Total DS Research Articles

Development and Validation of a Simple and Multifaceted Instrument, Chronic Constipation-Therapeutic Efficacy and Satisfaction Test, for the Clinical Evaluation of Patients with Chronic Constipation

Introduction: This study evaluated the psychometric properties of the newly developed chronic constipation-therapeutic efficacy and satisfaction test (CC-TEST) among patients with chronic constipation. Methods: Japanese patients with moderate or severe chronic constipation underwent a 4-week remedy. The baseline, 2-week, and 4-week assessments included the CC-TEST, Constipation Scoring System (CSS), Medical Outcome Study Short Form-8 Health Survey (SF-8), and Hospital Anxiety and Depression Scale (HADS). The CC-TEST comprises three domains: (1) symptoms; chronic constipation symptom severity (seven items), defecation status (five items), (2) impact for daily life; dissatisfaction with daily life level (DS; four items), and (3) therapeutic response; therapeutic efficacy measured by patients and medication compliance (four items). Results: Of 201 eligible patients at baseline, 110 completed the 4-week treatment and the survey responses. Cronbach’s α values for the stool, defecation, and abdominal symptom subscales, as well as the total symptom score and DS subscale, showed good internal consistency reliability (0.72–0.80). Pearson’s r for comparisons between corresponding items (CC-TEST symptoms with CSS, and CC-TEST DS with SF-8 physical and mental component summary scores) was significant. After 4 weeks, scores for symptoms, defecation status, and DS items/subscales notably decreased, with a significant effect size (p < 0.005, Cohen’s d; 0.30–1.16). Statistically significant differences emerged between treatment responders and nonresponders using the three responder definitions, in changes in scores for most CC-TEST symptoms, defecation status, and DS items/subscales (p < 0.05). Conclusion: CC-TEST demonstrates commendable reliability, convergent and known-group validity, and responsiveness to treatment effects. As a simple, comprehensive, and versatile patient-reported outcome measure, CC-TEST may be well suited for clinical trials and primary care of Japanese patients with chronic constipation.

Synthesis, characterization and seawater biodegradability of paramylon mix ester derivatives with different DS

A two-step synthesis method was established to prepare paramylon mix ester derivatives with low total DS by introducing long chain hexanoate into biodegradable polysaccharide esters with short chain acetate. The relationship between the chemical structure of paramylon mix esters and their thermal properties and seawater biodegradability was investigated. Among the possible hydroxyl groups of paramylon backbone, hydroxyl group on C6 position is prior to be substituted for both paramylon acetate (PaAc) and paramylon acetate hexanoate (PaAcHex). Prepared paramylon esters are amorphous and more thermal stable than neat paramylon. PaAcHex showed lower Tg and more flexibility when hexanoate were added more. The capability of biodegradability of mix esters with different collocations was also determined. Hexanoate with low DS provides paramylon esters with effective mechanical properties without losing the seawater biodegradability. These results of collocations of short and long ester chains were verified to be an effective thought to realize the coexistence of thermoformability, mechanical property and biodegradability.

Quaternization-butyrylation to improve the viscosity stability, adhesion to fibers, film properties and desizability of starch for warp sizing

The influence of the quaternization and butyrylation on the sizing properties of biological starch macromolecule was evaluated for acquiring a new starch bio-based size [quaternized-butyrylated starch (QBS)]. The sizing properties of granular QBS samples were investigated in comparison with acid-thinned starch (ATS) and quaternized starch (QS). The QBS samples with a DS range of 0.029–0.0779 exhibited bonding strengths of 17.0–18.3 cN/tex to cotton fibers [15.5 cN/tex (ATS, DS = 0) and 16.6 cN/tex (QS, DS = 0.0240)] and 31.0–34.3 cN/tex to polyester fibers [28.0 cN/tex (ATS) and 30.1 cN/tex (QS)], and their films showed breaking elongations of 2.99–3.51% [2.59% (ATS) and 2.81% (QS)] and tensile strengths of 36.5–32.1 MPa [38.1 MPa (ATS) and 37.3 MPa (QS)]. Compared with QS, significantly increased bonding strengths as well as obviously decreased strengths and increased elongations of the films for the QBS samples with the total DS ≥ 0.0635 were exhibited. As increasing the modification levels from 0.029 to 0.0779, QBS presented paste stabilities from 90.4% to 85.7% which met with the requirement in warp sizing, and displayed higher desizing efficiencies (93.2–93.8%) than ATS (91.5%) and QS (90.2%). Based on these results, the amphiphilic quaternization-butyrylation was a good means for starch to acquire good sizing properties.

