scholarly journals Effective Synthesis of Nucleosides Utilizing O-Acetyl-Glycosyl Chlorides as Glycosyl Donors in the Absence of Catalyst: Mechanism Revision and Application to Silyl-Hilbert-Johnson Reaction

Molecules ◽  
2017 ◽  
Vol 22 (1) ◽  
pp. 84 ◽  
Author(s):  
Chengyuan Liang ◽  
Weihui Ju ◽  
Shunjun Ding ◽  
Han Sun ◽  
Gennian Mao
Keyword(s):  
Effective Synthesis ◽  
Glycosyl Donors

New Effective Synthesis of (N-Acetyl- and N-Stearoyl-2-amino-2-deoxy-β-D-glucopyranosyl)-(1→4)-N-acetylnormuramoyl-L-2-aminobutanoyl-D-isoglutamine, Analogs of GMDP with Immunopotentiating Activity

1998 ◽  
Vol 63 (4) ◽  
pp. 577-589 ◽  
Author(s):  
Miroslav Ledvina ◽  
Daniel Zyka ◽  
Jan Ježek ◽  
Tomáš Trnka ◽  
David Šaman
Keyword(s):  
Protecting Group ◽  
Silver Triflate ◽  
Effective Synthesis ◽  
Methyl Triflate ◽  
Glycosyl Donors

Ethyl 3,4,6-tri-O-benzyl-2-deoxy-2-phthalimido-1-thio-β-D-glucopyranoside (5), prepared by benzylation of ethyl 2-deoxy-2-phthalimido-1-thio-β-D-glucopyranoside (4), was transformed by reaction with bromine into 3,4,6-tri-O-benzyl-2-deoxy-2-phthalimido-β-D-glucopyranosyl bromide (6). Thioglycoside 5 in the presence of methyl triflate and glycosylbromide 6 in the presence of silver triflate were used as glycosyl donors for condensation with benzyl 2-acetamido-3-O-allyl-6-O-benzyl-2-deoxy-α-D-glucopyranoside (7), to give benzyl 2-acetamido-3-O-allyl-6-O-benzyl-4-O-(3,4,6-tri-O-benzyl-2-deoxy-2-phthalimido-β-D-glucopyranosyl)-2-deoxy-α-D-glucopyranoside (8). Its reductive dephthaloylation with NaBH4/AcOH afforded benzyl 2-acetamido-3-O-allyl-4-O-(2-amino-3,4,6-tri-O-benzyl-2-deoxy-β-D-glucopyranosyl)- 6-O-benzyl-2-deoxy-α-D-glucopyranoside (11). Compound 11 was N-acylated to give benzyl 2-acetamido-4-O-(2-acylamino-3,4,6-tri-O-benzyl-2-deoxy-β-D-glucopyranosyl)-3-O-allyl-6-O-benzyl-2-deoxy-α-D-glucopyranosides (12a) or (12b). These compounds were converted into corresponding benzyl 2-acetamido-4-O-(2-acylamino-3,4,6-tri-O-benzyl-2-deoxy-β-D-glucopyranosyl)-6-O-benzyl-3-O-carboxymethyl-2-deoxy-α-D-glucopyranosides which, by condensation with H-L-Abu-D-isoGln(OBzl) followed by hydrogenolysis of protective benzyl groups, furnished glycopeptides 16a and 16b. Intramolecular O→N migration of the allyl protecting group followed by its reduction to the propyl residue by reaction of compound 8 with hydrazine or hydrazinium acetate, to give benzyl 2-acetamido-4-O-(3,4,6-tri-O-benzyl-2-deoxy-2-propylamino-β-D-glucopyranosyl)-6-O-benzyl-2-deoxy-α-D-glucopyranoside (9), is also described.

Molecular evolution of a cytochrome P450 for the synthesis of potential antidepressant (2R,6R)-hydroxynorketamine

2021 ◽  
Author(s):  
Ansgar Bokel ◽  
Michael C. Hutter ◽  
Vlada B. Urlacher
Keyword(s):  
Cytochrome P450 ◽  
Molecular Evolution ◽  
Cytochrome P450 Monooxygenase ◽  
P450 Monooxygenase ◽  
Effective Synthesis

Engineered cytochrome P450 monooxygenase CYP154E1 enables the effective synthesis of the potential antidepressant (2R,6R)-hydroxynorketamine via N-demethylation and regio- and stereoselective hydroxylation of (R)-ketamine.

Cost Effective Synthesis and Fabrication of Phase-Pure Kesterite Cu2-xZn1.3SnS4 P-type Absorber Layer Thin Films by Solvent Based Process Technique for Photovoltaic Solar Energy Applications

2018 ◽  
Vol 7 (4) ◽  
pp. 36
Author(s):  
B. Khadambari ◽  
S. S. Bhattacharya
Keyword(s):  
Solar Energy ◽  
Renewable Energy Sources ◽  
Cost Effective ◽  
Absorber Layer ◽  
Window Layer ◽  
Energy Applications ◽  
Process Technique ◽  
Absorber Material ◽  
Effective Synthesis ◽  
P Type

Solar has become one of the fastest growing renewable energy sources. With the push towards sustainability it is an excellent solution to resolve the issue of our diminishing finite resources. Alternative photovoltaic systems are of much importance to utilize solar energy efficiently. The Cu-chalcopyrite compounds CuInS2 and CuInSe2 and their alloys provide absorber material of high absorption coefficients of the order of 105 cm-1. Cu2ZnSnS4 (CZTS) is more promising material for photovoltaic applications as Zn and Sn are abundant materials of earth’s crust. Further, the preparation of CZTS-ink facilitates the production of flexible solar cells. The device can be designed with Al doped ZnO as the front contact, n-type window layer (e.g. intrinsic ZnO); an n-type thin film buffer layer (e.g. CdS) and a p-type CZTS absorber layer with Molybdenum (Mo) substrate as back contact. In this study, CZTS films were synthesized by a non-vaccum solvent based process technique from a molecular-ink using a non toxic eco-friendly solvent dimethyl sulfoxide (DMSO). The deposited CZTS films were optimized and characterized by XRD, UV-visible spectroscopy and SEM.

Model of Trust Monitoring and Updating Based on Dynamic Weighted Allocation

2019 ◽  
Vol 12 (1) ◽  
pp. 79-85
Author(s):  
Bin Hu ◽  
Yuemin Wu ◽  
Min Sun ◽  
Zheng Bang Liu ◽  
Lin Zhang ◽  
...  
Keyword(s):  
Fuzzy Clustering ◽  
Information Entropy ◽  
Network Environment ◽  
Mathematical Methods ◽  
Efficient Operation ◽  
Open Network ◽  
Dynamic Trust ◽  
Effective Synthesis ◽  
Effectiveness And Efficiency ◽  
And Performance

Backgrounds: In order to guarantee safe and efficient operation interaction in open network environment, a new dynamic trust monitoring and updating model based on behavior context is proposed in this paper. Methods: Setting four behavior attributes such as security, availability, reliability and performance. Then utilizing the fuzzy clustering and information entropy mathematical methods to carry out the effective synthesis on such attributes. Conclusion: The effectiveness and efficiency of the schema are verified by simulation.

scholarly journals An accelerated and effective synthesis of zinc borate from zinc sulfate using sonochemistry

2020 ◽  
Vol 43 (1) ◽  
pp. 7-14
Author(s):  
Ali Can Ersan ◽  
Azmi Seyhun Kipcak ◽  
Meral Yildirim Ozen ◽  
Nurcan Tugrul
Keyword(s):  
Inorganic Compounds ◽  
Zinc Borate ◽  
High Yield ◽  
X Ray Diffraction ◽  
Ultrasonic Probe ◽  
Minimum Particle Size ◽  
Effective Synthesis ◽  
Ft Ir ◽  
Lower Temperature ◽  
Borate Compound

AbstractRecently, sonochemistry has been used for the synthesis of inorganic compounds, such as zinc borates. In this study using zinc sulphate heptahydrate (ZnSO4·7H2O) and boric acid (H3BO3) as starting materials, a zinc borate compound in the form of Zn3B6O12·3.5H2O was synthesized using an ultrasonic probe. Product’s characterization was carried out with using X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR) and Raman spectroscopy. Zinc borate compound’s chemical bond structure was observed with Raman and FTIR. From the XRD results it was seen that Zn3B6O12·3.5H2O can be quickly synthesized upon heating at 80°C and 85°C (55 min) or 90°C (45 min) in very high yield (>90%). The minimum particle size obtained was ~143 μm from the SEM results. Zinc borate compound was synthesized at a lower temperature in less time than other synthesized zinc metal compound in literature.

Glycosyldisulfides: a new class of solution and solid phase glycosyl donors

2001 ◽  
pp. 189-190 ◽  
Author(s):  
Benjamin G. Davis ◽  
Sarah J. Ward ◽  
Phillip M. Rendle
Keyword(s):  
Solid Phase ◽  
New Class ◽  
Glycosyl Donors
Sign in / Sign up

Export Citation Format

Share Document