Novel practical stereoselective synthesis of a bicyclic hydantoino-thiolactone as the key intermediate for production of (+)-biotin.

Bicyclic hydantoinothiolactone (1), as the key intermediate for production of (+)-biotin, has been efficiently and high-stereoselectively synthesized from the cheap starting material l-cystine nine steps in 44% overall yield. In this new practical synthesis, there are two characteristic steps worthy of note. One step is TMSOTf-catalyzed efficient cyanation of (3,7a)-6-benzyl-5-oxo-3-phenyltetrahydro-1,3-imidazo[1,5-]thiazol-7-yl acetate, the other step is DBU-catalyzed rapid isomerization of -isomer to -isomer of the bicyclic hydantoinothiolactone.

Copper(ii)-catalyzed and acid-promoted highly regioselective oxidation of tautomerizable C(sp)-H bonds adjacent to 3,4-dihydroisoquinolines using air (O) as a clean oxidant.

A mild, efficient and eco-friendly method for the oxidation of 1-Bn-DHIQs to 1-Bz-DHIQs without concomitant excessive oxidation of 1-Bz-DHIQs to 1-Bz-IQs is very important for the syntheses of 1-Bz-DHIQ alkaloids and analogues. In this article, we developed a novel Cu(ii)-catalyzed and acid-promoted highly regioselective oxidation of tautomerizable C(sp)-H bonds adjacent to the C-1 positions of various 1-Bn-DHIQs. It was observed that when 0.

Diagnostic significance of CyclinD1 and D2-40 expression for follicular neoplasm of the thyroid.

Objectives: To evaluate the expression and differential diagnostic significance of CyclinD1 and D2-40 in follicular neoplasm (FN) and other thyroid adenomatoid lesions.

Methods: A total of 144 cases of thyroid adenomatoid lesions were enrolled. Immunohistochemistry for CyclinD1 and D2-40 was performed.

Novel Stereoselective Syntheses of (+)-Streptol and (-)-1-Streptol Starting from Naturally Abundant (-)-Shikimic Acid.

Novel highly stereoselective syntheses of (+)-streptol and (-)-1--streptol starting from naturally abundant (-)-shikimic acid were described in this article. (-)-Shikimic acid was first converted to the common key intermediate by 11 steps in 40% yield. It was then converted to (+)-streptol by three steps in 72% yield, and it was also converted to (-)-1--streptol by one step in 90% yield.

Thoracoscopic resection of a huge esophageal dedifferentiated liposarcoma: A case report.

Background: Esophageal liposarcoma is a rare malignant tumor and an esophageal dedifferentiated liposarcoma (DDL) is extremely rare. There are no reports on the treatment of DDL by thoracoscopic surgery.

Case Summary: A 38-year-old woman presented with dysphagia and dyspnea.

Efficient and Highly Stereoselective Syntheses of (+)--Quercitol and (-)--Quercitol Starting from the Naturally Abundant (-)-Shikimic Acid.

Efficient and highly stereoselective syntheses of (+)--quercitol and (-)--quercitol starting from the naturally abundant (-)-shikimic acid were described in this article. (-)-Shikimic acid was first converted to the key intermediate by eight steps in 53% yield. It was then converted to (+)--quercitol by three steps in 78% yield and was also converted to (-)--quercitol by five steps in 63% yield.

Novel stereoselective syntheses of -octyl-β-valienamine (NOV) and -octyl-4--β-valienamine (NOEV) from (-)-shikimic acid.

-Octyl-β-valienamine (NOV) 1 and -octyl-4--β-valienamine (NOEV) 2 are potent chemical chaperone drug candidates for the therapy of lysosomal storage disorders. Novel stereoselective syntheses of NOV 1 and NOEV 2 starting from naturally abundant (-)-shikimic acid are described in this article. The common key intermediate compound 5 was first synthesized from readily available (-)-shikimic acid 9 steps in 50% yield.

Deceptive Giant Dedifferentiated Liposarcoma of the Esophagus: An Extremely Rare Surgical Case.

Dedifferentiated liposarcoma rarely occurs in the esophagus. It always has atypical clinical manifestations and different pathologic features, which usually lead to misdiagnosis and mistreatment. Given its poor prognosis, early and accurate diagnosis is of the utmost importance.

Copper-Catalyzed Benign and Efficient Oxidation of Tetrahydroisoquinolines and Dihydroisoquinolines Using Air as a Clean Oxidant.

