Recent progress in O-glycosylation methods and its application to natural products synthesis

Toshima, Kazunobu; Tatsuta, Kuniaki

doi:10.1021/cr00020a006

Cited by 1,090 publications

(357 citation statements)

References 22 publications

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“…The only method used for production of the pure amylose with the desired average molecular weight is a phosphorylase-catalyzed enzymatic polymerization [4]. Polysaccharides are theoretically produced by the repeated glycosylations of a glycosyl donor with a glycosyl acceptor to form a glycosidic linkage [5][6][7][8]. To synthesize polysaccharides by such repeated glycosylations, the in vitro approach by enzymatic catalysis has been significantly investigated because enzymes have remarkable catalytic advantages compared with other types of catalysts in terms of the stereo-and regioselectivities [9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Preparation and Applications of Amylose Supramolecules by Means of Phosphorylase-Catalyzed Enzymatic Polymerization

Kadokawa

2012

Polymers

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This paper reviews preparation and applications of amylose supramolecules by means of phosphorylase-catalyzed enzymatic polymerization. When the enzymatic polymerization of α-D-glucose 1-phosphate (G-1-P) as a monomer was carried out in the presence of poly(tetrahydrofuran) (PTHF) of a hydrophobic polyether as a guest polymer, the supramolecule, i.e., an amylose-PTHF inclusion complex, was formed in the process of polymerization. Because the representation of propagation in the polymerization is similar to the way that vines of plants grow twining around rods, this polymerization method for the preparation of amylose-polymer inclusion complexes was proposed to be named -vine-twining polymerization‖. Various hydrophobic polyethers, polyesters, poly(ester-ether), and polycarbonates were also employed as the guest polymer in the vine-twining polymerization to produce the corresponding inclusion complexes. To obtain the inclusion complex from a strongly hydrophobic guest polymer, the parallel enzymatic polymerization system was developed as an advanced extension of the vine-twining polymerization. In addition, it was found that amylose selectively includes one side of the guest polymer from a mixture of two resemblant guest polymers, as well as a specific range in molecular weights of the guest PTHF. Amylose also exhibited selective inclusion behavior toward stereoisomers of poly(lactide)s. Moreover, the preparation of hydrogels through the formation of inclusion complexes of amylose in vine-twining polymerization was achieved.

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Section: Introductionmentioning

confidence: 99%

Preparation and Applications of Amylose Supramolecules by Means of Phosphorylase-Catalyzed Enzymatic Polymerization

Kadokawa

2012

Polymers

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“…Such result completely accords with the former report which indicated BF3·Et2O as the most efficient glycosylation catalyst, providing clean reactions as well as high conversions. 9 Prompted by such exciting outcome, optimization of the reaction condition was further actualized. Clearly, the yield decreased (47.8%) when using CHCl3 as the solvent (entry 5) whereas aprotic solvents such as DMF and MeCN provided deleterious impact as no apparent reacting trace could be monitored (entry 6, 7).…”

