Hyperpolarized [1-13C]-pyruvate MRS evaluates immune potential and predicts response to radiotherapy in cervical cancer.

BACKGROUND: Monitoring pyruvate metabolism in the spleen is important for assessing immune activity and achieving successful radiotherapy for cervical cancer due to the significance of the abscopal effect. We aimed to explore the feasibility of utilizing hyperpolarized (HP) [1-13C]-pyruvate magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) to evaluate pyruvate metabolism in the human spleen, with the aim of identifying potential candidates for radiotherapy in cervical cancer. METHODS: This prospective study recruited six female patients with cervical cancer (median age 55 years; range 39-60) evaluated using HP [1-13C]-pyruvate MRI/MRS at baseline and 2 weeks after radiotherapy. Proton (1H) diffusion-weighted MRI was performed in parallel to estimate splenic cellularity. The primary outcome was defined as tumor response to radiotherapy. The Student t-test was used for comparing 13C data between the groups. RESULTS: The splenic HP [1-13C]-lactate-to-total carbon (tC) ratio was 5.6-fold lower in the responders than in the non-responders at baseline (p = 0.009). The splenic [1-13C]-lactate-to-tC ratio revealed a 1.7-fold increase (p = 0.415) and the splenic [1-13C]-alanine-to-tC ratio revealed a 1.8-fold increase after radiotherapy (p = 0.482). The blood leukocyte differential count revealed an increased proportion of neutrophils two weeks following treatment, indicating enhanced immune activity (p = 0.013). The splenic apparent diffusion coefficient values between the groups were not significantly different. CONCLUSIONS: This exploratory study revealed the feasibility of HP [1-13C]-pyruvate MRS of the spleen for evaluating baseline immune potential, which was associated with clinical outcomes of cervical cancer after radiotherapy. TRIAL REGISTRATION: ClinicalTrials.gov NCT04951921 , registered 7 July 2021. RELEVANCE STATEMENT: This prospective study revealed the feasibility of using HP 13C MRI/MRS for assessing pyruvate metabolism of the spleen to evaluate the patients' immune potential that is associated with radiotherapeutic clinical outcomes in cervical cancer. KEY POINTS: • Effective radiotherapy induces abscopal effect via altering immune metabolism. • Hyperpolarized 13C MRS evaluates patients' immune potential non-invasively. • Pyruvate-to-lactate conversion in the spleen is elevated following radiotherapy.

A Very Deep Graph Convolutional Network for 13C NMR Chemical Shift Calculations with Density Functional Theory Level Performance for Structure Assignment.

Nuclear magnetic resonance (NMR) chemical shift calculations are powerful tools for structure elucidation and have been extensively employed in both natural product and synthetic chemistry. However, density functional theory (DFT) NMR chemical shift calculations are usually time-consuming, while fast data-driven methods often lack reliability, making it challenging to apply them to computationally intensive tasks with a high requirement on quality. Herein, we have constructed a 54-layer-deep graph convolutional network for 13C NMR chemical shift calculations, which achieved high accuracy with low time-cost and performed competitively with DFT NMR chemical shift calculations on structure assignment benchmarks. Our model utilizes a semiempirical method, GFN2-xTB, and is compatible with a broad variety of organic systems, including those composed of hundreds of atoms or elements ranging from H to Rn. We used this model to resolve the controversial J/K ring junction problem of maitotoxin, which is the largest whole molecule assigned by NMR calculations to date. This model has been developed into user-friendly software, providing a useful tool for routine rapid structure validation and assignation as well as a new approach to elucidate the large structures that were previously unsuitable for NMR calculations.

1H detection and dynamic nuclear polarization-enhanced NMR of Aß1-42 fibrils.