A green chemical method for mild oxidation of 1,2,3,4-tetrahydroisoquinolines (THIQs) and 3,4-dihydroisoquinolines (DHIQs) has been developed using air (O) as a clean oxidant. DHIQs and THIQs could be efficiently oxidized to isoquinolines in dimethyl sulfoxide at 25 °C under an open air atmosphere with CuBr (20 mol %) as the catalyst; different bases [NaOEt and/or 1,8-diazabicyclo[5,4,0]undec-7-ene] were used for the reaction according to the patterns of substituents (R, R).

Novel total syntheses of oxoaporphine alkaloids enabled by mild Cu-catalyzed tandem oxidation/aromatization of 1-Bn-DHIQs.

Novel total syntheses of oxoaporphine alkaloids such as liriodenine, dicentrinone, cassameridine, lysicamine, oxoglaucine and -methylmoschatoline were developed. The key step of these total syntheses is Cu-catalyzed conversion of 1-benzyl-3,4-dihydro-isoquinolines (1-Bn-DHIQs) to 1-benzoyl-isoquinolines (1-Bz-IQs) tandem oxidation/aromatization. This novel Cu-catalyzed conversion has been studied in detail, and was successfully used for constructing the 1-Bz-IQ core.

Cu-catalyzed mild and efficient oxidation of THβCs using air: application in practical total syntheses of perlolyrine and flazin.

A mild, efficient and environmentally benign method for synthesis of aromatic β-carbolines Cu(ii)-catalyzed oxidation of 1,2,3,4-tetrahydro-β-carbolines (THβCs) was developed, in which air (O) was used as the clean oxidant. This method has advantages such as environmentally friendliness, mildness, very good tolerance of functional groups, high yielding and easy experiment operation. In addition, this new methodology was successfully applied in the efficient and practical total syntheses of β-carboline alkaloids perlolyrine and flazin.

CuBr-Catalyzed Mild Oxidation of 3,4-Dihydro-β-Carbolines and Application in Total Synthesis of 6-Hydroxymetatacarboline D.

A green chemical method for the conversion of 3,4-dihydro-β-carbolines to β-carbolines has been developed using air as the oxidant. With 15 mol % CuBr as the catalyst, 3,4-dihydro-β-carbolines could be efficiently oxidized to β-carbolines in dimethyl sulfoxide at room temperature in the presence of 1,8-diazabicyclo[5,4,0]undec-7-ene (or EtN). By applying this method, the first total synthesis of 6-hydroxymetatacarboline D was performed through 12 steps in 22% overall yield starting from l-5-hydroxy-tryptophan.

[Prognostic value of circulating tumor cells and disseminated tumor cells in patients with esophageal cancer: a meta-analysis].

Objective: To explore the correlations of circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) with the clinicopathological characteristics, prognostic events, and survival outcomes in esophageal cancer (EC) patients.

Methods: The PubMed, Web of Science, Embase database and Cochrane database were searched for studies reporting the outcomes of interest. The studies were selected according to established inclusion/exclusion criteria.

[Expression of YY 1 protein in human insulinoma and its clinical implication].

Objective: To investigate the expression of Yin Yang 1 (YY1) protein in human insulinoma and explore its clinical significance.

Methods: Nineteen pancreatic neuroendocrine tumor tissue were collected from patients treated in Nanfang Hospital between 2000 and 2014. The protein expression of YY1 in benign and malignant insulinoma tissues were detected by immunohistochemistry.

Malignant transformation rate and p53, and p16 expression in teratomatous skin of ovarian mature cystic teratoma.

Objective: To investigate the incidence of malignant transformation and P53 and P16 expression in teratomatous skin of ovarian mature cystic teratoma.

Materials And Methods: Data on ovarian teratoma specimens in nearly 10 years were reviewed. P53 and P16 expression were detected by immunohistochemistry in 25 cases of teratomatous skin of ovarian mature cystic teratoma, 20 cases of squamous cell carcinoma and 2 cases of squamous cell carcinoma originated from teratomatous skin.

Dearomatization of tryptophols via a vanadium-catalyzed asymmetric epoxidation and ring-opening cascade.

An enantioselective epoxidation of tryptophols followed by an intramolecular epoxide opening reaction was realized by chiral vanadium catalysts derived from C2 symmetric bis-hydroxamic acid (BHA) ligands. 3a-Hydroxyfuroindoline derivatives with up to 89% yield and 90% ee were obtained under mild reaction conditions.

