- Polymer conjugates of the highly potent cytostatic drug 2-pyrrolinodoxorubicin
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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.
- Studenovsky,Ulbrich,Ibrahimova,Rihova
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- Bis(pyridine)iodonium tetrafluoroborate (IPy2BF4): A versatile oxidizing reagent
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The use of bis(pyridine)iodonium tetrafluoroborate (IPy2BF 4) as an oxidizing agent towards different types of alcohols is reported. The observed reactivity involves different reaction pathways, as a function both of the structures of the starting materials and of the experimental conditions. Interestingly, the title iodine-containing compound is capable of a tuneable reaction with simple cycloalkanols, providing straight and selective access either to ω-iodocarbonyl compounds or to ketones, a previously unreported and chemoselective range of oxidation potential. Furthermore, appropriate conditions for the preparation of aldehydes and esters from primary alcohols by easily performed experimental procedures were also established. The β-scission reactions of cycloalkanols and the α-oxidation processes of primary, secondary and benzylic alcohols are discussed.
- Barluenga, Jose,Gonzalez-Bobes, Francisco,Murguia, Marcelo C.,Ananthoju, Sreenivasa R.,Gonzalez, Jose M.
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p. 4206 - 4213
(2007/10/03)
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- Oxidative opening of cycloalkanols: An efficient entry to ω-iodocarbonyl compounds
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Simply mix and switch on the light: This is all that is required to obtain ωfunctionalized aldehydes and ketones from readily available cyclic alcohols and IPy2BF4. The unusual oxidation process is outlined in Equation (1). R1/
- Barluenga, Jose,Gonzalez-Bobes, Francisco,Ananthoju, Sreenivasa R.,Garca-Martn, Miguel A.,Gonzalez, Jose M.
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p. 3389 - 3392
(2007/10/03)
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- Palladium-catalyzed diastereoselective cyclization of the allylic precursors. A concise synthetic route to 3-azabicyclo[3.3.0]Octane and hydroisoindole skeletons
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A useful variant of palladium-catalyzed 1,2-diastereoselective cyclization of the allylic precursors based on the steric nature of the anion stabilizing groups has been developed. The 1,1,2-trisubstituted cycloalkane products have also been efficiently transformed into the azabicyclic systems.
- Suh, Young-Ger,Lee, Young-Choon,Ko, Jung-Ae,Kim, Soon-Ai,Kim, Jee-Young,Jung, Jae-Kyung,Seo, Seung-Yong,Lee, Kee-Ho
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p. 3053 - 3060
(2007/10/03)
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- Controlling the Outcome of a Carbocation-initiated Cyclisation
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The Z- and E-vinylsilanes, 6,6-dimethoxy-2-methyl-1-trimethylsilylhex-1-ene (6), gave only 3-methoxy-1-methylcyclohexene (7) on treatment with zinc bromide, and the allylsilane, 6,6-dimethoxy-2-methyl-3-trimethylsilylhex-1-ene (8), gave only 5-methoxy-1-methylcyclohexene (9) on treatment with tin(IV) chloride.Taken together with an earlier result, these results show that the silyl group completely controls the outcome of this carbocationic cyclisation.The syntheses of the two starting materials, (6) and (8), illustrate the usefulness of the silyl-cuprate reagent in the costruction of specific vinyl- and allyl-silanes.
- Chow, Hak-Fun,Fleming, Ian
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p. 1815 - 1819
(2007/10/02)
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- Diphosphorus Tetraiodide. A Valuable Reagent in Cyclopropane Chemistry
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The behaviour of P2I4 and PI3 towards cyclopropyl alcohols, cyclopropyl ketones, α-seleno ketones, and ozonides is reported.
- Denis, J. N.,Krief, Alain
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p. 229 - 230
(2007/10/02)
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