Production of Antibacterial Compounds Analogous to Chloramphenicol by a n-Paraffin-grown Bacterium

Corynebacterium sp. KY 4339, when grown on n-paraffin (a mixture of C–12 to C–14 fractions) as the sole carbon source, produced three kinds of antibacterial compounds which were tentatively named Corynecins. These compounds were isolated by the extraction from the culture broth with ethyl acetate and by the chromatographies on silicic acid and alumina columns. Each component demonstrated some similarity to chloramphenicol on thin-layer chromatogram. Although their biological activities were not so remarkably as that of chloramphenicol, the patterns of antibacterial spectra against gram-positive and gram-negative bacteria resembled to it.

For the production of corynecins, n-paraffin was a preferable carbon source. By controlling the pH of the medium in the neutral range and keeping the aeration at a high level during the fermentation, approximately 3 g of corynecins per liter of the medium were produced after 72-hr incubation.     

Toward more comprehensive environmental impact assessments: interlinked global models of LCIA and IAM applicable to this century

The International Journal of Life Cycle Assessment - Despite the long-standing demand for research on dynamic lifecycle assessment (LCA) for policymaking, only a few studies have addressed this...     

Macaque monkeys show reversed ocular following responses to two-frame-motion stimulus presented with inter-stimulus intervals

Journal of Computational Neuroscience - When two-frame apparent motion stimuli are presented with an appropriate inter-stimulus interval (ISI), motion is perceived in the direction opposite to the...     

Mesorhizobium sp. J8 can establish symbiosis with Glycyrrhiza uralensis,increasing glycyrrhizin production

Licorice (Glycyrrhiza uralensis) is a medicinal plant that contains glycyrrhizin (GL), which has various pharmacological activities. Because licorice is a legume, it can establish a symbiotic relationship with nitrogen-fixing rhizobial bacteria. However, the effect of this symbiosis on GL production is unknown. Rhizobia were isolated from root nodules of Glycyrrhiza glabra, and a rhizobium that can form root nodules in G. uralensis was selected. Whole-genome analysis revealed a single circular chromosome of 6.7 Mbp. This rhizobium was classified as Mesorhizobium by phylogenetic analysis and was designated Mesorhizobium sp. J8. When G. uralensis plants grown from cuttings were inoculated with J8, root nodules formed. Shoot biomass and SPAD values of inoculated plants were significantly higher than those of uninoculated controls, and the GL content of the roots was 3.2 times that of controls. Because uninoculated plants from cuttings showed slight nodule formation, we grew plants from seeds in plant boxes filled with sterilized vermiculite, inoculated half of the seedlings with J8, and grew them with or without 100 µM KNO₃. The SPAD values of inoculated plants were significantly higher than those of uninoculated plants. Furthermore, the expression level of the CYP88D6 gene, which is a marker of GL synthesis, was 2.5 times higher than in inoculated plants. These results indicate that rhizobial symbiosis promotes both biomass and GL production in G. uralensis.     

Successful adjuvant bi-weekly gemcitabine chemotherapy for pancreatic cancer without impairing patients’ quality of life

Background

Although adjuvant gemcitabine (GEM) chemotherapy for pancreatic cancer is standard, the quality of life (QOL) in those patients is still impaired by the standard regimen of GEM. Therefore, we studied whether mild dose-intensity adjuvant chemotherapy with bi-weekly GEM administration could provide a survival benefit with acceptable QOL to the patients with pancreatic cancer.

Methods

After a phase I trial, an adjuvant bi-weekly 1,000 mg/m² of GEM chemotherapy was performed in 58 patients with pancreatic cancer for at least 12 courses (Group A). In contrast, 36 patients who declined the adjuvant bi-weekly GEM chemotherapy underwent traditional adjuvant 5FU-based chemotherapy (Group B). Careful periodical follow-ups for side effects of GEM and disease recurrence, and assessment of patients’ QOL using the EORTC QOL questionnaire (QLQ-C30) and pancreatic cancer-specific supplemental module (QLQ-PAN26) were performed. Retrospectively, the degree of side effects, patients’ QOL, compliance rate, disease-free survival (DFS), and overall survival (OS) in Group A were compared with those in Group B.

Results

No severe side effects (higher than Grade 2 according to the common toxicity criteria of ECOG) were observed, except for patients in Group B, who were switched to the standard GEM chemotherapy. Patients’ QOL was better in Group A than B (fatigue: 48.9 ± 32.1 versus 68.1 ± 36.3, nausea and vomiting: 26.8 ± 20.4 versus 53.7 ± 32.6, diarrhea: 21.0 ± 22.6 versus 53.9 ± 38.5, difficulty gaining weight: 49.5 ± 34.4 versus 67.7 ± 40.5, P < 0.05). Compliance rates in Groups A and B were 93% and 47%. There was a significant difference in the median DFS between both groups (Group A : B =12.5 : 6.6 months, P < 0.001). The median OS of Group A was prolonged markedly compared with Group B (20.2 versus 11.9 months, P < 0.005). For OS between both groups, univariate analysis revealed no statistical difference in 69-year-old or under females, and T1–2 factors, moreover, multivariate analysis indicated three factors, such as bi-weekly adjuvant GEM chemotherapy, T2 or less, and R0.

Conclusions

Adjuvant chemotherapy with bi-weekly GEM offered not only the advantage of survival benefits but the excellent compliance with acceptable QOL for postoperative pancreatic cancer patients.     

Synthesis of 2′,3′-Dideoxypurinenucleosides via the Palladium Catalyzed Reduction of 9-(2,5-Di-O-acetyl-3-bromo-3-deoxy-β-d-xylofuranosyl)purine Derivatives

Abstract

Practical method to produce 2′,3′-dideoxypurinenucleosides from 9-(2,5-di-O-acetyl-3-bromo-3-deoxy-β-D-xylofuranosyl)purines (1) was developed. High ratio of 2′,3′-dideoxynucleoside to 3′-deoxyribonucleoside was obtained by selecting the reaction conditions (solvent, pH and/or base), or changing 2′-acyloxy leaving group. The reaction mechanism was studied by deuteration experiments of 1a and 1-(3,5-di-O-acety1-2-bromo-2-deoxy-β-D-ribofuranosyl)thymine (12).