Biomedical subjects

O Sticher

Publications and source records attributed to O Sticher.

At least 37 records · Page 2Linked to original sources

PubMed2000

Novel extracellular diterpenoids with biological activity from the cyanobacterium Nostoc commune.

Five novel extracellular metabolites with an unprecedented diterpenoid skeleton, 5-[(5-carboxy-2-hydroxy)benzyl]-11-hydroxymethyl-2,5,6,8a, 11-pentamethyldodecahydrocyclopenta naphthalene (1), 5-[(5-carboxy-2-hydroxy)benzyl]-11-formyl-2,5,6,8a, 11-pentamethyl-dodecahydrocyclopenta naphthalene (2), 5-[(5-carboxy-2-hydroxy)benzyl]-11-carboxy-2,5,6,8a, 11-pentamethyl-dodecahydrocyclopenta naphthalene (3), 5-[(5-carboxy-2-hydroxy)benzyl]-11-dihydroxymethyl-2,5,6,8a, 11-pentamethyldodecahydrocyclopenta naphthalene (4), and 5-[(5-carboxy-2-hydroxy)benzyl]-11-acetyl-2,5,6, 8a-tetramethyldodecahydrocyclopenta naphthalene (5), have been isolated from the culture medium of the terrestrial cyanobacterium Nostoc commune by means of bioguided isolation. The molecules were designated as comnostins A-E. The structures were determined by spectroscopic methods, mainly NMR and mass spectrometry. The relative stereochemistry of comnostin A was confirmed by single-crystal X-ray structure analysis. All comnostins showed antibacterial activities. Additionally, cytotoxic and molluscicidal activities were found for comnostin B.

Cyanobacteria↗

PubMed2000

New phloroglucinol derivatives from Hypericum papuanum.

Bioactivity-guided fractionation of the petroleum ether extract of the aerial parts of Hypericum papuanum led to the isolation of five new tricyclic phloroglucinol derivatives. On the basis of extensive 1D and 2D NMR experiments as well as MS studies, their structures were elucidated as the C-3 epimers of 8-hydroxy-4,4, 7-trimethyl-9-(2-methylpropionyl)-3-(1-methylvinyl)-5beta -H-tricyclo[ 5.3.1.0(1,5)]undec-8-ene-10,11-dione (1,2); the C-3 epimers of 8-hydroxy-4,4, 7-trimethyl-9-(2-methylbutyryl)-3-(1-methylvinyl)-5beta-H-++ +tricyclo[5. 3.1.0(1,5)]undec-8-ene-10,11-dione (3, 4), and 8-hydroxy-4,4, 7-trimethyl-9-(2-methylpropionyl)-5beta-H-tricyclo[5.3 .1.0(1, 5)]undec-8-ene-10,11-dione (5), and their corresponding tautomers (1a, 2a, 3a, 4a, 5a). Compounds 1/1a-5/5a were named ialibinones A-E, respectively. Compounds 1/1a-4/4a showed antibacterial activity against Bacillus cereus, Staphylococcus epidermidis, and Micrococcus luteus.

Anti-Bacterial Agents↗

PubMed2000

Quantitative high performance liquid chromatographic analysis of diterpenoids in agni-casti fructus.

Pharmacological data have indicated that part of the dopaminergic activity of Vitex agnus-castus is attributed to the labdan diterpenoids found in the fruits. Therefore an analytical method for the standardization of rotundifuran (1), vitexilactone (2) and 6 beta,7 beta-diacetoxy-13-hydroxy-labda-8,14-diene (3) was developed. Because of the time-consuming and expensive isolation of the diterpenoids, p-cymene was chosen as an internal standard. The concentration of rotundifuran in different extracts and trade samples of the drug varies between 0.04 and 0.30% in the drug and between 1.04 and 2.23% in the extract. The concentration of vitexilactone was generally lower between 0.016 and 0.167% for the drug and between 0.34 and 1.01% for the extract. The determined concentration of 6 beta,7 beta-diacetoxy-13-hydroxy-labda-8,14-diene in the drug was in the range of 0.02 and 0.10% and in the extract in the range of 0.18 and 0.80%. Determination of the factors of correction of p-cymene gave 5.63 for rotundifuran, 2.73 for vitexilactone and 3.74 for 6 beta,7 beta-diacetoxy-13-hydroxy-labda-8,14-diene.

