Laccaria bicolor pectin methylesterases are involved in ectomycorrhiza development with Populus tremula × Populus tremuloides.

The development of ectomycorrhizal (ECM) symbioses between soil fungi and tree roots requires modification of root cell walls. The pectin-mediated adhesion between adjacent root cells loosens to accommodate fungal hyphae in the Hartig net, facilitating nutrient exchange between partners. We investigated the role of fungal pectin modifying enzymes in Laccaria bicolor for ECM formation with Populus tremula × Populus tremuloides. We combine transcriptomics of cell-wall-related enzymes in both partners during ECM formation, immunolocalisation of pectin (Homogalacturonan, HG) epitopes in different methylesterification states, pectin methylesterase (PME) activity assays and functional analyses of transgenic L. bicolor to uncover pectin modification mechanisms and the requirement of fungal pectin methylesterases (LbPMEs) for ECM formation. Immunolocalisation identified remodelling of pectin towards de-esterified HG during ECM formation, which was accompanied by increased LbPME1 expression and PME activity. Overexpression or RNAi of the ECM-induced LbPME1 in transgenic L. bicolor lines led to reduced ECM formation. Hartig Nets formed with LbPME1 RNAi lines were shallower, whereas those formed with LbPME1 overexpressors were deeper. This suggests that LbPME1 plays a role in ECM formation potentially through HG de-esterification, which initiates loosening of adjacent root cells to facilitate Hartig net formation.

Efficacy and safety of 0.0584% hydrocortisone aceponate topical spray and systemic oclacitinib combination therapy in dogs with atopic dermatitis: a randomized, double-blinded, placebo-controlled trial.

BACKGROUND: Oclacitinib is an effective systemic therapy for dogs with atopic dermatitis (AD). Few studies have evaluated concurrent topical treatment with oclacitinib in dogs. OBJECTIVES: To evaluate the efficacy and safety of combination therapy of oclacitinib and 0.0584% hydrocortisone aceponate (HCA) spray in dogs with AD. ANIMALS: Eighteen dogs with AD. METHODS AND MATERIALS: This study was a randomized, double-blinded, placebo-controlled trial. All dogs were treated with oclacitinib (0.4-0.6 mg/kg twice daily for 14 days, then once daily for 14 days) and randomized to receive either HCA spray or placebo spray, applied once daily for seven days then every other day through to Day (D)28. Clinical assessments included the Canine Atopic Dermatitis Extent and Severity Index, 4th iteration (CADESI-4) and the pruritus Visual Analog Scale (PVAS) every seven days, and blood and urine tests every 14 days. RESULTS: The mean CADESI-4 and PVAS scores were significantly reduced on D7 and D14 compared to D0 in both groups (P < 0.05). From D14 to D21, CADESI-4 and PVAS scores were significantly increased in the placebo group (P < 0.005), and not in the HCA-treated group. The mean reduction from baseline of the HCA-treated group was significantly higher than that of the placebo group for the PVAS and CADESI-4 on D21 (59.9% versus 27.6%, P = 0.0216) and D28 (56.0% versus 30.5%, P = 0.0109), respectively. One dog in the HCA-treated group was withdrawn as a consequence of developing diarrhoea. CONCLUSION: Topical application of 0.0584% HCA spray may be useful for preventing exacerbation of pruritus and clinical lesions when tapering oclacitinib therapy in dogs with AD.

Why Concurrent CDDP and Radiotherapy Has Synergistic Antitumor Effects: A Review of In Vitro Experimental and Clinical-Based Studies.

Chemo-radiotherapy, which combines chemotherapy with radiotherapy, has been clinically practiced since the 1970s, and various anticancer drugs have been shown to have a synergistic effect when used in combination with radiotherapy. In particular, cisplatin (CDDP), which is often the cornerstone of multi-drug combination cancer therapies, is highly versatile and frequently used in combination with radiotherapy for the treatment of many cancers. Therefore, the mechanisms underlying the synergistic effect of CDDP and radiotherapy have been widely investigated, although no definitive conclusions have been reached. We present a review of the combined use of CDDP and radiotherapy, including the latest findings, and propose a mechanism that could explain their synergistic effects. Our hypothesis involves the concepts of overlap and complementation. "Overlap" refers to the overlapping reactions of CDDP and radiation-induced excessive oxidative loading, which lead to accumulating damage to cell components, mostly within the cytoplasm. "Complementation" refers to the complementary functions of CDDP and radiation that lead to DNA damage, primarily in the nucleus. In fact, the two concepts are inseparable, but conceptualizing them separately will help us understand the mechanism underlying the synergism between radiation therapy and other anticancer drugs, and help us to design future radiosensitizers.

