Roots Of Bupleurum Falcatum Research Articles

Structural characterisation of an anti-complementary pectic polysaccharide from the roots of Bupleurum falcatum L.

An anti-complementary pectic polysaccharide (BR-2-IIb), isolated from the roots of Bupleurum falcatum L., has an average molecular weight of 36,000 (gel filtration), and was subjected to methylation analysis before and after carboxyl-reduction, digestion with endo-polygalacturonase, base-catalysed β-elimination, and partial acid hydrolysis. BR-2-IIb consisted mainly of galacturonic acid, arabinose, rhamnose, and galactose in the molar ratios 13.0:2.1:1.4:1.0 and contained a large enzyme-sensitive polygalacturonan region. The enzyme-resistant region (PG-1) was rich in neutral sugars and contained a backbone of 4-linked GalA and 2-linked Rha to which a highly branched arabinogalactan was attached to position 4 of some 2-linked Rha units. Partial acid hydrolysis of BR-2-IIb gave Ara-(1→3)-Ara, Ara-(1→4)-Ara p, Ara-(1→5)-Ara f, Ara-(1→6)-Gal, Gal-(1→4)-Gal, GalA-(1→2)-Rha, GalA-(1→4)-Rha, GalA→Rha→Rha, Gal→Rha→Rha, and GalA-(1→6)-Gal in addition to (1→4)linked oligogalacturonides. The anti-complementary activity of BR-2-IIb was enhanced by de-esterification, but carboxyl-reduction decreased the activity.

Corticosterone secretion-inducing activity of saikosaponin metabolites formed in the alimentary tract.

The corticosterone secretion-inducing activities of saikosaponin a, saikosaponin c and saikosaponin d, isolated from the root of Bupleurum falcatum L., and 27 metabolites formed in the murine alimentary tract were studied in mice. Serum corticosterone was determined by high-performance liquid chromatography (HPLC). Intraperitoneal administration of saikosaponin a and its intestinal metabolite, prosaikogenin F, showed corticosterone secretion-inducing activity at a dose of 0.1 mmol/kg, and maximally increased it at a dose of 0.4 mmol/kg. On the other hand, the genuine sapogenin, saikogenin F, was inactive. Saikosaponin b1 and saikosaponin g, gastric metabolites of saikosaponin a, and their intestinal metabolites, prosaikogenin A, prosaikogenin H, saikogenin A and saikogenin H, were also inactive. Serum corticosterone was increased by the administration of saikosaponin d and its intestinal metabolite, prosaikogenin G, at a dose of 0.04 mmol/kg, and it reached the maximal level at the dose of 0.1 mmol/kg. Saikogenin G also showed a slight activity. A gastric metabolite of saikosaponin d, saikosaponin b2, and its intestinal metabolites, prosaikogenin D and saikogenin D, were inactive. In the experiments on saikosaponin c and its metabolites, saikosaponin c was inactive but its intestinal metabolites, especially prosaikogenin E-2, showed activity almost equal to that of saikosaponin a. Saikosaponin h and saikosaponin i, gastric metabolites of saikosaponin c, were also inactive, but their prosaikogenins showed slight activities. When these compounds were orally administered, their corticosterone secretion-inducing activities were similar to those obtained in the intraperitoneal experiment. These results suggest that a proper polar balance between the sugar moiety and the aglycone is important for the corticosterone secretion-inducing activity of saikosaponins and their metabolites.