Chromatography, High Pressure Liquid↗

PubMed2000

Radical scavenger activity of phenylethanoid glycosides in FMLP stimulated human polymorphonuclear leukocytes: structure-activity relationships.

Radical scavenger activities of 21 phenylethanoid glycosides, including 15 ester derivatives of caffeic, ferulic, vanillic and syringic acid as well as 6 deacyl derivatives were determined by quantifying their effects on the production of reactive oxygen species (ROS) in a luminol-enhanced chemiluminescence assay with formyl-methionyl-leucyl-phenylalanine (FMLP) stimulated human polymorphonuclear neutrophils (PMNs). All phenylethanoids acylated with phenolic acids showed strong antioxidant activity whereas the deacyl derivatives were more than 30-fold less active. Therefore, the antioxidant activity is mainly related to the number of aromatic methoxy and hydroxy groups and the structure of the acyl moiety (C6-C1 or C6-C3). In contrast, modification of the sugar chain or replacement of hydroxy groups by methoxy groups in the acyl or the phenylethanoid moiety is of minor importance. The position of the acyl moiety is without significance. Free caffeic, ferulic, vanillic and syringic acid are less active compared to the phenylethanoid derivatives. This points to the importance of dissociation and lipophilicity of these acids in a cellular test system.

Free Radical Scavengers↗

PubMed2000

Bioactive coumarin derivatives from the fern Cyclosorus interruptus.

Three new coumarin derivatives, compounds 1-3, three new furanocoumarins, compounds 4-6, and a novel dioxocane derivative, compound 7, were isolated from the fern Cyclosorus interruptus (Willd.) H. Itô. Based on spectrometric and spectroscopic analysis (FAB or El mass spectrometry as well as 1D and 2D NMR experiments) their structures were characterised as 5,7-dihydroxy-6-methyl-4-phenyl-8-(3-phenylpropionyl)-1-benzopyran-2-one (1), 5,7-dihydroxy-6-methyl-4-phenyl-8-(3-phenyl-trans-acryloyl)-1- benzopyran-2-one (2), 5,7-dihydroxy-8-(2-hydroxy-3-phenylpropionyl)-6-methyl-4-phenyl-1- benzopyran-2-one (3), 8-benzyl-5,8-dihydroxy-6-methyl-4-phenylfuro[2,3-h]-1-benzopyran-2,9- dione (4), 8-benzyl-5,8 beta,9 beta-trihydroxy-6-methyl-4-phenyl-8,9-dihydro- furo[2,3-h]-1-benzopyran-2-one (5), 8-benzyl-5,8 beta,9 alpha-trihydroxy-6-methyl-4-phenyl-8,9-dihydro- furo[2,3-h]-1-benzopyran-2-one (6) and 5,11-dihydroxy-6-methyl-4-phenyl-11-(1-phenylmethyl)-7,10-dioxocane [5,6-h]-1-benzopyran-2,12-dione (7). For these compounds we propose the trivial names interruptins A-F. Compounds 1, 5/6 and 7 showed antibacterial activity while compounds 1 and 2 were cytotoxic to a KB cell line.

Anti-Infective Agents↗

PubMed1999

Acylated flavonol glycosides from leaves of Stenochlaena palustris.

From the leaves of Stenochlaena palustris five new O-acylated flavonol glycosides, stenopalustrosides A-E (1-5), have been isolated along with five known compounds, kaempferol 3-O-(3' '-O-E-p-coumaroyl)-(6' '-O-E-feruloyl)-beta-D-glucopyranoside (6), kaempferol 3-O-(3' ',6' '-di-O-E-p-coumaroyl)-beta-D-glucopyranoside (7), kaempferol 3-O-(3' '-O-E-p-coumaroyl)-beta-D-glucopyranoside (8), kaempferol 3-O-(6' '-O-E-p-coumaroyl)-beta-D-glucopyranoside (9); and kaempferol 3-O-beta-D-glucopyranoside (10). The structures of the isolates were elucidated by spectroscopic methods, mainly 1D and 2D NMR. Compounds 1-4 showed significant antibacterial activities against Gram-positive strains. The structural difference between the isolated antibacterial and nonantibacterial compounds is discussed.