Phosphorylation and Octenylsuccinylation of Acid‐Thinned Starch for Enhancing Adhesion on Cotton/Polyester Blend Fibers at Varied Temperature Sizing

In this study, amphiphilic starch prepared by phosphorylation and octenylsuccinylation is surveyed to identify its effect on the adhesion of starch to cotton/polyester blend fibers at different temperature. Acid‐thinned cornstarch (ATS) is phosphorylated and octenylsuccinylated with pentasodium triphosphate and 2‐octenylsuccinic anhydride, respectively, to improve upon adhesion to cotton/polyester blend fibers. Two series of amphiphilic starch samples with different levels of the substitution (DS) are derived for determining desirable level of starch modification in sizing. Amphiphilic starch paste shows strong adhesion to cotton/polyester blend fibers than ATS paste. It is found that the modification reduces the crystallinity, changed the morphology, improves moisture regain, alleviates the adverse influence of starch retrogradation, and improves adhesion to fibers and desizing efficiency. The adhesion of amphiphilic starch paste to cotton/polyester blend fibers at 60 °C is statistically higher than adhesion of ATS at 95 °C. The amphiphilic starch with a total DS of 0.06 shows the highest potential use for strong cotton/polyester blend warp sizing due to its good sizing properties.

Potential of dibutyltin oxide for the manno/gluco- and regioselective methylation of Konjac glucomannan

Konjac glucomannan, built of β-1,4-linked mannose and glucose, was methylated after treatment with dibutyltin oxide/MeOH in pyridine. Best results were obtained in acetonitrile/DMF in the presence of TBAB and K2CO3. While total DS was only 0.1–0.15 and not significantly enhanced in the tin-promoted reaction, the manno-/gluco- (cis-/trans-diol) and the regioselectivity was completely changed with DSMan/DSGlc increasing from 0.9 to 1.8, a strong preference for secondary over primary OH, and a total order of reactivity being M3 > M2 ≥ G2 > G6 ≥ M6 ≥ G3. The influence of the amount of K2CO3, Bu2SnO, and temperature was studied. By repeated reaction a DS of 0.28 was gained without loss in selectivity. In a solvent-free one-pot stannylation/methylation reaction, a DS up to 0.3 was achieved. Surprisingly, any differences between the two stereoisomeric sugar constituents were leveled under these conditions, and regioselectivity was changed to the order M6 ≈ G6 ≫ M3 ≈ G3 > M2 ≈ G2.

Expression of saponin biosynthesis related genes in different tissues of Panax quinquefolius

The relationship between saponin content of Panax quinquefolius in different parts of the organization and expression of ginsenoside biosynthesis related gene was obtained by the correlation analysis between saponin content and gene expression. The 14 tissue parts of P. quinquefolius were studied, six saponins in P. quinquefolius. Samples (ginsenoside Rg₁, Re, Rb₁, Rc, Rb₂ and Rd), group saponins and total saponins were determined by high performance liquid chromatography and vanillin-sulfuric acid colorimetric method. Simultaneously, the expression levels of 7 ginsenoside biosynthesis related genes (SQS, OSC, DS, β-AS, SQE, P450 and FPS) in different tissues of P. quinquefolius were determined by Real-time fluorescence quantitative PCR. Although 7 kinds of ginsenoside biosynthesis related enzyme gene in the P. quinquefolius involved in ginsenoside synthesis, the expression of β-AS and P450 genes had no significant effect on the content of monosodium saponins, grouping saponins and total saponins, FPS, SQS, OSC, DS and SQE had significant or extremely significant on the contents of single saponins Re, Rg1, Rb1, Rd, group saponin PPD and PPT, total saponin TMS and total saponin TS (P<0.05 or P<0.01). The biosynthesis of partial saponins, grouping saponins and total saponins in P. quinquefolius was affected by the interaction of multiple enzyme genes in the saponin synthesis pathway, the content of saponins in different tissues of P. quinquefolius was determined by the differences in the expression of key enzymes in the biosynthetic pathway. Therefore, this study further clarified that FPS, SQS, OSC, DS and SQE was the key enzyme to control the synthesis of saponins in P. quinquefolius by correlation analysis, the biosynthesis of ginsenosides in P. quinquefolius was regulated by these five kind of enzymes in cluster co-expression of interaction mode.