Several publications describing high-resolution structures of amyloid-ß (Aß) and other fibrils have demonstrated that magic-angle spinning (MAS) NMR spectroscopy is an ideal tool for studying amyloids at atomic resolution. Nonetheless, MAS NMR suffers from low sensitivity, requiring relatively large amounts of samples and extensive signal acquisition periods, which in turn limits the questions that can be addressed by atomic-level spectroscopic studies. Here, we show that these drawbacks are removed by utilizing two relatively recent additions to the repertoire of MAS NMR experiments-namely, 1H detection and dynamic nuclear polarization (DNP). We show resolved and sensitive two-dimensional (2D) and three-dimensional (3D) correlations obtained on 13C,15N-enriched, and fully protonated samples of M0Aß1-42 fibrils by high-field 1H-detected NMR at 23.4 T and 18.8 T, and 13C-detected DNP MAS NMR at 18.8 T. These spectra enable nearly complete resonance assignment of the core of M0Aß1-42 (K16-A42) using submilligram sample quantities, as well as the detection of numerous unambiguous internuclear proximities defining both the structure of the core and the arrangement of the different monomers. An estimate of the sensitivity of the two approaches indicates that the DNP experiments are currently ∼6.5 times more sensitive than 1H detection. These results suggest that 1H detection and DNP may be the spectroscopic approaches of choice for future studies of Aß and other amyloid systems.

A simple method for quantifying de novo lipogenesis rate and substrate selection in cell cultures by 13 C NMR isotopomer analysis of the crude lipid fraction.

PURPOSE: De novo lipogenesis (DNL) is critical for cell growth and maintenance, and acetyl-CoA precursors can be derived from different substrates. We developed a 13 C NMR analysis of lipid extracts from cultured microglia cells administered with [U-13 C]glucose that informs overall lipogenic activity as well as the contribution of glucose to lipogenic acetyl-CoA. METHODS: BV-2 microglial cell line cultured with glucose and glutamine was provided with [U-13 C]glucose and unlabeled glutamine for 24 h and studied in either the presence or absence of lipopolysaccharide (LPS). Cells were then extracted for lipids and the crude lipid fraction was analyzed by 13 C NMR. 13 C-isotopomer signals in the fatty acid ω - 1 and ω - 2 signals representing consecutive or non-consecutive enrichment of the fatty acid chain by [1,2-13 C2 ]acetyl-CoA were quantified and applied to a probabilistic model of acetyl-CoA precursor and fatty acid enrichment. RESULTS: Glucose contributed 72 ± 2% of lipogenic acetyl-CoA while DNL from all sources accounted for 16 ± 2% of lipid turnover. With LPS, there was a significant decrease in glucose contribution (59 ± 4%, p < 0.05) while DNL was unchanged (11 ± 3%). CONCLUSIONS: A simple 13 C NMR analysis of the crude lipid fractions of BV-2 cells administered with [U-13 C]glucose informs DNL activity and the contribution of glucose to the acetyl-CoA precursors. While DNL was preserved in the presence of LPS, there was redirection of lipogenic acetyl-CoA sources from glucose to other substrates. Thus, in the present article, we describe a novel and simple 13 C NMR analysis approach to disclose the overall lipogenic activity and substrate contribution to DNL, suitable for evaluating DNL rates in cell cultures.

Isolation and characterization of flavonoid compounds from Stachytarpheta jamaicensis (L.) Vahl and its role as anti-gastro ulcerative agent in rats.

CONTEXT: Stomach ulcer is one of the most common gastrointestinal problems in the world. OBJECTIVE: This study aimed to isolate flavonoid compounds from methanol extract of the aerial parts of Stachytarpheta jamaicensis (L.) Vahl. and evaluate its protective and therapeutic effects against gastric ulcer. MATERIALS AND METHODS: Chromatographic techniques were used for the identification of the isolated compounds. To explore the effects of the plant extract, it was administrated by oral gavage for one week either before or post-ethanol ulcer induction. Ranitidine was also evaluated as a reference drug. Stomach pH, gastric juice volume, lesions number, glutathione, superoxide dismutase, malondialdehyde, succinate dehydrogenase, lactate dehydrogenase, acid phosphatase, Interleukin-10, intracellular adhesion molecule-1, prostaglandin E2, and total protein levels were estimated in gastric tissue. Stomach histopathological features were also monitored. RESULTS: Six flavonoid compounds were isolated, where five of them were isolated for the first time (vitexin, isovitexin, apigenin 7,4'-dimethyl ether, 5,7,2'-trimethoxyflavone, and scutellarein), while apigenin was previously reported. Treatment with plant extract recorded amelioration in all the biochemical parameters. CONCLUSION: The methanol extract of plant aerial parts had prophylactic and treatment effects against gastric ulcer in rats, where its treatment effect exceeded its protective role. The extract recorded anti-inflammatory, and antioxidant effects due to the presence of flavonoid compounds.

Trichilones A-E: New Limonoids from Trichilia adolfi.