Acylation↗

PubMed1999

Iridoid glycosides of Leonurus persicus.

Two new iridoid glucosides, 6-O-acetylajugol (1) and 7, 8-epoxy-8-epi-loganic acid (2), together with five known iridoid glucosides, galiridoside (3), ajugoside (4), 10-deoxygeniposidic acid (5), 7-deoxy-8-epi-loganic acid (6), and 8-O-acetylharpagide (7), have been isolated from the aerial parts of Leonurus persicus. Leucosceptoside A (8), eugenyl beta-rutinoside (9), and kaempferol 3-O-glucoside (10) were also isolated. The structures of 1 and 2 were elucidated by extensive 1D- and 2D-NMR spectroscopy and molecular modeling. The structure of 3 was confirmed by single-crystal X-ray diffraction. Antimicrobial activity of compounds (1-10) was also evaluated against a panel of gram-positive and gram-negative bacteria and two strains of fungi.

Anti-Bacterial Agents↗

PubMed1999

A novel extracellular diterpenoid with antibacterial activity from the cyanobacterium Nostoc commune.

A novel extracellular metabolite with an unprecedented diterpenoid skeleton, 8-[(5-carboxy-2-hydroxy)benzyl]-2-hydroxy-1,1,4a,7, 8-pentamethyl-1,2,3,4,4a,6,7,8,8a,9,10,10a-dodecahydrophenanthrene , has been isolated from the culture medium of the terrestrial cyanobacterium Nostoc commune Vaucher (EAWAG 122b) by means of bioguided isolation. The molecule was designated as noscomin. The structure was determined by spectroscopic methods, mainly NMR and mass spectrometry. Noscomin exhibited antibacterial activity against Bacillus cereus, Staphylococcus epidermidis, and Escherichia coli.

Anti-Bacterial Agents↗

PubMed1999

Phenylethanoid glycosides from Globularia trichosantha.

Five phenylethanoid glycosides, crenatoside (= oraposide) (1), verbascoside (= acteoside) (2), trichosanthoside A (3), rossicaside A (4), and trichosanthoside B (5), were isolated from the aerial parts of Globularia trichosantha. Compounds 3 and 5 are new natural compounds, and their structures were established as 3, 4-dihydroxy-beta-phenylethoxy-O-beta-D-xylopyranosyl-(1-->4)-alpha -L- rhamnopyranosyl-(1-->3)-4-O-caffeoyl-beta-D-glucopyranoside and 3, 4-dihydroxy-beta-phenylethoxy-O-[beta-D-xylopyranosyl-(1-->4)-alph a-L -rhamnopyranosyl-(1-->3)]-[beta-D-xylopyranosyl-(1-->6)]-4-O-caffeoyl -beta-D-glucopyranoside, respectively. The structures of all compounds were established by spectral evidence. Compounds 1-5 also demonstrated scavenging properties toward the 2, 2-diphenyl-1-picrylhydrazyl radical in TLC autographic assays.

Caffeic Acids↗

PubMed1999

Phenylvaleric acid and flavonoid glycosides from Polygonum salicifolium.

(3R)-O-beta-D-Glucopyranosyloxy-5-phenylvaleric acid (1), (3R)-O-beta-D-glucopyranosyloxy-5-phenylvaleric acid n-butyl ester (2), and a new dihydrochalcone diglycoside 4'-O-[beta-D-glucopyranosyl-(1-->6)-glucopyranosyl]oxy-2'-hydroxy-3', 6'-dimethoxydihydrochalcone (3), together with six known flavonoid glycosides [kaempferol-3-O-beta-D-glucopyranoside (= astragalin) (4), kaempferol-3-O-beta-D-galactopyranoside (5), quercetin-3-O-beta-D-glucopyranoside (= isoquercitrin) (6), quercetin-3-O-beta-D-galactopyranoside (= hyperoside) (7), quercetin-3-O-(2''-O-galloyl)-beta-D-glucopyranoside (8), and quercetin-3-O-beta-D-glucuronopyranoside (9)] were isolated from the aerial parts of Polygonum salicifolium. The structure elucidation of the isolated compounds was performed by spectroscopic (UV, IR, ESI-MS, 1D- and 2D-NMR), chemical (methylation, enzymatic hydrolysis, partial synthesis), and chromatographic methods (HPLC, Chiralcel OD). The flavonoid glycosides (4-9) demonstrated scavenging properties toward the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical in TLC autographic assays.

