Preparation of Tenuifolin from Polygala senega L. Root Using a Hydrolytic Continuous Flow System under High-Temperature, High-Pressure Conditions.

An improved process for preparing tenuifolin (presenegenin 3-ß-d-glucopyranoside) from the root of Polygala senega L. was developed. A crude saponin mixture extracted from P. senega was subjected to hydrolysis, and the reactivity of compounds in the extract was controlled by utilizing the combination of a flow reactor and experimental design. In addition, column chromatography with HP 20, a synthetic polystyrenic adsorbent, allowed the gram-scale preparation of tenuifolin in a continuous manner with fewer steps. This approach shortens the total time required for gram-scale preparation from 16 to 5 h in a continuous manner while improving the yield from 0.59% to 2.08% (w/w).

Efficient synthesis of diverse C-3 monodesmosidic saponins by a continuous microfluidic glycosylation/batch deprotection method.

Triterpene and steroid saponins have various pharmacological activities but the synthesis of C-3 monodesmosidic saponins remains challenging. Herein, a series of C-3 glycosyl monodesmosidic saponins was synthesized via the microfluidic glycosylation of triterpenoids or steroids at the C-3 position, without the formation of orthoester byproducts, and subsequent deprotection of the benzoyl (Bz) group. This microfluidic glycosylation/batch deprotection sequence enabled the efficient synthesis of C-3 saponins with fewer purification steps and a shorter reaction time than conventional batch synthesis and stepwise microfluidic glycosylation. Furthermore, this system minimized the consumption of the imidate donor. Using this reaction system, 18 different C-3 saponins and 13 different C-28-benzyl-C-3 saponins, including 8 new compounds, were synthesized from various sugars and triterpenes or steroids. Our synthetic approach is expected to be suitable for further expanding the C-3 saponin library for pharmacological studies.

Synthesis of Bisdesmosidic Oleanolic Acid Saponins via a Glycosylation-Deprotection Sequence under Continuous Microfluidic/Batch Conditions.

We report the first synthesis of a series of bisdesmosidic oleanolic acid saponins using microflow reactor Comet X-01 via a continuous flow glycosylation-batch deprotection sequence. The main results of this study can be summarized as follows: (1) The microfluidic glycosylation of oleanolic acid at C-28 was achieved in quantitative yield and was applied to the synthesis of six C-28-monoglycosidic saponins. (2) The microfluidic glycosylation of oleanolic acid at C-3 was achieved in good yield without orthoester byproduct formation and was applied to the synthesis of three bisdesmosidic saponins. (3) The continuous synthesis of saponins via a microfluidic glycosylation-batch deprotection sequence was achieved in four steps involving two purifications. Thus, the continuous microfluidic glycosylation-deprotection process is expected to be suitable for the preparation of a library of bisdesmosidic oleanolic acid saponins for in vivo pharmacological studies.

Regio- and stereoselective ß-mannosylation using a boronic acid catalyst and its application in the synthesis of a tetrasaccharide repeating unit of lipopolysaccharide derived from E. coli O75.

Regio- and stereoselective ß-mannosylations using 1,2-anhydromannose and diol sugar acceptors in the presence of a boronic acid catalyst proceeded smoothly to give the corresponding ß-mannosides with high regio- and ß-stereoselectivities in high yields without further additives under mild conditions. In addition, this glycosylation method was applied successfully to the synthesis of a tetrasaccharide repeating unit of lipopolysaccharide (LPS) derived from E. coli O75.

Syntheses and mucosal adjuvant activity of simplified oleanolic acid saponins possessing cinnamoyl ester.

A series of new simplified oleanolic acid saponins with a glycosyl ester moiety at C28, were efficiently prepared. Furthermore, the effect of nasal administration of the synthetic oleanolic acid saponins on the nasal anti-influenza virus antibody titer against secondary nasal inoculation of the influenza split vaccine was examined. The result revealed cinnamoyl saponin as a suitable candidate vaccine adjuvant.

