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AbstractPreventing the decrease in bone mineral density (BMD) is significant for postmenopausal women. We previously discovered that rhamnose, a deoxy monosaccharide used as a food additive, could suppress bone resorption; however, studies confirming this effect in postmenopausal women are lacking. Therefore, this pilot study aimed to explore whether rhamnose could help maintain BMD via bone resorption suppression in postmenopausal women. The participants consumed either 1.0 or 0.5 g/day of rhamnose or placebo for 24 weeks, and BMD (lumbar spine and femur) and bone turnover markers were measured. After 24 weeks, the group consuming rhamnose 1.0 g/day exhibited a significantly higher BMD of the lumbar spine than the placebo group. Furthermore, the levels of tartrate-resistant acid phosphatase 5b, a bone resorption marker, were significantly lower in both rhamnose groups. These results indicated that rhamnose might contribute to the maintenance of BMD by suppressing bone resorption in healthy postmenopausal women (UMIN000046570). [ABSTRACT FROM AUTHOR]

Sepsis progression is significantly associated with the disruption of gut eubiosis. However, the modulatory mechanisms of gut microbiota operating during sepsis are still unclear. Herein, we investigated how gut commensals impact sepsis development in a pre-clinical model. Cecal ligation and puncture (CLP) surgery was used to establish polymicrobial sepsis in mice. Mice depleted of gut microbiota by an antibiotic cocktail (ABX) exhibited a significantly higher level of mortality than controls. As determined by metabolomics analysis, ABX treatment has depleted many metabolites, and subsequent supplementation with l -rhamnose (rhamnose, Rha), a bacterial carbohydrate metabolite, exerted profound immunomodulatory properties with a significant enhancement in macrophage phagocytosis, which in turn improved organ damage and mortality. Mechanistically, rhamnose binds directly to and activates the solute carrier family 12 (potassium-chloride symporter), member 4 (SLC12A4) in macrophages and promotes phagocytosis by activating the small G-proteins, Ras-related C3 botulinum toxin substrate1 (Rac1) and cell division control protein 42 homolog (Cdc42). Interestingly, rhamnose has enhanced the phagocytosis capacity of macrophages from sepsis patients. In conclusion, by identifying SLC12A4 as the host interacting protein, we disclosed that the gut commensal metabolite rhamnose is a functional molecular that could promote the phagocytosis capacity of macrophages and protect the host against sepsis. The depletion of gut microbiota leads to increased mortality in sepsis, which is associated with decreased gut-derived rhamnose. The rhamnose enhances the macrophage's phagocytic activity and protects against sepsis by modulating the SLC12A4/Cdc42 and Rac1 axis. [Display omitted] [ABSTRACT FROM AUTHOR]

Sepsis progression is significantly associated with the disruption of gut eubiosis. However, the modulatory mechanisms of gut microbiota operating during sepsis are still unclear. Herein, we investigated how gut commensals impact sepsis development in a pre-clinical model. Cecal ligation and puncture (CLP) surgery was used to establish polymicrobial sepsis in mice. Mice depleted of gut microbiota by an antibiotic cocktail (ABX) exhibited a significantly higher level of mortality than controls. As determined by metabolomics analysis, ABX treatment has depleted many metabolites, and subsequent supplementation with l-rhamnose (rhamnose, Rha), a bacterial carbohydrate metabolite, exerted profound immunomodulatory properties with a significant enhancement in macrophage phagocytosis, which in turn improved organ damage and mortality. Mechanistically, rhamnose binds directly to and activates the solute carrier family 12 (potassium-chloride symporter), member 4 (SLC12A4) in macrophages and promotes phagocytosis by activating the small G-proteins, Ras-related C3 botulinum toxin substrate1 (Rac1) and cell division control protein 42 homolog (Cdc42). Interestingly, rhamnose has enhanced the phagocytosis capacity of macrophages from sepsis patients. In conclusion, by identifying SLC12A4 as the host interacting protein, we disclosed that the gut commensal metabolite rhamnose is a functional molecular that could promote the phagocytosis capacity of macrophages and protect the host against sepsis.