In Vivo Study of the Efficacy and Safety of 5-Aminolevulinic Radiodynamic Therapy for Glioblastoma Fractionated Radiotherapy.

To treat malignant glioma, standard fractionated radiotherapy (RT; 60 Gy/30 fractions over 6 weeks) was performed post-surgery in combination with temozolomide to improve overall survival. Malignant glioblastoma recurrence rate is extremely high, and most recurrent tumors originate from the excision cavity in the high-dose irradiation region. In our previous study, protoporphyrin IX physicochemically enhanced reactive oxygen species generation by ionizing radiation and combined treatment with 5-aminolevulinic acid (5-ALA) and ionizing radiation, while radiodynamic therapy (RDT) improved tumor growth suppression in vivo in a melanoma mouse model. We examined the effect of 5-ALA RDT on the standard fractionated RT protocol using U251MG- or U87MG-bearing mice. 5-ALA was orally administered at 60 or 120 mg/kg, 4 h prior to irradiation. In both models, combined treatment with 5-ALA slowed tumor progression and promoted regression compared to treatment with ionizing radiation alone. The standard fractionated RT protocol of 60 Gy in 30 fractions with oral administration of 120 and 240 mg/kg 5-ALA, the human equivalent dose of photodynamic diagnosis, revealed no significant increase in toxicity to normal skin or brain tissue compared to ionizing radiation alone. Thus, RDT is expected to enhance RT treatment of glioblastoma without severe toxicity under clinically feasible conditions.

Hunting monolignol transporters: membrane proteomics and biochemical transport assays with membrane vesicles of Norway spruce.

Both the mechanisms of monolignol transport and the transported form of monolignols in developing xylem of trees are unknown. We tested the hypothesis of an active, plasma membrane-localized transport of monolignol monomers, dimers, and/or glucosidic forms with membrane vesicles prepared from developing xylem and lignin-forming tissue-cultured cells of Norway spruce (Picea abies L. Karst.), as well as from control materials, comprising non-lignifying Norway spruce phloem and tobacco (Nicotiana tabacum L.) BY-2 cells. Xylem and BY-2 vesicles transported both coniferin and p-coumaryl alcohol glucoside, but inhibitor assays suggested that this transport was through the tonoplast. Membrane vesicles prepared from lignin-forming spruce cells showed coniferin transport, but the Km value for coniferin was much higher than those of xylem and BY-2 cells. Liquid chromatography-mass spectrometry analysis of membrane proteins isolated from spruce developing xylem, phloem, and lignin-forming cultured cells revealed multiple transporters. These were compared with a transporter gene set obtained by a correlation analysis with a selected set of spruce monolignol biosynthesis genes. Biochemical membrane vesicle assays showed no support for ABC-transporter-mediated monolignol transport but point to a role for secondary active transporters (such as MFS or MATE transporters). In contrast, proteomic and co-expression analyses suggested a role for ABC transporters and MFS transporters.

Immunostimulatory Effects of Radiotherapy for Local and Systemic Control of Melanoma: A Review.

Recently, modern therapies involving immune checkpoint inhibitors, cytokines, and oncolytic virus have been developed. Because of the limited treatment effect of modern therapy alone, the immunostimulatory effect of radiotherapy attracted increasing attention. The combined use of radiotherapy and modern therapy has been examined clinically and non-clinically, and its effectiveness has been confirmed recently. Because melanomas have high immunogenicity, better therapeutic outcomes are desired when using immunotherapy. However, sufficient therapeutic effects have not yet been achieved. Thus far, radiotherapy has been used only for local control of tumors. Although extremely rare, radiotherapy has also been reported for systemic control, i.e., abscopal effect. This is thought to be due to an antitumor immune response. Therefore, we herein summarize past information on not only the mechanism of immune effects on radiotherapy but also biomarkers reported in case reports on abscopal effects. We also reviewed the animal model suitable for evaluating abscopal effects. These results pave the way for further basic research or clinical studies on new treatment methods for melanoma. Currently, palliative radiation is administered to patients with metastatic melanoma for local control. If it is feasible to provide both systemic and local control, the treatment benefit for the patients is very large.

DNA Strand Break Properties of Protoporphyrin IX by X-Ray Irradiation against Melanoma.

