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Biomedical subjects

T Schöpke

Publications and source records attributed to T Schöpke.

At least 19 recordsLinked to original sources

Inhibitory effect of Bergenia ligulata on influenza virus A.

Methanol water extract from rhizomes of Bergenia ligulata, a plant used in Nepalese ethnomedicine, inhibited in vitro the replication of influenza virus in a dose dependent manner and did not show virucidal activity at effective concentration. Pretreatment of cells with B. ligulata extract was shown to be most effective to prevent cell destruction. The extract inhibited viral RNA synthesis and reduced viral peptide synthesis at 10 microg/ml. The virus inhibitory effect is related to the presence of condensed tannins in the extract.

Animals↗

Screening of Nepalese medicinal plants for antiviral activity.

In an ethnopharmacological screening, plants used in Nepalese traditional medicine were evaluated for antiviral activity. Methanolic and methanolic-aqueous extracts derived of 23 species were assayed in two in vitro viral systems, influenza virus/MDCK cells and herpes simplex virus/Vero cells. Two species, Bergenia ligulata and Nerium indicum showed the highest antiinfluenzaviral activity with 50% inhibitory dose of 10 microg/ml. Holoptelia integrifolia and N. indicum exhibited considerable antiviral activity against herpes simplex virus. None of these extracts showed cytotoxic effects. Additionally for B. ligulata and H. integrifolia partial protease inhibitory activity was estimated.

Animals↗

Actaeaepoxide 3-O-beta-D-xylopyranoside, a new cycloartane glycoside from the rhizomes of Actaea racemosa (Cimicifuga racemosa).

A new cycloartane glycoside (1) was obtained from a minor triterpene fraction of the rhizome extract of Actaea racemosa (synonym: Cimicifuga racemosa) along with a known compound, cimigenol 3-O-beta-D-xylopyranoside. The structure of 1 was elucidated as 20(S),22(R),23(R),24(S)-12beta-acetoxy-16beta:23,23alpha:24-diepoxy-3beta,22beta,25-trihydroxy-9,19-cyclolanost-7-ene 3-O-beta-D-xylopyranoside (actaeaepoxide 3-O-beta-D-xylopyranoside) on the basis of spectral and chemical evidence.

Chromatography, Gas↗

Effects of saponins on the water solubility of different model compounds.

The influence of saponins on the water solubility of compounds having poor aqueous solubility was investigated with the model compounds digitoxin, rutin and aesculin. The saponins that were tested represent the most abundant structural types. Only slight effects on aqueous solubility were obtained for all the model compounds. These effects include both enhancements and reductions in aqueous solubility depending on the saponin, the concentration of the saponin solution and the model compound. Structure-activity relationships of general significance were not observed. Hence, saponins generally should not be regarded as solubilizers.

Models, Chemical↗

Monodesmosidic saponins from Herniaria hirsuta.

Two new monodesmosidic saponins, herniaria saponins E and F, were isolated from the aerial parts of Herniaria hirsuta. On the basis of chemical and spectral evidence, their structures were established to be 2-O-acetyl medicagenic acid 28-O-beta-D-xylopyranosyl- (1-->4)-alpha-L-rhamnopyranosyl(1-->2)-[beta-D-glucopyranosyl(1-->6)]-be ta- D-glucopyranoside (herniaria saponin E, 1) and medicagenic acid 28-O-beta-D-xylopyranosyl(1-->4)-alpha-L- rhamnopyranosyl(1-->2)-[alpha-L-rhamnopyranosyl-(1-->4)-beta-D- glucopyranosyl-(1-->6)]-beta-D-glucopyranoside (herniaria saponin F, compound 2).

Carbohydrate Sequence↗

Silenosides A-C, triterpenoid saponins from Silene vulgaris.

Three new triterpenoid saponins named silenosides A-C (1-3) were obtained from the roots of Silene vulgaris. Their structures were elucidated by spectral and chemical methods as beta-D-galactopyranosyl(1-->2)-beta-D-glucuronopyranosyl-3beta- hydrox y-23-oxoolean-12-en-28-oic acid 28-O-beta-D-xylopyranosyl(1-->3)-beta-D-xylopyranosyl(1-->4)-alpha-L- rhamnopyranosyl(1-->2)-beta-D-fucopyranoside; 3-O-beta-D-galactopyranosyl(1-->2)-beta-D-glucuronopyranosyl-3beta , 16alpha-dihydroxy-23-oxoolean-12-en-28-oic acid 28-O-beta-D-xylopyranosyl(1-->4)-[beta-D-glucopyranosyl(1-->2)]-alpha -L-rhamnopyranosyl(1-->2)-beta-D-fucopyranoside; and 3-O-alpha-L-arabinopyranosyl(1-->3)-[beta-D-galactopyranosyl(1-->2 )]- beta-D-glucuronopyranosyl-3beta, 16alpha-dihydroxy-23-oxoolean-12-en-28-oic acid 28-O-beta-D-xylopyranosyl(1-->4)-[beta-D-glucopyranosyl(1-->2)]-alpha -L-rhamnopyranosyl(1-->2)-beta-D-fucopyranoside, respectively.