Characterization of anti-complementary neutral polysaccharides from the roots of Bupleurum falcatum

The anti-complementary neutral polysaccharide, BR-5-I, was purified from the roots of Bupleurum falcatum. It seemed to be a homogeneous polymer from the results of gel filtration, HPLC and electrophoresis. BR-5-I mainly consists of l-arabinose and d-glucose in a molar ratio of 9:10. Its M r was estimated to be 18 500 by gel filtration. From the results of methylation analysis, Smith degradation and NMR studies, it appeared that BR-5-I contained a three-branched (1→5)linked α- l-arabinan moiety and a (1→4)linked α- d-glucan moiety. When BR-5-I was treated with exo-α- l-arabinofuranosidase, a glucan-rich polymer was obtained, but when it was treated with β- and α-amylase, an arabinan-rich polymer was obtained. Both polymers showed reduced anti-complementary activities and had the same M r as BR-5-I. BR-5-I was, however, separated into Con-A unbound arabinan and Con-A bound glucan containing arabinose and glucan by affinity chromatography on Con-A Sepharose. These results indicated that BR-5-I was a mixture of highly 3-branched (1→5)linked α- l-arabinan, (1→4)linked α- d-glucan containing arabinose, and (1→4)linked α- d-glucan. Surprisingly, these polymers have almost the same M r and same electrophoretic mobility. All the polysaccharides showed potent anti-complementary activity but the α- l-arabinan showed the highest activity.

Effects of saikosaponin-d on aminonucleoside nephrosis in rats

The effects of saikosaponin-d extracted from the roots of Bupleurum falcatum L. on aminonucleoside nephrosis were studied in rats. Urine protein excretion in rats receiving aminonucleoside alone was significantly elevated on the 2nd day after the last injection of aminonucleoside and reached a peak on the 11th day. Urinary protein on the 11th day was reduced by 48 and 46%, respectively in animals treated with saikosaponin-d from the 2nd and 8th day after the last injection of aminonucleoside. Electron microscopically, the degree of abnormality, e.g. loss or fusion of foot processes, in the glomerular epitherial cells was significantly lower in the rats treated with saikosaponin-d after aminonucleoside injection than in the rats treated with aminonucleoside alone. It is concluded that saikosaponin-d prevents the development of proteinuria induced by aminonucleoside in the rat.

Histochemistry : IX. Distribution of saikosaponins in bupleurum falcatum root

The root of Bupleurum falcatum cultivated in Japan was examined by histological and chemical means in order to clarify the distribution of saikosaponins in the various kinds of tissues and parts of the root. By means of qualitative thin-layer chromatographic—densitometric and quantitative high-performance liquid chromatographic analyses, saikosaponins, bioactive principles in the root, were found to be abundant in the outer phloem layer, especially the pericycle and its neighbouring parenchyma cells in the root. It was also found that the highest level of saikosaponins was detected in thinner root hairs and that the level decreased towards the thicker root head.

Effects of saikosaponin-d on enhanced CCl4-hepatotoxicity by phenobarbitone.

The effects of saikosaponin-d extracted from the roots of Buplerum falcatum L. on increased toxicity of CCl4 and increased activities of microsomal enzymes induced by phenobarbitone have been examined. Saikosaponin-d showed protection against the CCl4-hepatotoxicity enhanced by phenobarbitone. It also inhibited increases in the content of cytochrome P450 and NADPH-cytochrome c reductase activity, which are induced by the phenobarbitone treatment, but the spectral characteristics of P450 were not altered. The rate of microsomal lipid peroxidation by NADPH and CCl4 was significantly lowered in-vitro in rats pretreated with phenobarbitone and saikosaponin-d compared with those pretreated with phenobarbitone alone.

Protective effect of saikosaponin-d isolated from Bupleurum falcatum L. on CCl4-induced liver injury in the rat.

The effects of saikosaponin-d extracted from the roots of Bupleurum falcatum L. on carbon tetrachloride-induced hepatic injury were studied in rats. Pretreatment with saikosaponin-d produced a remarkable inhibitory action on acute hepatic injury by CCl4. A significant inhibition of lipid peroxidation induced by an acute dose of CCl4 in the liver of rats pre-treated with saikosaponin-d was also noted. Continuous injection of CCl4 caused liver cirrhosis in rats but the severity of cirrhosis was reduced in rats treated simultaneously with CCl4 and saikosaponin-d.