In addition to the trichilianones A-D recently reported from Trichilia adolfi, a continuing investigation of the chemical constituents of the ethanol extract of the bark of this medicinal plant yielded the five new limonoids 1-5. They are characterized by having four fused rings and are new examples of prieurianin-type limonoids, having a ε-lactone which in 4 and 5 is α, ß- unsaturated. The structures of the isolated metabolites were determined by high field NMR spectroscopy and HR mass spectrometry. The new metabolites were shown to have the ε-lactone fused with a tetrahydrofuran ring which is connected to an oxidized hexane ring joined with a cyclo-pentanone having a 3-furanyl substituent. As the crude extract possesses antileishmanial activity, the compounds were assayed for cytotoxic and antiparasitic activities in vitro in murine macrophage cells (raw 264.7 cells) and in Leishmania amazoniensis as well as L. braziliensis promastigotes. Metabolites 1-3 and 5 showed moderate cytotoxicity (between 30-94 µg/mL) but are not responsible for the antileishmanial effect of the extract.

Triterpenes induced by young apple fruits in response to herbivore attack.

Apples Malus domestica, known as a rich source of triterpene acids, induced more variety and quantity of triterpene acids in response to herbivory or mechanical damage. There were 3 major induced compounds: pomaceic acid and euscaphic acid, both of which are known apple triterpene acids, and 2α,19α-dihydroxy-3-oxours-12-en-28-oic acid (named eriobotoric acid), which was first identified in apples. In this study, the 3 compounds' induction curves after damage, varietal differences in induction amounts, and physiological roles against pest insects were further investigated. Eriobotoric acid showed clear antifeedant activity against lepidopteran insect Spodoptera litura but not against apple pests.

Evaluation of biological activities of Barbarea integrifolia and isolation of a new glucosinolate derivated compound.

The aim of the present study is to determine the potent biological activities and carry out isolation studies on Barbarea integrifolia. The antioxidant capacity of the species was evaluated by total phenolic content, FRAP, CUPRAC, and DPPH radical scavenging activity. Anticancer activity studies were performed by MTT assay in MDA-MB-231, MCF-7, Hep3B, PC-3, A549, HCT116, L-929 cell lines. It was observed that the remaining aqueous fraction has higher total phenolic content while higher activity in the CUPRAC and FRAP assays was displayed for the methanolic extract and chloroform fraction. The extracts showed anticancer activity as compared with vincristine. It was observed that chloroform fraction has the highest anticancer activity on MCF-7 cell line, while ethyl acetate fraction has the highest anticancer activity on Hep-3B and A549 cell lines. Methanolic extract has the highest anticancer activity on HCT116 and MDA-MB-23 cell lines. The isolation studies have been performed using several chromatographic methods. The chemical structures of compounds have been identified by means of 1H NMR, 13C NMR, 2D-NMR, and MS. Five major compounds, one steroid (ß-Sitosterol), one phenolic acid (Rosmarinic acid), one flavonol heteroside (kaempferol 7-O-α-l-rhamnoside-3-O-ß-d-(2-O-ß- d -glucosyl)-ß-d-glucoside), and two glucosinolates (Gluconasturtiin, Gluconasturtiin choline salt) have been isolated.

A convenient approach to synthesize substituted 5-Arylidene-3-m-tolyl thiazolidine-2, 4-diones by using morpholine as a catalyst and its theoretical study.

Thiazolidinediones are very important and used as a drug for the treatment of type 2 diabetes. Here, we report a convenient approach to synthesis 3-m-tolyl-5-arylidene-2,4-thiazolidinediones (TZDs) derivatives 7a-e in two steps with moderate to good yield using morpholine as a catalyst. All the structures were confirmed by their spectral IR, 1H NMR and 13C NMR data. The anti-diabatic activity of all synthesized molecules is evaluated by docking with peroxisome proliferator-activated receptor-γ (PPARγ). Preliminary flexible docking studies reveals that our compounds 7a, 7d and 7e showed better binding affinity with the protein and could be a potential candidate for the treatment of type 2 diabetes in near future.

A method for increasing the solubility of industrial azo pigments for 13 C and 1 H NMR spectra and the assignments of their 13 C and 1 H NMR peaks.