Recent reports have suggested that 5-aminolevulinic acid (5-ALA), which is a precursor to protoporphyrin IX (PpIX), leads to selective accumulation of PpIX in tumor cells and acts as a radiation sensitizer in vitro and in vivo in mouse models of melanoma, glioma, and colon cancer. In this study, we investigated the effect of PpIX under X-ray irradiation through ROS generation and DNA damage. ROS generation by the interaction between PpIX and X-ray was evaluated by two kinds of probes, 3'-(p-aminophenyl) fluorescein (APF) for hydroxyl radical (•OH) detection and dihydroethidium (DHE) for superoxide (O2•-). •OH showed an increase, regardless of the dissolved oxygen. Meanwhile, the increase in O2•- was proportional to the dissolved oxygen. Strand breaks (SBs) of DNA molecule were evaluated by gel electrophoresis, and the enhancement of SBs was observed by PpIX treatment. We also studied the effect of PpIX for DNA damage in cells by X-ray irradiation using a B16 melanoma culture. X-ray irradiation induced γH2AX, DNA double-strand breaks (DSBs) in the context of chromatin, and affected cell survival. Since PpIX can enhance ROS generation even in a hypoxic state and induce DNA damage, combined radiotherapy treatment with 5-ALA is expected to improve therapeutic efficacy for radioresistant tumors.

The Truth of Toxicity Caused by Yttrium Oxide Nanoparticles to Yeast Cells.

Yttrium oxide (Y2O3) nanoparticles have widespread applications; however, toxicity due to these nanoparticles has also been reported. In this study, we evaluated the in vitro toxicity of Y2O3 nanoparticles according to the technical specifications published by the International Standard Organization (ISO/TS 19337:2016). We used Saccharomyces cerevisiae as a model microorganism represented the environment. We carried out catch ball analysis of yttrium oxide and yttrium ion toxicities. The result showed that Y2O3 nanoparticles (20 mg/5 ml) and YCl3 (5 mg/5 ml) treatment caused oxidative stress in yeast cells. Based on transcriptome analysis, fluorescent spectroscopy, and solubility analysis of Y2O3 nanoparticles, we conclude that the toxicity is due to yttrium ions derived from the nanoparticles. The ions induce oxidative stress and cause protein denaturation, which in turn induces proteasome formation to eliminate denatured proteins. Yttrium nanoparticles induce oxidative stress, which has associated with heavy metal ions. Thus, the use of yttrium nanoparticles or yttrium ions must be controlled like heavy metals.

Verification of 5-Aminolevurinic Radiodynamic Therapy Using a Murine Melanoma Brain Metastasis Model.

Melanoma is a highly aggressive cancer with a propensity for brain metastases. These can be treated by radiotherapy, but the radiation-resistant nature of melanoma makes the prognosis for melanoma patients with brain metastases poor. Previously, we demonstrated that treatment of mice with subcutaneous melanoma with 5-aminolevurinic acid (5-ALA) and X-rays in combination, ("radiodynamic therapy (RDT)"), instead of with 5-ALA and laser beams ("photodynamic therapy"), improved tumor suppression in vivo. Here, using the B16-Luc melanoma brain metastasis model, we demonstrate that 5-ALA RDT effectively treats brain metastasis. We also studied how 5-ALA RDT damages cells in vitro using a B16 melanoma culture. Cell culture preincubated with 5-ALA alone increased intracellular photosensitizer protoporphyrin IX. On X-ray irradiation, the cells enhanced their ∙OH radical generation, which subsequently induced γH2AX, a marker of DNA double-strand breaks in their nuclei, but decreased mitochondrial membrane potential. After two days, the cell cycle was arrested. When 5-ALA RDT was applied to the brain melanoma metastasis model in vivo, suppression of tumor growth was indicated. Therapeutic efficacy in melanoma treatment has recently been improved by molecular targeted drugs and immune checkpoint inhibitors. Treatment with these drugs is now expected to be combined with 5-ALA RDT to further improve therapeutic efficacy.

[Study of encoding and storage in memorization among patients with Alzheimer's disease].