Saponins of juk-siho and roots of Bupleurum longeradiatum Turcz.

In connection with our studies on the chemical evaluation of commercial Bupleuri Radix, isolation and identification of saponins of Juk-Siho (a Korean Bupleuri Radix) and roots of Bupleurum longeradiatum, the source plant of this crude drug, were carried out. From Juk-Siho, five saponins 1-5 were isolated. The saponins 1-3 were identified as saikosaponins-a (1), -c (2) and -d (3), respectively, all of which have already been isolated from roots of Bupleurum falcatum. The structures of the new saponins, named chikusaikosides-I (4) and -II (5), were estabished as 3-O-β-xylopyranosyl (1→2)-β-glucopyranosyl-(1→3)-β-fucopyranoside of saikogenin F (6) and 3-O-β-glucopyranosyl (1→6)-(α-rhamnopyranosyl (1→4)-β-glucopyranoside of 6, respectively. From roots of B. longeradiatum, saponins 1-4 were isolated and identified. During the course of the structure study of 4 by 13C-nuclear magnetic resonance (13C-NMR), an anomalous glycosylation shift for the 1, 2-linked glycoside was encountered.

Chemical structures and corticosterone secretion-inducing activities of saikosaponins.

The corticosterone secretion-inducing activities of saikosaponins isolated from the roots of Bupleurum falcatum L., their artifact saponins and genuine genins were examined in rats 30 minutes after administration. Intraperitoneal administration of saikosaponin-a (1) or -d (2) increased the plasma corticosterone level maximally at a dose of 2.5 mg/kg or 1.0mg/kg, respectively. Saikosaponin-c (9) did not increase the plasma corticosterone level at a dose of 100 mg/kg. Saikogenin-F (3) and -G (4), the genuine aglycones of 1 and 2, also increased the plasma corticosterone level but their activities were 1/70 to 1/90, respectively, of those of the corresponding saponins on a molar basis. Saikosaponin-b1 (5) and -b3 (7), artifact saponins derived from 1, showed 1/8 and 1/40 of the activity of 1, respectively. Saikosaponin-b2 (6) and -b4 (8), derived from 2 through the same structural change as in the case of 1, showed 1/50 and 1/30 of the activity of 2, respectively. Oral administration of 2, which was unstable to acid, increased plasma corticosterone to a maximum level at a dose of 50 mg/kg in fed rats but did not in fasted rats.

Stimulation of the pituitary-adrenocortical axis by saikosaponin of Bupleuri radix.

The effects of saikosaponin-a, -c and -d, isolated from the roots of Bupleurum falcatum L., on plasma adrenccotrcotropin (ACTH) and corticosterone concentrations in unanesthetized or pentobarbital-anesthetized rats were determined by radioimmunoassay and by the competitive protein binding method. A single dose of saikosaponin-a (5 mg/kg, i. p.) or -d (2.5 mg/kg, i. p.) significantly increased plasma ACTH and corticosterone levels 30 and 60 min after the treatment, but saikosaponin-c at a dose of 100 mg/kg had no effect. Intraperitoneal administration of saikosaponin-a or -d, but not -c, induced a transient hyperglycemia and a transient hypoinsulinemia. Dexamethasone pretreatment depressed the saponin-induced increase of both corticosterone and glucose. Treatment with hexamethonium partially depressed the saponin-induced responses in plasma corticosterone, but treatment with diphenhydramine did not.

Isolation, Characterization, and Nuclear Magnetic Resonance Spectra of New Saponins from the Roots of Bupleurum falcatum L.

A systematic separation of a saponin fraction of the root of Bupleurum falcatum L. furnished seven new saponins, i.e., five monoacetylsaikosaponins (15-18, 20) and saikosaponins-e (19) and -f (21), besides the known saikosaponins-a, -b2, -b4, -c, and -d. α-Spinasteryl β-D-glucoside (22) was also isolated. The structures of these new saponins were determined by means of carbon-13 nuclear magnetic resonance spectroscopy.

