Studies on the Synthesis of DMAP Derivatives by Diastereoselective Ugi Reactions

Diastereoselective Ugi reactions of DMAP-based aldehydes with α-amino acids and tert-butyl isocyanide were examined. The reactions of 4-(dimethylamino)-2-pyridine-carboxaldehyde with various α-amino acids afforded 2-substituted DMAP derivatives with low diastereoselectivity. On the contrary, reactions with 4-(dimethylamino)-3-pyridine-carboxaldehyde delivered 3-substituted DMAP derivatives with moderate to high diastereoselectivity. The combination of α-amino acid and DMAP-based aldehyde is thus important to achieve high diastereoselectivity. Kinetic resolution of a secondary alcohol using a chiral DMAP derivative obtained through these reactions was also examined

Marker-free genome editing in the edible mushroom, Pleurotus ostreatus, using transient expression of genes required for CRISPR/Cas9 and for selection

In a previous study, we reported a transient transformation system using repeated screening for hygromycin B (Hyg) resistance in the basidiomycete Ceriporiopsis subvermispora. In the present study, by combining this technique with CRISPR/Cas9, we demonstrated successful marker-free genome editing in Pleurotus ostreatus, which is one of the most economically important cultivated mushrooms as well as a model white-rot fungus. At first, transformant selection mediated by the transient expression of marker genes was demonstrated using a plasmid harboring the Hyg resistance gene (hph) in P. ostreatus. Then, genome editing of fcy1, which confers 5-fluorocytosine (5-FC) resistance to the host cell, was performed by the transient expression of Cas9, gRNA, and hph and strains with 5-FC resistance and Hyg sensitivity were isolated. Additionally, genome editing of fcy1 in these strains was confirmed by Sanger sequencing. To our knowledge, this is the first report of marker-free genome editing through the transient expression of Cas9, gRNA, and hph in agaricomycetes, which opens the door for repeated genome editing in these fungi

Analysis of Methoxymethylbenzoguanamine Resins Using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry and Electrospray Ionization Mass Spectrometry

Methoxymethylbenzoguanamine resins were analyzed by matrix-assisted laser　desorption/ionization timeof-flight mass spectrometry (MALDI-TOF-MS) and electrospray ionization mass spectrometry (ESI-MS). In　the case of MALDI-TOF-MS measurements, they could not be characterized because　fragmentation occurred considerably. On the ESI-MS measurement, optimization of needle voltage, cone voltage, and cationizing agent made their molecular-related ions intense with little fragmentation. Cluster ions were formed owing to hydrogen bond among their complex components. Gel permeation chromatography (GPC) was used to fractionate the resins. As a result, different oligomer components could be characterized in detail

Successful Endoscopic Closure Using Polyglycolic Acid Sheets with Fibrin Glue for Nonhealing Duodenal Ulcer with Perforation after Proton Beam Therapy of Liver Tumor

We describe the first case of a nonhealing duodenal ulcer with perforation after proton beam therapy (PBT) of a liver tumor that was successfully treated endoscopically using polyglycolic acid (PGA) sheets with fibrin glue. A 69-year-old man received PBT for a liver tumor. Esophagogastroduodenoscopy (EGD) 3 months after PBT revealed a duodenal ulcer. A proton pump inhibitor was administered for 7 weeks, and the ulcer healed. Six months after the EGD, recurrence of the duodenal ulcer with perforation occurred. An emergency open surgery with placement of the omental patch was performed. However, 5 days after the surgery, because the EGD revealed a perforation site in the duodenal ulcer that was not closed, the conservative treatment was continued. Twenty-eight days after the surgery, EGD revealed that the perforation size had increased. Therefore, we conducted endoscopic closure therapy using PGA sheets with fibrin glue. Eleven days after the closure procedure, the EGD showed that the perforation site was filled with granulation tissue and was closed. Forty-nine days after the procedure, EGD revealed that the ulcer had healed. This endoscopic closure treatment was effective for a nonhealing duodenal ulcer with perforation after PBT of a liver tumor

Drug treatment for chemotherapy-induced peripheral neuropathy in patients with pancreatic cancer

Pancreatic cancer (PC) is a lethal disease where most tumors are too advanced at diagnosis for resection, leaving chemotherapy as the mainstay of treatment. Although the prognosis of unresectable PC is poor, it has been dramatically improved by new chemotherapy treatments, such as the combination of 5-fluorouracil, oxaliplatin, irinotecan, and leucovorin (FOLFIRINOX) or gemcitabine plus nab-paclitaxel. However, as oxaliplatin and paclitaxel are common neurotoxic drugs, chemotherapy-induced peripheral neuropathy (CIPN) is a common and severe adverse effect of both treatments. As there are no agents recommended in the ASCO guidelines, we review the methods used to treat CIPN caused by PC treatment. The efficacy of duloxetine was observed in a large randomized controlled trial (RCT). In addition, pregabalin was more effective than duloxetine for CIPN in two RCTs. Although duloxetine and pregabalin can be effective for CIPN, they have several side effects. Therefore, the choice between the two drugs should be determined according to effect and tolerability. Mirogabalin is also used in patients with PC and there is hope it will yield positive outcomes when treating CIPN in the future

Large-Scale Gene Disruption in Magnaporthe oryzae Identifies MC69, a Secreted Protein Required for Infection by Monocot and Dicot Fungal Pathogens

To search for virulence effector genes of the rice blast fungus, Magnaporthe oryzae, we carried out a large-scale targeted disruption of genes for 78 putative secreted proteins that are expressed during the early stages of infection of M. oryzae. Disruption of the majority of genes did not affect growth, conidiation, or pathogenicity of M. oryzae. One exception was the gene MC69. The mc69 mutant showed a severe reduction in blast symptoms on rice and barley, indicating the importance of MC69 for pathogenicity of M. oryzae. The mc69 mutant did not exhibit changes in saprophytic growth and conidiation. Microscopic analysis of infection behavior in the mc69 mutant revealed that MC69 is dispensable for appressorium formation. However, mc69 mutant failed to develop invasive hyphae after appressorium formation in rice leaf sheath, indicating a critical role of MC69 in interaction with host plants. MC69 encodes a hypothetical 54 amino acids protein with a signal peptide. Live-cell imaging suggested that fluorescently labeled MC69 was not translocated into rice cytoplasm. Site-directed mutagenesis of two conserved cysteine residues (Cys36 and Cys46) in the mature MC69 impaired function of MC69 without affecting its secretion, suggesting the importance of the disulfide bond in MC69 pathogenicity function. Furthermore, deletion of the MC69 orthologous gene reduced pathogenicity of the cucumber anthracnose fungus Colletotrichum orbiculare on both cucumber and Nicotiana benthamiana leaves. We conclude that MC69 is a secreted pathogenicity protein commonly required for infection of two different plant pathogenic fungi, M. oryzae and C. orbiculare pathogenic on monocot and dicot plants, respectively