AIM: Memorization comprises three stages: encoding, storage, and retrieval. Using neuropsychological tests, we investigated the stage at which encoding and storage are retained in Alzheimer's disease (AD) patients with progressive memory disorder. METHODS: The target patients were an amnestic mild cognitive impairment (MCI) group (21 cases) and FAST 4 (37 cases), 5 (10 cases), and 6 (4 cases) AD groups. The neuropsychological tests performed were the Rivermead behavioral memory test and Wechsler memory scale-revised. These were carried out in the MCI group as well as in each AD stage group. We investigated the delayed recall (free recall and cued recall) based on the disease stage and raw score of the sub-items in delayed recognition. RESULTS: The MCI group had 48% (median 0 point) correct respondents (providing ≥1 correct answer) for free recall, whereas FAST 4 and 5 groups had ≤14% correct respondents. In the verbal paired associates II evaluated in cued recall, the MCI group had 90% correct respondents, and the FAST 4, 5, and 6 groups had rates of 51%, 60%, and 50%, respectively. For the pictures and photos in the delayed recognition tasks, there were no significant differences in the percentage of correct respondents between the MCI group (100%) and the FAST 4 and 5 groups (70%-90%). CONCLUSIONS: Given that retrieval is impossible if encoding and storage are impaired, we inferred that the encoding and retrieval abilities were retained even in moderately advanced AD.

Highly Sensitive Glycan Profiling of Hepatitis B Viral Particles and a Simple Method for Dane Particle Enrichment.

Hepatitis B virus (HBV) is a double-stranded DNA virus composed of three types of viral particles. The virions are called Dane particles and the others are noninfectious subviral particles (SVPs). In blood, SVPs are detected in abundance, about 1000-10000 fold higher than Dane particles. Dane particles are hazardous because of their strong infectivity, unlike SVPs. Dane particles are covered with an envelope of glycoprotein called HBV surface antigen (HBsAg). HBsAg glycosylation is involved in viral particle formation and secretion. In this study, we established a novel and highly sensitive method for viral glycan profiling of HBsAg using small aliquots of patient serum. Our lectin microarray system could sensitively profile the glycans exposed on HBV while retaining the intact viral particle structure under nonreducing conditions. Several typical lectins were chosen from the lectin microarray results. Specifically, jacalin, which recognizes O-glycan, showed specific and strong reactivity to the M-HBsAg required for Dane particle secretion. Employing the lectin-fractionation method using jacalin, HBV particles were fractionated into jacalin-bound and unbound fractions from patient serum. We measured HBsAg titer and viral DNA load in each fraction using clinical tests. Interestingly, the jacalin-bound fraction contained a major fraction of the HBV viral DNA load. Thus, in this study we have presented a glycan profiling method for HBsAg on the intact HBV particle and an easy and simple method to enrich Dane particles from patient serum by jacalin fractionation.

Structure-based design, synthesis, and binding mode analysis of novel and potent chymase inhibitors.

Based on insight from the X-ray crystal structure of human chymase in complex with compound 1, a lactam carbonyl of the diazepane core was exchanged with O-substituted oxyimino group, leading to amidoxime derivatives. This modification resulted in highly potent chymase inhibitors, such as O-phenylamidoxime 5f. X-ray crystal structure analysis indicated that compound 5f induced movement of the Leu99 and Tyr94 side chains at the S2 site, and the increase in inhibitory activity of O-phenyl amidoxime derivatives suggested that the O-phenyl moiety interacted with the Tyr94 residue. Surface plasmon resonance experiments showed that compound 5f had slower association and dissociation kinetics and the calculated residence time of compound 5f to human chymase was extended compared to that of amide compound 1.

Synthesis and evaluation of N-(4-benzylphenyl)piperazines as VGF inducers.

A series of compounds was discovered that induce the production of VGF mRNA in SH-SY5Y cells and exhibit cytoprotection under tunicamycin induced endoplasmic reticulum (ER) stress. The aminophenol ring and linker chain of the template SUN N8075 (1) was modified to yield compounds with higher efficacy and lower propensity for adverse effects.

RNA Quality Control Using External Standard RNA.

In this paper, we propose a new evaluation method using external standard RNA for quality control of the extracted RNA. RNA Integrity Number and UV absorption are generally used as a basis for RNA quality control; however, these methods do not always reflect the quality of mRNA. While standard RNA is supposedly designed on the basis of mRNA, it has the potential to be used to evaluate the quality of the mRNA. In this study, we took into consideration the three essential factors, viz., yield of mRNA, inhibition to DNA polymerase, and degradation of mRNA for determining the RNA quality using standard RNA. It would be possible to know yield of mRNA and inhibition of the enzyme reaction by adding standard RNA before RNA extraction and looking at standard RNA loss. Degradation was evaluated by comparing the differences in the 3' and 5' regions of the RNA. In our study, it was demonstrated that in the crude extract of Saccharomyces cerevisiae , degradation was comparatively higher at the 3' end of RNA than at the 5' end. Hence, the degree of RNA degradation can be evaluated by comparing the ratio of degradation from the 3' and 5' end.

