arabinopyrano syl(1-->6)]-beta-D- glucopyranosyl¿-oleanolate (2), 3 beta-¿O-D-glucopyranosyl-(1-->2)-[O-alpha-L-arabinopyranosyl(1-->6 )] beta-D-glucopyranosyloxy¿-machaerinic acid gamma-lactone (4), 3 beta-O-beta-D-glucopyranosiduronic acid (1-->2)-beta-D-glucopyranosyloxy]-machaerinic acid gamma-lactone (5), and A-homo-3a-oxa-5 beta-olean-12-en-3-one-28-oic acid (6), respectively. The complete assignment of the 1H and 13C resonances of 1, 2, 4 and 6 and of the peracetate of 5 were achieved by means of 2D-NMR studies.
Four main dammarane-type aglycones of gypenosides, extracted from the aerial parts of Gynostemma pentaphyllum were identified by gas chromatography-mass spectrometry. By detecting these aglycones as well as the aglycones of ginsenosides, a difference in sapogenin composition between Gynostemma pentaphyllum and Panax species was observed, which can be used in the differentiation of these plant drugs.
Seven new compounds, including three new flavans [tupichinol A-C (1-3)], three new spirostanol sapogenins [tupichigenin D-F (4-6)], and one new pregnane genin [tupipregnenolone (7)], together with 18 known compounds, were isolated from the underground parts of Tupistra chinensis. The structures of the new compounds were elucidated by spectroscopic analysis and chemical evidence. The structures and relative stereochemistry of 1 and 9 were further confirmed by single-crystal X-ray crystallographic analysis. Compounds Delta(25(27))-pentrogenin, 10, and ranmogenin A showed 100%, 96%, and 80% inhibition, respectively, against human gastric tumor (NUGC) cells at a concentration of 50 microM. Delta(25(27))-pentrogenin showed 100% inhibition against human nasopharyngeal carcinoma (HONE-1) cells at a concentration of 50 microM.
Four new sapogenins, porrigenins A (2a) and B (3a), identified as (25R)-5 alpha-spirostan-2 beta,3 beta,6 beta-triol and (25R)-2-oxo-5 alpha-spirostan-3 beta,6 beta-diol, respectively, and neoporrigenins A (2b) and B (3b) were also isolated from Allium porrum. In addition, the known agigenin (1a) and its 25S epimer, neoagigenin (1b), were also identified. Their structure elucidation was provided by comprehensive spectroscopic analyses. Compounds 1a, 2a, and 3a exhibited cytotoxicity and high antiproliferative activity on four different tumor cell lines in vitro.
Five new triterpenoid saponins, named saponariosides I-M, were isolated from the whole plants of Saponario officinalis. Their structures were established as saponarioside I (1) 3-O-beta-D-xylopyranosyl-16 alpha-hydroxygypsogenic acid 28-O-alpha-D-galactopyranosyl-(1-->6)-beta-D- glucopyranosyl-(1-->3)[-beta-D-glucopyranoside[, saponarioside J (3) 3-O-beta-D-xylopyranosylolean-11,13(18)-diene-23,28-dioic acid 28-O-beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranosyl-(1-->6)[- beta-D-glucopyranoside[, saponarioside K (4) 3,4-seco-16 alpha-hydroxygypsogenic acid 28-O-beta-D-glucopyranosyl- (1-->3)-beta-D-glucopyranosyl-(1-->6)[-beta-D-glucopyranoside[, saponarioside L (5) 3-O-beta-D-xylopyranosylgypsogenic acid 28-O-beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranosyl-(1-->6)[-beta- D- glucopyranoside[, and saponarioside M (6) 3-O-beta-D-glucopyrano-sylgypsogenic acid 28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1--6)-beta-D- glucopyranoside[ by NMR studies and chemical degradations. The aglycons of saponariosides J (3) and K (4) are new sapogenins.
A simple transformation of the eight-carbon side chain of a natural spirostan sapogenin into the cephalostatin north 1 spiroketal moiety is described. This methodology, based on an intramolecular hydrogen abstraction reaction promoted by alkoxy radicals, permits the synthesis of C-22 and C-25 stereoisomers of the dioxaspiro[4.4]nonane cephalostatin ring system. The acid-catalyzed isomerization of the spirocenter in the different isomers is studied. [reaction: see text]
Sixteen lambs exhibiting hepatogenous photosensitization (alveld) after grazing pasture containing Narthecium ossifragum and seven nonphotosensitized lambs grazing the same pastures were studied. All the alveld-affected lambs revealed liver damage dominated by single cell necrosis, portal fibroplasia and bile duct proliferation. Crystalloid clefts were demonstrated in the bile ducts of two and in the hepatocytes and Kupffer cells of nine photosensitized lambs. Plasma bilirubin concentration was severely increased in ten of the cases of alveld whereas the activity of aspartate aminotransferase was moderately to severely increased in seven cases. The activity of glutamate dehydrogenase was moderately elevated in one of the photosensitized lambs. The main histopathological findings in the kidneys from the alveld-affected lambs were dilated tubules, often with eosinophilic material in the tubular lumina. Regenerative changes were seen in a large proportion of the renal sections. Elevated plasma concentrations of urea and creatinine, and the renal histopathological changes, suggested that the photosensitized lambs had been through a phase of renal injury. Analysis of the free and conjugated sapogenin content in liver tissue and bile was performed by gas chromatography-mass spectrometry. There were significantly higher concentrations of conjugated episapogenins in both the liver and bile in the alveld-affected lambs than in the nonphotosensitized lambs.