A method for increasing the solubilities of industrial azo pigments in DMSO by adding DBU (1,8-diaza-7-bicyclo[5.4.0]undecene) has been developed. This facilitated the acquisition of solution 13 C NMR spectra of the pigments. This method was applied to four types of azo pigments: naphthol AS (3-hydroxy-2-naphthoic acid anilide) pigments, naphthol pigments, pyrazolone pigments and acetoacetanilide pigments. This represents the first solution 13 C NMR spectra for naphthol AS pigments. Altogether 18 industrial azo pigments were analysed using 1D and 2D NMR techniques. The proton and corresponding carbon NMR resonances of these pigments have all been assigned.

A precise and rapid isotopomic analysis of small quantities of cholesterol at natural abundance by optimized 1H-13C 2D NMR.

Cholesterol, the principal zoosterol, is a key metabolite linked to several health complications. Studies have shown its potential as a metabolic biomarker for predicting various diseases and determining food origin. However, the existing INEPT (insensitive nuclei enhanced by polarization transfer) 13C position-specific isotope analysis method of cholesterol by NMR was not suitable for very precise analysis of small quantities due to its long acquisition time and therefore is restricted to products rich in cholesterol. In this work, a symmetric and adiabatic heteronuclear single quantum coherence (HSQC) 2D NMR sequence was developed for the high-precision (few permil) analysis of small quantities of cholesterol. Adiabatic pulses were incremented for improving precision and sensitivity. Moreover, several strategies such as the use of non-uniform sampling, linear prediction, and variable recycling time were optimized to reduce the acquisition time. The number of increments and spectral range were also adjusted. The method was developed on a system with a cryogenically cooled probe and was not tested on a room-temperature system. Our new approach allowed analyzing as low as 5 mg of cholesterol in 31 min with a long-term repeatability lower than 2‰ on the 24 non-quaternary carbon atoms of the molecule comparing to 16.2 h for the same quantity using the existing INEPT method. This result makes conceivable the isotope analysis of matrices low in cholesterol. Graphical abstract.

Hyperpolarized Carbon (13C) MRI of the Kidneys: Basic Concept.

Existing clinical markers for renal disease are limited. Hyperpolarized (HP) 13C MRI is based on the technology of dissolution dynamic nuclear polarization (DNP) and provides new avenues for imaging kidney structure, function, and most notably, renal metabolism, addressing some of these prior limitations. Changes in kidney structure and function associated with kidney disease can be evaluated using [13C]urea, a metabolically inert tracer. Metabolic changes can be assessed using [1-13C]pyruvate and a range of other rapidly metabolized small molecules, which mainly probe central carbon metabolism. Results from numerous preclinical studies using a variety of these probes demonstrated that this approach holds great potential for monitoring renal disease, although more work is needed to bridge intelligently into clinical studies. Here we introduce the general concept of HP 13C MRI and review the most relevant probes and applications to renal disease, including kidney cancer, diabetic nephropathy and ischemic kidney injury.This chapter is based upon work from the PARENCHIMA COST Action, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This introduction chapter is complemented by two separate chapters describing the experimental procedure and data analysis.

Biomedical Applications of the Dynamic Nuclear Polarization and Parahydrogen Induced Polarization Techniques for Hyperpolarized 13C MR Imaging.

Since the first pioneering report of hyperpolarized [1-13C]pyruvate magnetic resonance imaging (MRI) of the Warburg effect in prostate cancer patients, clinical dissemination of the technique has been rapid; close to 10 sites worldwide now possess a polarizer fit for the clinic, and more than 30 clinical trials, predominantly for oncological applications, are already registered on the US and European clinical trials databases. Hyperpolarized 13C probes to study pathophysiological processes beyond the Warburg effect, including tricarboxylic acid cycle metabolism, intra-cellular pH and cellular necrosis have also been demonstrated in the preclinical arena and are pending clinical translation, and the simultaneous injection of multiple co-polarized agents is opening the door to high-sensitivity, multi-functional molecular MRI with a single dose. Here, we review the biomedical applications to date of the two polarization methods that have been used for in vivo hyperpolarized 13C molecular MRI; namely, dissolution dynamic nuclear polarization and parahydrogen-induced polarization. The basic concept of hyperpolarization and the fundamental theory underpinning these two key 13C hyperpolarization methods, along with recent technological advances that have facilitated biomedical realization, are also covered.

Neuroprotective constituents of Actaea acuminata (Wall. ex Royle) H. Hara roots.