Application of high performance liquid chromatography to the analysis of crude drugs: Separatory determination of saponins of Bupleuri radix.

The optimal conditions for conversion of saikosaponins-a (1) and -d (3), the pharmacologically active major saponins of roots of Bupleurum falcatum, into diene-saponins (saikosaponins-b1 (4) and -b2 (6)) was investigated. By means of high performance liquid chromatography (HPLC) on an octadecylsilylated silica gel column, complete separation and highly sensitive quantitative analysis of these diene-saponins, which exhibit characteristic ultraviolet maxima, were possible, offering a rapid and selective procedure for the determination of 1 and 3 in commercial samples of Bupleuri radix. Some of the crude drugs on the Japanese market were evaluated by this procedure and it was found that the HPLC pattern of "Chiku-Saiko" imported from Korea was different from those of other crude drugs and cultivated B. falcatum, but similar to that of roots of B. longeradiatum, supporting the morphological comparison of Konoshima et al.

The effects of saikosaponins on biological membranes. 1. The relationship between the structures of saikosaponins and haemolytic activity.

The relationship between haemolytic activity and the structure of saikosaponins which were isolated from the root of Bupleurum falcatum L. was investigated. It was confirmed that the bridged 13β, 28–epoxyoleanene system in saikosaponin is important to haemolytic activity and that the axial C16β–OH and C23–OH group are also significant for haemolysis as well as the number of sugar moieties. In addition it was found that haemolysis by saikosaponins is inhibited by the addition of adenine and inosine to the incubation medium.

Separation and Determination of Saponins of Bupleuri Radix by Droplet Counter Current Chromatography (DCC)

Droplet counter–current chromatography (DCC) was applied to separation and determination of saikosaponins a, c and d in Bupleuri Radix, the roots of Bupleurum falcatum L. and its congeners.

Studies on the Germination of Seeds of Bupleurum falcatum L. : I. Influence of the time elapse after seed harvesting and light conditions on the germination

The root of Bupleurum falcatum L., Bupleuri Radix, is so important a crude drug that it is used in almost all the prescriptions of Chinese drugs, being listed in the Japanese pharmacopoeia VIII-2. The quality, however, of the crude drug produced in Japan is excellent and the production is only a little. Hence a large portion is imported from China, an increased domestic production being much required. As yet few fundamental investigations have been made on the cultivation of this plant. The seeds require a long time for germination to take place and the germination itself is unstable and irregular. This is one of the main difficulties in the practical cultivation. The present studies were undertaken with a view to elucidating this characteristics of germination and to establishing the methods of hastening of germination and of storage, being conducted during a period from 1969 to 1973. In part I, the results of experiments, carried out in 1969 and 1970, on the influence of the time elapse after seed harvest and light conditions on the germination are reported. 1. Observations of the seed germination during one year from fresh seed harvest at intervals of one month showed that there was no great difference in germination percentages between plots from fresh seed harvest (M0) to four months after seed harvest (M4), the highest being five months after seed harvest (M5) (Table 1). 2. During a period of six months from M0 to M6, germination percentages were heightened in the presence of light, the seeds being confirmed to be a light germinator. 3. Regarding the mean necessary time (days) for germination, the plot of M0 was the longest (30.74 days), there being no great difference in those from M1 to M5 (26.50-28.93 days) (Table 2). 4. The embryo size of the freshly harvested seeds (M0) was the smallest (embryo rate, 5.10%), attaining to the largest five months after seed harvest (M5, embryo rate, 16.69%) (Table 3). 5. From the foregoing, it has been clearly demonstraied that the characteristits of germination of Bupleurum falcatum L. is due to the after-ripening of the seeds, i.e., the embryo at the time of fresh seed harvest is yet immature and underdeveloped morphologically.