A target-controlled infusion system with bispectral index monitoring of propofol sedation during endoscopic submucosal dissection.

BACKGROUND AND STUDY AIMS: Propofol administration via a target-controlled infusion system with bispectral index monitoring (BIS/TCI system) is expected to prevent complications from sedation during complex and long endoscopic procedures. We evaluated the feasibility of setting the BIS/TCI system for non-anesthesiologist administration of propofol (NAAP) during endoscopic submucosal dissection (ESD). PATIENTS AND METHODS: From May 2009 to February 2013, 250 patients with esophagogastric neoplasms were treated with ESD using the BIS/TCI system with NAAP. In the TCI system, the initial target blood concentration of propofol was set at 1.2 µg/mL. The titration speed of propofol was adjusted according to the BIS score and the movement of the patient. The BIS target level ranged from moderate to deep sedation, at which a stable BIS score between 60 and 80 was obtained. RESULTS: In 80.4 % of patients, it was possible to maintain stable sedation with a blood concentration of propofol of less than 1.6 µg/mL using TCI throughout the ESD procedure. The default setting for ideal blood concentration of propofol was 1.2 µg/mL, because the medians of the lower and upper bounds of blood concentration were 1.2 µg/mL (range 0.6 - 1.8 µg/mL) and 1.4 µg/mL (range 1.0 - 3.8 µg/mL), respectively. Although hypotension occurred in 27 patients (10.8 %), oxygen desaturation occurred in only nine patients (3.6 %), and severe desaturation in only two patients (0.8 %). CONCLUSIONS: Using our settings, it is possible for a non-anesthesiologist to maintain stable sedation during a lengthy endoscopic procedure through propofol sedation with a BIS/TCI system.

Glycosylation of a newly functionalized orthoester derivative.

Tandem glycosylation of the 6-O-Fmoc-substituted benzyl orthoester derivative 2a was carried out in moderate yields by electrogenerated acid (EGA). The Fmoc group was effectively removed under mild basic conditions, and the product was submitted to the subsequent glycosylation.

Is presence or history of extracolonic primary malignancy a risk for colorectal neoplasia? An analysis of patients who underwent colonoscopy.

Whether presence or history of extracolonic primary malignancy is a risk for colorectal neoplasia is not fully known. In this study, 26,452 first-time colonoscopy cases were examined using a colonoscopy database. Among the analyzed subjects, 3,026 (11%) subjects had history or concomitance of extracolonic primary malignancy, while the remaining 23,426 subjects did not. Colorectal neoplasia was observed in 39% of all the subjects. A crude comparison showed that the prevalence of any type of colorectal neoplasia was higher in subjects with extracolonic malignancy than in those without (42% vs. 39%, p＝0.0012). However, after adjusting for confounding factors, the odds ratios (ORs) of subjects with extracolonic malignancy for having colorectal neoplasia, advanced neoplasia, and cancer were all less than 1.0, and all significantly different from those of subjects without extracolonic malignancy. Analysis according to the type of extracolonic malignancy revealed that gastric cancer cases had a significantly lower risk for colorectal advanced neoplasia (OR:0.81;95% CI:0.67-0.99). Among major malignancies, only esophageal squamous cell cancer cases had increased risk for colorectal neoplasia (OR:1.66;95% CI:1.20-2.29). Patients with presence or history of extracolonic malignancy did not carry a higher risk of occurrence of colorectal neoplasia.

Development of glycosylation using the glucopyranose 1,2-orthobenzoate under electrochemical conditions.

Substituted glucopyranose 1,2-orthobenzoate undergoes ß-selective glycosylation. The developed orthobenzoate derivative was stable under standard workup conditions and efficiently provided a variety of glycosides by EGA (electrogenerated acid), produced by anodic oxidation of cyclohexanol. Upon comparison with Lewis and Brønsted acids, EGA superiorly affected activation of the orthoester to afford desired glycosides possessing such aglycons as sugars, steroids, and adamantanes.

