938-75-0Relevant academic research and scientific papers
Corrole-Substituted Fluorescent Heme Proteins
Lemon, Christopher M.,Marletta, Michael A.
supporting information, p. 2716 - 2729 (2021/02/16)
Although fluorescent proteins have been utilized for a variety of biological applications, they have several optical limitations, namely weak red and near-infrared emission and exceptionally broad (>200 nm) emission profiles. The photophysical properties of fluorescent proteins can be enhanced through the incorporation of novel cofactors with the desired properties into a stable protein scaffold. To this end, a fluorescent phosphorus corrole that is structurally similar to the native heme cofactor is incorporated into two exceptionally stable heme proteins: H-NOX from Caldanaerobacter subterraneus and heme acquisition system protein A (HasA) from Pseudomonas aeruginosa. These yellow-orange emitting protein conjugates are examined by steady-state and time-resolved optical spectroscopy. The HasA conjugate exhibits enhanced fluorescence, whereas emission from the H-NOX conjugate is quenched relative to the free corrole. Despite the low fluorescence quantum yields, these corrole-substituted proteins exhibit more intense fluorescence in a narrower spectral profile than traditional fluorescent proteins that emit in the same spectral window. This study demonstrates that fluorescent corrole complexes are readily incorporated into heme proteins and provides an inroad for the development of novel fluorescent proteins.
ANTIVIRAL 1,3-DI-OXO-INDENE COMPOUNDS
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Paragraph 0299, (2021/10/22)
The invention provides compounds of Formula (I): as described herein, along with pharmaceutically acceptable salts, pharmaceutical compositions containing such compounds, and methods to use these compounds, salts and compositions for treating viral infections.
Synthesis of 2,2′-bipyrrole-5-carboxaldehydes and their application in the synthesis of B-ring functionalized prodiginines and tambjamines
Kancharla, Papireddy,Reynolds, Kevin A.
, p. 8375 - 8385 (2013/09/02)
Facile, versatile, and cost-effective synthetic routes for the preparation of a range of new 3-alkyl-, 4-alkyl-, 3,4-dialkyl-, and 3-halo-4-alkyl-2, 2′-bipyrrole-5-carboxaldehydes have been developed. These 2,2′-bipyrrole-5-carboxaldehydes offer interesting potential as building blocks for making bioactive natural and unnatural products, as demonstrated by the synthesis of B-ring functionalized prodiginines (PGs) and tambjamines.
Facile synthesis of 2,3,7,8-tetramethyl-2,2′-dipyrrin trifluoroacetate and its X-ray crystal structure
Datta, Suchitra,Lightner, David A.
scheme or table, p. 1113 - 1117 (2009/12/01)
3,4-Dimethyl-1H-pyrrole-2-carboxylic acid was converted to 2,3,7,8-tetramethyl-2,2′-dipyrrin by the action of trifluoroacetic acid and ethyl orthoformate. A crystal of the dipyrrin was grown from dichloromethane-n-hexane and an X-ray crystallographic structure of its trifluoroacetate salt was determined.
Intermolecularly hydrogen-bonded dimeric helices: tripyrrindiones
Roth, Steven D.,Shkindel, Tetyana,Lightner, David A.
, p. 11030 - 11039 (2008/02/12)
A rare and unusual class of tripyrrolic compounds, violet-colored tripyrrin-1,14-diones, can be prepared easily and in moderately high yields from base (piperidine)-catalyzed condensation of 3-pyrrolin-2-ones with 2,5-diformylpyrroles. Dipyrrinones adopt the all-syn-Z conformation leading to helical, lock-washer like structures, which form dimers that are held together by intermolecular hydrogen bonds in nonpolar solvents and in the crystal. Strong bathochromic spectral shifts of the tripyrrindione ～480 nm long wavelength UV-visible absorption band are seen with added base: DBU, 615 nm; TFA, 573 nm; and Zn(OAc)2, 586 nm.
Remarkable solvent effect in Barton-Zard pyrrole synthesis: application in an efficient one-step synthesis of pyrrole derivatives
Bhattacharya, Apurba,Cherukuri, Sankara,Plata, Robert Erik,Patel, Nitinchandra,Tamez Jr., Victoriano,Grosso, John A.,Peddicord, Michael,Palaniswamy, Venkatapuram A.
, p. 5481 - 5484 (2007/10/03)
A unique solvent effect encountered in the Barton-Zard pyrrole synthesis was exploited to develop an efficient synthesis of pyrrole-2-esters. The chemistry was extended to a one-pot synthesis of pyrrole-2,4-dicarboxylates.
