N-Acyl O-amino phenol derivatives of CBI-TMI and CBI-indole2 are reported as prototypical members of a new class of reductively activated prodrugs of the duocarmycin and CC-1065 class of antitumor agents. The expectation being that hypoxic tumor environments, with their higher reducing capacity, carry an intrinsic higher concentration of "reducing" nucleophiles (e.g., thiols) capable of activating such derivatives (tunable N-O bond cleavage) and increasing their sensitivity to the prodrug treatment. Preliminary studies indicate the prodrugs effectively release the free drug in functional cellular assays for cytotoxic activity approaching or matching the activity of the free drug, yet remain essentially stable and unreactive to in vitro DNA alkylation conditions (<0.1-0.01% free drug release) and pH 7.0 phosphate buffer, and exhibit a robust half-life in human plasma (t1/2 = 3 h). Characterization of a representative O-(acylamino) prodrug in vivo indicates that they approach the potency and exceed the efficacy of the free drug itself (CBI-indole2), indicating that not only is the free drug effectively released from the inactive prodrug but also that they offer additional advantages related to a controlled or targeted release in vivo.
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http://dx.doi.org/10.1021/ja075398e | DOI Listing |
Yakugaku Zasshi
February 2022
Graduate School of Pharmaceutical Sciences, Tohoku University.
Among my recent work on the syntheses of complex natural products based on the development of a novel synthetic method for the heteroaromatic skeleton, this article primarily deals with the total syntheses of (+)-CC-1065, isobatzeline A/B, and batzeline A. These syntheses were accomplished via a novel indole synthesis utilizing a ring expansion reaction of benzocyclobutenone oxime sulfonate as the key step. The 1,2-dihydro-3H-pyrrolo[3,2-e]indole segments of (+)-CC-1065 were rapidly constructed via a two-directional double-ring expansion strategy.
View Article and Find Full Text PDFNat Commun
November 2021
Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA.
Microbes produce a broad spectrum of antibiotic natural products, including many DNA-damaging genotoxins. Among the most potent of these are DNA alkylating agents in the spirocyclopropylcyclohexadienone (SCPCHD) family, which includes the duocarmycins, CC-1065, gilvusmycin, and yatakemycin. The yatakemycin biosynthesis cluster in Streptomyces sp.
View Article and Find Full Text PDFNat Prod Rep
January 2020
State Key Laboratory of Bio-organic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China.
Covering: 2012 to 2019HemN-like radical S-adenosyl-l-methionine (SAM) enzymes have been recently disclosed to catalyze diverse chemically challenging reactions from primary to secondary metabolic pathways. In this highlight, we summarize the reaction examples catalyzed by HemN-like enzymes to date and the enzymatic mechanisms reported. From the recent mechanistic investigations, we reason that there is a shared initiating mechanism wherein a characteristic SAM methylene radical is proposed to abstract a hydrogen atom from an sp carbon or add onto an sp carbon center although variations occur thereafter from reaction to reaction, as well as providing a brief insight into some future prospects.
View Article and Find Full Text PDFNat Commun
July 2018
State Key Laboratory of Bio-organic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
Cyclopropanation of unactivated olefinic bonds via addition of a reactive one-carbon species is well developed in synthetic chemistry, whereas natural cyclopropane biosynthesis employing this strategy is very limited. Here, we identify a two-component cyclopropanase system, composed of a HemN-like radical S-adenosyl-L-methionine (SAM) enzyme C10P and a methyltransferase C10Q, catalyzes chemically challenging cyclopropanation in the antitumor antibiotic CC-1065 biosynthesis. C10P uses its [4Fe-4S] cluster for reductive cleavage of the first SAM to yield a highly reactive 5'-deoxyadenosyl radical, which abstracts a hydrogen from the second SAM to produce a SAM methylene radical that adds to an sp-hybridized carbon of substrate to form a SAM-substrate adduct.
View Article and Find Full Text PDFActa Biochim Biophys Sin (Shanghai)
May 2018
State Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China.
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