Externalization of saw-tooth architecture in small serrated polyps implies the presence of methylation of IGFBP7.

INTRODUCTION: Serrated polyps have been considered to be precursors of colorectal cancer with microsatellite instability. However, the biological and/or morphological changes which occur during the course of serrated polyp to cancer remain to be elucidated. METHODS: Twenty-eight colorectal serrated polyps including five mixed polyps (MP) from 20 patients were observed by chromoendoscopy with magnification, and subsequently resected endoscopically. The presence of mutations in two genes (K-ras and BRAF) and the methylation status of six genes (MLH1-A, MLH1-C, ESR1, P16, SOCS1, and IGFBP7) were examined. RESULTS: The 28 polyps included 32 histological serrated lesions (22 sessile serrated adenomas [SSA], six hyperplastic polyps [HP], and four traditional serrated adenoma [TSA]-like lesions). BRAF mutation was frequently observed in SSAs (19/22), while K-ras mutation was dominant in HPs (5/6). The externalization of saw-tooth architecture in serrated polyps was endoscopically observed more frequently in those with high levels of IGFBP7 methylation (P = 0.03). Moreover, the endoscopic finding was observed in five of six small serrated lesions (<10 mm) which contained both BRAF mutation and high levels of IGFBP7 methylation. TSA-like lesions in small MPs demonstrated the endoscopic finding with no or little MLH1 methylation, while the counterparts in the mixed polyps had high levels of MLH1 methylation with relatively low levels of IGFBP7 methylation. CONCLUSIONS: Our data suggests two distinct pathways may be involved in the early stages of the serrated pathway: one where MLH1 is primarily methylated, and a second where methylated IGFBP7 is associated with an externalization of saw-tooth architecture.

Detectability of colorectal neoplasia with fluorine-18-2-fluoro-2-deoxy-D-glucose positron emission tomography and computed tomography (FDG-PET/CT).

BACKGROUND: The purpose of this study was to analyze the detectability of colorectal neoplasia with fluorine-18-2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT). METHODS: Data for a total of 492 patients who had undergone both PET/CT and colonoscopy were analyzed. After the findings of PET/CT and colonoscopy were determined independently, the results were compared in each of the six colonic sites examined in all patients. The efficacy of PET/CT was determined using colonoscopic examination as the gold standard. RESULTS: In all, 270 colorectal lesions 5 mm or more in size, including 70 pathologically confirmed malignant lesions, were found in 172 patients by colonoscopy. The sensitivity and specificity of PET/CT for detecting any of the colorectal lesions were 36 and 98%, respectively. For detecting lesions 11 mm or larger, the sensitivity was increased to 85%, with the specificity remaining consistent (97%). Moreover, the sensitivity for tumors 21 mm or larger was 96% (48/50). Tumors with malignant or high-grade pathology were likely to be positive with PET/CT. A size of 10 mm or smaller [odds ratio (OR) 44.14, 95% confidence interval (95% CI) 11.44-221.67] and flat morphology (OR 7.78, 95% CI 1.79-36.25) were significant factors that were associated with false-negative cases on PET/CT. CONCLUSION: The sensitivity of PET/CT for detecting colorectal lesions is acceptable, showing size- and pathology-dependence, suggesting, for the most part, that clinically relevant lesions are detectable with PET/CT. However, when considering PET/CT for screening purposes caution must be exercised because there are cases of false-negative results.

DNA methylation of colon mucosa in ulcerative colitis patients: correlation with inflammatory status.

