13748-90-8Relevant articles and documents
A post-modification strategy for the synthesis of uniform, hydrophilic/hydrophobic patterned a-hydroxy acid oligomers
Franz, Nadja,Menin, Laure,Klok, Harm-Anton
, p. 5390 - 5405 (2009)
Hydrophilic/hydrophobic patterning is a well-established design strategy to guide secondary structure formation of both natural as well as non-natural oligomers and polymers. This contribution explores the feasibility of a new approach for the synthesis of uniform, sequence-defined, hydrophilic/hydrophobic patterned oligo(α-hydroxy acid)s. The proposed strategy is based on post-modification of a reactive oligoester scaffold composed of an alternating sequence of hydrophobic [(2S)-2-hydroxy-4-methylpentanoic acid] and masked hydrophilic [(2S)-2-hydroxypent-4-enoic acid] a-hydroxy acids. The use of (2S)-2-hydroxypent-4-enoic acid instead of a complex side-chain-protected hydrophilic building block obviates the need for additional protective group chemistry during chain extension. In a subsequent post-modification step, the allyl side chains can be quantitatively modified via free-radical addition of different co-functional thiols to afford hydrophilic/hydrophobic patterned oligoesters. The proposed synthetic strategy provides an interesting alternative to rapidly generate libraries of foldamers with identical chain length and monomer sequence but different side-chain functionalities.
Enantioselective synthesis of α-hydroxy carboxylic acids: Direct conversion of α-oxocarboxylic acids to enantiomerically enriched α-hydroxy carboxylic acids via neighboring group control
Wang, Zhe,La, Brittany,Fortunak, Joseph M.,Meng, Xian-Jun,Kabalka, George W.
, p. 5501 - 5504 (1998)
α-Oxocarboxylic acids can be reduced to the corresponding α-hydroxy carboxylic acids employing DIP-CI(TM) as a reducing agent. The α-carboxylic substituent exerts a remarkable neighboring group effect on the reduction. The reaction presumably proceeds in an intramolecular fashion through a 'rigid' bicyclic transition state assembly, which produces enantioselectivities approaching 99%.
ACCURATE DETERMINATION OF THE INTRINSIC RACEMIZATION IN CHIRAL SYNTHESIS VIA ENANTIOMER RESOLUTION OF UNDERIVATIZED VICINAL DIOLS
Koppenhoefer, B.,Trettin, U.,Figura, R.,Lin, B.
, p. 5109 - 5110 (1989)
The accurate assessment of the intrinsic racemization (down to 0.01percent), inherent to reactions typically applied in chiral synthesis, demands for (i) a precursor of almost 100percent e.e. (e.g., S-1a, e.e. >=99.99percent), and (ii) a reliable method for the determination of e.e. of the product (e.g., the derivatization-free enantiomer resolution of the vicinal diol 3a by GC on Chirasil-Val).
Cyclodepsipeptides, sesquiterpenoids, and other cytotoxic metabolites from the filamentous fungus Trichothecium sp. (MSX 51320)
Sy-Cordero, Arlene A.,Graf, Tyler N.,Adcock, Audrey F.,Kroll, David J.,Shen, Qi,Swanson, Steven M.,Wani, Mansukh C.,Pearce, Cedric J.,Oberlies, Nicholas H.
, p. 2137 - 2142 (2011)
Two new cyclodepsipeptides (1 and 2), two new sesquiterpenoids (3 and 4), and the known compounds guangomide A (5), roseotoxin S, and three simple trichothecenes were isolated from the cytotoxic organic extract of a terrestrial filamentous fungus, Trichothecium sp. The structures were determined using NMR spectroscopy and mass spectrometry. Absolute configurations of the cyclodepsipeptides were established by employing chiral HPLC, while the relative configurations of 3 and 4 were determined via NOESY data. The isolation of guangomide A was of particular interest, since it was reported previously from a marine-derived fungus.
Biocontrolled formal inversion or retention of L -α-amino acids to enantiopure (R)- or (S)-hydroxyacids
Busto, Eduardo,Grischek, Barbara,Kroutil, Wolfgang,Richter, Nina
, p. 11225 - 11228,4 (2014)
Natural L-α-amino acids and L-norleucine were transformed to the corresponding α-hydroxy acids by formal biocatalytic inversion or retention of absolute configuration. The one-pot transformation was achieved by a concurrent oxidation reduction cascade in aqueous media. A representative panel of enantiopure (R)- and (S)-2-hydroxy acids possessing aliphatic, aromatic and heteroaromatic moieties were isolated in high yield (67-85 %) and enantiopure form (>99 % ee) without requiring chromatographic purification.
Total Synthesis of the Natural Herbicide MBH-001 and Analogues
Barber, David M.,D?ller, Uwe,Dietrich, Hansj?rg,Hoffmann, Michael G.,Kocakaya, Tamer,Kuhn, Birgit,Maier, Martin E.,Morkunas, Marius,Schmutzler, Dirk,Schnatterer, Stefan
, p. 2271 - 2290 (2020/04/23)
The first total synthesis of the natural herbicide MBH-001 (1) is reported. Structurally it is a 2-methyloxazol-5(2H)-one with a (1-hydroxyethyl) substituent at the 2-position. By relying on cyclic nitrones, a flexible route to MBH-001 and relevant analogues was developed. Key steps include the reaction of a 2-hydroxyimino ester with an aldehyde to form a 5-oxo-2,5-dihydrooxazole 3-oxide. In an aldol-type reaction, the anion of these cyclic nitrones reacted with an aldehyde at the 2-position. A final reduction of the nitrone to the corresponding imine using zinc led to the target compounds. The cyclic nitrones are also accessible by reacting an α-keto acid with an oxime. These two versatile synthetic routes enabled us to prepare the first MBH-001 analogues for structure activity relationship analysis of the herbicidal efficacy. Thus, furthering our aim of developing new herbicides to tackle the ever-growing problem of weed resistance.
A novel Anti-Cancer Stem Cells compound optimized from the natural symplostatin 4 scaffold inhibits Wnt/β-catenin signaling pathway
Liu, Shuangwei,Gao, Xian,Zhang, Lisong,Qin, Shuanglin,Wei, Mingming,Liu, Ning,Zhao, Rui,Li, Benlong,Meng, Ye,Lin, Gang,Lu, Cheng,Liu, Xinhua,Xie, Maodun,Liu, Tongtong,Zhou, Honggang,Qi, Min,Yang, Guang,Yang, Cheng
, p. 21 - 42 (2018/07/06)
Cancer stem cells (CSCs) are responsible for carcinogenesis, cancer progression, relapse, metastasis and drug resistance. Therefore, the development of drug molecules targeting CSCs plays a vital role in medicinal researching field. However, there are extremely rare molecules that selectively ablate CSCs. The research and development of drugs targeting CSCs is limited due to a lack of anti-CSCs lead compounds. In this study, an anti-CSCs lead compound 35b was discovered, which was derived from the natural chemical scaffold of Symplostatin 4. This compound exhibited a significantly suppressive effect on tumor growth both in vitro and in vivo. Additionally, 35b could significantly reduce the number of melanoma tumor spheres and decrease the percentage of ALDH+ melanoma cells. Further mechanism study illustrated that compound 35b could eliminate the melanoma CSCs by efficiently blocking Wnt/β-catenin signaling pathway. Collectively, our findings would provide a novel chemical scaffold and alternative idea of molecular design for development of anti-CSCs drugs.
