33631-09-3Relevant articles and documents
Second generation of diazachrysenes: Protection of Ebola virus infected mice and mechanism of action
Selakovi?, ?ivota,Tran, Julie P.,Kota, Krishna P.,Lazi?, Marija,Retterer, Cary,Besh, Robert,Panchal, Rekha G.,Soloveva, Veronica,Sean, Vantongreen A.,Jay, Wells B.,Pavi?, Aleksandar,Verbi?, Tatjana,Vasiljevi?, Branka,Kuehl, Kathleen,Duplantier, Allen J.,Bavari, Sina,Mudhasani, Rajini,?olaja, Bogdan A.
supporting information, p. 32 - 50 (2018/11/21)
Ebola virus (EBOV) causes a deadly hemorrhagic fever in humans and non-human primates. There is currently no FDA-approved vaccine or medication to counter this disease. Here, we report on the design, synthesis and anti-viral activities of two classes of compounds which show high potency against EBOV in both in vitro cell culture assays and in vivo mouse models Ebola viral disease. These compounds incorporate the structural features of cationic amphiphilic drugs (CAD), i.e they possess both a hydrophobic domain and a hydrophilic domain consisting of an ionizable amine functional group. These structural features enable easily diffusion into cells but once inside an acidic compartment their amine groups became protonated, ionized and remain trapped inside the acidic compartments such as late endosomes and lysosomes. These compounds, by virtue of their lysomotrophic functions, blocked EBOV entry. However, unlike other drugs containing a CAD moiety including chloroquine and amodiaquine, compounds reported in this study display faster kinetics of accumulation in the lysosomes, robust expansion of late endosome/lysosomes, relatively more potent suppression of lysosome fusion with other vesicular compartments and inhibition of cathepsins activities, all of which play a vital role in anti-EBOV activity. Furthermore, the diazachrysene 2 (ZSML08) that showed most potent activity against EBOV in in vitro cell culture assays also showed significant survival benefit with 100% protection in mouse models of Ebola virus disease, at a low dose of 10 mg/kg/day. Lastly, toxicity studies in vivo using zebrafish models suggest no developmental defects or toxicity associated with these compounds. Overall, these studies describe two new pharmacophores that by virtue of being potent lysosomotrophs, display potent anti-EBOV activities both in vitro and in vivo animal models of EBOV disease.
Manganese salen complexes with acid-base catalytic auxiliary: Functional mimetics of catalase
Noritake, Yukinobu,Umezawa, Naoki,Kato, Nobuki,Higuchi, Tsunehiko
, p. 3653 - 3662 (2013/05/09)
Antioxidant therapies have been considered for a wide variety of disorders associated with oxidative stress, and synthetic catalytic scavengers of reactive oxygen species would be clinically superior to stoichiometric ones. Among them, salen-manganese complexes (Mn(Salen)) seem promising, because they exhibit dual functions, i.e. superoxide dismutase- and catalase-mimetic activities. We have been developing enzyme-mimetic Mn(Salen) complexes bearing a functional group that enhances their catalytic activity. Here, we describe the design and synthesis of novel Mn(Salen) complexes with general acid-base catalytic functionality, inspired by the reaction mechanism of catalase. As expected, these Mn(Salen) complexes showed superior catalase-like activity and selectivity, while retaining moderate SOD-like activity. An unsubstituted pyridyl group worked well as a functionality to promote catalase-like activity. The introduced functionality did not alter the redox potential suggesting that the auxiliary-modified complex acted as an acid-base catalyst analogous to catalase. We believe that our approach provides a new design principle for sophisticated catalyst design. Further, the compounds described here appear to be good candidates for use in antioxidant therapy.
Light-driven coordination-induced spin-state switching: Rational design of photodissociable ligands
Thies, Steffen,Sell, Hanno,Bornholdt, Claudia,Schuett, Christian,Koehler, Felix,Tuczek, Felix,Herges, Rainer
, p. 16358 - 16368 (2013/02/23)
The bistability of spin states (e.g., spin crossover) in bulk materials is well investigated and understood. We recently extended spin-state switching to isolated molecules at room temperature (light-driven coordination-induced spin-state switching, or LD-CISSS). Whereas bistability and hysteresis in conventional spin-crossover materials are caused by cooperative effects in the crystal lattice, spin switching in LD-CISSS is achieved by reversibly changing the coordination number of a metal complex by means of a photochromic ligand that binds in one configuration but dissociates in the other form. We present mathematical proof that the maximum efficiency in property switching by such a photodissociable ligand (PDL) is only dependent on the ratio of the association constants of both configurations. Rational design by using DFT calculations was applied to develop a photoswitchable ligand with a high switching efficiency. The starting point was a nickel-porphyrin as the transition-metal complex and 3-phenylazopyridine as the photodissociable ligand. Calculations and experiments were performed in two iterative steps to find a substitution pattern at the phenylazopyridine ligand that provided optimum performance. Following this strategy, we synthesized an improved photodissociable ligand that binds to the Ni-porphyrin with an association constant that is 5.36times higher in its trans form than in the cis form. The switching efficiency between the diamagnetic and paramagnetic state is efficient as well (72 % paramagnetic Ni-porphyrin after irradiation at 365nm, 32 % paramagnetic species after irradiation at 440nm). Potential applications arise from the fact that the LD-CISSS approach for the first time allows reversible switching of the magnetic susceptibility of a homogeneous solution. Photoswitchable contrast agents for magnetic resonance imaging and light-controlled magnetic levitation are conceivable applications. Turn the spin: Nickel-porphyrins with appropriately designed axial photochromic ligands change their coordination number and consequently their spin state reversibly upon irradiation. Rational design led to a substituted 3-phenylazopyridine as a photodissociable ligand with a switching efficiency of 40 % (see figure). Thus, the magnetic susceptibility of a homogeneous solution was switched by a factor of more than two at room temperature.