BACKGROUND: Although DNA methylation of colonic mucosa in ulcerative colitis (UC) has been suggested, the majority of published reports indicate the correlation between methylation of colon mucosa and occurrence of UC-related dysplasia or cancer without considering the mucosal inflammatory status. The aim of this study was to verify whether mucosal inflammation-specific DNA methylation occurs in the colon of UC. METHODS: Of 15 gene loci initially screened, six loci (ABCB1, CDH1, ESR1, GDNF, HPP1, and MYOD1) methylated in colon mucosa of UC were analyzed according to inflammatory status using samples from 28 surgically resected UC patients. RESULTS: Four of six regions (CDH1, GDNF, HPP1, and MYOD1) were more highly methylated in the active inflamed mucosa than in the quiescent mucosa in each UC patient (P = 0.003, 0.0002, 0.02, and 0.048, respectively). In addition, when the methylation status of all samples taken from examined patients was stratified according to inflammatory status, methylation of CDH1 and GDNF loci was significantly higher in active inflamed mucosa than in quiescent mucosa (P = 0.045 and 0.002, respectively). Multiple linear regression analysis revealed that active inflammation was an independent factor of methylation for CDH1 and GDNF. DNA methyltransferase 1 and 3b were highly expressed in colon epithelial cells with active mucosal inflammation, suggesting their involvement in inflammation-dependent methylation. CONCLUSIONS: Methylation in colonic mucosa of UC was correlated with mucosal inflammatory status, suggesting the involvement of methylation due to chronic active inflammation in UC carcinogenesis.

Colorectal endoscopic submucosal dissection for elderly patients at least 80 years of age.

BACKGROUND: Endoscopic submucosal dissection (ESD) has been used recently for successful en bloc resection of even large lesions, although no consensus appears in medical literature concerning its application to elderly patients. This prospective cohort study aimed to evaluate the efficacy and safety of colorectal ESD for patients 80 years of age or older. METHODS: Colorectal ESD procedure findings were compared with clinical outcomes, including associated complications and mortalities, for two age groups totaling 196 consecutive patients with 202 colorectal lesions. Of the 196 patients, 31 patients (16%) were 80 years of age or older (group E), and 165 patients (84%) were younger than 80 years (group Y). RESULTS: The median ages were 82 years in group E and 68 years in group Y. The frequency of chronic concomitant diseases was significantly higher in group E (65%) than in group Y (27%) (p = 0.003). No significant pressure decrease or need for oxygenation was observed in either group. In addition, groups E and Y did not differ significantly in terms of mean lesion sizes (40.9 vs. 39.7 mm) en bloc resection rates (84% vs. 93%), curative rates (78% vs. 84%), median procedure times (65 vs. 70 min), or associated complications (no perforation or delayed bleeding cases [0%] vs. 5 perforations [3%]) The median postprocedure hospitalization period was 3 days in both groups. Except for 10 cases requiring subsequent lymph node dissection surgery, follow-up colonoscopy examinations showed no recurrences or ESD-related mortalities in either group. CONCLUSION: Colorectal ESD is a safe and effective treatment for elderly patients (age ≥ 80 years) despite a significantly higher frequency of chronic concomitant diseases than among younger patients.

Analysis of K-ras, BRAF, and PIK3CA mutations in laterally-spreading tumors of the colorectum.

BACKGROUND AND AIMS: Laterally-spreading tumors (LST) are a newly-recognized category of colorectal neoplasia, and are defined as lesions larger than 10 mm in diameter and extending circumferentially rather than vertically. However, genetic features of this new category of tumors are not fully elucidated. The aim of this study was to evaluate genetic alterations in LST. METHODS: We examined K-ras, BRAF, and phosphoinositide-3-kinase catalytic-α polypeptide (PIK3CA) mutations in 101 LST, including 68 LST-granular type (LST-G) and 33 LST-non-granular type by direct sequencing. As controls, we examined these gene mutations in 66 protruded colon adenomas (10 mm or larger) and 44 advanced colon cancers. RESULTS: K-ras, BRAF, and PIK3CA mutations were observed in 59 (58%), zero (0%), and three (3%) LST, respectively. LST-G morphology in the right-sided colon was significantly correlated with the existence of K-ras mutations, whereas a size of 20 mm or larger was the only predictor of mutations in the left-sided colorectum. The frequency of K-ras mutations in LST was particularly marked in the left-sided colorectum compared to protruded adenomas or advanced cancers (LST vs protruded adenomas, P < 0.001; LST vs advanced cancers, P = 0.002), whereas in the right-sided colon, K-ras mutations were equally frequent. PIK3CA mutations were not familiar in either LST (3%) or advanced cancers (9%). CONCLUSIONS: K-ras mutations were involved in colorectal LST in different manners according to tumor location.