Electroneutral cornstarch by quaternization and sulfosuccinylation to improve the adhesion of cold starch paste to raw cotton for low-temperature sizing

The objective of this research was to survey the effects of starch quaternization and sulfosuccinylation on the adhesion of cold starch paste to raw cotton fibers for cotton warp sizing at low temperature. Acid-thinned cornstarch (ATS) was quaternized and then sulfosuccinylated to introduce 3-(trimethylammonium chloride)-2-hydroxypropyl and sulfosuccinate substituents onto its backbones. The electroneutrality of starch samples prepared was achieved by maintaining a constant mole ratio (5.3:1) of the two substituents. A series of electroneutral cornstarch (ECS) samples with different levels of the substituents were derived by altering the feed ratio of the modifying reagents to starch for determining desirable level of starch modification. Adverse influences of cotton wax and starch retrogradation on the adhesion of cold starch paste to raw cotton fibers were evaluated to illustrate the effectiveness of starch quaternization and sulfosuccinylation. It was found that the modification was able to alleviate the adverse influence of starch retrogradation and ameliorate the adhesion to the fibers at low temperature. Higher level of the modification led to less retrogradation and resulted in strong adhesion. Furthermore, the adverse influence of cotton wax on the adhesion could be eliminated after a pre-wetting treatment of raw cotton warps with hot water. The adhesion of ECS paste to raw cotton at 60 °C was statically the same as that of ATS at 95 °C when total DS of ECS was 0.0443 or higher.

Distribution of traffic-related contaminants in urban topsoils across a highway in Moscow

The objective of this research is to find out the spatial distribution of different traffic-related contaminants in urban topsoils across a highway (125,000 vehicles per day) in the city of Moscow, Russia. The topsoils (0–3 cm depth) were sampled 1, 6, 10, 18, and 50 m perpendicular to the roadbed in three replicates 10 m apart. We analyzed total petroleum hydrocarbons (TPH), polycyclic aromatic hydrocarbons (PAH), heavy metals in total and phyto-available forms (HM; Cu, Zn, and Pb), and deicing salts (DS; Cl−). The TPH were extracted with carbon tetrachloride and detected by spectrometry and PAH were extracted with methylene chloride, separated by high-performance liquid chromatography, and determined by fluorescence detector. Total HM were extracted by microwave acid digestion with aqua regia and phyto-available forms were extracted by NH4OAc and determined by inductively coupled plasma mass spectrometry. The DS were analyzed using an ion liquid chromatograph with a conductometric detector. Heavy soil pollution was found within 1–6 m of the road. The TPH, B[a]P, and phyto-available HM concentrations exceeded permissible levels for Russia, while total HM and DS did not. The contaminant contents sharply decreased 10 m from the road. Within 10–50 m, they reached background levels, while PAH levels were elevated. We attribute this to the greater age of soils at 10–50 m than 1–6 m from the road. The different contaminant distribution patterns are attributed to their different transportation pathways: TPH, DS, and HM generally reach soils through road spray, splashes, melting snow moved from the road surface to roadsides, and aerosol sedimentation, whereas PAH are mainly transported as airborne particles and are thus able to reach more distant locations. Traffic-related soil pollution creates ecotoxicological and human-health risks. Distribution patterns vary by type of soil contaminant. The influence of the road on soil contamination was greatest within 10 m from the roadbed for TPH, HM, and DS and within 50 m for PAH. The increased PAH concentration levels with increased distance from the road highlights the importance of PAH monitoring in roadside soils.

Electrophysical properties of Schottky diodes with inhomogeneous contact surface

In Cu–nSi Schottky diode (SD) with inhomogeneous contact surface at the active participation of the additional electric field (AEF) is formed a effective potential barrier height. Forward and initial reverse I–V characteristics SD are determined by the current flowing through almost the entire contact surface and is well described by the thermionic emission theory, as in the idealized homogeneous SD. In a forward and primary reverse bias the effective potential barrier height, the ideality factor (dimensionless coefficient), the contact resistance, the peripheral area and width of the contact surface, the contribution of peripheral current to the total current DS have appropriate similar values. The contribution of peripheral current to the total current SD increases with increasing reverse voltage. The second portion of the reverse I–V characteristics SD, which consists only of peripheral current is represented by a straight line in a semi-logarithmic scale. Its electrophysycal parameters are differed from that for of the first initial portion I–V characteristics SD.