Enantioselective synthesis of benzofurans and benzoxazines via an olefin cross-metathesis-intramolecular oxo-Michael reaction.

Chiral phosphoric acid and Hoveyda-Grubbs II were found to catalyze an olefin cross-metathesis-intramolecular oxo-Michael cascade reaction of the ortho-allylphenols and enones to provide a variety of benzofuran and benzoxazine derivatives in moderate to good yields and enantioselectivity.

Synthesis of (glycopyranosyl-triazolyl)-purines and their inhibitory activities against protein tyrosine phosphatase 1B (PTP1B).

Development of novel purine derivatives has attracted considerable interest, since both purine and purine-based nucleosides display a wide range of crucial biological activities in nature. We report here a novel expansion of these studies by introducing gluco- or galactopyranosyl scaffold to the N- or 9-position (or both) of 6-Cl purine moiety via Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition. By such an efficient reaction, a series of glycosyl-triazolyl-purines were successfully synthesized in good yields.

Discovering the distinct inhibitory effects between C4-epimeric glycosyl amino acids: new insight into the development of protein tyrosine phosphatase inhibitors.

There has been increasing interest in the development of drug candidates based on sugar templates that possess rich structural and, especially, configurational diversities. We disclose herein that the epimeric identity between methyl 3,4-bis-phenylalanyl/tyrosinyl triazolyl-alpha-D-galactopyranoside and glucopyranoside may lead to their distinct inhibitory effects on specific protein tyrosine phosphatases (PTPs). Subsequently performed molecular docking study elucidated the plausible binding behaviors of the more potent galactosyl inhibitors with their primary PTP target, i.

Click to a focused library of benzyl 6-triazolo(hydroxy)benzoic glucosides: novel construction of PTP1B inhibitors on a sugar scaffold.

With an aim of developing novel protein tyrosine phosphatase (PTP) 1B inhibitors based on sugar scaffolds, a focused library of benzyl 6-triazolo(hydroxy)benzoic glucosides was efficiently constructed via the modular and selective Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddtion (click chemistry). These glycoconjugates bearing alkyl chain length-varied bridges between the sugar and (hydroxy)-benzoic moieties were identified as new PTP1B inhibitors with selectivity over T-Cell PTP (TCPTP), SH2-Containing PTP-1 (SHP-1), SHP-2 and Leukocyte Antigen-Related Tyrosine Phosphatase (LAR). Molecular docking study sequentially elaborated the plausible binding modes of the structurally diverse sugar-based inhibitors with PTP1B.

Facile fabrication of promising protein tyrosine phosphatase (PTP) inhibitor entities based on 'clicked' serine/threonine-monosaccharide hybrids.

Protein tyrosine phosphatases (PTPs) are well-validated therapeutic targets for many human major diseases. The development of their potent inhibitors has therefore become a main focus of both academia and the pharmaceutical industry. We report herein a facile strategy toward the fabrication of new and competent PTP inhibitor entities by simply 'clicking' alkynyl amino acids onto diverse azido sugar templates.

Synthesis of novel 6-triazologlycolipids via click chemistry and their preliminary cytotoxicity assessments.

Series of novel 6-triazole-linked galacto- or glucolipids were efficiently synthesized from O-benzylated sugar azides and various lipid alkynes via Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition (click chemistry) followed by hydrogenolysis with PdCl(2)/H(2). Subsequent MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay toward a panel of human cancer cell lines revealed that these triazologlycolipids possess low-to-modest toxicity on A549 (lung), MCF-7 (breast), HeLa (cervix), and HepG2 (liver). Furthermore, both the carbon chain length at the lipid end and the epimeric identity of the glycosyl moiety were determined to impact their corresponding bioactivity.

Epimeric monosaccharide-quinone hybrids on gold electrodes toward the electrochemical probing of specific carbohydrate-protein recognitions.

Carbohydrates represent one of the most significant natural building blocks, which govern numerous critical biological and pathological processes through specific carbohydrate-receptor interactions on the cell surface. We present here a new class of electrochemical probes based on gold surface-coated epimeric monosaccharide-quinone hybrids toward the ingenious detection of specific epimeric carbohydrate-protein interactions. Glucose and galactose, which represent a pair of natural monosaccharide C4 epimers, were used to closely and solidly conjugate with the 1,4-dimethoxybenzene moiety via a single C-C glycosidic bond, followed by the introduction of a sulfhydryl anchor.