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1.
Org Biomol Chem ; 22(17): 3396-3404, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38576351

RESUMO

Fairy chemicals (FCs), such as 2-azahypoxanthine (AHX), are a potential new class of plant hormones that are naturally present in plants and produced via a novel purine metabolic pathway. FCs support plant resilience against various stresses and regulate plant growth. In this study, we developed a four-step method for synthesising AHX from 2-cyanoacetamide, achieving a good yield. Oxime was obtained from 2-cyanoacetamide via the oximation reaction. Cascade-type one-pot selective Pt/C-catalysed reduction of oxime, followed by a coupling reaction with formamidine acetate, yielded intermediate 5-amino-1H-imidazole-4-carboxamide (AICA). For the synthesis of AICA from oxime, we used modern fine bubble technology, affording AICA in 69% yield. Subsequently, we synthesised 4-diazo-4H-imidazole-5-carboxamide (DICA) from AICA via the diazotisation reaction. Notably, the synthesis of DICA from AICA was achieved, and the stability of previously known less stable DICA in the solid state was confirmed. Finally, PhI(OAc)2 (0.5 mol%) catalysed the intramolecular cyclisation of DICA in the green solvent water to yield AHX (overall yield of 47%). This study's innovative techniques and substantial discoveries highlight its potential influence and significance in FC science, thereby establishing a new standard for subsequent research.

2.
DEN Open ; 3(1): e228, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36998349

RESUMO

Intraductal papillary neoplasms of the bile duct (IPNB) are a tumor derived from bile duct epithelium that tends to spread laterally and non-invasively. Surgery is the first-choice treatment for IPNB. It is extremely important to accurately diagnose the extent of lateral tumor extension. Although peroral cholangioscopy (POCS) is a potentially useful modality for detecting tumor range with direct observation, poor image quality is a limitation of POCS. Recently, a new-generation endoscopy system (EVIS X1) was equipped with functions such as red dichromatic imaging to improve image quality. A 75-year-old man with cholangitis was referred to our department. Various imaging studies showed a mass in the middle to lower bile duct and dilatation of the common bile duct and the intrahepatic bile duct. Endoscopic retrograde cholangiopancreatography was performed. A biopsy of the main tumor in the lower common bile duct revealed IPNB. It was difficult to determine the extent of superficial tumor extension with modalities such as contrast-enhanced computed tomography, magnetic resonance imaging, and endoscopic ultrasonography but the detailed evaluation was possible using POCS with red dichromatic imaging 3. The patient underwent hepatopancreatoduodenectomy. This case suggests the usefulness of direct observation using POCS with red dichromatic imaging 3 to determine the range of IPNB.

3.
Case Rep Gastroenterol ; 15(2): 578-586, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34616259

RESUMO

Schwannomas are benign tumors originating from Schwann cells, which are the main component of the neural sheath. Biliary schwannomas are extremely rare. We report the case of a 78-year-old man who presented with no abdominal symptoms or jaundice. CT imaging showed a hyperdense mass extending along the extrahepatic bile duct, and the upstream bile ducts were dilated. We performed extrahepatic bile duct resection under a preoperative diagnosis of the extrahepatic bile duct cancer. A histopathological examination of the resected specimen revealed that the tumor consisted of spindle cells which exhibited a palisading arrangement. Immunohistochemical staining was positive for protein S-100 and vimentin. Based on these pathological findings, we diagnosed the patient with schwannoma of the extrahepatic bile duct. Our search of the relevant literature revealed 19 case studies of biliary schwannomas. In our case, the surgical findings showed that the tumor was noninvasive and mobile. During surgery, a fast frozen section analysis was performed, and no malignant findings were observed. These results enabled us to avoid extrahepatic bile duct resection with major hepatectomy. We experienced a case of biliary schwannoma that was difficult to distinguish from bile duct cancer.

4.
Gan To Kagaku Ryoho ; 47(4): 625-627, 2020 Apr.
Artigo em Japonês | MEDLINE | ID: mdl-32389965

RESUMO

A 60-year-old man underwent surgical distal gastrectomy 10 years prior to receiving treatment for stomach cancer. He visited our hospital with complaints of abdominal fullness and weight loss. Abdominal computed tomography(CT)revealed intestinal blockage starting at the duodenum near the Treitz ligament. During upper alimentary canal endoscopy, a type 2 tumor coveringthe entire circumference of the horizontal duodenum was found, and biopsy results indicated that the tumor was a well-differentiated adenocarcinoma. Although no distant metastasis was observed in the abdominal CT scan, multiple attached bulky lymph nodes were observed leadingto a suspicion of metastasis. Finally, the patient was diagnosed as having progressive duodenal cancer accompanied with advanced lymph node metastasis. A gastrojejunal bypass surgery with laparoscopy was performed. When the patient's overall condition improved, mFOLFOX6 chemotherapy was started, and 6 courses were completed. As the sizes of the primary tumor and bulky lymph nodes decreased, surgery to completely remove the cancer was performed. UFT/UZEL supplemental postoperative chemotherapy was administered for 6 months. The patient remained alive, with no remissions 3 years post-surgery.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Duodenais , Procedimentos Cirúrgicos do Sistema Digestório , Neoplasias Duodenais/tratamento farmacológico , Neoplasias Duodenais/cirurgia , Humanos , Linfonodos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante
5.
Expert Opin Drug Discov ; 10(4): 411-26, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25724579

RESUMO

INTRODUCTION: Natural products (NPs) are evolutionarily designed and contain more complex and challenging structures than synthetic compounds. Since the 1980s, the pharmaceutical industry has gradually shifted to a strategy of developing targeted agents by screening libraries of synthetic compounds. However, NPs have recently received renewed focus as a rich repository for drug discovery. Irinotecan was developed as a derivative of camptothecin and was applied in standard regimens for metastatic colorectal cancer (CRC) worldwide. Additionally, polysaccharide K is approved for CRC in Japan and Taiwan in combination with cytotoxic agents. However, after the approval of irinotecan in 1996, no anti-cancer agents derived from NPs have been approved for CRC. AREAS COVERED: This review discusses NPs that are currently under investigation for the treatment of CRC. In addition, other NPs derived as purified ingredients and crude extracts are listed and also discussed. EXPERT OPINION: The use of NPs for the discovery of anti-cancer agents has not been fully investigated. New technologies that are currently applied for synthetic compounds may be utilized for anti-cancer drug discovery including NPs for CRC.


Assuntos
Antineoplásicos/uso terapêutico , Produtos Biológicos/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Animais , Neoplasias Colorretais/patologia , Desenho de Fármacos , Descoberta de Drogas/métodos , Humanos
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