Structure elucidation of three triterpene glycosides from the trunk of Argania spinosa

Drs. John Elce and Peter Davies, biochemists at Queen's University, Kingston, Ont., are investigating the molecular structure of calpain, an enzyme that has been implicated in the cellular damage that occurs after such events as myocardial infarction and stroke. This damage is precipitated by an imbalance in the regulation of calpain that arises as an indirect result of ischemia. Elce and Davies hope that their research, which involves techniques such as recombinant DNA technology and x-ray crystallography, will lead to the development of a calpain inhibitor that will prevent such damage from occurring and enhance recovery.     

Pregnane glycosides, gymnepregosides A-F from the roots of Gymnema alternifolium

The structural elucidation of six new related polyoxypregnane glycosides, gymnepregosides A (1), B (2), C (3), D (4), E (5) and F (6), together with two known compounds, from the roots of Gymnema alternifolium (Asclepiadaceae) was achieved through on a detailed study of 1H- and 13C-NMR spectral data and chemical means. The results obtained for new compounds, 1-6, show that they are (20S)-pregn-6-ene-3 beta,5 alpha,8 beta,12 beta,14 beta,17 beta,20-heptaol or sarcostin 3-O-glycosides, and all the sugars at C-3 are beta(1-->4)-linked. Some of them possessed benzoyl, cinnamoyl and tigloyl residues as the ester linkages located at C-12 and/or C-20 of the aglycon.     

Action of triterpene glycosides of the dammarane series and their aglycones on lipid membranes

The action of the dammarane triterpene glycosides Rb1 and Rg1 and their aglycones 20(S) protopanaxatriole and 20(S) protopanaxadiole from Korean ginseng on permeability of bilayer lipid membranes formed of monolayers was studied. RgI, protopanaxatriole and protopanaxadiole in concentrations of 3, 0.5 and 30 micrograms/ml respectively formed single ionic channels in the water phase on the membrane side containing cholesterol. The channel conductivity was 5 to 30 pSm in 1 M KCl. The ionic channels were more selective with respect to K+ as compared to Cl-. Rb1 was also able to increase the conductivity of the lipid membranes. However, no jumps in the current characteristics of the single channels were detected. All the substances in high concentrations on one side of the membrane independently of the cholesterol content induced fluctuation of the high amplitude current (from several tens of pSm to several hundreds of nSm).     

Effect of triterpene glycosides on RNA biosynthesis in a yeast cell culture of Saccharomyces carlsbergensis

The effect of triterpen glycosides of cauloside C from Caulophyllum robustum, theasaponine from Thea sinensis ahd stichoposide A from Stichopus japonicus on multiplication and biosynthesis of RNA in the cells of a 7-hour culture of Saccharomyces carlsbergensis was studied. It was shown that cauloside C, theasaponine and stichoposide A in concentrations of 7.5 gamma/ml inhibited multiplication of the yeast cells by 65, 10 and 90 per cent respectively. The summation RNA of the yeast cells is divided into 3 zones on Sephadex G-100. The glycosides induced no pronounced changes in the chromotographic profile of RNA. Biosynthesis of the transport and ribosomal RNA were inhibited to the same extent. Triterpen glycosides inhibited the biosynthesis of RNA at the stage of 14C-uridine in corporation into the nucleotide pool of the yeast cells.     

Medicinal foodstuffs. X. Structures of new triterpene glycosides, gymnemosides-c, -d, -e, and -f, from the leaves of Gymnema sylvestre R. Br.: influence of gymnema glycosides on glucose uptake in rat small intestinal fragments

Following the characterization of gymnemosides-a and -b, new triterpene glycosides, gymnemosides-c, -d, -e, and -f, were isolated from the leaves of Gymnema (G.) sylvestre R. BR. Their chemical structures were elucidated on the basis of chemical and physicochemical evidence as follows: 21-O-benzoyl-28-O-acetylgymnemagenin 3-O-beta-D-glucopyranosiduronic acid (gymnemoside-c), 23-O-[beta-D-xylopyranosyl (1-->6)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl] gymnestrogenin (gymnemoside-d), 23-O-[beta-D-xylopyranosyl (1-->6)-beta-D-glucopyranosyl (1-->6)-beta-D- glucopyranosyl]-28-O-[beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl] 23-hydroxylongispinogenin (gymnemoside-e), 23-O-[beta-D-xylopyranosyl (1-->6)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl]-28-O-[beta-O-glucopyranosyl (1-->6)-beta-D-glucopyranosyl] 3 beta,16 beta,23,28-tetrahydroxyolean-18-ene (gymnemoside-f). The inhibitory effects of gymnemosides-c, -d, -e, and -f and principal triterpene glycosides from G. sylvestre on glucose uptake in rat small intestinal fragments were examined, and gymnemic acids II, III, and IV, gymnemasaponin V, and gymnemoside-f were found to exhibit the inhibitory activity.     