Polysaccharide is one of the four fundamental substances that make up life and have various important biological activities. A deep understanding of the structure and activity of polysaccharide molecules is of guiding significance for the development of polysaccharides. The structure characterization of two new polysaccharides from Armillariella tabescens (AT-P) and Tricholoma portentosum (TP-P) by HPGPC, GC-MS, NMR and FT-IR indicated that AT-P was composed of glucose and galactose in a ratio of 3:8. Its skeleton structure was consisted of (1→6)-galactose residues and (1→3,6)-galactose residues with three branched chains. The TP-P was consisted of composed of rhamnose, xylose, glucose, galactose in the ratio of 1:1:2:9. Its skeleton structure was consisted of (1→4)-galactose residues, (1→4)-glucose residues and (1→2,6)-galactose residues with one branched chain. Within the concentration range of 1.25 and 40 µg/mL, both AT-P and TP-P could enhance the proliferation ability of T cells, B cells, and RAW 264.7 cells. AT-P and TP-P could significantly (P < 0.01) improve the proliferation efficiency of B cells at 20 µg/mL and 10 µg/mL, respectively, with a maximum of 70.16% and 76.28%, respectively. Both AT-P and TP-P could promote the secretion of IL-1β and TNF-α by RAW 264.7 cells and promote the secretion of IL-1 by B and T cells. However, neither of they could not promote the secretion of IL-10 by RAW 264.7 cells and T cells. Their effects on the secretion of TNF-α by T and B cells were also different. [ABSTRACT FROM AUTHOR]

To explore the composition of anthocyanins and expand their biological activities, anthocyanins were systematically isolated and purified from tubers of Solanum tuberosum L., and their tyrosinase inhibitory activity was investigated. In this study, two new anthocyanin degradation compounds, norpetanin (9) and 4-O-(p-coumaryl) rhamnose (10), along with 17 known anthocyanins and their derivatives, were isolated and purified from an acid-ethanolic extract of fresh purple potato tubers. Their structures were elucidated via 1D and 2D NMR and HR-ESI-MS and compared with those reported in the literature. The extracts were evaluated for anthocyanins and their derivatives using a tyrosinase inhibitor screening kit and molecular docking technology, and the results showed that petanin, norpetanin, 4-O-(p-coumaryl) rhamnose, and lyciruthephenylpropanoid D/E possessed tyrosinase inhibitory activity, with 50% inhibiting concentration (IC50) values of 122.37 ± 8.03, 115.53 ± 7.51, 335.03 ± 12.99, and 156.27 ± 11.22 μM (Mean ± SEM, n = 3), respectively. Furthermore, petanin was validated against melanogenesis in zebrafish; it was found that it could significantly inhibit melanin pigmentation (p < 0.001), and the inhibition rate of melanin was 17% compared with the normal group. This finding may provide potential treatments for diseases with abnormal melanin production, and high-quality raw materials for whitening cosmetics. [ABSTRACT FROM AUTHOR]

This article discusses the development of a new generation of multivalent antibody-recruiting molecules (ARMs) for cancer immunotherapy. The ARMs are designed to recruit endogenous antibodies and target tumor cells, and they rely on the binding affinity of antibody-binding termini (ABT) and tumor-binding termini (TBT). The study focuses on the use of hyaluronic acid (HA) as the ligand for targeting CD44, a transmembrane glycoprotein overexpressed in various cancers. The researchers also incorporate a second TBT, either nanobody 7D12 or peptide GE11, to target epidermal growth factor receptor (EGFR). The ARMs are constructed using a host-guest interaction between HA and the TBTs, and they show promise in efficiently recruiting antibodies to destroy cancer cells. [Extracted from the article]