Saponins isolated from Bupleurum falcatum L.; components of saikosaponin b.

The components of the saikosaponins a and b derived from the root of Bupleurum falcatum L. have been re-investigated. Saikosaponin b has been shown to consist of 16α, 23, 28-trihydroxyoleana-11,13(18)-dien-3β-yl D-glucopyranosyl-(1 → 3)-β-D-fucopyranoside (II)(saikosaponin b2) and 16α, 23,28-trihydroxy-11α-methoxy-olean-12-en-3β-yl D-glucopyranosyl-(1 → 3)-β-D-fucopyranoside (V)(saikosaponin b4), and saikosaponin a contains 16β, 23,28-trihydroxy-11α-methoxyolean-12-en-3β-yl D-glucopyranosyl-(1 → 3)-β-D-fucopyrano-side (XXI)(saikosaponin b3) and a small amount of 16β, 23,28-trihydroxyoleana-11,13(18)-dien-3β-yl D-glucopyranosyl-(1 → 3)-β-D-fucopyranoside (XXII)(saikosaponin b1).

Triterpenoids from bupleurum falcatum L.—III : Isolation of genuine sapogenins, Saikogenins E, F and G

The crude saponins from the root of Bupleurum falcatum L. previously yielded, on acid hydrolysis, saikogenins A, B, C and D (triterpenoids having conjugated dienes) together with longispinogenin. Examination of the saponins demonstrates that saikogenins A, B and C are artifacts formed during the acid hydrolysis and that the saponin leading to saikogenin D has already suffered transformation during the functionation of the saponins by the effects of acidic components. Extraction of the plant with alcohol containing pyridine gives the saponins showing no UV absorption due to a heteroannular diene. The newly obtained saponins, on repeated degradations by sodium periodate oxidation and alkaline treatment, afford three new triterpenoids, sakogenins E, F and G, which are shown to be genuine sapogenins corresponding to the previously obtained saikogenins A, B, C and D. The structure of saikogenins E, F and G has been elucidated as 13β,28-epoxyloean-11-ene-3β,16β-diol (Ia), -3β,16β,23-triol (IIa) and -3β,16α,23-triol (IIIa), respectively. Some modifications for the degradation of the saponins are also investigated.

Triterpenoids from bupleurum falcatum L.—I : The structure of saikogenins A, C and D

The saponin from the roots of Bupleurum falcatum L. on acid hydrolysis affords three triterpenes containing a heteroannular diene and an unidentified triterpene fraction which shows a homoannular diene chromophore. The structures of the three heteronnular dienes, saikogenins A, C and D, have been shown to be olean-11,13(18)-diene-3β,16β,23,28-tetrol (Ia), -3β,16β,28-triol (IIa) and -3β,16α,23,28-tetrol (IIIa), respectively.

Triterpenoids from bupleurum falcatum L.—II : Isolation of saikogenin B and longispinogenin

A new triterpenoid triol having a homoannular diene together with the known longispinogenin have been isolated, as minor components, by acid hydrolysis of the saponin from the roots of Bupleurum falcatum L. The new triol, saikogenin B, has been shown to have the structure olean-9(11),12-diene-3β,16β,28-triol. In the course of the structure elucidation, the epimeric 11-OH derivatives of longispinogenin were prepared and the results compared with those described for β-amyrin.

Studies on the Steroidal Components of Domestic Plants. XVIII. Components of the Root of Bupleurum falcatum L. (2).

α-Spinasterol had been isolated previously from the root of Bupleurum falcatum L. Its more-soluble sterol fractions were investigated by fractional crystallization and chromatography on alumina. Besides α-spinasterol three sterols, Δ7-stigmastenol, Δ22-stigmastenol, and stigmasterol, were isolated and identified. Although Δ22-Stigmastenol was already known as synthetic material, this work is the first example of its isolation from plants.