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51.
In vitro EVALUATION OF PHOTOTOXIC PROPERTIES OF FOUR STRUCTURALLY RELATED BENZOPORPHYRIN DERIVATIVES 总被引:1,自引:0,他引:1
Anna M. Richter Elizabeth Waterfield Ashok K. Jain Ethan D. Sternberg David Dolphin Julia G. Levy 《Photochemistry and photobiology》1990,52(3):495-500
Four structural analogs of benzoporphyrin derivative (BPD) have been studied and compared for photosensitizing activity in vitro. All analogs have an identical reduced tetrapyrrol porphyrin ring, and differ by the position of a cyclohexadiene ring (fused at either ring A or ring B of the porphyrin) and the presence of either two acid groups or one acid and one ester group at rings C and D of the porphyrin. Photosensitizer activity was tested with the M1 tumor cell line using an assay (the MTT assay) which detects mitochondrial hydrogenases as a measure of cell viability. This assay was shown to be equivalent to the standard clonogenicity or [3H]thymidine uptake assay. Comparative studies with the BPD analogs showed that the monoacid derivatives had equivalent cytotoxicity and were about five-fold more active than the diacid forms. This was the case whether the assays were performed in the presence or absence of fetal calf serum. 相似文献
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Molecular beacon strategies using PNA are currently restricted to fluorophore attachment to the ends of the PNA. We report the synthesis of PNA oligomers wherein fluorophores can be attached to the PNA backbone from novel gamma-lysine PNA monomers. Oligomers incorporating the modified PNA showed comparable thermal stability to the corresponding aegPNA oligomer with DNA. When the modified PNA oligomer was annealed with complementary DNA, the fluorescence intensity increased 4-fold over the unbound PNA. [structure: see text] 相似文献
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Ethan R. Sauv Don M. Mayder Saeid Kamal Martins S. Oderinde Zachary M. Hudson 《Chemical science》2022,13(8):2296
Energy transfer (EnT) is a fundamental activation process in visible-light-promoted photocycloaddition reactions. This work describes the performance of imidazoacridine-based TADF materials for visible-light mediated triplet–triplet EnT photocatalysis. The TADF material ACR-IMAC has been discovered as an inexpensive, high-performance organic alternative to the commonly used metal-based photosensitizers for visible-light EnT photocatalysis. The efficiency of ACR-IMAC as a photosensitizer is comparable with Ir-based photosensitizers in both intra- and intermolecular [2 + 2] cycloadditions. ACR-IMAC mediated both dearomative and non-dearomative [2 + 2] cycloadditions in good yields, with high regio- and diastereocontrol. Cyclobutane-containing bi- tri- and tetracylic scaffolds were successfully prepared, with broad tolerance toward functional groups relevant to drug discovery campaigns. Fluorescence quenching experiments, time-correlated single-photon counting, and transient absorption spectroscopy were also conducted to provide insight into the reaction and evidence for an EnT mechanism.This work describes the performance of imidazoacridine-based TADF materials for visible-light mediated triplet–triplet EnT photocatalysis. 相似文献
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Jessica F. Burkhart Neil J. Calkin Shuhong Gao Justine C. Hyde-Volpe Kevin James Hiren Maharaj Shelly Manber Jared Ruiz Ethan Smith 《Designs, Codes and Cryptography》2009,51(3):301-314
In this paper, we recursively construct explicit elements of provably high order in finite fields. We do this using the recursive
formulas developed by Elkies to describe explicit modular towers. In particular, we give two explicit constructions based
on two examples of his formulas and demonstrate that the resulting elements have high order. Between the two constructions,
we are able to generate high order elements in every characteristic. Despite the use of the modular recursions of Elkies,
our methods are quite elementary and require no knowledge of modular curves. We compare our results to a recent result of
Voloch. In order to do this, we state and prove a slightly more refined version of a special case of his result.
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Dr. Mohamed Fares Dr. Xin Wu Deepthi Ramesh Dr. William Lewis Prof. Paul A. Keller Dr. Ethan N. W. Howe Prof. Ricardo Pérez-Tomás Prof. Philip A. Gale 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(40):17767-17774
Anion transporters have shown potential application as anti-cancer agents that function by disrupting homeostasis and triggering cell death. In this research article we report switchable anion transport by gold complexes of anion transporters that are “switched on” in situ in the presence of the reducing agent GSH by decomplexation of gold. GSH is found in higher concentrations in tumors than in healthy tissue and hence this approach offers a strategy to target these systems to tumors. 相似文献
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