Saponin and sapogenol. XLIX. On the constituents of the roots of Glycyrrhiza inflata Batalin from Xinjiang, China. Characterization of two sweet oleanane-type triterpene oligoglycosides, apioglycyrrhizin and araboglycyrrhizin

Two sweet oleanane-type triterpene oligoglycosides named apioglycyrrhizin and araboglycyrrhizin were isolated from the air-dried roots of Glycyrrhiza inflata Batalin, collected in Xinjiang province (Shinkyo-Kanzo in Japanese), together with glycyrrhizin (3), licorice-saponins A3 (8), G2 (10), and H2 (11) and known flavonoid glycosides. On the basis of chemical and physicochemical evidence, the structures of apioglycyrrhizin and araboglycyrrhizin have been determined to be expressed as 3-O-[beta-D-apiofuranosyl(1-->2)-beta-D- glucuronopyranosyl]glycyrrhetic acid (1) and 3-O-[alpha-L- arabinopyranosyl(1-->2)-beta-D-glucuronopyranosyl]glycyrrhet ic acid (2), respectively. During the course of these studies, it has been found that the hydroxyl groups in the oligosaccharide moiety of the glucuronide saponins may be partially methylated by prolonged treatment with diazomethane in methanol. The sweetness of the saponins hitherto isolated from various Glycyrrhizae Radix has been examined and a structure-sweetness relationship, as compared with glycyrrhizin, has been found.     

Flavonol and chalcone ester glycosides from Bidens andicola

OBJECTIVES: To examine the effect of black race and acute (negative life events) and chronic (lack of social support) psychological stress on the risk of herpes zoster in late life. DESIGN: A population-based, prospective cohort study. SETTING: Central North Carolina. PARTICIPANTS: Duke Established Populations for Epidemiological Studies of the Elderly, a stratified probability sample of community-dwelling persons more than 65 years of age. MEASUREMENTS: Interviewers administered a comprehensive health survey to the participants in 1986-1987 (P1, n = 4162), 1989-1990 (P2, n = 3336), and 1992-1994 (P3, n = 2568). Incident cases of zoster between P1 and P2 and P2 and P3 served as the dependent variable. Hypothesis-testing variables included race, negative life events, and five measures of social support. Control variables included age, sex, education, cancer, chronic diseases, basic ADLs, instrumental ADLs, depression, self-rated health, hospitalization, and cigarette smoking. Statistical analyses employed chi-square tests and proportional hazards model. RESULTS: At baseline, the sample had a mean age of 73.6 years and was 55% black, 45% white, and 65% female. There were 65 cases of zoster between P1 and P2 and 102 cases of zoster between P2 and P3. From P1 to P2, 1.4% of blacks and 3.4% of whites developed zoster (P < .001). From P2 to P3, 2.9% of blacks and 7.5% of whites developed zoster (P < .001). After controlling for the above variables, blacks were significantly less likely to develop zoster (adjusted risk ratio = 0.35; 95% confidence interval (CI), 0.24-0.51; P < .001). Negative life events increased the risk of zoster, but the result was borderline for statistical significance (adjusted RR = 1.38, 95% CI 0.96-1.97; P = .078). No measures of social support were significantly associated with zoster. CONCLUSION: Black race decreased the risk of zoster in late life significantly. Measures of stress were not significantly related to zoster, but study limitations preclude definitive conclusions. Future research should focus on these factors in larger samples and different populations.     

A saponin from the roots of Gypsophila bermejoi

A new saponin was isolated from the methanol extract of the roots of Gypsophila bermejoi and identified by a combination of chemical degradation and spectral methods, which included negative FABMS and extensive 1D and 2D-NMR analysis (DQCOSY, TOCSY, ROESY, HMQC and HMBC), as gypsogenin 28-O-beta-D-glucopyranosyl(1-->2)-[beta-D-glucopyranosyl (1-->6)]-beta-D-glucopyranoside.     