Required cefazolin concentration to maximize diagnostic accuracy of the basophil activation test for cefazolin-induced anaphylaxis.

PURPOSE: Identifying the causative agent of perioperative anaphylaxis is key to preventing its recurrence. Besides skin testing, the basophil activation test (BAT) is increasingly being accepted as an additional and reliable method. Cefazolin seems to be a major cause of perioperative anaphylaxis. However, few studies have described use of the BAT for cefazolin-induced anaphylaxis. In this study, we aimed to determine the optimum cefazolin concentration required in the BAT for an accurate diagnosis. METHODS: Seven patients who presented with immediate hypersensitivity to cefazolin and 21 control subjects were studied. We conducted skin tests and performed BATs using both CD203c and CD63 as markers of activated basophils. We measured the ratio of activated basophils after stimulation with serial dilutions of cefazolin and investigated the cefazolin concentration that resulted in better sensitivity and specificity. RESULTS: All patients demonstrated positive reactions to cefazolin, while all control subjects showed negative reactions on skin tests. The net percentage of both CD203c- and CD63-labeled activated basophils was greater when higher concentrations of cefazolin than previously reported were used. In control subjects, however, the number of activated basophils by cefazolin stimulation was negligible regardless of its concentration. In the case of CD203c, the sensitivity was 86% with a cefazolin concentration of 3 mg/ml, while in the case of CD63, the sensitivity was 100% with a cefazolin concentration of 10 mg/ml. CONCLUSION: Using a higher concentration of cefazolin than previously reported for the BAT might increase the accuracy of diagnosis of cefazolin-induced anaphylaxis.

Suppression of xylan endotransglycosylase PtxtXyn10A affects cellulose microfibril angle in secondary wall in aspen wood.

Certain xylanases from family GH10 are highly expressed during secondary wall deposition, but their function is unknown. We carried out functional analyses of the secondary-wall specific PtxtXyn10A in hybrid aspen (Populus tremula × tremuloides). PtxtXyn10A function was analysed by expression studies, overexpression in Arabidopsis protoplasts and by downregulation in aspen. PtxtXyn10A overexpression in Arabidopsis protoplasts resulted in increased xylan endotransglycosylation rather than hydrolysis. In aspen, the enzyme was found to be proteolytically processed to a 68 kDa peptide and residing in cell walls. Its downregulation resulted in a corresponding decrease in xylan endotransglycosylase activity and no change in xylanase activity. This did not alter xylan molecular weight or its branching pattern but affected the cellulose-microfibril angle in wood fibres, increased primary growth (stem elongation, leaf formation and enlargement) and reduced the tendency to form tension wood. Transcriptomes of transgenic plants showed downregulation of tension wood related genes and changes in stress-responsive genes. The data indicate that PtxtXyn10A acts as a xylan endotransglycosylase and its main function is to release tensional stresses arising during secondary wall deposition. Furthermore, they suggest that regulation of stresses in secondary walls plays a vital role in plant development.

Molecular Dynamics Study of the Photodesorption of CO Ice.

Photodesorption of CO ice is suggested to be the main process that maintains a measurable amount of gaseous CO in cold interstellar clouds. A classical molecular dynamics simulation is used to gain insight into the underlying mechanism. Site-site pair potentials were developed on the basis of ab initio calculations for the ground and excited nonrigid CO dimer. Both amorphous and crystalline CO clusters were created and characterized by their densities, expansion coefficients, binding energies, specific heats, and radial distribution functions. Selected CO molecules were electronically excited with 8.7-9.5 eV photons. CO returns to the ground state after a finite lifetime on the excited potential surface. Two desorption mechanisms are found: (1) direct desorption where excited CO itself is released from the cluster after landing on the ground state in an unfavorable orientation; (2) "kick-out" desorption where excited CO kicks out a neighboring CO molecule. These findings are in accord with laboratory experiments. Little dependence on size of the cluster, excitation energy and temperature in the 6-18 K range was found. The predicted photodesorption probability is 4.0 × 10(-3) molecules photon(-1), smaller by a factor of 3-11 than that given by experiments.

Defining the Jr(a-) phenotype in the Japanese population.