Carbohydrate Sequence↗

PubMed1999

New triterpenoids with antibacterial activity from Zizyphus joazeiro.

The stem bark of the Brazilian medicinal plant Zizyphus joazeiro C. Mart. was phytochemically investigated. Three known compounds (betulinic, ursolic and alphitolic acid) and three new derivatives of betulinic acid, 7 beta-(4-hydroxybenzoyloxy)-betulinic acid, 7 beta-(4-hydroxy-3'-methoxybenzoyloxy)-betulinic acid and 27-(4-hydroxy-3'-methoxybenzoyloxy)-betulinic acid which showed a considerable activity against Gram-positive bacteria were isolated from the dichloromethane extract. The structures were established on the basis of NMR spectroscopy and mass spectrometry.

Anti-Bacterial Agents↗

PubMed1998

Dammarane Triterpenes from the Leaves of Securinega melanthesoides

Two new dammarane triterpenoids, trans-securinegin [(20S)-24-methylidenedammarane-3alpha-yl(2E)-3-(4-hydroxyphenyl)-2-propenate (1)] and cis-securinegin [(20S)-24-methylidenedammarane-3alpha-yl(2Z)-3-(4-hydroxyphenyl)-2-propenate (2)], were isolated from the leaves of Securinega melanthesoides, along with the known compound bergenin. The structures of 1 and 2 were elucidated using spectroscopic methods, mainly 2D NMR techniques.

Journal Article↗

PubMed1998

Triterpene saponins from Scabiosa rotata.

Four new allose-containing triterpenoid saponosides, scabriosides A, B, C and D were isolated from the roots of Scabiosa rotata. Their structures were established as 3-O-beta-D-xylopyranosyl-28-O-[beta-D-allopyranosyl (1-->6)-beta-D-glucopyranosyl]-pomolic acid, 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-xylopyranosyl]-28-O-[beta-D-allopyranosyl (1-->6)-beta-D-glucopyranosyl]-pomolic acid, 3-O-[alpha-L-rhamnopyranosyl (1-->2)-alpha-L-arabinopyranosyl]-28-O-[beta-D-allopyranosyl (1-->6)-beta-D-glucopyranosyl]-pomolic acid, and 3-O-[beta-D-glucopyranosyl (1-->3)-alpha-L-rhamnopyranosyl (1-->2)-beta-D-xylopyranosyl]-28-O-[beta-D-allopyranosyl(1-->6) -beta-D-glucopyranosyl]-pomolic acid, respectively, by the help of spectral evidence (IR, 1D- and 2D-NMR, FAB-MS).

Carbohydrate Conformation↗

PubMed1998

Medicinal plants in Mexico: healers' consensus and cultural importance.

Medicinal plants are an important element of indigenous medical systems in Mexico. These resources are usually regarded as part of a culture's traditional knowledge. This study examines the use of medicinal plants in four indigenous groups of Mexican Indians, Maya, Nahua, Zapotec and - for comparative purposes - Mixe. With the first three the methodology was similar, making a direct comparison of the results possible. In these studies, the relative importance of a medicinal plant within a culture is documented using a quantitative method. For the analysis the uses were grouped into 9-10 categories of indigenous uses. This report compares these data and uses the concept of informant consensus originally developed by Trotter and Logan for analysis. This indicates how homogenous the ethnobotanical information is. Generally the factor is high for gastrointestinal illnesses and for culture bound syndromes. While the species used by the 3 indigenous groups vary, the data indicate that there exist well-defined criteria specific for each culture which lead to the selection of a plant as a medicine. A large number of species are used for gastrointestinal illnesses by two or more of the indigenous groups. At least in this case, the multiple transfer of species and their uses within Mexico seems to be an important reason for the widespread use of a species. Medicinal plants in other categories (e.g. skin diseases) are usually known only in one culture and seem to be part of its traditional knowledge.

