Structural Studies of Some Phenoxazine Derivatives

Sridhar, M. A.; Ramegowda, M.; Lokanath, N.K.; Prasad, J. Shashidhara; Gowda, G. Byre; Thimmaiah, Κ. N.

doi:10.1080/10587259908025415

Cited by 7 publications

(5 citation statements)

References 14 publications

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“…In contrast, angles of 21.7 • or 34.76 • are observed for the corresponding interplanar geometry of the phenothiazine groups of 1 and 5, respectively. These angles are consistent with other solid-state structures of phenothiazine [3] or phenoxazine [30,31] derivatives.…”

Section: Synthesis Of Dyads and Triadssupporting

confidence: 90%

Donor-Acceptor Dyads and Triads Employing Core-Substituted Naphthalene Diimides: A Synthetic and Spectro (Electrochemical) Study

et al. 2022

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Donor-acceptor dyads and triads comprising core-substituted naphthalene diimide (NDI) chromophores and either phenothiazine or phenoxazine donors are described. Synthesis combined with electrochemical and spectroelectrochemical investigations facilitates characterisation of the various redox states of these molecules, confirming the ability to combine arrays of electron donating and accepting moieties into single species that retain the redox properties of these individual moieties.

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Section: Synthesis Of Dyads and Triadssupporting

confidence: 90%

Donor-Acceptor Dyads and Triads Employing Core-Substituted Naphthalene Diimides: A Synthetic and Spectro (Electrochemical) Study

et al. 2022

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“…Earlier studies on the secondary metabolites produced by C. gambosa, demonstrated that in culture, this fungal species synthesized an orange crystalline metabolite which was shown to be the phenoxazine derivatives (phenoxazone and a-amino-phenoxazone) (Clemencon, 1987;Moncalvo et al, 1991;Schlunegger et al, 1976). These derivatives are used extensively in medicine, biology and chemistry (Eregowda et al, 2000;Kalpana et al, 1999;Shimizu et al, 2004;Sridhar et al, 1999).…”

Section: Introductionmentioning

confidence: 99%

In vitro antifungal activity of Calocybe gambosa extracts against yeasts and filamentous fungi

Angelini¹,

Tirillini²,

Venanzoni³

2012

Afr. J. Microbiol. Res.

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Three strains of Calocybe gambosa (Fr.) Donk were investigated as possible sources of biologically active substances with antifungal activity. After submerged cultivation of C. gambosa mycelium, biologically active materials were isolated as ethyl acetate extracts from culture liquids. The in vitro activity of these C. gambosa extracts (Cg1, Cg2, Cg3) against yeasts and filamentous fungi was evaluated using the Clinical and Laboratory Standards Institute (CLSI) M27-A2 and M38-A2. The minimum inhibitory concentration (MIC) against most of the tested clinical fungal strains for Cg1 and Cg2 extracts ranges from 12.5 to 50 µg/ml while Cg3 ranged from 1.56 to 12.5 µg/ml. Candida albicans (DBVPG 4268) were the most sensitive fungal strain to C. gambosa extracts, with MIC ranges of 1.56 to 12.5 µg/mL, while the strains of Aspergillus tubingensis showed the least sensitivity to the extracts. The high performance liquid chromatography (HPLC) fingerprint of the isolates shows four principal compounds produced by the cultured mycelium. Considering the potential use of natural antifungal compounds in medicine, we are currently working on a small-scale extraction, isolation and structural characterization of compounds produced from the C. gambosa.

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“…The pentacyclic moiety of the molecule is virtually planar (the rms deviation from the plane is 0.109 Å). However, although the phenyl rings are planar within 0.006-0.044 Å, the O (14) and N(5) atoms in the oxazine ring deviate in the same direction from the plane passing through the other four C atoms of the oxazine ring by 0.072 and 0.064 Å, respectively. The geometric param eters of molecule 2c are within 3σ of the mean values.…”