Large scale, efficient synthesis of 9-unsubstituted dipyrrinone
Chen, Qingqi,Wang, Tianyu,Zhang, Yi,Wang, Qiuan,Ma, Jinshi
, p. 1031 - 1040 (2007/10/03)
9-Unsubstituted dipyrrinone 8, the useful precursor for the synthesis of biliverdins, bilirubins, and other bile pigments, was synthesized in large scale and high yield starting from acetaldehyde and nitroethane in eight steps with overall yield 10%. The key intermediate 3,4-dimethyl-2-ethoxycarbonylpyrrole 3 was synthesized via Zard-Barton's method in high yield.
Photochemical substitution of halogenopyrrole derivatives
D'Auria, Maurizio,De Luca, Eliana,Mauriello, Giacomo,Racioppi, Rocco,Sleiter, Giancarlo
, p. 2369 - 2373 (2007/10/03)
The photochemical behaviour of some iodo substituted pyrroles when they are irradiated in the presence of an aromatic compound is reported. N-Methyl-3,4-diiodopyrrole-2-carbaldehyde and 5-iodopyrrole-2-carbaldehyde are unreactive when they are irradiated in benzene solution. In contrast, ethyl 3,4-dimethyl-5-iodopyrrole-2-carboxylate gives a 1:1 mixture of ethyl 3,4-dimethyl-5-phenylpyrrole-2-carboxylate and ethyl 3,4-dimethylpyrrole-2-carboxylate in quantitative yields. The same reaction when attempted with acetonitrile as solvent gives ethyl 3,4-dimethylpyrrole-2-carboxylate as the sole product in quantitative yield. Use of 4,5-diiodopyrrole-2-carbaldehyde as substrate and irradiation in benzene gives the corresponding 5-phenyl derivative. The same behaviour is observed with m-xylene, thiophene and 2-chlorothiophene as solvents. With acetonitrile as solvent, the reaction with benzene does not work. With 2-methylthiophene as solvent 2-(5-methyl-2-thienyl)-3-iodopyrrole is obtained as the sole product. The observed behaviour can be explained on the basis of the previously reported data on the mechanism of the photochemical arylation of halogenothiophene derivatives.
SYNTHESIS AND UNUSUAL PROPERTIES OF C(10)-gem-DIMETHYL BILIRUBIN ANALOGS
Xie, Meiqiang,Lightner, David A.
, p. 2185 - 2200 (2007/10/02)
The characteristic thermodynamically-favored intramolecularly hydrogen-bonded conformation adopted by bilirubin pigments is destabilized by substituting methyl groups on the C(10) central methylene.These methyl groups impose conformation-destabilizing methyl-methylene non-bonded steric interactions with the propionic acid β-CH2 groups at C(8) and C(12) when the propionic acids are engaged in intramolecular hydrogen bonding with the opposing dipyrrinones.Amphiphilic 10,10-dimethylbilirubins (1) and (2) are found to be more polar, but also more soluble than the parents (3) and (4) in organic solvents; yet, 1H-NMR studies in non-polar solvents indicate that a deformed but folded, intramolecularly hydrogen-bonded conformation is retained.The dimethyl esters of 10,10-dimethylbilirubins 1 and 2 did not exhibit the typical strong tendency of bilirubin dimethyl esters to form intermolecular hydrogen bonds in non-polar solvents such as chloroform and benzene.
Electron transfer in bis-porphyrin donor-acceptor compounds with polyphenylene spacers shows a weak distance dependence
Helms, Anna,Heiler, David,McLendon, George
, p. 6227 - 6238 (2007/10/02)
A series of phenylene-bridged bis-porphyrin adducts have been synthesized, containing one, two, or three phenyl bridges. Complete synthetic details are provided. For studies of photochemical electron transfer, mixed metals wre incorporated, with zinc in one porphyrin macrocycle and FeIII (bis-imidazole) in the other macrocycle. When photoexcited, an electron is transferred from Zn to FeIII. The rate of this process drops only slowly with distance: kα exp(βr), with β = 0.4 A?-1. This dependence can be predicted by a simple theory which assumes that the drop does not reflect increased distance, but rather reflects the break in conjugation which occurs at each phenyl juncture due to the biphenyl twist angle of ca. 50°. Inefficient overlap in this angle results in a rate drop of ca. 6-fold per phenyl ring, in good agreement with the observed results.