Culture↗

PubMed1998

Medical ethnobotany of the Zapotecs of the Isthmus-Sierra (Oaxaca, Mexico): documentation and assessment of indigenous uses.

The Zapotec inhabitants of the Sierra de Oaxaca foothills (Mexico) live in an area of great botanic diversity. In daily subsistence and in response to illness, plants play a major role. An inventory of the Zapotec medicinal ethnobotany was carried out during 17 months of fieldwork. A total of 3611 individual responses concerning medicinal and non-medicinal uses for 445 different species of plants were documented. For the subsequent semi-quantitative analysis of data, the uses were grouped into ten categories and the responses for each species were summed up in each of these ten groups to yield rank-ordered lists. For the high rank-ordered and, hence, culturally important species, an assessment of the therapeutic potential was conducted using ethnobotanical, phytochemical and pharmacological data in the literature. Studies confirming the attributed properties or a scientific explanation of therapeutic use, as well as toxicological data, are still lacking for many of these species. The quantitative approach described will be the basis for future studies on the pharmacology and phytochemistry of Zapotec medicinal species. Finally, these data should also serve as a basis for biodiversity conservation and community development.

Ethnobotany↗

PubMed1998

Gibbilimbols A-D, cytotoxic and antibacterial alkenylphenols from Piper gibbilimbum.

Fractionation of the petroleum ether extract from the leaves of Piper gibbilimbum collected in Papua New Guinea afforded four new alkenylphenols, gibbilimbols A-D (1-4). The structures of the isolates were elucidated by spectroscopic methods, mainly 1D- and 2D-NMR spectroscopy. Gibbilimbols A-D were found to be toxic to brine shrimp with an LC50 of approximately 5 microg/mL. Gibbilimbols A-D were further found to be cytotoxic toward KB nasopharyngal carcinoma cells (ED50 7.8-2.1 microg/mL). All isolates also showed antibacterial activity toward Staphylococcus epidermidis and Bacillus cereus.

Anti-Bacterial Agents↗

PubMed1997

Leonticins D-H, five triterpene saponins from Leontice kiangnanensis.

Five new triterpene saponins, leonticins D-H, were isolated from the tubers of Leontice kiangnanensis. Based on a combination of chemical degradation and spectroscopic analysis (negative ion FAB mass spectrometry and 2D NMR experiments), their structures were characterized as 3-O-alpha-L-arabinopyranosyl-caulophyllogenin 28 -O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->6-beta-D- glucopyranoside, 3-O-[beta-D-glucopyranosyl -(1-->3)]-[beta-D-glucopyranosyl- (1-->2)]-alpha-L-arabinopyranosyl-oleanolic acid 28-O-alpha-L-rhamnopyranosyl- (1-->4)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside, 3-O-[beta-D-glucopyranosyl-(1-->3)]-[beta-D-glucopyranosyl-(1-->2)]-alph a-L -arabinopyranosyl-hederagenin 28-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D- glucopyranosyl-(1-->6)-beta-D-glucopyranoside, 3-O-beta-D-xylopyranosyl- (1-->3)-beta-D-galactopyranosyl-(1-->4)-beta-D- glucopyranosyl-(-->3)-alpha-L-arabinopyranosyl-echinocystic acid 28-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D- glucopyranosyl-(1-->6)-beta-D-glucopyranoside, respectively.

Carbohydrate Conformation↗

PubMed1997

Triterpene saponins from Cyclamen mirabile and their biological activities.

Six saponins, cyclaminorin (1), deglucocyclamin (2), cyclacoumin (3), cyclamin (4), isocyclamin (5), and mirabilin (6) were isolated from the tubers of Cyclamen mirabile. Compound 6 is a new natural compound, and its structure was established as 3-[O-beta-[[beta-D-xylopyranosyl-(1-->2)]- [beta-D-glycopyranosyl-(1-->6)]-beta-D-glucopyranosyl-(1-->4)]-[be ta-D- glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl]-3 beta,16 alpha,28-trihydroxyolean-12-en-30-oic acid (6). The structure elucidation of this compound was accomplished using both spectral and chemical methods. Antimicrobial and uterocontractile activities of the saponins were also investigated.

Acetylcholine↗