Chemical Compounds as Trigger Factors of Immediate Contact Skin Reactions
Ana M. Giménez-Arnau, Howard I. Maibach in Contact Urticaria Syndrome, 2014
CoU to permanent hair dyes such as para-phenylenediamine, which is a very well-known skin sensitizer, is almost exclusively reported in consumers, but has also been described in a beautician.[70,71] Other chemical compounds of LMW reported as inducing ICoU are aliphatic polyamides,[72] methyl ethyl ketone, widely used as solvent in plastic manufacture,[73] and monoamylamine,[74] a vehicle ingredient of topical medicaments.
Affinity Modification — Organic Chemistry
Dmitri G. Knorre, Valentin V. Vlassov in Affinity Modification of Biopolymers, 1989
A similar reaction with pentandione yielding a more stable six-member ring was described in Chapter 1, Section II. Modified residues are stable under acidic conditions while at alkaline pH they decompose with the regeneration of the original compounds. Demodification of proteins can be achieved by treatment with 1,2-phenylenediamine. Borate reacts with the modified residues yielding more stable adducts.
3-(Aminomethyl)Pyridyl Salicylate
Anton C. de Groot in Monographs in Contact Allergy, 2021
A cross-reaction has been suggested with p-phenylenediamine (PPD) and other para-compounds (2, 4). Two of two patients (2), one of one (1) and 9 of 11 (4) were allergic to both 3-(aminomethyl)pyridyl salicylate and PPD, some of who also to other para-substances such as benzocaine and aniline (2, 4). No cross-reaction to ethyl salicylate or methyl salicylate (4).
Comparison between patch test results of natural dyes and standard allergens in batik workers with occupational contact dermatitis
Published in Cutaneous and Ocular Toxicology, 2022
Eka Devinta Novi Diana, Suci Widhiati, Moerbono Mochtar, Muhammad Eko Irawanto
Some standard allergen properties are thought to cause ACD, including having a small molecular weight (less than 500 Da), being electrophilic, and being a strong sensitiser. The study of Handa et al. in India reported that a positive patch test for PPD of 0.1% was found in 13% of cases18. In this study, out of 5 subjects with ACD due to exposure to standard allergens, a positive patch test for 0.1% PPD was found in 1 subject (20%). P-phenylenediamine is a hapten with a small molecular weight of 108.1 Da. The low molecular weight of PPD facilitates the penetration of allergens into the stratum corneum, which in turn causes sensitisation. P-phenylenediamine easily binds to proteins to form a complete antigen and is electrophilic. P-phenylenediamine sensitisation of the skin is thought to be due to the formation of benzoquinone. P-phenylenediamine, which is exposed to oxygen (O2) in the air for a long time, will be oxidised to reactive benzoquinone diimine, a necessary substance to react with proteins19.
Incidence and inheritance of hyperphosphorylated paratarg-7 in patients with Waldenstrom’s macroglobulinaemia in Sweden
Published in Acta Oncologica, 2019
Lena Brandefors, Jack Lindh, Klaus-Dieter Preuss, Natalie Fadle, Michael Pfreundschuh, Eva Kimby
The control group included blood samples from 57 Swedish patients with WM participating in the Scandinavian Lymphoma Aetiology study (SCALE), a nationwide population-based case-control study of risk factors, including blood sampling, for malignant lymphomas carried out in Denmark and Sweden [18]. The analyses of the pP-7 and the titres of the corresponding antibodies were analysed at José Carreras Centre for Immuno and Gene Therapy, Department of Internal Medicine I, Saarland University Medical School, Homburg/Saar, Germany and performed as previously described. In summary, all paratarg proteins and HSP90-SUMO were produced with an additional FLAF tag by recombinant expression in HEK293 cells and coated to Nunc maxisorb plates. Sera were diluted 1:100 and the ELISAs were performed according to standard protocols with goat anti-human Ig-mix. Paratarg-7 ELISA: Chicken anti-STOML2 (Abcam, Cambridge, UK) was coated to Nunc maxisorb plates at 4 °C overnight, before plates were blocked with 1.5% gelatine/PBS-T × 100. Whole blood cell lysate was added for 1 h at room temperature. Recombinant Fabs (10 mg/mL) specific for wild-type P-7 (wtP-7) or pP-7 were added for 1 h at room temperature, followed by anti-human-IgG-(Fab)2-biotin (1:2500) for 1 h and Strep-Pox (1:50,000 1 h RT). Between each step, intensive washing with TBS-T × 100 was performed. Development was done using o-phenylenediamine (OPD) tablets. After stopping with 3 M HCl, absorbance was measured at 490 nm on a Wallac Victor II ELISA reader (Perkin Elmer, Rodgau, Germany) [12].
Discovery of new VEGFR-2 inhibitors based on bis([1, 2, 4]triazolo)[4,3-a:3',4'-c]quinoxaline derivatives as anticancer agents and apoptosis inducers
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2021
Nawaf A. Alsaif, Mohammed S. Taghour, Mohammed M. Alanazi, Ahmad J. Obaidullah, Abdulrahman A. Al-Mehizia, Manal M. Alanazi, Saleh Aldawas, Alaa Elwan, Hazem Elkady
The general synthetic pathways adopted for the synthesis of the designed compounds are illustrated in Schemes 1–3. Scheme 1 depicts the synthesis of potassium bis[1, 2, 4]triazolo[4,3-a]quinoxaline-4-thiolate 14. Initially, o-phenylenediamine 6 was refluxed with oxalic acid 7 in the presence of 4 N HCl to afford 2,3-(1H,4H)-quinoxalinedione 849. Chlorination of compound 8 was done by refluxing with thionyl chloride yielding 2,3- dichloroquinoxaline 949. Subsequent treatment of the latter with hydrazine hydrate in absolute ethanol afforded 2-chloro-3-hydrazinylquinoxaline 1050. Heating of compound 10 with triethyl orthoformate gave 4-chloro[1, 2, 4]triazolo[4,3-a]quinoxaline 1150. The obtained compound 11 was heated with hydrazine hydrate to afford 4-hydrazinyl-[1, 2, 4] triazolo[4,3-a]quinoxaline 1251. Moreover, reflux of 12 in an alcoholic mixture of carbon disulphide and potassium hydroxide afforded bis[1, 2, 4]triazolo[4,3-a:3′,4′-c]quinoxaline-3-thiol 1344. Heating compound 13 with an alcoholic solution of potassium hydroxide gave the corresponding potassium salt 1444. (Scheme 1)
Related Knowledge Centers
- O-Phenylenediamine
- M-Phenylenediamine
- P-Phenylenediamine
- Dimethyl-4-Phenylenediamine
- Wurster'S Blue
- Color Developing Agent 1