BACKGROUND: The Jr(a-) phenotype is rare in European and North American populations but is not so rare in Japanese and other Asian populations. Recently, two groups have established the connection between the Jr(a-) phenotype and the ATP-binding cassette, member G2 (ABCG2) gene and concluded that ABCG2-null alleles encode the Jr(a-) phenotype. In Japanese Red Cross Blood Centers, the Jr(a-) phenotype is found with a prevalence of 0.05% among blood donors, and we applied DNA-based genotyping to investigate the molecular basis of the Jr(a-) phenotype in Japan, in addition to serologic typing. STUDY DESIGN AND METHODS: Purified genomic DNA extracts of Japanese donor samples [500 Jr(a+) and 85 Jr(a-) phenotypes] were amplified using specific amplification primers for the c.376C>T mutation, which is the most common mutation in the Asian JRnull allele. Polymerase chain reaction products were examined by high-resolution melt techniques and DNA sequence analyses. RESULTS: Seventy-nine of 85 Jr(a-) samples were homozygous for the single-nucleotide polymorphism c.376C>T (Gln126Stop) change. In other samples, two novel null alleles were detected: c.2T>C and c.421C>A: c.1515delC. CONCLUSION: In this study, more than 90% of the Japanese Jr(a-) phenotypes had c.376C>T (Gln126Stop) nucleotide change. In the other Jr(a-), a new mutation (c.2T>C) in the start codon encoding Thr instead of Met, c.1515delC encoding Ala505AlafsStop and heterozygous for c.337C/T and c.736C/T were detected. DNA-based genotyping is accurate and useful for Jr(a-) donor typing.

Isolation of cellular membranes from lignin-producing tissues of Norway spruce and analysis of redox enzymes.

There are no earlier reports with successful isolation of plasma membranes from lignin-forming tissues of conifers. A method to isolate cellular membranes from extracellular lignin-producing tissue-cultured cells and developing xylem of Norway spruce was optimized. Modifications to the homogenization buffer were needed to obtain membranes from these phenolics-rich tissues. Membranes were separated by aqueous polymer two-phase partitioning. Chlorophyll a determination, marker enzyme assays and western blot analyses using antibodies for each membrane type showed that mitochondrial, chloroplastic and to a certain extent also ER and Golgi membranes were efficiently diminished from the upper phase, but tonoplast and plasma membranes distributed evenly between the upper and lower phases. Redox enzymes present in the partially purified membrane fractions were assayed in order to reveal the origin of H(2)O(2) needed for lignification. The membranes of spruce contained enzymes able to generate superoxide in the presence of NAD(P)H. Besides members of the flavodoxin and flavodoxin-like family proteins, cytochrome b5, cytochrome P450 and several stress responsive proteins were identified by nitroblue tetrazolium staining of isoelectric focusing gels and by mass spectrometry. Naphthoquinones juglone and menadione increased superoxide production in activity-stained gels. Some juglone-activated enzymes were preferentially using NADH. With NADH, menadione activated only some of the enzymes that juglone did, whereas with NADPH the activation patterns were identical. Duroquinone, a benzoquinone, did not affect superoxide production. Superoxide dismutase, ascorbate peroxidase, catalase and an acidic class III peroxidase isoenzyme were detected in partially purified spruce membranes. The possible locations and functions of these enzymes are discussed.

Quantitative and qualitative saccharide analysis of North Atlantic brown seaweed by gas chromatography/mass spectrometry and infrared spectroscopy.

Brown seaweeds contain a variety of saccharides which have potential industrial uses. The most abundant polysaccharide in brown seaweed is typically alginate, consisting of mannuronic (M) and guluronic acid (G). The ratio of these residues fundamentally determines the physicochemical properties of alginate. In the present study, gas chromatography/mass spectrometry (GC/MS) was used to give a detailed breakdown of the monosaccharide species in North Atlantic brown seaweeds. The anthrone method was used for determination of crystalline cellulose. The experimental data was used to calibrate multivariate prediction models for estimation of total carbohydrates, crystalline cellulose, total alginate and alginate M/G ratio directly in dried, brown seaweed using three types of infrared spectroscopy, using relative error (RE) as a measure of predictive accuracy. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) performed well for the estimation of total alginate (RE = 0.12, R2 = 0.82), and attenuated total reflectance (ATR) showed good prediction of M/G ratio (RE = 0.14, R2 = 0.86). Both DRIFTS, ATR and near infrared (NIR) were unable to predict crystalline cellulose and only DRIFTS performed better in determining total carbohydrates. Multivariate spectral analysis is a promising method for easy and rapid characterization of alginate and M/G ratio in seaweed.