Mitomycin C

Mitochondrial monoamine oxidase, 1, 253 Mitomycin synthesis, 7, 658, 659 Mitomycin-A, 7, 93 Mitomycin-B, 7, 93 Mitomycin-C, 7, 93 as antitumor drug, 4, 374 Mixed function oxidases, 1, 224 Mobam... 

Leptosins D-F (258a-c, Scheme 39) [94JCS(P1)1859] were isolated by Takahashi and co-workers from the culture of a strain of Leptosphaeria sp. as cytotoxic substances against the P388 lymphocytic leukemia cell line comparable to that of mitomycin C. Utilizing the nucleophilic substitution reaction of 1-hydroxytryptamines, a simple methodology for the synthesis of core structures of leptosins has been developed (2000H1255). 

Figure 11.16 Chromatograms of plasma samples obtained by using SPE-SFC with super-aitical desorption of the SPE cartridge (a) blank plasma (20 p.1), UV detection at 215 nm (b) blank plasma (20 p.1), UV detection at 360 nm (c) plasma (1 ml) containing 20 ng mitomycin C (MMC), UV detection at 360 nm. Reprinted from Journal of Chromatography, 454, W. M. A. Niessen et al., Phase-system switching as an on-line sample pretreatment in the bioanalysis of mitomycin C using supercritical fluid cliromatography, pp. 243-251, copyright 1988, with permission from Elsevier Science.

W. M. A. Niessen, R J. M. Bergers, U. R. Tjaden and J. van der Greef, Phase-system switclring as an on-line sample preti eatment in the bioanalysis of mitomycin C using supercritical fluid clrromatogi aphy , 7. Chromatogr. 454 243-251 (1988). 

Mitomycin Mitomycin C Ametycine Mutamycin Mytomycin C Mutamycin Mitomycin C... 

The antitumor antibiotic mitomycin C functions by forming cross-links in DNA chains. 

Microwaves, electromagnetic spectrum and. 419 Mincralocorticoid, 1083 Minor groove (DNA), 1104-1105 Mitomycin C, structure of, 970 Mixed aldol reaction, 885-886 requirements for. 885-886 Mixed Claisen condensation reaction, 890-891... 

Mitomycin C was found to have broad activity against a range of tumors and has been used clinically since the early 1960s [14, 15]. It causes many specific cellular effects, including inhibition of DNA synthesis, recombination, chromosome breakage, sister chromatid exchange, induction of DNA repair, and induction of... 

The requirement for reduction prior to DNA alkylation and crosslinking was first demonstrated by Iyer and Szybalski in 1964 [29], and can be induced both by chemical reducing agents such as sodium dithionite and thiols in vitro and by various reductive enzymes such as DT-diaphorase (NAD(P)H-quinone oxidoreduc-tase) in vitro and in vivo [47]. Much work to characterize the mechanism of reductive activation and alkylation has been carried out, principally by the Tomasz and Kohn groups, and Figure 11.1 illustrates a generally accepted pathway for mitomycin C [16, 48-50] based on these experiments, which is very similar to the mechanism originally proposed by Iyer and Szybalski [29]. 

The different possible adducts formed between mitomycin C and DNA have been isolated by degradation of DNA after in vitro alkylation/crosslinking reactions and structurally characterized. Monoadduct 21 (Scheme 11.3), derived from alkylation at C-l only [53], and monoadducts 22 [54] and 23 [55, 56] (derived from C-10 alkylation by 16 at N-7 or N-2 of guanine, respectively) have been isolated, together with bisadducts 24 [57] and 25 [58], derived from interstrand and intrastrand crosslinks, respectively, and adduct 26 [59], formed by addition of a molecule of water to C-10 instead of the second guanine. All of these adducts have also been isolated from DNA after in vivo crosslinking [60, 61]. 

Figure 11.3 Biosynthetic origin of the O-methyl and carbamoyl groups of mitomycin C.

Figure 11.4 Carbohydrate precursors to the carbon skeleton of mitomycin C.

A number of mitomycin analogues have been prepared by precursor-directed biosynthesis [104]. A range of amines were fed to S. caespitosus, and novel derivatives of mitomycin C (type I analogues) and mitomycin B (type II analogues) were identified and in some cases (42-46 and 52-56 Scheme 11.4) isolated and characterized. Antibiotic and antitumor activities were comparable to those of mitomycin C, with the type I analogues more active than the type II analogues. 

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