Fermented foods containing probiotic Leuconostoc mesenteroides 201607 (LM) were used to extract exopolysaccharides. An incomplete understanding exists regarding the immunomodulatory characteristics of exopolysaccharides (EPSs), which are important constituents of bacterial biofilms. In this instance, we examined the immunomodulatory capacity of EPSs from fermented food extracted from L. mesenteroides 201607. Partially purified exopolysaccharide from L. mesenteroides 201607 (PP-LMEPS) consists of glucose (57.1%), rhamnose (29.53%), and galactose (13.36%). The maximum EPS yield was attained after 30 h of incubation at 37 °C and an initial pH of 7.0. When lipopolysaccharide-stimulated RAW264.7 was exposed to PP-LMEPS, the inflammatory cytokines were considerably decreased or elevated dose-dependently. Upon the exposure of lipopolysaccharide-stimulated RAW264.7 cells to PP-LMEPS, a dose-dependent modulation of inflammatory cytokines was observed. This suggests that the extracted EPS possesses immunomodulatory characteristics, as evidenced by a significant decrease or increase in inflammatory cytokine levels. However, further research is warranted to fully elucidate the precise mechanisms and potential therapeutic implications of the immunomodulatory properties of PP-LMEPS. [ABSTRACT FROM AUTHOR]

Transdermal drug delivery systems (TDDS) demand both high drug loading capacity and efficient delivery. In order to improve both simultaneously, this study aims to develop a novel rhamnose-induced pressure-sensitive adhesive (HPR) by dispersing the drug in the supramolecular helical structure. Ten model drugs, categorized as acidic and basic compounds, were chosen to understand the characteristics of the HPR and its inner mechanism. Notably, it enhanced drug loading by 1.41 to 5 times over commercially available pressure-sensitive adhesives Duro-Tak@ 87–4098 and Duro-Tak@ 87–2287, in addition to increasing drug release efficiency by a factor of about 5. Pharmacokinetic evaluation demonstrated that the HPR group had >4-fold (Tulobuterol TUL) and 3-fold (Diclofenac DIC) more area under the blood drug concentration curve (AUC) than the commercial TUL and DIC patches in the absence of added excipients and a significantly prolonged mean residence time (MRT) of >4-fold (TUL) and 3-fold (DIC), demonstrating the potential for highly efficacious and prolonged dosing. Furthermore, its safety and mechanical properties meet the requisite standards. Mechanistic inquiries unveiled that both acidic and basic drugs establish hydrogen bonds with HPR and become encapsulated within supramolecular helical structures. The supramolecular helical structures, significantly elevated both the enthalpy of the drug-HPR and entropy of the drugs release, thereby substantially enhancing drug delivery efficiency. In summary, HPR enabled a significant simultaneous enhancement of drug loading and drug delivery, which, together with its unique spatial structure, would contribute to the development of TDDS. In addition, the establishment of rhamnose-induced supramolecular helical structures would provide innovative pathways for different drug delivery systems. [Display omitted] [ABSTRACT FROM AUTHOR]

RLPa-2 (Mw 15.6 kDa) is a polysaccharide isolated from Rosa laevigata Michx. It consists of arabinose (Ara), galactose (Gal), rhamnose (Rha), glucose (Glc), xylose (Xyl), and galacturonic acid (Gal-UA) with a molar ratio of 1.00:0.91:0.39:0.34:0.25:0.20. Structural characterization was performed by methylation and NMR analysis, which indicated that RLPa-2 might comprise →6)-α-D-Galp-(1→, →4)-α-D-GalpA-(1→, α-L-Araf-(1→, →2,4)-α-D-Glcp-(1→, β-D-Xylp, and α-L-Rhap. In addition, the bioactivity of RLPa-2 was assessed through an in vitro macrophage polarization assay. Compared to positive controls, there was a significant decrease in the expression of M1 macrophage markers (CD80, CD86) and p-STAT3/STAT3 protein. Additionally, there was a down-regulation in the production of pro-inflammatory mediators (NO, IL-6, TNF-α), indicating that M1 macrophage polarization induced with lipopolysaccharide (LPS) and interferon-γ (IFN-γ) stimulation could be inhibited by RLPa-2. These findings demonstrate that the RLPa-2 might be considered as a potential anti-inflammatory drug to reduce inflammation. [ABSTRACT FROM AUTHOR]

