3-(Diethoxyphosphoryloxy)-1,2,3- benzotriazin-4(3<i>H</i>)-one (DEPBT):  A New Coupling Reagent with Remarkable Resistance to Racemization

Li, Haitao; Jiang, Xiaohui; Ye, Yun‐Hua; Fan, Chun‐An; Romoff, Todd T.; Goodman, Murray

doi:10.1021/ol990573k

Cited by 238 publications

(160 citation statements)

References 13 publications

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“…However, several studies have reported the presence of just traces of racemization at Gln thioesters [38,39,[42][43][44][45]48] when using protocols similar to those used in our study (PyBOP-coupling conditions); this rules out racemization at the Gln residue of Rev3. On the other hand, the level of racemization in the case of the C-terminal Ser thioester, which we prepared by using BF 3 ·etherate on trichloroacetimidate activated Wang resin, has not been investigated.…”

Section: Chemical Synthesis Of Hiv-1 Revmentioning

confidence: 68%

“…The Rev3 thioester was prepared in similar yield by anchoring Fmoc-(Glu)-OAll on Rink amide resin (Supporting Information). [42][43][44][45] We then turned our focus to the synthesis of the full length Rev protein by applying the above-described strategy. We first ligated Rev1 to Rev2 under NCL conditions, followed by conversion of the 1,3-thiazolidine-4-carboxo (Thz) to Cys by using methoxylamine, [46] to give Rev2-Rev1 in 35 % isolated yield for the two steps ( Figure 1 A and B).…”

Section: Chemical Synthesis Of Hiv-1 Revmentioning

confidence: 99%

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Chemical Synthesis and Expression of the HIV‐1 Rev Protein

et al. 2011

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The HIV‐1 Rev protein is responsible for shuttling partially spliced and unspliced viral mRNA out of the nucleus. This is a crucial step in the HIV‐1 lifecycle, thus making Rev an attractive target for the design of anti‐HIV drugs. Despite its importance, there is a lack of structural, biophysical, and quantitative information about Rev. This is mainly because of its tendency to undergo self‐assembly and aggregation; this makes it very difficult to express and handle. To address this knowledge gap, we have developed two new highly efficient and reproducible methods to prepare Rev in large quantities for biochemical and structural studies: 1) Chemical synthesis by using native chemical ligation coupled with desulfurization. Notably, we have optimized our synthesis to allow for a one‐pot approach for the ligation and desulfurization steps; this reduced the number of purification steps and enabled the obtaining of desired protein in excellent yield. Several challenges emerged during the design of this Rev synthesis, such as racemization, reduced solubility, formylation during thioester synthesis, and the necessity for using orthogonal protection during desulfurization; solutions to these problems were found. 2) A new method for expression and purification by using a vector that contained an HLT tag, followed by purification with a Ni column, a cation exchange column, and gel filtration. Both methods yielded highly pure and folded Rev. The CD spectra of the synthetic and recombinant Rev proteins were identical, and consistent with a predominantly helical structure. These advances should facilitate future studies that aim at a better understanding of the structure and function of the protein.

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Section: Chemical Synthesis Of Hiv-1 Revmentioning

confidence: 68%

Section: Chemical Synthesis Of Hiv-1 Revmentioning

confidence: 99%

Chemical Synthesis and Expression of the HIV‐1 Rev Protein

et al. 2011

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“…This was deprotected with TBAF, and the product was submitted to a Swern oxidation to obtain aldehyde 6 in 94% yield for two steps. Jones oxidation of 6 led to the carboxylic acid intermediate, which was immediately coupled as a crude with aniline in the presence of Goodman's reagent (DEBPT), 24 leading to anilide 7 in 75% yield. Finally, conversion to hydroxamic acid (R/S)-2 was easily achieved by treating methyl ester 7 with hydroxylamine and NaOH in MeOH.…”

mentioning

confidence: 99%

Vorinostat-Like Molecules as Structural, Stereochemical, and Pharmacological Tools

Hanessian

Auzzas

Larsson

et al. 2010

ACS Med. Chem. Lett.