Carbohydrate Sequence↗

Noroleanane saponins from Celmisia spectabilis.

Two new saponins were isolated as the major components of the deacylated saponin extract from the underground parts of Celmisia spectabilis. Their structures were established by NMR and mass spectral data and derivative formation as 2 beta,3 beta,17,23- tetrahydroxy-28-norolean-12-en-16-one-3-O-alpha-L-arabinopyrano syl (1-->2)-alpha-L-arabinopyranosyl(1-->6)-beta-D-glucopyranoside and 2 beta,3 beta,17,23- tetrahydroxy-28-norolean-12-en-16-one-3-O-alpha-L-arabinopyrano syl (1-->2)-alpha-L-arabinopyranosyl(1-->6)-[alpha-L-rhamnopyranosyl (1-->2)]-beta-D-glucopyranoside.

Carbohydrate Conformation↗

Saniculoside R-1: a new triterpenoid saponin from Sanicula europaea.

A new acylated triterpenoid saponin was obtained from the leaves of Sanicula europaea. The structure has been elucidated from NMR and MS data, and by chemical derivatisation as 21-O-[2-methylbutanoyl]-3 beta, 15 alpha, 16 alpha, 21 beta, 22 alpha, 28-hexahydroxyolean-12-ene 3-O-[alpha-L-arabinopyranosyl (1-->3)] beta-D-glucopyranosyl(1-->2)-beta-D-glucuronopyranoside.

Carbohydrate Sequence↗

Triterpenoid saponins from Aster bellidiastrum.

Seven triterpenoid saponins were isolated from both the aerial and the underground parts of Aster bellidiastrum. Five of the compounds were common to both parts. The structures were elucidated mainly from their NMR and mass spectral data, and showed significant similarity to the corresponding data for the saponins from plants of the Bellis genus. Two of the saponins are novel compounds with the structures 3-O-beta-D-xylopyranosyl-2 beta,3 beta, 23-trihydroxyolean-12-en-28-oic acid 28-O-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside and 3-O-beta-D-glucopyranosyl-2 beta,3 beta,16 alpha, 23-tetrahydroxyolean-12-en-28-oic acid 28-O-alpha-L-arabinofuranosyl(1-->3)-[alpha-L-rhamnopyranosyl(1-->2)]-be ta- D-fucopyranoside.

Carbohydrate Sequence↗

Triterpenoid saponins from Bellium bellidioides. Structures of the minor deacylsaponins.

A new deacylsaponin of polygalacic acid, desacylbellidioside B4, was obtained from the whole plants of Bellium bellidioides L. The structure has been elucidated by a general strategy involving mass spectrometry (ESI-MS, including tandem MS, and GC-MS) and high-field one- and two-dimensional NMR spectroscopy (1H and 13C NMR, COSY-45, HMQC, HMBC) as 3-O-alpha-L-rhamnopyranosyl-2 beta, 3 beta, 16 alpha, 23-tetrahydroxyolean-12-en-28-oic acid 28-O-alpha-L-rhamnopyranosyl(1-->3)-beta-D-xylopyranosyl(1-->4)-alpha-L- rhamnopyranosyl(1-->2)-[alpha-L-arabinofuranosyl(1-->3)-beta-D-fucopyran oside. Moreover, bellissaponin BS2 and besysaponin C12 have also been isolated, demonstrating the close chemical relationship of B. bellidioides to the Bellis genus.

Carbohydrate Conformation↗

Triterpenoid saponins from Bellis sylvestris. 2. Structures of partially deacylated saponins.