Biopreservation refers to the use of natural or controlled microbial single strains or consortia, and/or their metabolites such as short‐chain carboxylic acids (SCCA), to improve the shelf‐life of foods. This study aimed at establishing a novel Lactobacillaceae‐driven bioprocess that led to the production of the SCCA propionate through the cross‐feeding on 1,2‐propanediol (1,2‐PD) derived from the deoxyhexoses rhamnose or fucose. When grown as single cultures in Hungate tubes, strains of Lacticaseibacillus rhamnosus preferred fucose over rhamnose and produced 1,2‐PD in addition to lactate, acetate, and formate, while Limosilactobacillus reuteri metabolized 1,2‐PD into propionate, propanol and propanal. Loigolactobacillus coryniformis used fucose to produce 1,2‐PD and only formed propionate when supplied with 1,2‐PD. Fermentates collected from batch fermentations in bioreactor using two‐strain consortia (L. rhamnosus and L. reuteri) or fed‐batch fermentations of single strain cultures of L. coryniformis with rhamnose contained mixtures of SCCA consisting of mainly lactate and acetate and also propionate. Synthetic mixtures that contained SCCA at concentrations present in the fermentates were more antimicrobial against Salmonella enterica if propionate was present. Together, this study (i) demonstrates the potential of single strains and two‐strain consortia to produce propionate in the presence of deoxyhexoses extending the fermentation metabolite profile of Lactobacillaceae, and (ii) emphasizes the potential of applying propionate‐containing fermentates as biopreservatives. [ABSTRACT FROM AUTHOR]

N-glycanase 1 (NGLY1) is an essential enzyme involved in the deglycosylation of misfolded glycoproteins through the endoplasmic reticulum (ER)-associated degradation (ERAD) pathway, which could hydrolyze N-glycan from N-glycoprotein or N-glycopeptide in the cytosol. Recent studies indicated that NGLY1 inhibition is a potential novel drug target for antiviral therapy. In this study, structure-based virtual analysis was applied to screen candidate NGLY1 inhibitors from 2960 natural compounds. Three natural compounds, Poliumoside, Soyasaponin Bb, and Saikosaponin B2 showed significantly inhibitory activity of NGLY1, isolated from traditional heat-clearing and detoxifying Chinese herbs. Furthermore, the core structural motif of the three NGLY1 inhibitors was a disaccharide structure with glucose and rhamnose, which might exert its action by binding to important active sites of NGLY1, such as Lys238 and Trp244. In traditional Chinese medicine, many compounds containing this disaccharide structure probably targeted NGLY1. This study unveiled the leading compound of NGLY1 inhibitors with its core structure, which could guide future drug development. [ABSTRACT FROM AUTHOR]

The aim of this set of randomised cross‐over studies was to determine the impact of progressive heat exposure and carbohydrate or protein feeding during exertional stress on small intestine permeability using a dual sugar test. In our previous work, and typically in the field, recovery of lactulose and l‐rhamnose is measured cumulatively in urine. This follow‐up study exploits our novel high‐performance anion exchange chromatography with pulsed amperometric detection (HPAEC‐PAD) protocol to accurately quantify the sugars in plasma. Endurance‐trained participants completed experimental trial A (ET‐A; n = 8), consisting of 2 h running at 60% V̇O2max${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ in temperate, warm and hot ambient conditions, and/or experimental trial B (ET‐B; n = 9), consisting of 2 h running at 60% V̇O2max${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ in the heat while consuming water, carbohydrate or protein. Blood samples were collected and plasma lactulose (L) and l‐rhamnose (R) appearance, after dual sugar solution ingestion at 90 min of exercise, was quantified by HPAEC‐PAD to measure plasma L/R and reveal new information about intestinal permeability immediately post‐exercise and during recovery. In ET‐A, plasma L/R increased immediately post‐exercise in hot compared with temperate and warm conditions, while, in ET‐B, carbohydrate alleviated this, and this information was otherwise missed when measuring urine L/R. Consuming carbohydrate or protein before and during exercise attenuated small intestine permeability throughout recovery from exertional heat stress. We recommend using the dual sugar test with quantification of plasma sugars by HPAEC‐PAD at intervals to maximise intestinal permeability data collection in exercise gastroenterology research, as this gives additional information compared to urinary measurements. Key points: Intestinal permeability is typically assessed using a dual sugar test, by administering a drink containing non‐metabolisable sugars (e.g. lactulose (L) and l‐rhamnose (R)) that can enter the circulation by paracellular translocation when the epithelium is compromised, and are subsequently measured in urine.We demonstrate that our recently developed ion chromatography protocol can be used to accurately quantify the L/R ratio in plasma, and that measuring L/R in plasma collected at intervals during the post‐exercise recovery period reveals novel acute response information compared to measuring 5‐h cumulative urine L/R.We confirm that exercising in hot ambient conditions increases intestinal epithelial permeability immediately after exercise, while consuming carbohydrate or protein immediately before and during exercise attenuates this.We recommend using our dual sugar absorption test protocol to maximise intestinal epithelial permeability data collection in exercise gastroenterology research and beyond. [ABSTRACT FROM AUTHOR]

