6986-80-7Relevant articles and documents
Tunable NIR-II emitting silver chalcogenide quantum dots using thio/selenourea precursors: Preparation of an MRI/NIR-II multimodal imaging agent
Basel, Siddhant,Bhardwaj, Karishma,Borthakur, Sukanya,Brito, Beatriz,Clarke, Mitchell,Pariyar, Anand,Pradhan, Sajan,Roy, Pankaj,Saikia, Lakshi,Shankar, Amit,Stasiuk, Graeme J.,Tamang, Sudarsan,Thapa, Surakcha
supporting information, p. 15425 - 15432 (2020/11/18)
Aqueous-stable, Cd- and Pb-free colloidal quantum dots with fluorescence properties in the second near-infrared region (NIR-II, 1000-1400) are highly desirable for non-invasive deep-tissue optical imaging and biosensing. The low band-gap semiconductor, silver chalcogenide, offers a non-toxic and stable alternative to existing Pd, As, Hg and Cd-based NIR-II colloidal quantum dots (QDs). We report facile access to NIR-II emission windows with Ag2X (X = S, Se) QDs using easy-to-prepare thio/selenourea precursors and their analogues. The aqueous phase transfer of these QDs with a high conservation of fluorescence quantum yield (retention up to ~90%) and colloidal stability is demonstrated. A bimodal NIR-II/MRI contrast agent with a tunable fluorescence and high T1 relaxivity of 408 mM-1 s-1 per QD (size ~ 2.2 nm) and 990 mM-1 s-1 per QD (size ~ 4.2 nm) has been prepared by grafting 50 and 120 monoaqua Gd(iii) complexes respectively to two differently sized Ag2S QDs. The size of the nanocrystals is crucial for tuning the Gd payload and the relaxivity.
Structural requirement of phenylthiourea analogs for their inhibitory activity of melanogenesis and tyrosinase
Thanigaimalai, Pillaiyar,Lee, Ki-Cheul,Sharma, Vinay K.,Joo, Cheonik,Cho, Won-Jea,Roh, Eunmiri,Kim, Youngsoo,Jung, Sang-Hun
experimental part, p. 6824 - 6828 (2011/12/22)
Effect of a series of 1-phenylthioureas 1a-k and 1,3-disubstituted thioureas 2a-k were evaluated against melanin formation in melanoma B16 cell line and mushroom tyrosinase. Inhibitory activity of tyrosinase of 1-phenylthioureas 1a-k is parallel to their melanogenic inhibition. Thus, the melanogenic inhibition in melanoma B16 cells of 1-phenylthioureas could be the result of inhibition of tyrosinase. However, 1,3-diaryl or 1-phenyl-3- alkylthioureas, 2a-k, appears as melanogenic inhibitor without inhibition of tyrosinase. The molecular docking study of 1e and 2b to binding pocket of tyrosinase provided convincing explanation regarding the necessity of direct connection of planar phenyl to thiourea unit without N′-substitution of phenylthioureas 1 as tyrosinase inhibitor and 2 as non-tyrosinase inhibitor.