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The inhibitory activity of an ω-alkoxy analogue of the HDAC inhibitor, Vorinostat (SAHA), against the 11 isoforms of HDAC is described and evaluated with regard to structural biology information retrieved through computational methods. Preliminary absorption and metabolism studies were performed, which positioned this compound as a potential candidate for further preclinical studies and delineated measures for improving its pharmacokinetic profile.KEYWORDS HDAC promiscuous inhibitors, SAHA analogues, HDAC1-11 profile, class IIa-specific profile, absorption and metabolism I n spite of the significant progress made in HDAC research, 1-4 the quest for isoform-selective inhibitors continues to present a major challenge. [5][6][7] To date, detailed biostructural information is available only regarding a few among the known 11 metallo-enzymes. 1,[8][9][10][11] Consequently, the design of isoform-and class-selective inhibitors is somewhat arbitrary and derivative. 1,7,[12][13][14] In addition, complete data regarding the factual HDAC profile for most of the early discovered agents are not available, since the development of effective isozyme-based assays is relatively recent. [5][6][7][15][16][17][18] As a consequence of the complex, pleiotropic nature of cancer, promiscuous HDAC inhibitors such as Vorinostat (1) (SAHA, suberoylanilide hydroxamic acid) 19 (Figure 1) seem superior and as safe in the clinic as compared to the few class-specific agents available. [5][6][7]15 Ligand-based approaches are a first-choice solution to delineate the structural requirements for HDAC selectivity, especially with the emergence of ω-aryl alkanoyl hydroxamates such as Vorinostat as clinical candidates. 1,7,[12][13][14] In this regard, simple and readily accessible surrogates are worthy of study, provided that they bear pharmacophoric determinants as close as possible to a maximum common substructural consensus required to target the whole HDAC panel. The judicious inclusion of specific appendages capable of interacting with specific residues in the cap region of HDACs can provide valuable structural, functional, and stereochemical insight into the design of new inhibitors.In a previous study, we determined the optimal alkyl chain length for activity against a single isoform, HDAC2. 20 Designed for understanding the role of the chirality in simple ω-alkoxy analogues of Vorinostat, compound (R/S)-2 emerged as a promising lead for its preliminary cytotoxic activity against leukemia, colon, and lung tumor cell lines. Here, we describe the details for the improved and shortened synthesis of 2, together with the biostructural insights through molecular modeling and a preliminary study of its in vitro activity against an extended panel of HDACs.Although relatively simple in conception, the previous nine-step synthesis of racemic 2 20 was shortened and adapted to produce gram-scale material for pharmacological studies (Supporting Information) (Scheme 1). The required 8-carbon chain of (R/S)-2 was assembled by a cross metathesis reac...

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“…To a mixture of 429 mg (1.56 mmol) of glycolate 19, 249 mg (0.510 mmol) of diacid 18, and 360 μL (2.07 mmol) of DIEA in 4.0 mL of THF was added 614 mg (2.05 mmol) of DEPBT 26 . After stirring overnight, the mixture was diluted with 30 mL of ethyl acetate and washed with 10 mL portions of the following: 10% citric acid, water, sat.…”

Section: Chemistrymentioning

confidence: 99%

“…The crude diamine was dissolved in 5 mL of CH 2 Cl 2 , cooled to 0°C, and 222 mg (0.658 mmol) of 9-fluorenylmethyl N-succinimidyl carbonate was added, followed by 90 µL (0.65 mmol) of TEA. After 30 min, the mixture was diluted with 65 mL of ethyl acetate and washed with 20 mL portions of 5% citric acid, 50% brine, and dried over Na 2 26 . After stirring at room temperature for 15 h, the mixture was diluted with 30 mL of ethyl acetate and washed with 10 mL portions of 5% aq.…”

Section: Chemistrymentioning

confidence: 99%