Phenoxazine-3-one

Phenoxazin-3-ones synthesis, 3, 1034 Phehprocoumon H NMl 3, 582 Phensuximide as anticonvulsant, 1, 166 Phentolamine... 

Resorufin (7-hydroxy-3H-phenoxazine-3-one Na salt) [635-78-9] M 213.2, pK 6.93, pKj 9.26, pK l0.0. Washed with water and recrystd from EtOH several times. 

Fig. 5 Example of steric CoMFA contour map results using APO (2-amino-3H-phenoxazin-3-one) for visualization near green area greater toxicity is correlated with more bulky groups and near yellow area with the less bulky group. 

Dactinomycin Dactinomycin, 2-amino-l,9-bis-(2,9-diisopropyl-6,10,13-trimethyl-l,4,8,ll,14-pentaoxo-7-oxa-3,10,13-17a-tetraaza-5-bicyclo[14.3.0]nonadecylcarbamoyl)-4,6-dimethyl-3//-phenoxazin-3-one (30.3.1), is one of the first antibiotics isolated from a liquid culture of microorganisms of the family Streptomyces parvulus [80-87]. It is a chromonopeptide with a phenoxazine ring and two cyclic polypeptides joined to the carboxyl group at position 2 and 9 of the phenoxazine ring. 

Phenoxazin-3-ones and phenothiazin-3-ones can be prepared by condensation of 2-aminophenols or -thiols with quinones. Alizarin Green G (61), for example, is obtained from (59) and (60). Similarly, 2-aminothiophenols and 6-chloro-2-methoxy-l,4-benzoquinone (62) afford phenothiazin-3-ones (63). 

Actinomycin D has been clinically used for the treatment of many cancers and is known to be a DNA intercalator. The structure of actinomycin D is based on a phenoxazine ring bound to two cyclic pentapeptides [33]. The presence of the phenoxazine ring in the structure of actinomycin D suggests that phenoxazine derivatives may possess anticancer activity. Phenoxazine derivatives are known to be effective multidrug resistance (MDR) modulators in cancer cells [34], potent inhibitors of Akt signaling in cells [35], inhibitors of human plasma cholinesterase [36], and photo-chemotherapeutic agents in cancer cells [37]. Recent studies also show that the relatively water-soluble phenox-azines, such as 2-amino-4,4a-dihydro-4a,7-dimethyl-2H-phenoxazine-3-one and 2-aminophenoxazine-3-one, exert antitumor effects on various cancer cells in vitro and in vivo. [38]. We have investigated 24 phenoxazines [23,39] (Fig. 4). 

Phenoxazine and 3-acetoxyphenoxazine, as well as their 10-acetyl derivatives, when oxidized with nitrous acid at 5°, are converted into 3H-phenoxazin-3-ones.40... 

Reductive acetylation of various 3//-phenoxazin-3-ones has been shown to yield the corresponding 3-acetoxyphenoxazines.40... 

Tecoma stans,93 have been shown to catalyze the condensation of o-aminophenol to 2-amino-3i/-phenoxazin-3-one (52, R = H) to which the name questiomycin A has been given by Anzai et al.9i This compound has been isolated also from Streptomyces fungicidicus,9 and, along with 2-acetylamino-3i/-phenoxazin-3-one (52, R = COCH3), from members of the actinomycete genus Waksmania.96... 

The change in color from various shades of red to yellow, which accompanies the reduction of substituted 3iZ-phenoxazin-3-ones, has made them suitable as bromometric and stannometric redox indicators111-113 RuziCka114 reported also the microdetermination of compounds containing SH groups with such derivatives. Phenoxazine has been described as a stabilizer for polymerizable vinylpyridines115... 

Polarographic studies of dyes have been described Pamfilov et al. reported the polarography of Methylene Blue and Thionine at a dropping mercury electrode, and other Soviet workers have reported a polarographic study of 3i/-phenoxazin-3-one and its benzo derivatives. 

A flash-photolytic study of phenoxazine has been reported.Three transient species were observed the first triplet state, 253, and 248. The results are consistent with the formation of 248 in a biphotonic process involving the triplet. In the presence of oxygen, neither the triplet nor 248 was observed continuous-irradiation experiments indicated that probably 253 reacts with oxygen, via unstable hydroperoxide intermediates, to give, as stable photooxidation product, 3i/-phenoxazin-3-one. 

Uptake kinetics with oat had to be performed in presence of antibiotics, because the benzoxazolin-2(3//)-one was converted to orange-red compounds, due to microbial activity. One compound was identified as 2-amino-5//-phenoxazin-3-one [180], which is known to appear within 10 days in nonsterile soil after incubation with DIBOA [181]. Microorganisms degrade BOA to 2-aminophenol, that reacts subsequently without further enzymatic catalysis resulting in 2-amino-i//-phenoxazin-3-one [182-185]. Acinetobacter calcoacetius was identified as an organism responsible for 2-aminophenol production [183]. In antibiotic-... 

ReSOmfin (7-hydroxy-3ff-phenoxazin-3-one Na salt) [34994-50-8] M 252.2, decomp on heating, pK 5,8 (H2O), 6.10 (50% aqueous MeOH). The free acid is purified by dissolving it in cone H2SO4 which on dilution precipitates resorufin and is filtered off, washed well with hot H2O and dried. [Eichler J Prakt Chem 139 113 1934 Detailed UV and IR studies were reported by Musso Mattheis Chem Ber 90 1814 1957]. [pKa Musso Rathjen Chem Ber 92 751 1959, Beilstein 27 IV 2263.]... 

The irradiation of the phenoxazin-3-one dye, resazurin (21), in the presence of tertiary amines results in its efficient deoxygenation via the triplet state, forming the dye resorufin (22). The radiolysis/photolysis of aqueous solutions of pyrimidines produces radicals which are the result, in general, of 1-electron reduction involving hydrated electrons. The structures of the radicals were assigned on the basis of their by EPR spectra. The study included 2-hydroxypyrimidine... 

Heating benzoxazinone under the same conditions leads to 4,5,6-tetrafluoro-3f/-pyrido[3,2,l-k]phenoxazin-3-one (97ZOR1418) (Scheme 160). 

---