The Impact of Down Syndrome Screening on Taiwanese Down Syndrome Births: A Nationwide Retrospective Study and a Screening Result from a Single Medical Centre

A retrospective analysis of the Taiwanese National Birth Defect Registration and Notification System was conducted in order to determine the live birth- and stillbirth rates in infants with Down syndrome, trisomy 18, trisomy 13 and Turner syndrome between 2001 and 2010. The objective was to investigate the impact of Down syndrome screening on the Taiwanese Down syndrome live birth rate. In addition, the results of first-trimester Down syndrome screening between 2006 and 2011, and of second-trimester quadruple testing between 2008 and 2011, were obtained from the National Taiwan University Hospital. All Taiwanese infants born between 2001 and 2010 were included in the first part of the analysis, and women receiving first-trimester Down syndrome screening or second-trimester quadruple testing from the National Taiwan University Hospital were included in the second part. The live birth rate of infants with Down syndrome, per 100 000 live births, decreased from 22.28 in 2001 to 7.79 in 2010. The ratio of liveborn DS to total DS was 48.74% in 2001, and then decreased to 25.88% in 2006, when first-trimester screening was widely introduced in Taiwan. This ratio dropped to 20.64% in 2008, when the second-trimester quadruple test was implemented. The overall positive rate in first-trimester screening in the National Taiwan University Hospital was 3.1%, with a Down syndrome detection rate of 100%; the quadruple test had values of 9.0% and 75%, respectively. The use of first-trimester screening and the second-trimester quadruple test may be responsible for the marked decrease in the Taiwanese Down syndrome live birth rate observed between 2001 and 2010.

SIGNED TOTAL {K}-DOMINATION AND {K}-DOMATIC NUMBERS OF GRAPHS

Let k be a positive integer, and let G be a simple graph with vertex set V(G). A function f : V(G) → {±1, ±2, …, ±k} is called a signed total {k}-dominating function if ∑u∈N(v) f(u) ≥ k for each vertex v ∈ V(G). A set {f1, f2, …, fd} of signed total {k}-dominating functions on G with the property that [Formula: see text] for each v∈V(G), is called a signed total {k}-dominating family (of functions) on G. The maximum number of functions in a signed total {k}-dominating family on G is the signed total {k}-domatic number of G, denoted by [Formula: see text]. Note that [Formula: see text] is the classical signed total domatic number dS(G). In this paper, we initiate the study of signed total k-domatic numbers in graphs, and we present some sharp upper bounds for [Formula: see text]. In addition, we determine [Formula: see text] for several classes of graphs. Some of our results are extensions of known properties of the signed total domatic number.

Intra- and Extraluminal Structural and Functional Venous Anomalies in Multiple Sclerosis, as Evidenced by 2 Noninvasive Imaging Techniques

Chronic cerebrospinal venous insufficiency (CCSVI) is a vascular condition characterized by anomalies of the main extracranial cerebrospinal venous routes that interfere with normal venous outflow. Research into CCSVI will determine its sensitivity and specificity for a diagnosis of MS, its prevalence in MS patients, and its clinical, MRI, and genetic correlates. Our aim was to investigate the prevalence and number of intra- and extraluminal structural and functional extracranial venous abnormalities by using DS and MRV, in patients with MS and HCs. One hundred fifty patients with MS, 104 (69.3%) with RR and 46 (30.7%) with a progressive MS course, and 63 age- and sex-matched HCs were scanned with 3T MR imaging by using TOF and TRICKS sequences (only patients with MS). All subjects underwent DS examination for intra- and extraluminal structural and functional abnormalities of the IJVs. Absent/pinpoint IJV flow morphology on MRV was considered an abnormal finding. Prominence of collateral extracranial veins was assessed with MRV. Patients with MS had a significantly higher number of functional (P < .0001), total (P = .001), and intraluminal (P = .005) structural IJV DS abnormalities than HCs. There was a trend for more patients with MS with extraluminal IJV DS abnormalities (P = .023). No significant differences were found on the MRV IJV flow morphology scale between patients with MS and HCs. Patients with progressive MS showed more extraluminal IJV DS abnormalities (P = .01) and more MRV flow abnormalities on TOF (P = .006) and TRICKS (P = .01) than patients with nonprogressive MS. There was a trend for a higher number of collateral veins in patients with MS than in HCs (P = .016). DS is more sensitive than MRV in detecting intraluminal structural and functional venous abnormalities in patients with MS compared with HCs, whereas MRV is more sensitive in showing collaterals.

