Polymer conjugates of the highly potent cytostatic drug 2-pyrrolinodoxorubicin
摘要:
This paper describes the synthesis and biological evaluation of a conjugate of the highly cytotoxic drug 2-pyrrolinodoxorubicin (p-DOX) with an N-(2-hydroxypropyl)methacrylamide copolymer (PHPMA) as a water-soluble biocompatible polymer carrier, utilizing the advantageous concept of polymer-drug conjugates. The conjugate of p-DOX with HPMA copolymer (PHPMA/p-DOX) was prepared by reacting the PHPMA/DOX conjugate, where the DOX was bound via a hydrazone bond, with 4-iodobutyraldehyde. The hydrazone bond between the polymer and drug is susceptible to pH-controlled hydrolysis, enabling prolonged stability in circulation and fast p-DOX release under conditions mimicking the intracellular environment. The in vitro cytostatic activity of free p-DOX was in accordance with literature, whereas its PHPMA conjugate exhibited a 1.3- to 5-fold lower cytotoxicity, depending on the cancer cell line, when compared to the free p-DOX. This is in qualitative agreement with the data obtained for DOX and its HPMA copolymer conjugates. On mice bearing T-cell EL4 lymphoma, no tumor suppression was observed from the free p-DOX at a subtoxic dose of 0.1 mg/kg, whereas the PHPMA/p-DOX conjugate significantly inhibited the initial tumor growth at approximately equitoxic doses of 0.4 and 0.8 mg p-DOX eq/kg. However, moderately elevated doses of the p-DOX equivalent in the conjugate caused toxic effects, making accurate dosage setting essential. (C) 2010 Elsevier B.V. All rights reserved.
Asymmetric synthesis and structural assignment of (−)-α-conhydrine
摘要:
The first asymmetric synthesis of the conium alkaloid (-)-alpha-conhydrine is reported. Starting from a protected glycol aldehyde hydrazone as chiral precusor, a short route based on our alpha-alkylation/1,2-addition methodology has been developed. After cleavage of the auxiliary and simultaneous deprotection, the concluding ring closure is accomplished under reductive amination conditions. The title compound is obtained in moderate overall yield and in excellent diastereo- and enantiomeric excess (d.e., e.e. >96%). Single-crystal X-ray crystallography as well as H-1 NMR NOE experiments confirm the expected relative and absolute (2R,7S)-configuration of the product. (C) 2002 Elsevier Science Ltd. All rights reserved.
Preparation of (S)-2-amino-6, 6-dimethoxyhexanoic acid methyl ester via
申请人:Bristol-Myers Squibb Co.
公开号:US06166227A1
公开(公告)日:2000-12-26
The glycinamide of the formula (I) ##STR1## is reacted with the dioxolane of the formula (II) ##STR2## wherein L is a leaving group such as iodo, bromo, alkylsulfonyloxy, or arylsulfonyloxy to give the dioxolane of the formula (III) ##STR3## Treatment of (III) gives the dioxolane pentanoic acid IV ##STR4## which can be converted to (S)-2-amino-6,6-dimethoxyhexanoic acid, methyl ester.
Preparation of (s)-2-amino-6,6-dimethoxyhexanoic acid methyl ester via novel dioxolanes
申请人:Bristol-Myers Squibb Co.
公开号:US06248882B1
公开(公告)日:2001-06-19
The glycinamide of the formula
is reacted with the dioxolane of the formula
wherein L is a leaving group such as iodo, bromo, alkylsulfonyloxy, or arylsulfonyloxy to give the dioxolane of the formula
Treating the dioxolane of formula III under aqueous refluxing conditions followed by exchanging the dioxolane acetal with a dimethoxy acetal and introduction of the methyl ester gives (S)-2-amino-6,6-dimethoxyhexanoic acid, methyl ester which is an intermediate in the preparation of the dual inhibitor [4S-[4&agr;(R*),7&agr;, 10a&bgr;]]-)octahydro-4-[(2-mercapto-1-oxo-3-phenylpropy)-amino]-5-oxo-7H-pyrido[2,1-b][1,3]thiazepine-7-carboxylic acid. Also disclosed are storage stable salts of (S)-2-amino-6,6-dimethoxyhexanoic acid, methyl ester.
Asymmetric Total Synthesis of Twin Bufogargarizins A and B
作者:Li-Ping Zhong、Rui Feng、Jing-Jing Wang、Chuang-Chuang Li
DOI:10.1021/jacs.2c13494
日期:2023.2.1
The first and asymmetric total synthesis of bufogargarizins A and B, two unusual and highly oxygenated twin steroids with rearranged A/B rings, was achieved. The synthetically challenging [7–5–6–5] tetracyclic ring system of bufogargarizin A was efficiently constructed by the first intramolecular Ru-catalyzed [5 + 2] cycloaddition reaction of a vinyl ether cyclopropane-yne. Notably, the interesting
bufogargarizins A 和 B 是两种不寻常且高度氧化的双类固醇,具有重排的 A/B 环,首次实现了不对称全合成。通过乙烯基醚环丙烷炔的第一个分子内 Ru 催化的 [5 + 2] 环加成反应,有效地构建了具有合成挑战性的 bufogargarizin A [7-5-6-5] 四环系统。值得注意的是,有趣的 [5-7-6-5] 蟾蜍加利津 B 四环骨架通过来自 [7-5-6-5] 四环框架的独特逆醛醇/跨环醛醇级联反应非对映选择性地重新组装。
Asymmetric epoxidation of allylic alcohols employing 4,5-diphenyloxazole as a masked ester functionality
作者:Lendon N. Pridgen、S.C. Shilcrat、I. Lantos
DOI:10.1016/s0040-4039(01)81303-4
日期:1984.1
Thromboxane synthase inhibitors. Synthesis and pharmacological activity of (R)-, (S)-, and (.+-.)-2,2-dimethyl-6-[2-(1H-imidazol-1-yl)-1-[[(4-methoxyphenyl)methoxy]methyl]ethoxy]hexanoic acids
作者:Paul W. Manley、David P. Tuffin、Nigel M. Allanson、Philip E. Buckle、Nagin Lad、Steve M. F. Lai、David O. Lunt、Roderick A. Porter、Patricia J. Wade
DOI:10.1021/jm00393a022
日期:1987.10
A series of substituted omega-[2-(1H-imidazol-1-yl)ethoxy]alkanoic acid derivatives were synthesized and evaluated for their ability to inhibit thromboxane synthase both in vitro and in vivo. Compound 13 was identified as a potent and selective competitive inhibitor of human platelet thromboxane synthase having a Ki value of 9.6 X 10(-8) M. In collagen-treated human whole blood, 13 potentiated levels of 6-keto PGF1 alpha. Enantiospecific syntheses afforded the R and S enantiomers of 13, of which the S enantiomer 13b was the more potent. Compounds 13 and 13b were potent in vivo inhibitors of thromboxane synthase with good oral activity and duration of action.