13552-87-9Relevant academic research and scientific papers
CAL-B catalyzed regioselective bulk polymerization of l-aspartic acid diethyl ester to α-linked polypeptides
Totsingan, Filbert,Centore, Robert,Gross, Richard. A.
, p. 4030 - 4033 (2017)
This paper reports that the bulk polymerization of l-aspartic acid diethyl ester catalyzed by immobilized CAL-B at 80 °C for 24 h gives primarily (～95%) α-linked poly(l-aspartate) in 70% yield with DPavg = 50 and regioselectivity (α/β) = 94?:?6. Plots of log{[M]0/[M]t} vs. time and DPavgvs. conversion indicate that this polymerization proceeds in a controlled manner by a chain-growth mechanism up to 90% conversion. Thereafter, competition occurs between chain growth and step mechanisms.
Ionic liquids with methotrexate moieties as a potential anticancer prodrug: Synthesis, characterization and solubility evaluation
Moshikur, Rahman Md.,Chowdhury, Md. Raihan,Wakabayashi, Rie,Tahara, Yoshiro,Moniruzzaman, Muhammad,Goto, Masahiro
, p. 226 - 233 (2019)
The technological utility of active pharmaceutical ingredients (APIs) is enormously improved when they are converted into ionic liquids (ILs). API-ILs possess better aqueous solubility and thermal stability than that of solid-state salt or crystalline drugs. However, many such API-ILs are not biocompatible or biodegradable. In the current study, we synthesized a series of IL-APIs using methotrexate (MTX), a potential anticancer prodrug, and biocompatible IL-forming cations (choline and amino acid esters). The MTX-IL moieties were characterized through 1H NMR, FTIR, p-XRD, DSC and thermogravimetric analysis. The solubility of the MTX-ILs was evaluated in simulated body fluids (phosphate-buffered saline, simulated gastric, and simulated intestinal fluids). An assessment of the in vitro antitumor activity of the MTX-ILs in a mammalian cell line (HeLa cells) was used to evaluate their cytotoxicity. The MTX-ILs showed aqueous solubility at least 5000 times higher than that of free MTX and two orders of magnitude higher compared with that of a sodium salt of MTX in both water and simulated body fluids. Importantly, a proline ethyl ester MTX prodrug showed similar solubility as the MTX sodium salt but it provided improved in vitro antitumor activity. These results clearly suggest that the newly synthesized API-ILs represent promising potential drug formulations.
Novel pyridinium-type fullerene derivatives as multitargeting inhibitors of HIV-1 reverse transcriptase, HIV-1 protease, and HCV NS5B polymerase
Kobayashi, Toi,Mashino, Tadahiko,Nakamura, Shigeo,Ohe, Tomoyuki,Takahashi, Kyoko,Yasuno, Takumi
supporting information, (2021/08/12)
In the present study, we newly synthesized four types of novel fullerene derivatives: pyridinium/ethyl ester-type derivatives 3b?3l, pyridinium/carboxylic acid-type derivatives 4a, 4e, 4f, pyridinium/amide-type derivative 5a, and pyridinium/2-morpholinone
Stereoretentive N-Arylation of Amino Acid Esters with Cyclohexanones Utilizing a Continuous-Flow System
Ichitsuka, Tomohiro,Komatsuzaki, Shingo,Masuda, Koichiro,Koumura, Nagatoshi,Sato, Kazuhiko,Kobayashi, Shū
supporting information, p. 10844 - 10848 (2021/05/31)
The N-arylation of chiral amino acid esters with minimal racemization is a challenging transformation because of the sensitivity of the α-stereocenter. A versatile synthetic method was developed to prepare N-arylated amino acid esters using cyclohexanones as aryl sources under continuous-flow conditions. The designed flow system, which consists of a coil reactor and a packed-bed reactor containing a Pd(OH)2/C catalyst, efficiently afforded the desired N-arylated amino acids without significant racemization, accompanied by only small amounts of easily removable co-products (i. e., H2O and alkanes). The efficiency and robustness of this method allowed for the continuous synthesis of the desired product in very high yield and enantiopurity with high space-time yield (74.1 g L?1 h?1) and turnover frequency (5.9 h?1) for at least 3 days.
One-Pot Conversion of Carbohydrates into Pyrrole-2-carbaldehydes as Sustainable Platform Chemicals
Adhikary, Nirmal Das,Kwon, Sunjeong,Chung, Wook-Jin,Koo, Sangho
, p. 7693 - 7701 (2015/08/18)
A practical conversion method of carbohydrates into N-substituted 5-(hydroxymethyl)pyrrole-2-carbaldehydes (pyrralines) was developed by the reaction with primary amines and oxalic acid in DMSO at 90°C. Further cyclization of the highly functionalized pyrralines afforded the pyrrole-fused poly-heterocyclic compounds as potential intermediates for drugs, food flavors, and functional materials. The mild Maillard variant of carbohydrates and amino esters in heated DMSO with oxalic acid expeditiously produced the pyrrole-2-carbaldehyde skeleton, which can be concisely transformed into the pyrrole alkaloid natural products, 2-benzyl- and 2-methylpyrrolo[1,4]oxazin-3-ones 8 and 9, lobechine 10, and (')-hanishin 11 in 23-32% overall yields from each carbohydrate.
SELECTIVE INHIBITORS FOR CYCLIN-DEPENDENT KINASES
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Page/Page column 137, (2009/01/24)
This invention provides a class of compounds which are useful for specifically inhibiting cyclin-dependent kinases. This class of compounds finds use in treating diseases resulting from inappropriate activity of cyclin-dependent kinases, including cancer, viral infections (e.g., HIV) neurodegenerative disorders (e.g. Alzheimer's disease), and cardiovascular disorders (e.g. atherosclerosis). Moreover, certain members of this class are particularly useful for inhibiting cyclin-dependent kinase 7 and are especially useful for the treatment of breast cancer.
Studies towards the total synthesis of batzelladine A
Elliott, Mark C.,Long, Matthew S.
, p. 2003 - 2011 (2007/10/03)
Application of a diastereoselective three-component coupling to the bicyclic core of the batzelladine alkaloids is described. The synthesis features the elaboration of glutamic acid by use of Eschenmoser sulfide contraction. An earlier approach is also included, which shows some limitations of dithiane chemistry when applied to the particular compounds required for this target.