The methanol extract and its ethyl acetate fraction (EAF) of Actaea acuminata (Wall. ex. Royle) H. Hara roots were reported to exhibit significant antianxiety, anticonvulsant and antidepressant activities, and mild sedative activity. But the constituents responsible for these activities have not been isolated. The present study was undertaken to isolate neuroprotective compounds of A. acuminata following bioactivity-guided-fractionation. The column chromatography of EAF and its sub-fractions led to the isolation of four phenolic compounds (bergenin, gallic acid, acetyl bergenin and racemic mixture of diacetyl bergenin), which were characterized by IR and NMR spectral analysis. All the compounds exhibited significant antianxiety and antidepressant activities with respect to control. The gallic acid and bergenin did not show anticonvulsant activity, whereas acetyl bergenin and racemic mixture of diacetyl bergenin exhibited significant anticonvulsant activity. Neuropharmacological activities of A. acuminata are attributed due to polyphenolic compounds. Scientific validation of traditional claims of A. acuminata has opened up roadmap of research for the development of CNS affecting lead molecules.

A Methionine Chemical Shift Based Order Parameter Characterizing Global Protein Dynamics.

Coupling of side chain dynamics over long distances is an important component of allostery. Methionine side chains show the largest intrinsic flexibility among methyl-containing residues but the actual degree of conformational averaging depends on the proximity and mobility of neighboring residues. The 13 C NMR chemical shifts of the methyl groups of methionine residues located at long distances in the same protein show a similar scaling with respect to the values predicted from the static X-ray structure by quantum methods. This results in a good linear correlation between calculated and observed chemical shifts. The slope is protein dependent and ranges from zero for the highly flexible calmodulin to 0.7 for the much more rigid calcineurin catalytic domain. The linear correlation is indicative of a similar level of side-chain conformational averaging over long distances, and the slope of the correlation line can be interpreted as an order parameter of the global side-chain flexibility.

Denigrins and Dactylpyrroles, Arylpyrrole Alkaloids from a Dactylia sp. Marine Sponge.

Seven new arylpyrrole alkaloids (1-7), along with four known compounds, were isolated from an extract of a Dactylia sp. nov. marine sponge, and their structures were elucidated by interpretation of NMR and MS spectroscopic data. Denigrins D-G (1-4) have highly substituted pyrrole or pyrrolone rings in their core structures, while dactylpyrroles A-C (5-7) have tricyclic phenanthrene cores. Due to the proton-deficient nature of these scaffolds, key heteronuclear correlations from 1H-15N HMBC and LR-HSQMBC NMR experiments were used in the structure assignment of denigrin D (1). Dictyodendrin F (8), a previously described co-metabolite, inhibited transcription driven by the oncogenic PAX3-FOXO1 fusion gene with an IC50 value of 13 µM.

Computationally Assisted Structural Revision of Flavoalkaloids with a Seven-Membered Ring: Aquiledine, Isoaquiledine, and Cheliensisine.

Aquiledine and cheliensisine are flavoalkaloids isolated from Aquilegia ecalcarata and Goniothalamus cheliensis, respectively. Different structures have been proposed for these flavoalkaloids; however, their 1H and 13C NMR spectroscopic data were virtually identical. In this study, the structures of aquiledine and cheliensisine were revised on the basis of the DFT calculation of NMR data including DP4+ and J-DP4 analysis, as well as specific rotations. Similarly, the structure of isoaquiledine, a regioisomer of aquiledine, was also revised. A biosynthetic pathway of these flavoalkaloids is proposed.

NMR Spectroscopy of Large Functional RNAs: From Sample Preparation to Low-Gamma Detection.