Section: Resultsmentioning

confidence: 99%

A Shortcut to the Preparation of Naturally Occurring Arbutin

Xue¹,

Yang²,

Deng³

et al. 2010

Bulletin of the Korean Chemical Society

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Naturally occurring arbutin (4-hydroxyphenyl β-D-glucopyranoside) was initially isolated from medical plants such as bearberry leaves (Arctostaphylos uvae ursi), etc.1 Besides the multiple pharmaceutical applications it owns, arbutin is also well-known as a green, reliable and highly efficient skin-whitening agent, which effectively inhibits human tyrosinase. 2 The preparation of arbutin mainly falls into two pathways: organic synthesis and enzymatic glycosylation. Indeed, since the first chemical approach to arbutin was realized from tetra-O-acetyl-α-bromo-D-glucopyranoside with hydroquinone in the last century, 3 various other strategies have been successively developed. Among which, penta-O-acetyl-β-D-glucopyranoside seems to be the most utilized glyco-donor. 4 More recently, Cepanec et al. reported a simple and efficient synthesis starting from penta-O-acetyl-β-D-glucopyranoside and 4-hydroxyphenylacetate catalyzed via BF 3 ·Et 2 O in a total yield of around 50%.5 Nevertheless, although these glycosylations proceeded smoothly and afforded effectively the final product, there still remain several drawbacks such as incomplete anomeric retention, relatively low total yield and especially, long reaction time (commonly more than 24 h for 2 -3 steps).Microwave irradiation is known as a powerful tool for both enhancing the reaction efficacy and economizing the reaction time. To our surprise, though this methodology has been massively introduced into carbohydrate chemistry, 6 its elongation to the preparation of arbutin is still unreported. Consequently, with a continuing interest on arbutin and its derivatives, 7 we describe here a shortcut to the synthesis of arbutin via microwave irradiation. Experimental SectionSolvents were purified by standard procedures.1 H NMR spectra were recorded on a Bruker DRX500 spectrometer in CDCl3 or D2O solutions. Microwave-assisted syntheses were performed in a Whirlpool VIP273F system. Optical rotations were measured using a SG WZZ-2A polarimeter at room temperature and a 10 cm 1 mL cell. Column chromatography was performed on E. Merck Silica Gel 60 (230 -400 mesh). Analytical thin-layer chromatography was performed on E. Merck aluminum percolated plates of Silica Gel 60F-254 with detection by UV and by spraying with 6 N H2SO4 and heating at 300 o C. High resolution mass spectra (HRMS) were recorded on a KE465 LCT Premier/XE instrument using standard conditions (ESI, 70 eV). Preparation of tetra-O-acetyl-arbutin (2). To a soln. of penta-O-acetyl-β-D-glucopyranoside(200 mg, 0.5 mmol) and hydroquinone (112.4 mg, 1.0 mmol) in MeOH (10 mL), was added dry BF3·Et2O (40.8 µL, 0.2 mmol). This was then transferred to the microwave oven (240 W) for 10 min. After completion of the reaction monitored by TLC, the mixture was evaporated, washed with brine, extracted with CH2Cl2 and dried over MgSO4. The dried organic layer was concentrated, then purified by column chromatography (petroleum ether/EtOAc; 3:1) to give the known 2 8 as a white solid (140.2 mg, 62.1%). TLC Rf = 0.57 (petroleum eth...

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“…During total syntheses of natural products possessing aromatic rings and oxygenated cyclohexanes, we developed a novel methodology to synthesize those structures in short steps with convergency, meaning tandem Michael-Dieckmann cyclization [1][2][3]. Herein, we describe the total syntheses of 1$4 using Micheal-Dieckmann cyclization combined with carbohydrate chemistry [1][2][3][4].…”

Section: The Total Syntheses Of Pyranonaphthoquinone Antibiotics Usinmentioning

confidence: 99%

“…Reduction of 95 with Et 3 SiH to the corresponding aldehyde [100] accompanied the cyclization to the acetal 96. Further reduction to lactone 96 was realized by our newly developed method using CBr 4 and PPh 3 [101,102]. Deacetonation of 97 afforded the diol 98, which, upon treatment with Eschenmoser's reagent [103], underwent introduction of an exo-methylene group to give (À)-tetrodecamycin (68).…”

Section: Article In Pressmentioning

confidence: 99%

Total syntheses of bioactive natural products from carbohydrates

Tatsuta

Hosokawa

2006

Science and Technology of Advanced Materials

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Total syntheses of bioactive natural products recently accomplished in our laboratories are described. They are classified by structures of target molecules and are focused on our original approach to their own structures. The target molecules include nanaomycin, kalafungin, BE-54238B, tetracycline, rosmarinecine, thienamycin, luminacines C 1 and C 2 , tetrodecamycin, cochleamycin A, and tubelactomicin A, which have been synthesized as optically pure form from carbohydrates.

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Recent progress in O-glycosylation methods and its application to natural products synthesis

Cited by 1,090 publications

References 22 publications

Preparation and Applications of Amylose Supramolecules by Means of Phosphorylase-Catalyzed Enzymatic Polymerization

Preparation and Applications of Amylose Supramolecules by Means of Phosphorylase-Catalyzed Enzymatic Polymerization

A Shortcut to the Preparation of Naturally Occurring Arbutin

Total syntheses of bioactive natural products from carbohydrates

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