Steroidal glycosides from Allium albopilosum and A. ostrowskianum

Chemical studies of the bulbs of Allium albopilosum and A. ostrowskianum have led to the isolation of two new steroidal saponins and four new cholestane glycosides together with several known compounds. The structures of the new compounds were established by the spectroscopic data, hydrolysis and chemical correlations as (25 R and S)-5 alpha-spirostane-2 alpha,3 beta,6 beta-triol 3-O-(O-beta-D-glucopyranosyl-(1-->2)-O-[3-O-acetyl-beta-D-xylopyranosyl- (1-->3)]-O-beta-D-glucopyranosyl-(1-->4)-beta-D-galactopyranoside), (25R)-2-O-[(S)-3-hydroxy-3-methylglutaroyl]-5 alpha-spirostane-2 alpha, 3 beta, 6 beta-triol 3-O-(O-beta-D-glucopyranosyl-(1-->2)-O-[beta-D-xylopyranosyl-(1-->3)]-O- beta-D-glucopyranosyl-(1-->4)-beta-D-galactopyranoside), (22S)-cholest-5-ene-1 beta,3 beta,16 beta,22-tetraol 1-O-alpha-L-rhamnopyranoside 16-O-(O-alpha-L-rhamnopyranosyl-(1-->3)-beta-D-glucopyranoside), 1 beta,3 beta,16 beta-trihydroxycholest-5-en-22-one 1-O-alpha-L-rhamnopyranoside 16-O-(O-alpha-L-rhamnopyranosyl-(1-->3)-beta-D-glucopyranoside), 1 beta,3 beta,16 beta-trihydroxy-5 alpha-cholestan-22-one 1-O-alpha-L-rhamnopyranoside 16-O-(O-alpha-L-rhamnopyranosyl-(1-->3)-beta-D-glucopyranoside) and (22S)-cholest-5-ene-1 beta,3 beta,16 beta,22-tetraol 16-O-(O-beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranoside).     

Flavonol glycosides and flavonol glucoside gallates from Peltophorum africanum

In this study of interactions occurring within the heart, isolated superfused strips of rabbit atria, containing the sinoatrial (s.a.) node, were subjected to sinusoidal subthreshold current pulses of varied frequencies and intensities. A.C. current from an R.C. oscillator was applied through a Grass stimulation isolation unit, push-pull connection, and non-polarizing (Ag-AgCl-KCl-Tyrode Agar-Agar) electrodes. A Grass polygraph and tachometer were used to record the applied pulses and nodal firing rates; simultaneous magnetic tape recordings were obtained and used for data analysis. Suction electrode recordings and oscilloscope displays were used to determine how the cyclic impulses affected cellular activity. The s.a. nodal rhythm was modified by subthreshold A.C. current applications; when frequencies were low, firing rates of the node were modulated by the A.C. and mean rates were reduced. As frequencies were progressively increased, slow waxings and wanings in heart rate were produced. These periodic fluctuations were not readily correlated with either the A.C. frequency nor the intrinsic nodal rate, but were representative of the difference between the two. As applied current frequency neared the pacemaker's intrinsic rate, a synchronization occurred and the discharges locked in at a specific phase of the applied current alternation. This synchronization maintained during slight further increases in A.C. frequency but above a critical rate this relationship broke down and the waxing and wanings in frequency of pacemaker rate again developed. It was concluded that pacemaker action of the s.a. node is effected by integration of cellular activity through electron coupling.     

Hydroxycinnamoyl ester glycosides and saponins from flowers of Verbascum phlomoides

A new iridoid ester glycoside acylated with p-coumaric acid was isolated from the flowers of Verbascum phlomoides, together with one known one, specioside. Caffeic acid esters, verbascoside and forsythoside B were found as minor constituents. A new saponin was also obtained and identified as desrhamnosylverbascosaponin.     

Saikosaponins from roots of Bupleurum scorzonerifolium

Saikosaponin u and saikosaponin v, were isolated from the roots of Bupleurum scorzonerifolium and these saponins were identified as 3-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl- (1-->3)-beta-D-fucopyranosyl]-3 beta,16 alpha,23,28-tetrahydroxy-olean- 11,13(18)-dien-30-oic acid-30-O-[pentito(1-->1)-beta-D-glucopyranosyl-(6-->)] ester and 3-O-[beta-D-glucopyranosyl-(1-->3)-beta-D-fucopyranosyl]-3 beta,16 alpha,23,28-tetrahydroxy-olean-11,13(18)-dien-30-oic acid-30-O-[pentito(1-->1)-beta-D-glucopyranosyl(6-->)] ester, respectively.     

New taxane diterpenoids from the roots of Taxus mairei

OBJECTIVE: We tested the hypothesis that nitric oxide synthesis by the kidney is increased in children with primary nephrotic syndrome. METHODS: We examined the urinary excretion of nitrite, a stable metabolite of nitric oxide, using the Griess reaction, in children with nephrotic syndrome. RESULTS: In comparison with healthy children, patients with minimal change nephrotic syndrome had increased urinary nitrite excretion regardless of whether the disease was in relapse or remission (p < 0.025). In contrast, urinary nitrite excretion was similar in control subjects and patients with focal segmental glomerulosclerosis or IgA nephropathy. CONCLUSION: These findings indicate that measurement of urinary nitrite excretion may be a useful test to help discriminate between minimal change nephrotic syndrome and focal segmental glomerulosclerosis in children with idiopathic nephrotic syndrome.     

