36468-53-8Relevant articles and documents
60CO-irradiation as an alternate method for sterilization of Penicillin G, neomycin, novobiocin, and dihydrostreptomycin
Tsuji,Rahn,Steindler
, p. 23 - 26 (1983)
The effects of the use of 60Co-irradiation to sterilize antibiotics were evaluated. The antibiotic powders were only occasionally contaminated with microorganisms. The D-values of the products and environmental isolates were 0.028, 0.027, 0.015, 0.046, 0.15, 0.018, and 0.19 Mrads for Aspergillus species (UC 7297, 7298), A. fumigatus (UC 7299), Rhodotorula species (UC 7300), Penicillium oxalicum (UC 7269), Pseudomonas maltophilia (UC 6855), and a biological indicator microorganism, Bacillus pumilus spores (ATCC 27142). An irradiation dose of 1.14 Mrads, therefore, was sufficient to achieve a six-log cycle destruction of B. pumilus spores. Based on the bioburden data, a minimum irradiation dose of 1.05 Mrads was calculated to be sufficient to obtain a 10-6 probability of sterilizing the most radioresistant isolate, Pen. oxalicum. To determine the radiolytic degradation scheme and the stability of the antibiotics following irradiation, high-performance liquid chromatographic (HPLC) methods were developed. The resulting rates of degradation for the antibiotics were 0.6, 1.2, 2.3, and 0.95%/Mrad for penicillin G, neomycin, novobiocin, and dihydrostreptomycin, respectively. Furthermore, radiolytic degradation pathways for the antibiotics were identified and found to be similar to those commonly encountered when antibiotics are subjected to acidic, basic, hydrolytic, or oxidative treatments. No radiolytic compounds unique to 60Co-irradiation were found.
Dihydronicotinamide riboside: synthesis from nicotinamide riboside chloride, purification and stability studies
Abbaspourrad, Alireza,Enayati, Mojtaba,Khazdooz, Leila,Madarshahian, Sara,Ufheil, Gerhard,Wooster, Timothy J.,Zarei, Amin
, p. 21036 - 21047 (2021/07/01)
In the present work, we describe an efficient method for scalable synthesis and purification of 1,4-dihydronicotinamide riboside (NRH) from commercially available nicotinamide riboside chloride (NRCl) and in the presence of sodium dithionate as a reducing agent. NRH is industrially relevant as the most effective, synthetic NAD+precursor. We demonstrated that solid phase synthesis cannot be used for the reduction of NRCl to NRH in high yield, whereas a reduction reaction in water at room temperature under anaerobic conditions is shown to be very effective, reaching a 55% isolation yield. For the first time, by using common column chromatography, we were able to highly purify this sensitive bio-compound with good yield. A series of identifications and analyses including HPLC, NMR, LC-MS, FTIR, and UV-vis spectroscopy were performed on the purified sample, confirming the structure of NRH as well as its purity to be 96%. Thermal analysis of NRH showed higher thermal stability compared to NRCl, and with two major weight losses, one at 218 °C and another at 805 °C. We also investigated the long term stability effects of temperature, pH, light, and oxygen (as air) on the NRH in aqueous solutions. Our results show that NRH can be oxidized in the presence of oxygen, and it hydrolyzed quickly in acidic conditions. It was also found that the degradation rate is lower under a N2atmosphere, at lower temperatures, and under basic pH conditions.
Synthesis, Radiosynthesis, and in vitro Studies on Novel Hypoxia PET Tracers Incorporating [18F]FDR
Musolino, Manuele,Fleming, Ian N.,Schweiger, Lutz F.,O'Hagan, David,Dall'Angelo, Sergio,Zanda, Matteo
, p. 1429 - 1439 (2021/02/26)
We report the synthesis of five radiotracers incorporating different oxyamine spacers between the hypoxia-reactive 2-nitroimidazole moiety and the 5-[18F]-fluorodeoxyribose ([18F]FDR, 12) prosthetic group: three linear alkyl chains w