Prunus mahaleb (Mahlab) is one of the gums-producing species of the Rosaceae family. The gums produced by many members of this family were extensively investigated except those of Mahlab. Hence, the work aims to study the chemical and functional properties of this gum which is produced from trees grown in Jordan. Exudate nodules were collected in the summer of 2021 from Mahlab trees and sorted according to their color into grades I, II, and III. The chemical composition, hygroscopicity, swelling index, water absorption, emulsification and foaming capacities, solubility, and foam stability of these grades were measured. Proximate composition showed significant (P ≤0.05) variations between the three grades in all of their proximate components except protein. Grade I had the greatest moisture and fat content of 18.0 and 3.29%, respectively. Grade III had the highest protein (though nonsignificantly (P>0.05) different from other grades) and ash content of 1.10 and 2.91%, respectively. All grades had similar, though significantly (P≤ 0.05) different levels of calcium, sodium, potassium, and magnesium. Also, their HPLC - detected sugar profiles consisted of xylose (17.65-19.77% w/w), rhamnose (10.10-12.34%w/w), arabinose (53.35-62.01% w/w) and galactose (9.88-14.50%w/w). Results showed significant (P ≤0.05) differences between the three grades in their functional properties, with grade III having the greatest swelling index and water absorption capacity of 7.52 and 16.52%, respectively. Grade I has the greatest hygroscopicity of 6.57% while grade II has the greatest foaming capacity of 21.02%. All grades showed a non-Newtonian-type shear-thinning behavior. Based on the results of this study, it is evident that Mahlab tree exudate gums pose chemical and functional properties typical of other known hydrocolloids. [ABSTRACT FROM AUTHOR]

Bacillus licheniformis and its related strains have found extensive applications in diverse industries, agriculture, and medicine. However, the current breeding methods for this strain primarily rely on natural screening and traditional mutagenesis. The limited availability of efficient genetic engineering tools, particularly recombination techniques, has hindered further advancements in its applications. In this study, we conducted a comprehensive investigation to identify and characterize a recombinase, RecT, derived from a Bacillus phage. Remarkably, the recombinase exhibited a 105-fold enhancement in the recombination efficiency of the strain. To facilitate genome editing, we developed a system based on the conditional expression of RecT using a rhamnose-inducible promoter (Prha). The efficacy of this system was evaluated by deleting the amyL gene, which encodes an α-amylase. Our findings revealed that the induction time and concentration of rhamnose, along with the generation time of the strain, significantly influenced the editing efficiency. Optimal conditions for genome editing were determined as follows: the wild-type strain was initially transformed with the genome editing plasmid, followed by cultivation and induction with 1.5% rhamnose for 8 h. Subsequently, the strain was further cultured for an additional 24 h, equivalent to approximately three generations. Consequently, the recombination efficiency reached an impressive 16.67%. This study represents a significant advancement in enhancing the recombination efficiency of B. licheniformis through the utilization of a RecT-based recombination system. Moreover, it provides a highly effective genome editing tool for genetic engineering applications in this strain. [ABSTRACT FROM AUTHOR]