NMR spectroscopy is a potent method for the structural and biophysical characterization of RNAs. The application of NMR spectroscopy is restricted in RNA size and most often requires isotope-labeled or even selectively labeled RNAs. Additionally, new NMR pulse sequences, such as the heteronuclear-detected NMR experiments, are introduced. We herein provide detailed protocols for the preparation of isotope-labeled RNA for NMR spectroscopy via in vitro transcription. This protocol covers all steps, from the preparation of DNA template to the transcription of milligram RNA quantities. Moreover, we present a protocol for a chemo-enzymatic approach to introduce a single modified nucleotide at any position of any RNA. Regarding NMR methodology, we share protocols for the implementation of a suite of heteronuclear-detected NMR experiments including 13 C-detected experiments for ribose assignment and amino groups, the CN-spin filter heteronuclear single quantum coherence (HSQC) for imino groups and the 15 N-detected band-selective excitation short transient transverse-relaxation-optimized spectroscopy (BEST-TROSY) experiment. © 2020 The Authors. Basic Protocol 1: Preparation of isotope-labeled RNA samples with in vitro transcription using T7 RNAP, DEAE chromatography, and RP-HPLC purification Alternate Protocol 1: Purification of isotope-labeled RNA from in vitro transcription with preparative PAGE Alternate Protocol 2: Purification of isotope-labeled RNA samples from in vitro transcription via centrifugal concentration Support Protocol 1: Preparation of DNA template from plasmid Support Protocol 2: Preparation of PCR DNA as template Support Protocol 3: Preparation of T7 RNA Polymerase (T7 RNAP) Support Protocol 4: Preparation of yeast inorganic pyrophosphatase (YIPP) Basic Protocol 2: Preparation of site-specific labeled RNAs using a chemo-enzymatic synthesis Support Protocol 5: Synthesis of modified nucleoside 3',5'-bisphosphates Support Protocol 6: Preparation of T4 RNA Ligase 2 Support Protocol 7: Setup of NMR spectrometer for heteronuclear-detected NMR experiments Support Protocol 8: IPAP and DIPAP for homonuclear decoupling Basic Protocol 3: 13 C-detected 3D (H)CC-TOCSY, (H)CPC, and (H)CPC-CCH-TOCSY experiments for ribose assignment Basic Protocol 4: 13 C-detected 2D CN-spin filter HSQC experiment Basic Protocol 5: 13 C-detected C(N)H-HDQC experiment for the detection of amino groups Support Protocol 9: 13 C-detected CN-HSQC experiment for amino groups Basic Protocol 6: 13 C-detected "amino"-NOESY experiment Basic Protocol 7: 15 N-detected BEST-TROSY experiment.

Solid-state NMR spectroscopy identifies three classes of lipids in Cryptococcus neoformans melanized cell walls and whole fungal cells.

A primary virulence-associated trait of the opportunistic fungal pathogen Cryptococcus neoformans is the production of melanin pigments that are deposited into the cell wall and interfere with the host immune response. Previously, our solid-state NMR studies of isolated melanized cell walls (melanin "ghosts") revealed that the pigments are strongly associated with lipids, but their identities, origins, and potential roles were undetermined. Herein, we exploited spectral editing techniques to identify and quantify the lipid molecules associated with pigments in melanin ghosts. The lipid profiles were remarkably similar in whole C. neoformans cells, grown under either melanizing or nonmelanizing conditions; triglycerides (TGs), sterol esters (SEs), and polyisoprenoids (PPs) were the major constituents. Although no quantitative differences were found between melanized and nonmelanized cells, melanin ghosts were relatively enriched in SEs and PPs. In contrast to lipid structures reported during early stages of fungal growth in nutrient-rich media, variants found herein could be linked to nutrient stress, cell aging, and subsequent production of substances that promote chronic fungal infections. The fact that TGs and SEs are the typical cargo of lipid droplets suggests that these organelles could be connected to C. neoformans melanin synthesis. Moreover, the discovery of PPs is intriguing because dolichol is a well-established constituent of human neuromelanin. The presence of these lipid species even in nonmelanized cells suggests that they could be produced constitutively under stress conditions in anticipation of melanin synthesis. These findings demonstrate that C. neoformans lipids are more varied compositionally and functionally than previously recognized.

Sulfoethylation of polysaccharides-A comparative study.

The heterogeneous sulfoethylation of cellulose, xylan, α-1,3-glucan, glucomannan, pullulan, curdlan, galactoglucomannan, and agarose was studied using sodium vinylsulfonate (NaVS) as reagent in presence of sodium hydroxide and iso-propanol (i-PrOH) as slurry medium. The influence of the concentration of polymer, water, and NaOH (solid or aqueous solution) on the degree of substitution (DS) was investigated. The sulfoethylation rendered the polysaccharides studied water-soluble. Sulfoethylation of heteropolysaccharides yielded products with higher DS compared to the conversion of homopolysaccharides. Structure characterization was carried out by means of 13C-NMR spectroscopy.