Section: Resultsmentioning

confidence: 95%

“…11 It should be noted that we found no structures containing a similar pentacyclic moiety in the Cambridge Structural Database. 12 The most similar compounds containing the phenoxazine moiety, such as 2 methyl 2 (10 phenoxazi nyl)propionitrile, 13 10 piperidylacetylphenoxazine, 14 10 acetyl 1 cyanophenoxazine, 15 and 10 acetyl 3 cyano phenoxazine, 16 are nonplanar, and the oxazine ring in these compounds adopts a boat conformation. The bond lengths and bond angles in the phenoxazine fragment of molecule 2c are similar to the corresponding parameters in the above mentioned compounds.…”

Section: Resultsmentioning

confidence: 99%

Photocyclization of 2-azido-1-(4-tert-butylphenoxy)-9,10-anthraquinone in the presence of substituted phenols

et al. 2007

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New types of phototransformations in the quinone series, viz., photocyclizations of 1 aryloxy 2 azido 9,10 anthraquinone in the presence of phenols, were studied. The photoly sis affords mainly 5H naphtho[2,3 c]phenoxazine 8,13 diones, in which the nitrogen atom is covalently bound to the phenyl ring of the attached phenol. As a result, complex polycyclic derivatives of phenoxazines were prepared in high yields in one step.It is known 1,2 that visible light irradiation of 1 aryloxy 9,10 anthraquinone derivatives causes migration of the aryl group to the peri oxygen atom to form highly reactive 9 aryloxy 1,10 anthraquinones. Earlier, we have modi fied 1 aryloxy 9,10 anthraquinones by introducing the second photoactive (acyloxy, 3 nitroso, 4 diazo, azo, 5 or azido 6,7 ) group into the quinone molecule and studied the factors determining the reactivity and the preference of a particular reaction pathway. The photolysis and thermoly sis of 2 diazo and azido derivatives proved to be a conve nient general approach to the synthesis of new hetero cyclic 9,10 anthraquinone derivatives annelated at posi tions 1 and 2 with furan, thiophene, phenoxazine, or phenothiazine heterocycles. A new photoreaction, viz., the cyclization of 2 azido 1 (4 tert butylphenoxy) 9,10 anthraquinone in the presence of excess 4 tert butylphenol yielding 5H naphtho[2,3 c]phenoxazine 8,13 dione sub stituted at the nitrogen atom, was discovered in the study. 7 To our knowledge, data on analogous photoinitiated cy clizations of azido derivatives are lacking in the literature.Undoubtedly, a detailed investigation of this cycliza tion is of theoretical interest because the mechanism of this reaction and the dependence of its efficiency on the chemical nature of the reagents remain unclear. These data can be useful also in the applied aspect because the observed photocyclization is a new one step synthesis of various polycyclic phenoxazines and phenothiazines.The aim of the present study was to investigate photo chemical transformations of 2 azido 1 (4 tert butyl phenoxy) 9,10 anthraquinone in the presence of phenol and its alkyl derivatives, compare the efficiency of the phototransformations, and determine the structures of photocyclization products. Results and Discussion2 Azido 1 (4 tert butylphenoxy) 9,10 anthraquinone (1) was synthesized from 2 amino 1 chloro 9,10 anthra quinone by introducing the 4 tert butylphenoxy group according to a known procedure 8 followed by the diazoti zation of the amino group and the reaction of the result ing solution of the diazonium salt with NaN 3 by analogy with the study. 9A solution of azidoanthraquinone 1 and phenol ArOH in a ratio of 1 : 3 in dry benzene was irradiated at 20 °C with full light from a mercury lamp or with sunlight until azide 1 was completely consumed (Scheme 1). The photocyclization in the presence of unsubstituted phenol or ortho and para alkyl substituted phenols afforded the corresponding 5H naphtho[2,3 c]phenoxazine 8,13 diones 2a-d in high yields. In all cases, small amounts (<5%) of 1 hy...

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Structural Studies of Some Phenoxazine Derivatives

Cited by 7 publications

References 14 publications

Donor-Acceptor Dyads and Triads Employing Core-Substituted Naphthalene Diimides: A Synthetic and Spectro (Electrochemical) Study

Donor-Acceptor Dyads and Triads Employing Core-Substituted Naphthalene Diimides: A Synthetic and Spectro (Electrochemical) Study

In vitro antifungal activity of Calocybe gambosa extracts against yeasts and filamentous fungi

Photocyclization of 2-azido-1-(4-tert-butylphenoxy)-9,10-anthraquinone in the presence of substituted phenols

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