Synthesis and characterization of low sulfoethylated cellulose

The synthesis and characterization of sulfoethyl cellulose (SEC) exhibiting low degrees of substitution ascribed to sulfoethyl groups (DS SE) were reported. The effects of reaction temperature, duration, reaction mediums as well as sulfoethylating agents on DS SE were investigated. The total DS SE was determined via elemental analysis and the structure of SEC was elucidated by FT Raman, one- (1D-) and two-dimensional (2D-) NMR spectroscopy. Based on the characterization, SEC with diverse total DS SE up to 0.65 were obtained and the primary hydroxyl groups were found to be preferably substituted. Finally, the feasibility of using FT Raman spectroscopy with the band at 1044, 811 or 747 cm −1 as marker band to determine total DS SE of SEC was presented.

Homogenous Carboxymethylation of Cellulose in the New Alkaline Solvent LiOH/Urea Aqueous Solution

AbstractIn this work, the carboxymethylation of cellulose in a new alkaline cellulose solvent, LiOH/urea aqueous solution, was investigated. Carboxymethyl cellulose (CMC) samples were characterized with FT‐IR, NMR, HPLC, and viscosity measurements. Water‐soluble CMC with DS = 0.36∼0.65 was prepared, from both Avicel cellulose and cotton linters in the LiOH/urea system. The total DS of CMC could be controlled by varying the molar ratio of reagents and the reaction temperature. The results from structure analysis by HPLC after complete depolymerization showed that the mole fractions of the different carboxymethylated repeating units as well as those of unmodified glucose follow a simple statistic pattern. A distribution of the carboxymethyl groups of the AGU was determined to be in the order O‐6 &gt; O‐2 &gt; O‐3 position at the level.

FT Raman investigation of novel chitosan sulfates exhibiting osteogenic capacity

Chitosan sulfates (CHS) exhibiting various total degrees of substitution ascribed to sulfate groups (DS S) were synthesized. The sulfation could be under homogeneous or non-homogeneous conditions. The obtained CHS were characterized and total DS S of up to 1.73 were determined. Using chlorosulfonic acid as sulfating agent, CS with total DS S between 0.86 and 1.67 were obtained and the total DS S can be regulated by varying the sulfation parameters. Using other sulfating agents, CS with distinct total DS S of up to 1.73 were prepared. By means of FT Raman spectroscopy, marker bands at 1070 cm −1 or 1014 cm −1 attributed to vibrations of sulfation groups can be applied for quantifying the total DS S of CHS. Calibration curves with correlation coefficients of more than 0.95 were established, suggesting the feasibility of Raman spectroscopy for quantifying the total DS S of CHS. Finally, the capacity of CHS to improve the osteogenic activity of bone morphogenetic protein-2 (BMP-2) was presented.

A facile method for the homogeneous synthesis of cyanoethyl cellulose in NaOH/urea aqueous solutions

A series of cyanoethyl cellulose (CEC) samples were synthesized from cellulose in NaOH/urea aqueous solutions by a homogeneous method. Structure and properties of CECs were characterized with FT-IR, 1H and 13C NMR, DSC, SEC-LLS, polarized light microscopy and solubility measurements. The total DS values of the obtained CECs were in the range of 0.26 to 1.93, and the relative reactivity of hydroxyl groups is in the order C-6 > C-2 > C-3. As the molar ratio of acrylonitrile to anhydroglucose unit (AGU) of cellulose increased to 5 : 1, the C-6 hydroxyl groups of AGU were fully substituted. The total DS value for water-soluble CEC is as low as 0.54. CEC could be dissolved in many organic solvents when its total DS value reached 1.37. Organic-soluble CEC samples displayed thermotropic liquid crystalline behavior in the temperature range of 180 to 280 °C. Moreover, NaOH/urea aqueous solution was proved to be a stable medium for cyanoethylation of cellulose, the reaction products could be easy isolated and purified, and the solvents could be recycled by a simple filtration. Therefore, this work provides a facile method for the homogeneous synthesis of CEC in an aqueous system.