Misgurnus anguillicaudatus, also known as oriental weather loach, is widely consumed and favored in East Asia due to its superior nutritional values and excellent flavor. In this study, a crude Misgurnus anguillicaudatus carbohydrates (MAC) was isolated from Misgurnus anguillicaudatus. Subsequently, two parts, which were named MAO and MAP, respectively, were separated from MAC, and their primary structures and immunomodulatory activity were investigated. The results showed that MAO had a molecular weight of 2854 Da, and principally consisted of arabinose (77.11%) and rhamnose (21.97%), together with minor levels of fucose (0.92%); MAP, with a molecular weight of 3873 Da, was mainly composed of fucose (87.55%) and a small amount of rhamnose (8.86%) and galactose (3.59%). The in vitro assay showed that MAC could significantly enhance the proliferation of macrophages without cytotoxicity and increase the production of immune substances (TNF-α, IL-6). Together with Western blot results, we speculated that MAC could stimulate RAW264.7 murine macrophage cells to secrete TNF-α and IL-6 through up-regulating TLR4-MAPK-p38 signaling pathways. The results indicated that MAC could be a potential immune agent and might provide meaningful information for further chain conformation and immune mechanism research. [ABSTRACT FROM AUTHOR]

This review describes the various innovative approaches implemented for naringin extraction as well as the recent developments in the field. Naringin was assessed in terms of its structure, chemical composition, and potential food sources. How naringin works pharmacologically was discussed, including its potential as an anti-diabetic, anti-inflammatory, and hepatoprotective substance. Citrus flavonoids are crucial herbal additives that have a huge spectrum of organic activities. Naringin is a nutritional flavanone glycoside that has been shown to be effective in the treatment of a few chronic disorders associated with ageing. Citrus fruits contain a common flavone glycoside that has specific pharmacological and biological properties. Naringin, a flavone glycoside with a range of intriguing characteristics, is abundant in citrus fruits. Naringin has been shown to have a variety of biological, medicinal, and pharmacological effects. Naringin is hydrolyzed into rhamnose and prunin by the naringinase, which also possesses l-rhamnosidase activity. D-glucosidase subsequently catalyzes the hydrolysis of prunin into glucose and naringenin. Naringin is known for having anti-inflammatory, antioxidant, and tumor-fighting effects. Numerous test animals and cell lines have been used to correlate naringin exposure to asthma, hyperlipidemia, diabetes, cancer, hyperthyroidism, and osteoporosis. This study focused on the many documented actions of naringin in in-vitro and in-vivo experimental and preclinical investigations, as well as its prospective therapeutic advantages, utilizing the information that is presently accessible in the literature. In addition to its pharmacokinetic characteristics, naringin's structure, distribution, different extraction methods, and potential use in the cosmetic, food, pharmaceutical, and animal feed sectors were discussed. [ABSTRACT FROM AUTHOR]

Mycobacterium abscessus causes severe lung infections. Clinical isolates can have either smooth (S) or rough (R) colony morphotypes; of these, S but not R variants have abundant cell wall glycopeptidolipids (GPL) consisting of a peptidolipid core substituted by a 6-deoxy-α-L-talose (6-dTal) and rhamnose residues. Deletion of gtf1, encoding the 6-dTal transferase, results in the S-to-R transition, mycobacterial cord formation, and increased virulence, underscoring the importance of 6- dTal in infection outcomes. However, since 6-dTal is di-Oacetylated, it is unclear whether the gtf1 mutant phenotypes are related to the loss of the 6-dTal or the result of the absence of acetylation. Here, we addressed whether M. abscessus atf1 and atf2, encoding two putative O-acetyltransferases located within the gpl biosynthetic locus, transfer acetyl groups to 6-dTal. We found deletion of atf1 and/or atf2 did not drastically alter the GPL acetylation profile, suggesting there are additional enzymes with redundant functions. We subsequently identified two paralogs of atf1 and atf2, MAB_1725c and MAB_3448. While deletion of MAB_1725c and MAB_3448 had no effect on GPL acetylation, the triple atf1-atf2-MAB_1725c mutant did not synthetize fully acetylated GPL, and the quadruple mutant was totally devoid of acetylated GPL. Moreover, both triple and quadruple mutants accumulated hyper-methylated GPL. Finally, we show deletion of atf genes resulted in subtle changes in colony morphology but had no effect on M. abscessus internalization by macrophages. Overall, these findings reveal the existence of functionally redundant O-acetyltransferases and suggest that O-acetylation influences the glycan moiety of GPL by deflecting biosynthetic flux in M. abscessus [ABSTRACT FROM AUTHOR]

