Biocatalytic Methyl Ether Cleavage: Characterization of the Corrinoid‐Dependent Methyl Transfer System fromDesulfitobacterium hafniense

Nine Saussurea species, S. alberti, S. elegans, S. gnaphalodes, S. involucrata, S. konuroba, S. kuschakewiczii, S. leucophylla, S. schanginiana and S. sordida, and Serratula lyratifolia from the Tien Shan Mountains and adjacent area were chemically characterized for flavonoids. Thirty-one flavonoids and one hydroquinone were isolated from the leaves of these species and identified from mass spectrometric, UV, 1H and 13C NMR spectroscopic data, by characterization of hydrolyzates, and direct TLC and HPLC comparisons with authentic samples as kaempferol 3-O-rutinoside (1), quercetin 3-O-rutinoside (2), isorhamnetin 3-O-rutinoside (3), quercetin 3-O-glucoside (4), quercetin 3-O-galactoside (5), kaempferol 5-O-glucoside (6), kaempferol 7-O-glucoside (7), quercetin 5-O-glucoside (8), quercetin 7-O-glucoside (9), isorhamnetin 5-O-glucoside (10), luteolin (11), hispidulin (12), nepetin (13), selagin 7-methyl ether (14), selagin (15), velutin (16), luteolin 7-methyl ether (17), jaceosidin (18), apigenin 7-O-rutinoside (19), apigenin 7-O-glucoside (20), luteolin 7-O-rutinoside (21), luteolin 7-O-glucoside (22), luteolin 7-O-galactoside (23), luteolin 7-O-glucuronide (24), hispidulin 7-O-glucoside (25), nepetin 7-O-glucoside (26), luteolin 5-O-glucoside (27), isovitexin (28), apigenin 6,8-di-C-glycoside (29), isoorientin (30), luteolin 8-C-glycoside (31), and arbutin (32). The nine surveyed Saussurea species differed in their flavonoid composition. It was shown that the genus is not only morphologically, but also chemically diversified.

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ChemInform Abstract: SELECTIVE ETHER CLEAVAGE IN THE APORPHINE SERIES. CONVERSION OF (S)-BULBOCAPNINE INTO (S)-CORYTUBERINE AND (S)-CORYDINE METHYL ETHER

Chemischer Informationsdienst ◽

10.1002/chin.197705346 ◽

1977 ◽

Vol 8 (5) ◽

pp. no-no

Author(s):

M. GERECKE ◽

R. BORER ◽

A. BROSSI

Keyword(s):

Methyl Ether ◽

Ether Cleavage

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Phytochemical Characterization of an Adaptogenic Preparation from Rhodiola heterodonta

Natural Product Communications ◽

10.1177/1934578x0900400807 ◽

2009 ◽

Vol 4 (8) ◽

pp. 1934578X0900400 ◽

Cited By ~ 1

Author(s):

Mary H. Grace ◽

Gad G. Yousef ◽

Anvar G. Kurmukov ◽

Ilya Raskin ◽

Mary Ann Lila

Keyword(s):

Methyl Ether ◽

Epigallocatechin Gallate ◽

Ethanol Extract ◽

Biologically Active ◽

Etoh Extract ◽

Phytochemical Constituents ◽

First Time ◽

Adaptogenic Activity ◽

Oligomeric Compounds

The phytochemical constituents of a biologically active, standardized, 80% ethanol extract of Rhodiola heterodonta were characterized. The extract was fractionated over a Sephadex LH-20 column to afford two main fractions representing two classes of secondary metabolites: phenylethanoids and proanthocyanidins. This fractionation facilitated the identification and quantification of individual compounds in the fractions and sub-fractions using HPLC, and LC-MS. The major compounds in the phenylethanoid fraction were heterodontoside, tyrosol methyl ether, salidroside, viridoside, mongrhoside, tyrosol, and the cyanogenic glucoside rhodiocyanoside A. These seven compounds comprised 17.4% of the EtOH extract. Proanthocyanidins ranged from oligomers to polymers based on epigallocatechin and gallate units. The main identified oligomeric compounds in the proanthocyanidin fraction were epigallocatechin gallate, epigallocatechin-epigallocatechin-3-O-gallate and 3-O-galloyl-epigallocatechin-epigallocatechin-3-O-gallate, which constituted 1.75% of the ethanol extract. Tyrosol methyl ether, mongrhoside, and the two proanthocyanidin dimers were reported for the first time from this species in this study. Intra-peritoneal injection of the 80% ethanol extract increased survival time of mice under hypoxia by 192%, as an indication of adaptogenic activity.

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Synthesis and surface characterization of well-defined amphiphilic block copolymers composed of polydimethylsiloxane and poly[oligo(ethylene glycol) methacrylate]

RSC Advances ◽

10.1039/c7ra02569f ◽

2017 ◽

Vol 7 (41) ◽

pp. 25199-25207 ◽

Cited By ~ 4

Author(s):

Raita Goseki ◽

Ling Hong ◽

Manabu Inutsuka ◽

Hideaki Yokoyama ◽

Kohzo Ito ◽

...

Keyword(s):

Block Copolymers ◽

Ethylene Glycol ◽

Methyl Ether ◽

Surface Characterization ◽

Diblock Copolymers ◽

Amphiphilic Block Copolymers ◽

Glycol Methacrylate ◽

Glycol Methyl Ether

A series of amphiphilic polydimethylsiloxane-b-poly[tri(ethylene glycol) methyl ether methacrylate] (PDMS-b-PM3) diblock copolymers were prepared with varying PM3 compositions.

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