Methods of Protein Iodination
Erwin Regoeczi in Iodine-Labeled Plasma Proteins, 2019
An acyl group is the univalent group, , where R is any organic group attached to one bond of the bivalent carbonyl group ,. The alkyl group has already been defined in Section C.1.a. An aryl group is an organic group derived from an aromatic hydrocarbon by the removal of a hydrogen (e.g., the phenyl group, C6H5-, derived from benzene, C6H6). Amines are organic derivatives of ammonia (NH3) formed by the replacement of one, two, or three of the hydrogen atoms by an alkyl or aryl group; correspondingly, the resulting aliphatic and aromatic (and other) amines are classified as primary (RNH2), secondary (R2NH), or tertiary (R3N) amines. Amides are carboxylic acid derivatives obtained by the replacement of the OH group of an acid by an amino group (NH2). Azo compounds are organic compounds which contain the group, -N:N-, attached to two alkyl or aryl groups (e.g., azobenzene, C6H5-N:N-C6H5). In contrast, only one of the two N atoms bonded together in diazo compounds is attached to a carbon of an organic structure (RN=N, see further below). Imines, containing the grouping, -CH=N-, arise from the condensation of primary amines with aldehydes (or ketones) through the loss of H2O. Imides are nitrogen analogs of anhydrides:
Disposition and Metabolism of Drugs of Dependence
S.J. Mulé, Henry Brill in Chemical and Biological Aspects of Drug Dependence, 2019
Studies on structure-activity relationship in barbiturates have provided some generalizations: (a) substitution of both hydrogen atoms on C(5) was an essential requisite for activity; (b) substitution with phenyl group on C(5) conferred anticonvulsant properties in compounds; (c) increase in length of alkyl side chains on C(5) to five or six carbon atoms increased depressant action and larger carbon chains produced stimulant activity; (d) branched chains on C(5) produced long-acting barbiturates and substitution of cyclopentenyl or cyclohexenyl groups on C(5) resulted in short-acting compounds; (e) unsatura-tion in side chains on C(5) enhanced depressant properties; and (f) substitution of S atom in place of 0 at 2-position produced short-acting barbiturates. The names and chemical structures of different barbiturates are given in Table 1.
Antitumor Titanium Compounds and Related Metallocenes
Astrid Sigel, Helmut Sigel in Metal Ions in Biological Systems, 2004
Extensive variation of fast leaving groups, metal and β-diketonato ligand was performed in budotitane and about 200 compounds were examined [5]. Replacing the ethoxy fast leaving group with Cl, F, Br or I, shows no effect as was observed in titanocene dichloride for equivalent replacement of its CI. These groups have no direct role in antitumor mechanism simply because they become lost upon dissolution in the biological fluid although the ethoxy group aids in drug formulation. Antitumor activity is very sensitive to the diketonato moiety in S180 tests in vivo. There is no activity for (acac)2TiX2 where acac possesses two methyl groups, i.e., the Ph of bzac is replaced by a methyl group. Replacement of one methyl by a different group in acac increases activity. One phenyl group promotes activity when it is placed so that extended conjugation is allowed; this implies coplanarity with the metal-enolato ring and suggests the possibility of DNA intercalation. In comparison, budotitane showed T/C higher than 300% in this S180 test. A clear conclusion is that asymmetric ligands are needed for high activity and planar groups enhance activity. These geometrical features have been considered in designing novel antitumor octahedral Ti drugs related to budotitane (see Section 5.3).
A patent review of pharmaceutical and therapeutic applications of oxadiazole derivatives for the treatment of chronic diseases (2013–2021)
Published in Expert Opinion on Therapeutic Patents, 2022
Abbas Hassan, Abid Hussain Khan, Faiza Saleem, Haseen Ahmad, Khalid Mohammed Khan
The structure–activity relationship (SAR) for the oxadiazole compounds, which demonstrates antibacterial potential, was disclosed by evaluating the structural variants. Certain heterocycles that can act as hydrogen bond donors are tolerated well at ring A. The 4-aniline and 4-phenol derivatives are therefore active against S. aureus, but some functionalities such as amides, phosphates, carboxylic acids, and sulfonamides limit the activity. While in ring A, the presence of hydrogen bond acceptor groups decreases the activity. In some circumstances, substituting a heteroaromatic ring for the phenyl group of ring A retains activity. Pyrazoles containing halogen, nitro, and isopropylamine, or sp-hybridized groups, as well as indoles and imidazoles, are all active. Antibacterial activity is generally lost in compounds having heteroaromatic groups including pyrazoles having amino groups with bulky substituents, pyridines, triazoles, and pyrroles, as well as aliphatic heterocycles.
1,3,4-Oxadiazole-naphthalene hybrids as potential VEGFR-2 inhibitors: design, synthesis, antiproliferative activity, apoptotic effect, and in silico studies
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Mohamed Hagras, Marwa A. Saleh, Rogy R. Ezz Eldin, Abdelrahman A. Abuelkhir, Emad Gamil Khidr, Ahmed A. El-Husseiny, Hesham A. El-Mahdy, Eslam B. Elkaeed, Ibrahim H. Eissa
Sorafenib had a binding affinity of −22.46 kcal/mol. Three hydrogen bonding interactions occurred between the urea moiety and Glu883 and Asp1044. Four hydrophobic interactions were formed by the central phenyl group with Val914, Val846, Cys1043, and Phe1045. The hinge region was occupied by the N-methylpicolinamide moiety, which formed one hydrogen bond with Cys917 and five hydrophobic interactions with Val846, Leu838, Leu1033, Phe1045, and Ala864. The allosteric binding pocket was occupied by the terminal 1-chloro-2-(trifluoromethyl)benzene moiety, which formed five hydrophobic interactions with His1024, Ile890, Ile886, and Leu887. It also had one electrostatic interaction with Asp1044 (Figure 6).
Synthesis, telomerase inhibitory and anticancer activity of new 2-phenyl-4H-chromone derivatives containing 1,3,4-oxadiazole moiety
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2021
Xu Han, Yun Long Yu, Duo Ma, Zhao Yan Zhang, Xin Hua Liu
Interestingly, as compared to compounds A22 and A23, compounds A26 and A27 bearing two the methoxy groups on the phenyl ring at R2 exhibited stronger activity. A similar trend was also observed at compounds B22, B23, B26 and B27. However, compounds A30 and B30 with a benzyl group at the meta position of the phenyl ring at R2 completely lost inhibitory activity, which might be affected by steric hindrance. Finally, we found that replacement of the phenyl group at R2 with aromatic fused rings and different aromatic heterocycles was also greatly important for activity.
Related Knowledge Centers
- Aromaticity
- Benzene
- Cyclic Compound
- Functional Group
- Organic Chemistry
- Substituent
- Triphenylmethane
- Chlorobenzene
- Radical
- Arene Substitution Pattern