Homogenous carboxymethylation of cellulose in the NaOH/urea aqueous solution

In this work, the carboxymethylation of cellulose in the alkaline cellulose solvent, 7 wt% NaOH/12 wt% urea aqueous solution, was investigated. Carboxymethyl cellulose (CMC) samples were characterized with FT-IR, NMR, HPLC, and viscosity measurements. Water-soluble CMC with DS = 0.20–0.62 was prepared from both Avicel cellulose and cotton linters. Thus, carboxymethylation of cellulose in NaOH/urea leads to a polymer with the lowest DS value for water solubility (0.20) of CMC known. The total DS of CMC could be controlled by varying the molar ratio of reagents and NaOH to AGU and the reaction temperature. Structure analysis by means of HPLC after complete depolymerization showed that the mole fractions of the different carboxymethylated repeating units as well as those of unmodified glucose follow the simple statistic pattern. A distribution of the carboxymethyl groups at the level of the AGU in the order O-6 > O-2 > O-3 was determined. The results were similar with findings for CMC obtained by totally homogeneous reaction of cellulose in aqueous solvents such as Ni[tris(2-aminoethyl)amine](OH) 2.

Practical assessment of myocardial viability with a positron coincidence gamma camera using 18F-fluorodeoxyglucose in acute myocardial infarction: Comparison with dedicated positron emission tomography and 201Tl single photon emission computed tomography

2-[(18)F] fluoro-2-deoxy-D-glucose ((18)F-FDG) began to be supplied commercially to our hospital, which does not have a cyclotron, in autumn of 2005. The purpose of this study was to compare the utility of a dual-head positron coincidence detection (PCD) gamma camera in the detection of myocardial viability using (18)F-FDG with that of dedicated positron emission tomography (PET) and with that of thallium-201 ((201)Tl) single photon emission computed tomography (SPECT). A total of 15 patients (14 men and 1 woman, mean age: 60+/-7 years, range: 46-73) with a large acute myocardial infarction (AMI) underwent (18)F-FDG PET, (18)F-FDG PCD imaging after oral glucose loading (75 g) and (201)Tl SPECT imaging. We divided the SPECT and PET images into a total of 20 segments, and semiquantitative visual analysis was performed by assessing regional tracer activities on a 4-point scoring system (DS): 0=normal uptake, 1=mildly reduced uptake, 2=severely reduced uptake, and 3=no uptake. We summed the DS in each patient as the total DS (TDS). The TDS of the (18)F-FDG PET image was 14.4+/-7.7. The TDS of the (18)F-FDG PCD image was 18.7+/-7.7. The TDS of the (201)Tl SPECT image was 24.1+/-11.5. The TDS of the (18)F-FDG PET image was significantly smaller than that of the (18)F-FDG PCD image. The TDS of the (18)F-FDG PET image was significantly smaller than that of the (201)Tl SPECT image. The TDS of the (18)F-FDG PCD image was significantly smaller than that of the (201)Tl SPECT image. The findings of the project suggest that (18)F-FDG PCD is a good modality based on its accuracy, convenience, and cost-performance for detecting myocardial viability in hospitals that do not have a PET system.

Novel Nanoparticles Based on Dextran Esters with Unsaturated Moieties

Applying a dialysis process, new nanoparticles based on well-defined dextran esters of furan-2-carboxylic-and pyrpglutamic acids were prepared, which can undergo cross-linking by UV irradiation. The highly functionalized products (total DS >2) avoid the collapse of nanoparticles due to the prevention of hydrogen bond formation. The major fraction of the dextran ester nanospheres exhibits narrow size distribution down to 250 nm as mean diameter investigated by SEM.

Determination of the DS and substituent distribution of cationic alkyl polyglycosides and cationic starch ethers by GLC after dealkylation with morpholine

The total DS and substituent distribution of starch and alkyl polyglycosides functionalised as O-(2-hydroxy-3-trimethylammonium)propyl ethers were determined by GLC. To achieve volatile analytes, the samples were submitted to methanolysis, N-demethylation and O-trimethylsilylation. Alternatively hydrolysis, reduction with NaBH 4 and subsequent O-acetylation were performed, but suffered from intramolecular acetal formation of 2- O-substituted residues, preventing reduction. Morpholine as nucleophile was superior to thiophenolate with regard to quantitative dealkylation and side product formation. The ratio of un-, mono-, di-, tri-, and tetrasubstituted compounds was determined. The total DS values calculated from these mole fractions were in good agreement with those obtained from elemental analysis or NMR from standards. Regioselectivity of the cationisation reaction was determined after methanolysis, permethylation and Hofmann elimination by GLC.