A phytochemical investigation of the ethyl acetate fraction of root bark extract of Synadenium glaucescens Pax (Euphorbiaceae) led to the isolation of two derivatives of ellagic acid. These included one new 3′,4′ -di-O-methylellagic acid-4α, L-rhamnopyranoside (1) and a known 3,4,3′-tri-O-methylellagic acid (2). Their structures were elucidated by 1D and 2D NMR, while a High res. MS (FTMS-ESI–) was used for accurate mass measurement, which was compared with SciFinder data as well as with available literature. The BSLT results indicated that both 1 (LC50 = 2736.03 μg/mL) and 2 (LC50 = 531.19 μg/mL) were nontoxic at a maximum test concentration of 2400 ppm. [ABSTRACT FROM AUTHOR]

Industrial application of icariin and baohuoside I has been hindered by the short supply to a great extent. In this work, a novel GH78 α-l-rhamnosidase AmRha catalyzed the bioconversion of low-value epimedin C in crude Epimedium Folium flavonoids (EFs) to icariin and baohuoside I was developed. Firstly, the high-level expression of AmRha in Komagataella phaffii GS115 attained an enzyme activity of 571.04 U/mL. The purified recombinant AmRha could hydrolyze α-1,2-rhamnoside bond between two rhamnoses (α-Rha(2 → 1)α-Rha) in epimedin C to produce icariin with a molar conversion rate of 92.3%, in vitro. Furtherly, the biotransformation of epimedin C to icariin by the recombinant Komagataella phaffii GS115 cells was also investigated, which elevated the EFs concentration by fivefold. In addition, biotransformation of epimedins A-C and icariin in the raw EFs to baohuoside I was fulfilled by a collaboration of AmRha and β-glucosidase/β-xylosidase Dth3. The results obtained here provide a new insight into the preparation of high-value products icariin and baohuoside I from cheap raw EFs. [ABSTRACT FROM AUTHOR]

Spinosad, a combination of spinosyn A and D produced by Saccharopolyspora spinosa, is a highly efficient pesticide. There has been a considerable interest in the improvement of spinosad production because of a low yield achieved by wild‐type S. spinosa. In this study, we designed and constructed a pIBR‐SPN vector. pIBR‐SPN is an integrative vector that can be used to introduce foreign genes into the chromosome of S. spinosa. Different combinations of genes encoding forasamine and rhamnose were synthesized and used for the construction of different recombinant plasmids. The following recombinant strains were developed: S. spinosa pIBR‐SPN (only the vector), S. spinosa pIBR‐SPN F (forosamine genes), S. spinosa pIBR‐SPN R (rhamnose genes), S. spinosa pIBR‐SPN FR (forosamine and rhamnose genes), S. spinosa pIBR‐SPN FRS (forosamine, rhamnose, and SAM [S‐adenosyl‐L‐methionine synthetase] genes), and S. spinosa MUV pIBR‐SPN FR. Among these recombinant strains, S. spinosa pIBR‐SPN FR produced 1394 ± 163 mg/L spinosad, which was 13‐fold higher than the wild‐type. S. spinosa MUV pIBR‐SPN FR produced 1897 (±129) mg/L spinosad, which was seven‐fold higher than S. spinosa MUV and 17‐fold higher than the wild‐type strain. [ABSTRACT FROM AUTHOR]