Serum folate and homocysteine levels are associated with colon tumorigenesis in end-stage renal disease patients.

The aim of this study was to evaluate the effect of folate and homocysteine on colon tumorigenesis by performing colonoscopy and examining serum folate and homocysteine levels in end-stage renal disease (ESRD) patients. We performed colonoscopy in 72 ESRD patients who were undergoing hemodialysis and also measured their serum folate and homocysteine levels. Serum folate and homocysteine concentrations of the 72 ESRD patients were 6.0±3.9 µg/l and 37.3±25.5 µmol/l, respectively. Colorectal neoplasia was detected in 47 (65%) of the patients. Compared to a control group, ESRD patients had significantly more and larger neoplasia (P=0.002 and 0.001, respectively). Multivariate analysis revealed that ESRD patients with lower levels of serum homocysteine had significantly more and larger neoplasia than those with higher levels (P=0.02 and 0.03, respectively). In addition, patients with a shorter duration of hemodialysis were likely to have larger neoplasia. ESRD patients had higher than normal serum homocysteine levels. Interestingly, patients with lower homocysteine levels were likely to carry more and larger colorectal neoplasia. These results suggest that suppression of folate metabolism and an elevated serum homocysteine concentration are inversely associated with colon tumorigenesis in ESRD patients.

The presence of large serrated polyps increases risk for colorectal cancer.

BACKGROUND & AIMS: There is evidence that serrated polyps (serrated adenomas and hyperplastic polyps) have different malignant potential than traditional adenomas. We used a colonoscopy database to determine the association between the presence of serrated colorectal polyps and colorectal neoplasia. METHODS: We performed a multicenter observational study of 10,199 subjects who underwent first-time colonoscopies. Data collected on study subjects included age and sex and the location, size, and histology of polyps or tumors found at colonoscopy. Serrated polyps were defined as those diagnosed by the pathologists in the participating hospitals as a serrated lesion (a lesion given the term of "classical hyperplastic polyp," "traditional serrated adenoma," "sessile serrated adenoma," or "mixed serrated polyp"). Large serrated polyps (LSPs) were defined as those ≥ 10 mm. RESULTS: There were 1573 patients (15.4%) with advanced neoplasia, 708 patients (6.9%) with colorectal cancer (CRC), and 140 patients (1.4%) with LSPs in our cohort. Multivariate analysis associated the presence of LSPs with advanced neoplasia (odds ratio [OR], 4.01; 95% confidence interval [CI], 2.83-5.69) and CRC (OR, 3.34; 95% CI, 2.16-5.03). The presence of LSPs was the greatest risk factor for CRC, particularly for proximal CRC (OR, 4.79; 95% CI, 2.54-8.42). Proximal and protruded LSPs were the highest risk factors for proximal CRC (OR, 5.36; 95% CI, 2.40-10.8 and OR, 9.00; 95% CI, 2.75-19.2, respectively). CONCLUSIONS: The presence of LSPs is a risk factor for CRC, particularly CRC of the proximal colon.

Advantages of using thin endoscope-assisted endoscopic submucosal dissection technique for large colorectal tumors.

