Derivatives of a Novel Cyclopeptolide. 2. Synthesis, Activity against Multidrug Resistance in CHO and KB Cells in vitro, and Structure-Activity Relationships
摘要:
A series of derivatives of the novel cyclopeptolide 1 was prepared, and their ability to chemosensitize multi drug resistant CHO and KB cells in vitro was evaluated. In contrast to the parent compound, several of the derivatives were found to be highly active. In particular, conversion of the R-lactic acid residue of 1 into its S-isomer via lactone ring cleavage and recyclization with inversion resulted in a marked enhancement of activity. Some of these derivatives (e.g., 15a, SDZ 280.446) belong to the most potent resistance modulating compounds known so far.
Structural modification and biological activity studies of tagitinin C and its derivatives
作者:Thi Hang Au、Charles Skarbek、Stephanie Pethe、Raphael Labruere、Jean-Pierre Baltaze、Thi Phuong Hoa Nguyen、Thi Thu Ha Vu、Giang Vo-Thanh
DOI:10.1016/j.tet.2021.132248
日期:2021.7
amines, phosphonates and thiols to Tagitinin C containing in its structure an α-methylene-γ-lactone motif and two α,β-unsaturated ketone systems has been described. 27 Tagitinin C derivatives were synthesized and isolated in good to excellent yield (up to 99% yield) under mild reaction conditions. The biologicalactivity of Tagitinin C and its derivatives were evaluated against three human cancer cell
胺、膦酸酯和硫醇与 Tagitinin C 的迈克尔加成反应在其结构中包含一个 α-亚甲基-γ-内酯基序和两个 α,β-不饱和酮系统已被描述。在温和的反应条件下,合成并分离了 27 种 Tagitinin C 衍生物,收率非常好(收率高达 99%)。Tagitinin C 及其衍生物对三种人类癌细胞系(乳腺癌人类癌细胞 MCF-7、对药物 MCF7-MDR 多重耐药的乳腺癌人类癌细胞、胰腺癌细胞 MiaPaCa-2)和正常细胞的生物活性进行了评估线(HEK-293)作为对照。我们表明 Tagitinin C 衍生物的生物活性仍然存在。这些化合物具有增强的水溶性,可以提高其生物利用度和药理学特征。
Chiral 2-vinyl-1,3,2-oxazaphospholidin-2-ones: new dienophiles for asymmetric Diels–Alder reactions
DielsâAlder reactions of chiral dienophiles: (2R,4S)- and (2R,4S)-2-vinyl-1,3,2-oxazaphospholidin-2-ones (3 and 4) derived from (S)-valinol with cyclopentadiene led to mixtures of endo- and exo-adducts with high diastereofacial selectivity (>90% for 3 and 80 and 88% respectively for 4); an explanation is proposed based on X-ray crystallographic structures for the dienophile and the derived endo-cycloadduct 5.
A convenient method for the synthesis of unsymmetrical 3,4-disubstituted pyrroles
作者:Patrick W. Shum、Alan P. Kozikowski
DOI:10.1016/s0040-4039(00)97171-5
日期:1990.1
A simplified procedure for the synthesis of 3,4-dibromo-1-[tris(1-methylethyl)silyl]-1H-pyrrole (2) is described together with its sequential halogen-metal exchange chemistry to afford 3,4-disubstituted pyrroles.
A simple chiral derivatisation protocol for 1H NMR spectroscopic analysis of the enantiopurity of O-silyl-1,2-amino alcohols
作者:Magdalena E. Powell、Andrew M. Kelly、Steven D. Bull、Tony D. James
DOI:10.1016/j.tetlet.2008.12.013
日期:2009.2
A simplechiral derivatisation protocol for determining the enantiopurity of O-silyl-protected-1,2-amino alcohols by 1HNMRspectroscopicanalysis is described, which involves their treatment with 2-formylphenylboronic acid and enantiopure (syn)-methyl-2,3-dihydroxy-3-phenylpropionate to afford mixtures of imino-boronate esters whose diastereoisomeric ratio is an accurate reflection of the enantiopurity
描述了一种简单的手性衍生方案,可通过1 H NMR光谱分析确定O-甲硅烷基保护的1,2-氨基醇的对映体纯度,涉及用2-甲酰基苯基硼酸和对映纯(syn)-甲基-2处理3-二羟基-3-苯基丙酸酯提供亚氨基-硼酸酯的混合物,其非对映异构体比率准确反映了母体氨基醇的对映体纯度。
A model study for the synthesis of the tumor promoting agents lyngbyatoxin a and teleocidin b—further aspects of a new isoxazoline-based indole synthesis.
作者:Alan P. Kozikowski、X.-M. Cheng
DOI:10.1016/s0040-4039(00)89289-8
日期:1985.1
A newindole synthesis developed in our laboratories has been shown to be applicable to the preparation of 4-amino-7-carbon substituted indoles, a result of some relevance to the preparation of the title compounds.