Four saponins have been isolated from the herbal parts of Bellis sylvestris and the same, together with three further compounds, from the underground parts. The structures were elucidated by electrospray ionization mass spectrometry, including tandem mass spectrometry, and by 1D and 2D homonuclear and heteronuclear NMR spectroscopy. Two of the compounds are new saponins with the structures 3-O-beta-D-glucopyranosyl-2 beta, 3 beta, 23-trihydroxyolean-12-en-28-oic acid 28-O-beta-D-glucopyranosyl (1-->3)-[alpha-L-rhamnopyranosyl (1-->2)]-beta-D- glucopyranoside and 3-O-beta-D-glucopyranosyl-2 beta, 3 beta,16 alpha, 23-tetrahydroxyolean-12-en- 28-oic acid 28-O-alpha-L-rhamnopyranosyl (1-->3)-beta-D-xylopyranosyl(1-->4)-alpha-L- rhamnopyranosyl(1-->2)-[(E)-2-butenoic acid (1-->3)]-beta-D-fucopyranoside. Taxonomically these data provide significant evidence of a link between the Bellis genus and Bellium bellidioides.

Carbohydrate Sequence↗

Triterpenoid saponins from Bellis bernardii.

Nine saponins were isolated from the deacylated saponin mixture obtained from the whole plants of Bellis bernardii. Their structures have been elucidated from NMR and MS data and by chemical derivatization. Three were glycosides of the recently reported bellisonic acid (2 beta, 3 beta,-23-trihydroxy-16-oxoolean-12-en-28-oic acid), with the major compounds being related glycosides of polygalacic acid (2 beta, 3 beta, 16 alpha, 23-tetrahydroxyolean-12-en-28-oic acid). In addition, a saponin of bayogenin (2 beta, 3 beta, 23-trihydroxyolean-12-en-28-oic acid) was obtained and is the first acyl glycoside of this aglycon with a free hydroxyl group at C-3.

Carbohydrate Sequence↗

Application of MS-MS for the rapid, comparative analysis of saponin mixtures as exemplified by the deacylated and partially deacylated triterpenoid saponins of Bellis annua.

While most species of the Bellis genus are characterized by saponins in concentrations of ca.4% dry weight, Bellis annua only contains ca.0.3% saponins. Hence positive-ion electrospray ionization mass spectrometry, including MS-MS analysis, has been used extensively for the rapid identification of the saponins of B. annua obtained after mild alkaline hydrolysis. The saponin composition is similar to that of other Bellis species and, in addition, glycosides of the rare bellisonic acid, which has recently been found in B. bernardii, have been identified.

Carbohydrate Conformation↗

An in vitro perfusion model for the determination of absorption properties of drugs in isolated rat small intestine.

A two-compartment model was developed to perform in vitro permeability studies of drugs. Preparations of surviving small intestine are continuously perfused under permanent oxygenation. The apparatus especially allows the usage of variable volumes of donor and adaptable length of intestinal segments ranging from 3 to 20 cm. Both the mucosal and the serosal side of the apparatus are open for sample collection and additional instrumentation. Due to the construction the use of high-surface activity compounds is possible. Data may be derived as absorption rates (micrograms.cm-1.min-1) and concentration increases vs. time profiles.

Animals↗

Triterpenoid saponins from the aerial parts of Aster bellidiastrum.

Four major triterpenoid saponins were isolated from the aerial parts of Aster bellidiastrum. The structures were elucidated from their NMR and mass spectral data, and from derivatization. One is a new compound with the structure 3-O-beta-D-glucopyranosyl-2 beta,3 beta,16 alpha,23-tetrahydroxyolean-12-en-28- oic acid 28-O-beta-D-xylopyranosyl(1-->4)-alpha-L-rhamnopyranosyl(1-->2)-beta- D-fucopyranoside, while the three others have been previously identified in extracts from various Bellis species.

Carbohydrate Sequence↗

Structure elucidation of a glycoside of 2 beta, 3 beta, 23-trihydroxy-16-oxoolean-12-en-28-oic acid from Bellis bernardii using mass spectrometry for the sugar sequence determination.

The structure of a novel saponin, possessing an unusual aglycone named bellisonic acid and isolated from whole plants of Bellis bernardii, has been elucidated by modern ms and nmr techniques as 3-O-alpha-L-rhamnopyranosyl-2 beta, 3 beta, 23-trihydroxy-16-oxoolean-12-en-28-oic acid 28-alpha-L-rhamnopyranosyl(1-->3)-O-beta-D-xylopyranosyl(1-->4)-alpha-L- rhamnopyranosyl(1-->2)-beta-D-fucopyranoside [1]. Ms procedures of general applicability allowed unambiguous sugar sequence determination from very small amounts of material.

Carbohydrate Conformation↗