Three phenylethanoid glycosides and an iridoid glycoside from Picrorhiza scrophulariiflora

To identify risk factors associated with death in traumatized children, we prospectively studied 507 consecutive patients (7+/-4 yr) admitted to a level I pediatric trauma center over a 3-yr period. Pediatric Trauma Score (PTS), Glasgow Coma Scale (GCS) score, and Injury Severity Score (ISS) were calculated. Age, injury mechanism, injury pattern, and initial critical care were recorded. Univariate and multivariate analyses were performed for potential risk factors associated with mortality. Receiver operating characteristic curves were used to determine threshold values of variables identified by univariate analysis. Most children suffered from blunt trauma (99.6%), and head trauma was noted in 85%. Median values (range) of GCS scores, PTS, and ISS were 10 (3-15), 7 (-4 to 12), and 16 (3-75), respectively. The mortality rate was 12%. Using multivariate analysis, death was significantly associated with an ISS > or = 25 (odds ratio [OR] 22.2, 95% confidence interval 2.8-174.9), GCS score < or = 7 (OR 4.77, 1.8-12.7), emergency blood transfusion > or = 20 mL/kg (OR 4.3, 2.1-9.1), and PTS < or = 4 (OR 3.7, 1.4-9.7). An ISS > or = 25, GCS score < or = 7, immediate blood transfusion > or = 20 mL/kg, and PTS < or = 4 were significant and independent risk factors of death in an homogenous population of severely injured children. The probability of traumatic death was therefore 0 (95% confidence interval 0-0.0135) in children with no one of these threshold values in the four predictive factors and 0.63 (95% confidence interval 0.47-0.76) in those children with all the threshold values. IMPLICATIONS: Methods used for evaluating outcome of trauma patients have essentially been derived from adult series, and attempts to apply them to children have usually been inaccurate. Univariate and multivariate analyses were performed to identify risk factors associated with death in severely traumatized children, and Receiver operating characteristic curves were used to determine threshold values.     

Steroidal glycosides of the 14,15-seco-18-nor-pregnane series from Cynanchum ascyrifolium

Three new steroidal glycosides named cynascyrosides A-C were isolated from the roots of Cynanchum ascyrifolium. The structures of these compounds were determined on the basis of spectroscopic and chemical evidence as cynajapogenin A 3-O-alpha-D-oleandropyranosyl-(1-->4)-beta-L-cymaropyranosyl -(1-->4)-beta-D- digitoxopyranoside; cynajapogenin A 3-O-beta-D-glucopyranosyl-(1-->4)-alpha-L-cymaropyranosyl- (1-->4)-beta-L-cymaropyranosyl-(1-->4)-beta-L-cymaropyranoside+ ++; cynajapogenin A 3-O-beta-D-glucopyranosyl-(1-->4)-alpha-L-cymaropyranosyl- (1-->4)-beta-D-digitoxopyranosyl-(1-->4)-beta-L-cymaropyranosid e.     

Purification of peroxidase isoenzymes from turnip roots

Simple reproducible procedures for purification of the main soluble (S) and ionically bound (IB) cationic peroxidase isoenzymes from turnip roots were established. The procedures included ammonium sulfate precipitation of the isoenzymes, chromatographic separation of the main isoenzymes using cellulose phosphate columns and purification to homogeneity by hydrophobic interaction chromatography on phenyl Sepharose columns. The specific activity of the phenyl Sepharose purified S and IB isoenzymes were 2760 and 896 units/mg protein with 140 and 4.8 fold increase over the crude extract and 38 and 13% recovery. The pH maxima and K(m) for phenol and H2O2 of purified S and IB were determined.     

Studies on the triterpenoids from roots of Glycyrrhiza squamulosa Franch

A new triterpenoid, squasapogenol (S-11), was isolated from the hydrolytic products of dilute ethanol (10%) extract of the roots of Glycyrrhiza squamulosa Franch, along with four known triterpenoids. The structure of S-11 was elucidated as olean-11,13(18)-diene-3 beta, 22 beta-diol on the basis of chemical and spectroscopic data. The four known compounds were identified as betulinic acid(S-8), methyl ester of macedonic acid(S-9), soyasapogenol B (S-10) and olean-13(18)-ene-22 alpha-Cl-3 beta, 24-diol(S-12).