Background: Recently, it has been found that nitrogen (N) deposition strongly affects the coverage of biocrusts. However, we know little about the response of exopolysaccharides (EPSs), the key cementing material in the formation and stability of biocrusts, to N deposition. Method: Three N-sources including nitrate, ammonia and urea were added to biocrusts at three rates (2 mg/g, 4 mg/g, 8 mg/g) to evaluate the effect of N additions on the growth of biocrusts and the abundance of EPS. Results: Our results showed 2 mg/g of nitrate–N had no obvious effect on the cyanobacterial biomass, while 4 and 8 mg/g of nitrate–N inhibited the growth of Microcoleus vaginatus, the dominant cyanobacterium in biocrusts, but promoted other cyanobacteria growth. Ammonia-N and urea-N strongly decreased the cyanobacterial biomass, indicated by chlorophyll-a and 16 s rRNA gene copy-numbers. On the whole, N additions had a positive impact on the α-biodiversity of biocrusts. However, Ammonia-N and urea-N shifted the bacterial communities from more Cyanobacteria to more Proteobacteria and Actinobacteria. Notably, lesser-N (2 mg/g) promoted the excretion of EPSs, while greater-N (8 mg/g) had the opposite effect, and the total proportion of rhamnose and fucose in EPSs decreased in all treatment groups. Conclusion: N additions (except 2 mg/g of nitrate–N) reduced cyanobacterial biomass and affected the bacterial communities in biocrusts, which would obstruct the development and succession of biocrusts. Meanwhile, the simultaneous reductions of the EPSs contents and proportion of rhamnose and fucose in EPSs may further reduce stability and persistence of cyanobacterial biocrusts, after N additions. [ABSTRACT FROM AUTHOR]

The use of radiolabeled glucose for PET imaging resulted in the most commonly used tracer in the clinic, 2-deoxy-2-[18F]fluoroglucose (FDG). More recently, other radiolabeled sugars have been reported for various applications, including imaging tumors and infections. Therefore, in this study, we developed a series of fluorine-18-labeled L-rhamnose derivatives as potential PET tracers of various fungal and bacterial strains. Acetyl-protected triflate precursors of rhamnose were prepared and radiolabeled with fluorine-18 followed by hydrolysis to produce L-deoxy [18F]fluororhamnose. The overall radiochemical yield was 7–27% in a 90 min synthesis time with a radiochemical purity of 95%. In vivo biodistribution of the ligands using PET imaging showed that 2-deoxy-2-[18F]fluoro-L-rhamnose is stable for at least up to 60 min in mice and eliminated via renal clearance. The tracer also exhibited minimal tissue or skeletal uptake in healthy mice resulting in a low background signal. [ABSTRACT FROM AUTHOR]

Context • The persistent use of anticancer medicines can cause multidrug resistance in many tumors and serious cytotoxicity for healthy cells, including adriamycin (ADR), a treatment for breast cancer (BC). Cell resistance to ADR in patients with recurrent advanced BC can occur. Creating effective treatments that can grapple with multidrug resistance is still challenging. Traditional Chinese medicine (TCM) may offer a solution in D Rhamnose beta-hederin (DRβ-H), an oleanane type of triterpenoid saponin. Objective • The study intended to assess the ability of DRβ-H to inhibit the ADR resistance of two BC-lineage cell lines, MCF-7 and SUM-1315, and to explore the causal link between DRβ-H and the reversal of chemoresistance. Design • The research team performed a cell biology study. Setting • The study took place at laboratory in China. Outcome Measures • The research team: (1) assessed cell viability and the migration and invasion the cell lines; (2) investigated the molecular mechanism and identified the downstream targets of DRβ-H, and (3) comprehensively examined the expression pattern, underlying functions, and evident prognostic significance of NAP1L5 in BC by gathering the online information available. Results • DRβ-H can inhibit the viability of the MCF-7/ ADR and SUM-1315/ADR cancer cells in a dosagedependent manner. NAP1L5 might be the main target of DRβ-H in reversing ADR resistance. Its expression decreased in BC cells, and the more advanced the BC was, the lower the NAP1L5 expression was. Conclusion • DRβ-H at nontoxic concentrations was related to ADR resistance in BC through its downstream target NAP1L5. NAP1L5 is potentially a preferable prognostic marker for BC. [ABSTRACT FROM AUTHOR]

To explain the reason for different flower color adjustabilities of Hydrangea macrophylla, non-adjustable color ