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Peptide Structure and Analysis
Published in Marco Chinol, Giovanni Paganelli, Radionuclide Peptide Cancer Therapy, 2016
Carlo Pedone, Giancarlo Morelli, Diego Tesauro, Michele Saviano
The esterification of the first amino acid to the hydroxyl group on the resin is one of the key steps to producing a high quality peptide. The incomplete loading and racemization will cause truncated and epimeric peptides, respectively, as a result of slow esterification reaction. The commonly used loading methods are the 1-hydroxybenzotriazole (HOBt) active ester, symmetrical anhydride, and dichlorobenzoyl chloride procedures. The first amino acid residue can be loaded to trityl-based resins with no racemization.
Novel Developments in Photoprotection: Part II
Published in Henry W. Lim, Herbert Hönigsmann, John L. M. Hawk, Photodermatology, 2007
André Rougier, Sophie Seite, Henry W. Lim
This was first introduced in the European Academy of Dermatology and Venereology meeting in 1998. It is the first broad UV filter against UVA and UVB spectrum (Fig. 4). Mexoryl® XL belongs to the photostable group of the hydroxybenzotriazole. Its structure composes of two different chemical groups: hydroxyphenylbenzotriazol, which provides photostable UVA and UVB absorption, and short siloxan chain, which provides liposolubility of the molecule. Mexoryl® XL has two absorption spectra in UVB and UVA range (290–320 nm, λmax 303 nm and 320–360 nm, λmax 344 nm). By combining the lipophilic Mexoryl® XL with hydrophilic Mexoryl® SX, a high level of photoprotection can be achieved (9). Since 1999, the combination of Mexoryl® SX and Mexoryl® XL has been used in the Anthélios product line of La Roche-Posay.
Enzymatic Syntheses of Biologically Active Peptides
Published in Willi Kullmann, Enzymatic Peptide Synthesis, 1987
As already mentioned, all attempts, via protease catalysis, to couple Boc-Asp(OBzl)-Tyr-Met-Gly-OH and H-Trp-Met-Asp(OBzl)-Phe-N2H2Ph to yield the desired octapeptide amide were unsuccessful. Consequently, it was finally assembled in the presence of the chemical condensing agents dicyclohexylcarbodiimide and 1-hydroxybenzotriazole.
Rational repurposing, synthesis, in vitro and in silico studies of chromone-peptidyl hybrids as potential agents against Leishmania donovani
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2023
Ahmed H. E. Hassan, Waleed A. Bayoumi, Selwan M. El-Sayed, Trong-Nhat Phan, Yeon Ju Kim, Chae Hyeon Lee, Soo Bin Cho, Taegeun Oh, Gyeongpyo Ham, Kazem Mahmoud, Joo Hwan No, Yong Sup Lee
Towards a concise synthesis of targeted chromone-peptidyl hybrids, the synthesis of target compounds (7a–q) was conducted in two or three linear steps as depicted in Scheme 1. The intermediate β-amino-α-hydroxy amides (10a–l) were obtained through a coupling reaction between the appropriate chromone-2-carboxylic acid derivative (8a–e)39 and the appropriate β-amino-α-hydroxy amide (9a–c), using 1-ethyl-3–(3-dimethylaminopropyl)carbodiimide.HCl (EDC)/1-hydroxybenzotriazole (HOBt) coupling system. Subsequent oxidation of (10a–l) under Dess-Martin periodinane (DMP) conditions52 afforded the corresponding chromone-peptidyl hybrids (7a–l) in good yields. Concerning the chromone-peptidyl hybrids (7m–q) carrying free hydroxyl group(s) on the phenyl ring, their synthesis was achieved through acidic deprotection of the methoxymethoxy groups using methanolic HCl.
SREKA-targeted liposomes for highly metastatic breast cancer therapy
Published in Drug Delivery, 2023
Balázs Vári, Levente Dókus, Adina Borbély, Anikó Gaál, Diána Vári-Mező, Ivan Ranđelović, Anna Sólyom-Tisza, Zoltán Varga, Norbert Szoboszlai, Gábor Mező, József Tóvári
Solvents for the syntheses and purification were obtained from Reanal (Budapest, Hungary) or VWR International Kft. (Debrecen, Hungary). All amino acid derivatives used for the synthesis of peptides and Fmoc-Rink-amide MBHA resin were purchased from Iris Biotech GmbH (Marktredwitz, Germany). Reagents applied for SPPS [N,N′-diisopropylcarbodiimide (DIC), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1-hydroxybenzotriazole hydrate (HOBt), triisopropylsilane (TIS)], ninhydrin, acetic anhydride, N,N-diisopropylethylamine were delivered by Sigma-Aldrich, St. Louis, Missouri, USA. Aminooxyacetic acid and methoxyamine were TCI (Tokyo, Japan) products. Daunomycin was donated from IVAX (Budapest Hungary). The PEGylated phospholipid derivatives were purchased from Biopharma PEG (Watertown, USA).
Novel anti-PD-L1 peptide selected from combinatorial phage library inhibits tumor cell growth and restores T-cell activity
Published in Journal of Drug Targeting, 2021
Raheleh Tooyserkani, Mohammad Javad Rasaee, Mojgan Bandehpour, Dennis W. P. M. Löwik
At the start of the synthesis, the resin was swollen in DMF for 30 min. Fmoc groups were then removed with 20% v/v piperidine in DMF (3 * 6 min). Moreover, coupling reactions were performed using 3 equivalents of amino acid that were dissolved in N, N’ Diisopropylcarbodiimide (DIPCDI, 3.3 equiv), and hydroxybenzotriazole (HOBt, 3.6 equiv). Accordingly, Fmoc deprotection and couplings were both monitored using a Kaiser test. After performing each step, the resin was washed with DMF (3 * 30 s). Upon the completion of the solid phase synthesis, the resin was washed twice with DCM and methanol, followed by a final wash with DCM diethyl ether. After drying in vacuo, the peptide was deprotected and then cleaved from the resin with a solution containing 92.5% TFA, 2.5% TIS, 2.5% EDT, and 2.5% water. After the filtration step, the obtained product was precipitated in excess diethyl ether, and the resulting orange powder was dissolved in water and analysed by LCMS acquired on a Thermo Finnigan LCQ Fleet Advantage Max (ESI-Q) system.