scholarly journals Novel Nontoxic 5,9-Disubstituted SN38 Derivatives: Characterization of Their Pharmacological Properties and Interactions with DNA Oligomers

2021 ◽  
Vol 22 (15) ◽  
pp. 8190
Author(s):  
Elżbieta Bednarek ◽  
Wojciech Bocian ◽  
Magdalena Urbanowicz ◽  
Jerzy Sitkowski ◽  
Beata Naumczuk ◽  
...  
Keyword(s):  
Water Solution ◽  
Pharmacological Properties ◽  
Dna Oligomers ◽  
Biological Target ◽  
Self Association ◽  
Stereogenic Center ◽  
Further Development ◽  
Derivatives Of ◽  
As Solubility

Novel nontoxic derivatives of SN38 with favorable antineoplastic properties were characterized in water solution using NMR. The phenomena observed by NMR were linked to basic pharmacological properties, such as solubility, bioavailability, chemical and stereochemical stability, and binding to natural DNA oligomers through the terminal G-C base pair, which is commonly considered a biological target of Topo I inhibitors. Compound 1, with bulky substituents at both C5(R) and C20(S) on the same side of a camptothecin core, manifests self-association, whereas diastereomers 2, with bulky C5(S) and C20(S) substituents are mostly monomeric in solution. The stereogenic center at C5 is stable in water solution at pH 5–6. The compound with an (N-azetidinyl)methyl substituent at C9 can undergo the retro Mannich reaction after a prolonged time in water solution. Both diastereomers exhibit different abilities in terms of binding to DNA oligomers: compound 1 is strongly bound, whereas the binding of compound 2 is rather weak. Molecular modeling produced results consistent with NMR experiments. These complementary data allow linking of the observed phenomena in NMR experiments to basic preliminary information on the pharmacodynamic character of compounds and are essential for planning further development research.

Synthesis and Spectral Characterization of Derivatives of Benzotriazole and Piperidine

2018 ◽  
Vol 8 (2) ◽  
pp. 278-287
Author(s):  
Selvarathy Grace P ◽  
Ravindran Durainayagam B ◽  
Pon Matheswari P.
Keyword(s):  
Spectral Characterization ◽  
Derivatives Of

scholarly journals Characterization of Native Reversible Self-Association of a Monoclonal Antibody Mediated by Fab-Fab Interaction

2020 ◽  
Vol 109 (1) ◽  
pp. 443-451 ◽  
Author(s):  
Lorenzo Gentiluomo ◽  
Dierk Roessner ◽  
Werner Streicher ◽  
Sujata Mahapatra ◽  
Pernille Harris ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Self Association

scholarly journals Biguanide-Based Synthesis of 1,3,5-Triazine Derivatives with Anticancer Activity and 1,3,5-Triazine Incorporated Calcium Citrate Nanoparticles

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1028
Author(s):  
Monnaya Chalermnon ◽  
Sarocha Cherdchom ◽  
Amornpun Sereemaspun ◽  
Rojrit Rojanathanes ◽  
Tanatorn Khotavivattana
Keyword(s):  
Anticancer Activity ◽  
Cell Lines ◽  
Anticancer Agent ◽  
Drug Loading ◽  
Calcium Citrate ◽  
Colorectal Cancer Cell Lines ◽  
Triazine Derivatives ◽  
Further Development ◽  
Derivatives Of ◽  
Potential Use

Twelve derivatives of biguanide-derived 1,3,5-triazines, a promising class of anticancer agent, were synthesised and evaluated for their anticancer activity against two colorectal cancer cell lines—HCT116 and SW620. 2c and 3c which are the derivatives containing o-hydroxyphenyl substituents exhibited the highest activity with IC50 against both cell lines in the range of 20–27 µM, which is comparable to the IC50 of cisplatin reference. Moreover, the potential use of the calcium citrate nanoparticles (CaCit NPs) as a platform for drug delivery system was studied on a selected 1,3,5-triazine derivative 2a. Condition optimisation revealed that the source of citrate ions and reaction time significantly influence the morphology, size and %drug loading of the particles. With the optimised conditions, “CaCit-2a NPs” were successfully synthesised with the size of 148 ± 23 nm and %drug loading of up to 16.3%. Furthermore, it was found that the release of 2a from the synthesised CaCit-2a NPs is pH-responsive, and 2a could be control released under the acidic cancer environment. The knowledge from this study is perceptive for further development of the 1,3,5-triazine-based anticancer drugs and provide the platform for the incorporation of other drugs in the CaCit NPs in the future.

