Me2CO Extract Research Articles

Terpenoids isolated from Viburnum ternatum

Four iridoids (1-4), five iridoid glucosides (5-9), and three triterpenoids (10-12) were isolated from the ethyl acetate soluble fraction of 70% Me2CO extract of the aerial parts of Viburnum ternatum through various column chromatographies over silica gel, ODS, Sephadex LH-20 and MCI. Their structures were elucidated as ternatumin A (1), 2,9-dioxatricyclo[4.3.1.03，7]decanes (2), 7,10,2'-triacetylsuspensolide F (3), 7,10,2',3'-tetraacetylsuspensolide F (4), viburtinoside IV (5), viburtinoside II (6), viburtinoside B (7), luzonoside A (8), luzonoside B (9), 2α,3β,24-trihydroxy-12-ursen-28-oic acid (10), 6-hydroxy-20(29)-lupen-3-one (11), and pomalic acid (12) based on the their chromatographic properties, chemical and physicochemical methods, and spectroscopic data. Compound 1 was a new compound and compounds 3-12 were isolated from this plant for the first time. Furthermore, we note here the first isolation of compound 2 as a new natural product.

In vitro antimicrobial activity of extracts and compounds isolated from Cladonia uncialis

Heptane (Hep), diethyl ether (Et2O), acetone (Me2CO) and methanolic (MeOH) extracts, as well as ( − )-usnic acid and squamatic acid, were obtained from thallus of Cladonia uncialis (Cladoniaceae). The antimicrobial activities of these extracts, ( − )-usnic acid and squamatic acid, were tested against reference strains: Staphylococcus aureus, Escherichia coli and Candida albicans. In addition, Me2CO extract was analysed against 10 strains of Methicillin-resistant S. aureus (MRSA) isolated from patients. All extracts exerted antibacterial activity against the reference strain S. aureus, comparably to chloramphenicol [minimum inhibitory concentration (MIC) = 5.0 μg/mL]. The Me2CO extract exhibited the strongest activity against S. aureus (MIC = 0.5 μg/mL), higher than ( − )-usnic acid, whereas squamatic acid proved inactive. The Me2CO extract showed potent antimicrobial activity against MRSA (MIC 2.5–7.5 μg/mL). Also no activity of C. uncialis extracts against E. coli and C. albicans was observed.

Inhibition of matrix metalloproteinase-1 and type-I procollagen expression by phenolic compounds isolated from the leaves of Quercus mongolica in ultraviolet-irradiated human fibroblast cells

The aim of this study was to investigate the effect of Quercus mongolica (QM) which induce anti-photoaging process of skin in vitro. Bioassay-guided isolation of 80% Me2CO extract of the leaves of QM led to the isolation and identification of six known phenolic compounds: pedunculagin (1), (-)-epigallocatechin (2), (+)-catechin (3), quercetin 3-O-(6″-O-galloyl)-β-D-glucopyranoside (4), kaempferol-3-O-β-D-glucopyranoside-7-O-α-L-rhamnopyranoside (5) and kaempferol 3-O-(6″-galloyl)-β-D-glucopyranoside (6). The effects of compounds 1-6 on expression of matrix metalloproteinase-1 (MMP-1) and type-I procollagen were further evaluated. Among them, compound 1 showed potent inhibitory effect on MMP-1 and the increased type-I procollagen synthesis in ultraviolet B-induced human fibroblast. These results suggest that pedunculagin, an ellagitannin, is a potential candidate for the prevention and treatment of skin aging.

Inhibition of Inducible Nitric Oxide Synthase and Cyclooxygenase‐2 Expression by Phenolic Compounds from Roots of Rhododendron mucronulatum

The roots of Rhododendron mucronulatum Turzaninov have been used in Oriental traditional medicine for the treatment of dysuria, fever, increase of digestive activity and tonics in China and Korea. Activity guided isolation of the roots of Rhododendron mucronulatum Turzaninov has led to the isolation of three flavonoids, one flavan 3-ol and one proanthocyanidin. Chemical investigation of the 80% Me2 CO extract from the roots of Rhododendron mucronulatum led to the isolation and identification of five compounds: taxifolin (1), taxifolin 3-O-β-D-glucopyranoside (2), quercetin 3-O-α-L-arabinofuranoside (3), (-)-epicatechin (4), procyanidin B-3 (5). To investigate the antioxidative and antiinflammatory effects of these compounds, their 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities and the protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in LPS-stimulated HaCaT cells were also quantified by western blotting and their end products, nitric oxide (NO) and prostaglandin E2 (PGE2 ), respectively. Compounds (1-5) showed potent DPPH radical scavenging compared with positive controls (L-ascorbic acid). Also, compounds 1 and 2 dose-dependently inhibited the expressions of inflammatory mediators, NO and PGE2 , suggesting they are promising candidates as antiinflammatory agents.

Sterenin A, B, C and D, Novel 11β-Hydroxysteroid Dehydrogenase Type 1 Inhibitors from Stereum sp. SANK 21205

The novel 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) inhibitors known as sterenin A, B, C and D were found in a solid-state culture of the producing basidiomycetes identified as Stereum sp. SANK 21205. Purification of the 50% aq Me(2)CO extract of the culture was performed by EtOAc extraction, reversed phase open-column chromatography and successive ODS HPLC preparation. These compounds, whose structures were determined by several spectroscopic methods, were found to be novel isoindolinone alkaloids which exhibited potent selective inhibitory activities against 11beta-HSD1.

