Electron nuclear double resonance detection of distinct multimodal inclusion complexes of .beta.-cyclodextrin with a nitroxide spin adduct probe

1992 ◽  
Vol 114 (8) ◽  
pp. 2872-2874 ◽  
Author(s):  
Yashige Kotake ◽  
Edward G. Janzen
2021 ◽  
Vol 11 (14) ◽  
pp. 6597
Author(s):  
Aldo Arrais ◽  
Marta Manzoni ◽  
Alessia Cattaneo ◽  
Valentina Gianotti ◽  
Nadia Massa ◽  
...  

Essential oils are widely recognized as natural alternatives to pharmaceutical antibacterial and antifungal agents. With respect to standard pharmaceutics, the advantages of essential oils are their (i) low production costs, (ii) lack of chemical and biochemical drawbacks that are intrinsic to the synthetic production process and (iii) good tolerance by humans. On the other hand, the liquid nature of essential oils poses concerns about their actual application in different therapeutic issues regarding their persistence and the ability to control or prolong drug release. In this study, two essential oils from oregano and winter savory showing antibacterial and antifungal features were complexed in a solid state with beta-cyclodextrin. Host–guest inclusion complexes were characterized using FT-IR spectroscopy, ESI-MS and GC-MS techniques. Manyfold terpenic and non-terpenic components of the oils could be observed and unambiguously identified as being included inside the carbohydrate hosts. Many of them provided a specific biocidal action. Indeed, essential oil host–guest inclusion products were tested against two Candida species and an S. aureus reference strain, showing that the oils effectively maintained their liquid performances. Solid-state tablets of the essential oil inclusion complexes embedded in polyvinylpyrrolidone could be obtained. These results pave the way for the solid-state application of essential oils in antibacterial and antifungal pharmaceutical treatments.


1996 ◽  
Vol 442 ◽  
Author(s):  
J.-M. Spaeth ◽  
S. Greulich-Weber ◽  
M. März ◽  
E. N. Kalabukhova ◽  
S. N. Lukin

AbstractThe electronic structure of nitrogen donors in 6H-, 4H- and 3C-SiC is investigated by measuring the nitrogen hyperfine (hf) interactions with electron nuclear double resonance (ENDOR) and the temperature dependence of the hf split electron paramagnetic resonance (EPR) spectra. Superhyperfine (shf) interactions with many shells of 13C and 29Si were measured in 6H-SiC. The hf and shf interactions are discussed in the framework of effective mass theory. The temperature dependence is explained with the thermal occupation of the lowest valley-orbit split A1 and E states. It is proposed that the EPR spectra of P donors observed previously in neutron transmuted 6H-SiC at low temperature (<10K) and high temperature (>60K) are all due to substitutional P donors on the two quasi-cubic and hexagonal Si sites, whereby at low temperature the E state is occupied and at high temperature the A1 state. The low temperature spectra are thus thought not to be due to P-vacancy pair defects as proposed previously.


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