BACKGROUND: Our purpose was to evaluate the effectiveness of a newly developed non-invasive traction technique known as thin endoscope-assisted endoscopic submucosal dissection (TEA-ESD) procedure for the removal of colorectal laterally spreading tumors (LST). PATIENTS AND METHODS: A total of 37 LST located in the rectum and distal sigmoid colons of 37 patients were eligible for outcome analysis. Twenty-one LST were treated with TEA-ESD and were then retrospectively compared to 16 LST that had previously been treated with standard ESD. Tumor size, en bloc resection rate, procedure time, combined number of different electrical surgical knives used during each procedure and associated complications were evaluated in this case-control study. RESULTS: There was no statistically significant difference in tumor size between the TEA-ESD group and the ESD control group (43.6+/-16 mm and 42.4+/-14 mm, respectively). All LST were successfully resected en bloc in both groups. Procedure duration was shorter for the TEA-ESD group than the ESD control group, although the difference was not statistically significant (96+/-53 minutes vs 116+/-74 minutes; P=0.18). The percentage of cases in which only one electrical surgical knife was used during the entire procedure was significantly higher in the TEA-ESD group compared to the ESD control group (85.7% vs 31.3%; P=0.0005). There were no perforations in the TEA-ESD group while the ESD control group experienced one perforation. At the present time, TEA-ESD is limited to the rectum and distal sigmoid colon. CONCLUSION: It was technically easier, safer and more cost-effective to perform ESD for LST in the rectum and the distal sigmoid colon using the newly developed TEA-ESD traction technique.

Improved catalytic and stereoselective glycosylation with glycosyl N-trichloroacetylcarbamate: application to various 1-hydroxy sugars.

Efficient catalytic and stereoselective glycosylation was achieved by activating a glycosyl N-trichloroacetylcarbamate with a catalytic amount of Lewis acid in the presence of a glycosyl acceptor and 5A molecular sieves. Catalytic one-pot dehydrative glycosylation of a 1-hydroxy carbohydrate was achieved stereoselectively by reaction with trichloroacetyl isocyanate, followed by activation with a catalytic amount of activators.

A case of hepatic angiomyolipoma difficult to distinguish from hepatocellular carcinoma.

We report a case of hepatic angiomyolipoma with uncommon clinical features. A 56-year-old man presented with a hepatic tumor in the caudate lobe. The tumor was hypoechoic on ultrasonography, showed early-phase hyperattenuation on enhanced computed tomography and did not absorb iron on superparamagnetic iron oxide-enhanced magnetic resonance imaging. Hepatocellular carcinoma was highly suspected, and the patient underwent hepatic resection. Histologically, the tumor was mainly composed of smooth muscle cells and contained small amounts of adipose cells and blood vessels. On immunohistochemical staining, the smooth muscle cells were positive for a melanocytic cell-specific monoclonal antibody. In cases with uncommon features of angiomyolipoma, it is quite difficult to distinguish angiomyolipoma from hepatocellular carcinoma.

Methylation of estrogen receptor 1 in colorectal adenomas is not age-dependent, but is correlated with K-ras mutation.

The promoter region of estrogen receptor 1 (ESR1) has been shown to be methylated in normal colorectal mucosa in an age-dependent manner. However, the methylation of this region in colorectal tumors has not sufficiently been investigated. The methylation status of ESR1 in 105 colorectal adenoma tissues was examined by MethyLight and presented as the percentage of methylated references (PMR). Factors that affect the PMR of ESR1 in adenomas were determined using parameters including patient age, sex, past history of malignancy, family history of colorectal cancer, smoking and drinking habits, clinical characteristics of adenomas (location, size, macroscopic appearance, and histology), and K-ras mutation. Multiple linear regression revealed that the PMR was not correlated with patient age. K-ras mutation was significantly correlated with the higher methylation status of ESR1 in adenoma (t-value = 3.21, P = 0.0018), whereas alcohol exposure was significantly correlated with lower methylation status (t-value = -2.37, P = 0.02). Because methylation of O6-methylguanine DNA methyltransferase (MGMT) has been reported to be correlated with K-ras G-to-A transition, methylation of ESR1 was compared with that of MGMT with regard to K-ras mutation. Contrary to expectations, methylation of MGMT was not significantly correlated with K-ras G-to-A transition, but that of ESR1 was strongly correlated with K-ras G-to-A transition. Thus, the methylation status of ESR1 in adenomas was not correlated with patient age, but was associated with K-ras mutation, suggesting that methylation of ESR1 in tumors functions differently from that in normal colon mucosa.