A New Sesquiterpene-Coumarin Ether and a New Abietane Diterpene and their Effects as Inhibitors of P-Glycoprotein

A new sesquiterpene-coumarin ether (5'beta,9'alpha,10'alpha)-7-0-(3alpha-methoxy-8'(12')-drimen-11'-yl)-scopoletin, designated driportlandin (1) and a new abietane quinoid diterpene 16-hydroxy-abieta-8,12-diene-11,14-dione, named portlanquinol (2) together with lupeol, nepehinol, wrightial, formonetin and davidigenin were isolated and characterized from the Me2CO extract of whole dried plant of Euphorbia portlandica. The structures of the new compounds were elucidated from spectral data including 2D-NMR experiments of COSY, HMQC, HMBC and NOESY. When examined for their effects on the reversal of multidrug resistance(MDR) on mouse lymphoma cells, compound 1 proved to be more active than the positive control verapamil and compound 2 was found to be toxic. This is the first report on the isolation of a sesquiterpene-coumarin and a quinoid-type diterpenoid from Euphorbia.

Diterpene polyesters from euphorbia seguieriana

An Me2CO extract of Euphorbia seguieriana (Euphorbiaceae) afforded seven new diterpene polyesters (1-7). Five of them (1-5), having a new parent alcohol that was named 17-hydroxymyrsinol, were structurally related to myrsinol. The other two compounds (6, 7) were new derivatives of the known parent alcohols cyclomyrsinol and lathyrane. The structure elucidations of the new compounds by highfield spectroscopic methods, including 1D and 2D NMR techniques, are described.

Norepinephrine-augmenting lipolytic effectors from Astilbe thunbergii rhizomes.

An EtOAc-soluble fraction from a 80% Me2CO extract of the rhizomes of Astilbe thunbergii enhanced norepinephrine-induced lipolysis in rat fat cells, while an EtOAc-insoluble fraction had no effect. The active substances isolated from the EtOAc-soluble fraction of the rhizomes were identified as eucryphin (1), bergenin (2), and astilbin (3), which enhanced norepinephrine-induced lipolysis at concentrations of 10-1000 microgram/mL, while they themselves did not cause lipolysis. Furthermore, these compounds slightly stimulated adrenocorticotrophic hormone-induced lipolysis and inhibited insulin-induced lipogenesis from glucose.

Two 6-substituted 5,6-dihydropyran-2-ones from piper reticulatum

The Me2CO extract of the aerial parts of Piper reticulatum yielded two 6-substituted 5,6-dihydropyran-2-ones 1 and 2 and dihydrowisanidine. The structures of 1 and 2 were elucidated by spectroscopic methods.

Neoclerodane Diterpenoids from Scutellaria polyodon

Nine new neoclerodane diterpenoids, scupolins A−I, have been isolated from an Me2CO extract of the aerial parts of Scutellaria polyodon (3−11), together with the known neoclerodanes jodrellin B (1) and scutecolumnin A (2). Structures 3−11 were established by spectroscopic means and by comparison with closely related compounds.

Dendrinolide, a New Degraded Diterpenoid from the Antarctic Sponge Dendrilla membranosa

A new glacian diterpenoid, named dendrinolide (5), was isolated, together with the 9,11-dihydrogracilin A (1), from the Me2CO extract of the Antarctic sponge Dendrilla membranosa. Its structure has been elucidated by interpretation of spectral data and comparison with the similar product 6, previously found in the Mediterranean sponge Spongionella gracilis.

Neoclerodane Diterpenoids from Scutellaria pontica

Seven novel neoclerodane diterpenoids, scupontins A−G, have been isolated from the Me2CO extract of the aerial parts of Scutellaria pontica (1−7), together with the known neoclerodanes scutalbin A and scutalpin M. Structures 1−7 were established by exhaustive NMR spectroscopic studies and chemical transformations. Scupontins A−D (1−4, respectively) and scupontins E (5) and F (6) possess unusual [(3‘S,3‘‘S)-3‘-[(3‘‘-acetoxybutyryl)oxy]butyryloxy and [(3‘S,3‘‘S,3‘‘‘S)-3‘-[[3‘‘-[(3‘‘‘-hydroxybutyryl)oxy]butyryl]oxy]butyryl]oxy substituents, respectively, attached to the C-19 position of the neoclerodane framework. In the case of the 6α,7β-dibenzoate derivative 7 (scupontin G) its absolute configuration was established by the CD exciton chirality method.

Characterization of silkworm chlorophyll metabolites as an active photosensitizer for photodynamic therapy.

Silkworm excreta containing chlorophyll metabolites have long been used for their medicinal activities in the Far East. The major chlorophyll derivative (CpD) fraction in the Me2CO extract from the silkworm excreta exhibits strong photodynamic action on mice and human tumor cells in vitro. The main CpD component was isolated, purified, and subjected to extensive structural and characterization studies to assess its photodynamic therapeutic activity. According to the spectral analyses, the structure of the major unknown CpD was determined to be 10-hydroxypheophytin a [1]. The CpD component possessed a high quantum efficiency (50%) for the photosensitized production of singlet molecular oxygen, thus providing a molecular basis for its photodynamic therapeutic efficiency. A further advantage is that the "photooxidation/degradation" product(s) from this CpD retains all the characteristics of a photodynamic sensitizer.