15028-41-8Relevant articles and documents
Expected and unforeseen reactions of 2,3,3-trimethyl-1λ6-isothiazolidine-1,1,4-trione and their spiro derivative
Popova, Maria V.,Dobrydnev, Alexey V.,Dyakonenko, Viktoriya V.,Konovalova, Irina S.,Shishkina, Svitlana V.,Volovenko, Yulian M.
, p. 1231 - 1245 (2019)
Herein, we present a full account of our studies with respect to the reactivity of insufficiently explored 1λ6-isothiazolidine-1,1,4-triones (so-called β-keto-γ-sultams). This heterocyclic system possesses two reaction centers: the EWG-activate
Stapling of a 310-helix with click chemistry
Jacobsen, yvind,Maekawa, Hiroaki,Ge, Nien-Hui,Goerbitz, Carl Henrik,Rongved, Pal,Ottersen, Ole Petter,Amiry-Moghaddam, Mahmood,Klaveness, Jo
, p. 1228 - 1238 (2011)
Short peptides are important as lead compounds and molecular probes in drug discovery and chemical biology, but their well-known drawbacks, such as high conformational flexibility, protease lability, poor bioavailability and short half-lives in vivo, have prevented their potential from being fully realized. Side chain-to-side chain cyclization, e.g., by ring-closing olefin metathesis, known as stapling, is one approach to increase the biological activity of short peptides that has shown promise when applied to 310-and α-helical peptides. However, atomic resolution structural information on the effect of side chain-to-side chain cyclization in 310-helical peptides is scarce, and reported data suggest that there is significant potential for improvement of existing methodologies. Here, we report a novel stapling methodology for 310-helical peptides using the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction in a model aminoisobutyric acid (Aib) rich peptide and examine the structural effect of side chain-to-side chain cyclization by NMR, X-ray diffraction, linear IR and femtosecond 2D IR spectroscopy. Our data show that the resulting cyclic peptide represents a more ideal 310-helix than its acyclic precursor and other stapled 310-helical peptides reported to date. Side chain-to-side chain stapling by CuAAC should prove useful when applied to 3 10-helical peptides and protein segments of interest in biomedicine.(Figure Presented)
Conformation-specific spectroscopy of capped, gas-phase Aib oligomers: Tests of the Aib residue as a 310-helix former
Gord, Joseph R.,Hewett, Daniel M.,Hernandez-Castillo, Alicia O.,Blodgett, Karl N.,Rotondaro, Matthew C.,Varuolo, Adalgisa,Kubasik, Matthew A.,Zwier, Timothy S.
, p. 25512 - 25527 (2016)
The conformational preferences of a series of capped peptides containing the helicogenic amino acid aminoisobutyric acid (Aib) (Z-Aib-OH, Z-(Aib)2-OMe, and Z-(Aib)4-OMe) are studied in the gas phase under expansion-cooled conditions. Aib oligomers are known to form 310-helical secondary structures in solution and in the solid phase. However, in the gas phase, accumulation of a macrodipole as the helix grows could inhibit helix stabilization. Implementing single-conformation IR spectroscopy in the NH stretch region, Z-Aib-OH and Z-(Aib)2-OMe are both observed to have minor conformations that exhibit dihedral angles consistent with the 310-helical portion of the Ramachandran map (φ, ψ = -57°, -30°), even though they lack sufficient backbone length to form 10-membered rings which are a hallmark of the developed 310-helix. For Z-(Aib)4-OMe three conformers are observed in the gas phase. Single-conformation infrared spectroscopy in both the NH stretch (Amide A) and CO stretch (Amide I) regions identifies the main conformer as an incipient 310-helix, having two free NH groups and two C10 H-bonded NH groups, labeled an F-F-10-10 structure, with a calculated dipole moment of 13.7 D. A second minor conformer has an infrared spectrum characteristic of an F-F-10-7 structure in which the third and fourth Aib residues have φ, ψ = 75°, -74° and -52°, 143°, Ramachandran angles which fall outside of the typical range for 310-helices, and a dipole moment that shrinks to 5.4 D. These results show Aib to be a 310-helix former in the gas phase at the earliest stages of oligomer growth.
N-(tert-Butoxycarbonyl)-α-aminoisobutyryl-α-aminoisobutyric acid methyl ester: Two polymorphic forms in the space group P21/n
Gebreslasie, Hadgu Girmay,Jacobsen, yvind,Goerbitz, Carl Henrik
, p. o283-o287 (2011)
The title compound (systematic name: methyl 2-{2-[(tertbutoxycarbonyl) amino]-2-methylpropanamido}-2-methylpropanoate), C14H 26N2O5, (I), crystallizes in the monoclinic space group P21/n in two polymorphic forms, each with one molecule in the asymmetric unit. The mol-ecular conformation is essentially the same in both polymorphs, with the α-amino-isobutyric acid (Aib) residues adopting φ and ψ values characteristic of α-helical and mixed 310- and α-helical conformations. The helical handedness of the C-terminal residue (Aib2) is opposite to that of the N-terminal residue (Aib1). In contrast to (I), the closely related peptide Boc-Aib-Aib-OBn (Boc is tert-butoxycarbonyl and Bn is benzyl) adopts an αL-PII backbone conformation (or the mirror image conformation). Compound (I) forms hydrogen-bonded para-llel β-sheet-like tapes, with the carbonyl groups of Aib1 and Aib2 acting as hydrogen-bond acceptors. This seems to represent an unusual packing for a protected dipeptide containing at least one ,-disubstituted residue.
Microwave-Assisted Ruthenium- and Rhodium-Catalyzed Couplings of α-Amino Acid Ester-Derived Phosphinamides with Alkynes
Li, Xue-Hong,Gong, Jun-Fang,Song, Mao-Ping
supporting information, (2021/12/23)
Two different types of new phosphinamide α-amino ester derivatives have been prepared in moderate to high yields via ruthenium(II) and rhodium(III)-catalyzed ortho-C?H functionalization under microwave irradiation. Specifically, the ortho-alkenylated phosphinamides were produced through coupling of phosphinamides containing an α-substituted or α,α-disubstituted α-amino ester with internal alkynes under ruthenium catalysis. In contrast, Ru and the more effective Rh-catalyzed coupling of the α-unsubstituted glycine ester phosphinamide with alkynes resulted in formation of oxidative annulation products, phosphaisoquinolin-1-ones. The developed methods feature the use of easily accessible starting materials, short reaction time, exclusive E-stereoselectivity (for ortho-alkenylation) and good functional group tolerance. The alkenylation reaction was readily scaled up to gram scale. Furthermore, the obtained alkenylated phosphinamide could be transformed into P-containing dipeptides through hydrolysis of the ester group in the catalysis product and subsequent condensation with an α-amino ester.
AZOLE DERIVATIVE, AGRICULTURAL AND HORTICULTURAL CHEMICAL AND INDUSTRIAL MATERIAL PROTECTIVE AGENT
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Paragraph 0153, (2020/12/05)
PROBLEM TO BE SOLVED: To provide a plant disease-controlling agent which has low toxicity to humans and animals and excellent handling safety and exhibits an excellent controlling effect on a wide range of plant diseases and a high antifungal activity aga