The effects of diosgenin (3beta-hydroxy-5-spirostene), a plant-derived sapogenin, on ion currents in human cortical neurons (HCN-1A) were investigated. In the whole-cell configuration, diosgenin (0. -30 microM) increased the amplitude of K+ outward current (I(K)). Diosgenin-stimulated I(K) was sensitive to inhibition by paxilline (1 microM), but not by apamin (200 nM) or glibenclamide (10 muM). In the cell-attached configuration, diosgenin applied to the bath increased the activity of large-conductance Ca2+-activated K+ (BK(Ca)) channels without altering single-channel conductance. Diosgenin enhanced BK(Ca)-channel activity with an EC50 value of 25 microM. However, in inside-out patches, diosgenin applied to the intracellular surface had no effect on BK(Ca)-channel activity, while cilostazol or caffeic acid phenethyl ester increased it. As shown with the aid of intracellular Ca2+ measurements, diosgenin elevated intracellular Ca2+ in HCN-1A cells. Western blotting also revealed the presence of the alpha-subunit of BK (Ca) channels in these cells. The sustained stimulation of I(K) arises primarily from the diosgenin-induced Ca2+ influx across the cell membrane. The effect of diosgenin on these channels may affect the functional activity of cortical neurons. Abbreviations. I(K):K+ outward current I(K(Ca)):Ca2+-activated K+ current BK(Ca) channel:Large-conductance Ca2+-activated K+ channel CAPE:caffeic acid phenethyl ester [Ca2+] (i):intracellular Ca2+ concentration I/V relationship:current/voltage relationship K (ATP) channel:ATP-sensitive K+ channel K(Ca) channel:Ca2+-activated K+ channel.
Chikusetsusaponin IV and V, whose genin is oleanolic acid, exhibited weak hemolytic activities. Removal of glucose residue at position 29 of chikusetsusaponin V by partial hydrolysis increased the activity more than 30-fold. Methylation of the carboxyl group at position 28 increased the activity furthermore by about 10-fold, showing HD50 value of 3.77 microM. On the other hand, removal of the sugar chain at position 3 of chickusetsusaponin V by partial hydrolysis completely lost the activity. These facts suggest that the sugar chain at position 3 of oleanolic acid is essential but that at position 29 is pernicious for the activity. The cytolytic agents, whose target has been regarded as membrane cholesterol, were inactivated not only by cholesterol but also by sapogenins such as oleanolic acid, gitogenin and hederagenin. Among saponins tested, akebia saponin B and C were inactivated by cholesterol, but not by the genins, probably because their affinities for the genins are too low to form complexes.
Incubation of ginseng sapogenins with microsomes from rat liver resulted in formation of their 20,24-epoxides as major metabolites. Identification of the metabolites was performed by HPLC, FAB-MS and EI-MS.
Supplementation of dairy rations with steroidal sapogenins was evaluated in an in vitro, an in situ, and a production trial. Sixteen in vitro semicontinuous rumen cultures were supplied a 55:45 concentrate to roughage substrate with Sarsaponin concentrations of 0, 33, 55, and 77 ppm of air-dry feed for 22 d. Supplementation decreased protozoa numbers and increased bacterial numbers and acid detergent fiber digestion. Digestion of feed nitrogen tended to be lowest at the highest concentration of Sarsaponin, whereas microbial nitrogen output was similar for all concentrations. In rumen-cannulated animals fed a typical dairy ration, in situ rate of disappearance of organic matter, acid detergent fiber, and nitrogen of a complete ration substrate tended to be lower with 77 ppm added Sarsaponin. In a production trial, 16 primiparous dairy cows 6 to 10 wk postpartum were fed rations containing either 0 or 77 ppm Sarsaponin. Sarsaponin did not alter dry matter intake, digestibility, body weight change, or milk production and composition. Supplementation had no significant effect on ruminal fermentation in vivo as reflected by concentrations of ruminal ammonia nitrogen, blood urea, or molar ratios and concentrations of ruminal volatile fatty acids.