Structural Characterization of Two Novel Oxidative Derivatives of Cyclosporine Generated By a Chemical Method

1998 ◽  
Vol 31 (3) ◽  
pp. 173-180 ◽  
Author(s):  
WingT Liu ◽  
Kirk Marat ◽  
Ying Ren ◽  
RonaldT Eng ◽  
PuiY Wong
Keyword(s):  
Structural Characterization ◽  
Chemical Method ◽  
Derivatives Of

scholarly journals Identification of pigments in artworks by inverse tangent derivative of spectrum and a new filtering method

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
F. Fazlali ◽  
S. Gorji Kandi
Keyword(s):  
Reflectance Spectrum ◽  
Practical Method ◽  
Chemical Methods ◽  
Munk Function ◽  
Absorption Of Light ◽  
Spectrophotometric Data ◽  
First Time ◽  
Non Destructive ◽  
Derivatives Of

Abstract Employing an economical and non-destructive method for identifying pigments utilized in artworks is a significant aspect for preserving their antiquity value. One of the non-destructive methods for this purpose is spectrophotometry, which is based on the selected absorption of light. Mathematical descriptive methods such as derivatives of the reflectance spectrum, the Kubelka–Munk function and logarithm have been employed for the characterization of the peak features corresponding to the spectrophotometric data. In the present study, the mentioned mathematical descriptive methods were investigated with the aim to characterize the constituents of an Iranian artwork but were not efficient for the samples. Therefore, inverse tangent derivative equation was developed on spectral data for the first time, providing considerable details in the profile of reflectance curves. In the next part, to have a simpler and more practical method it was suggested to use filters made up of pure pigments. By using these filters and placing them on the samples, imaging was done. Then, images of samples with and without filter were evaluated and pure pigments were distinguished. The mentioned methods were also used to identify pigments in a modern Iranian painting specimen. The results confirmed these methods with reliable answers indicating that physical methods (alongside chemical methods) can also be effective in determining the types of pigments.

scholarly journals Carbohydrate binding activities of Bradyrhizobium japonicum. II. Isolation and characterization of a galactose-specific lectin.

1990 ◽  
Vol 111 (4) ◽  
pp. 1639-1643 ◽  
Author(s):  
S C Ho ◽  
M Schindler ◽  
J L Wang
Keyword(s):  
Isoelectric Focusing ◽  
Bradyrhizobium Japonicum ◽  
Affinity Column ◽  
Carbohydrate Binding ◽  
Binding Affinities ◽  
Isolation And Characterization ◽  
Relative Binding ◽  
Mannose Derivatives ◽  
Derivatives Of

Extracts of Bradyrhizobium japonicum were fractionated on Sepharose columns covalently derivatized with lactose. Elution of the material that was specifically bound to the affinity column with lactose yielded a protein of Mr approximately 38,000. Isoelectric focusing of this sample yielded two spots with pI values of 6.4 and 6.8. This protein specifically bound to galactose-containing glycoconjugates, but did not bind either to glucose or mannose. Derivatives of galactose at the C-2 position showed much weaker binding; there was an 18-fold difference in the relative binding affinities of galactose versus N-acetyl-D-galactosamine. These results indicate that we have purified a newly identified carbohydrate-binding protein from Bradyrhizobium japonicum, that can exquisitely distinguish galactose from its derivatives at the C-2 position.

Syntheses and Characterization of μ,η1,η1-3,5-Di-tert-butylpyrazolato Derivatives of Aluminum†

2001 ◽  
Vol 40 (10) ◽  
pp. 2363-2367 ◽  
Author(s):  
Wenjun Zheng ◽  
Holger Hohmeister ◽  
Nadia C. Mösch-Zanetti ◽  
Herbert W. Roesky ◽  
Mathias Noltemeyer ◽  
...  
Keyword(s):  
Derivatives Of
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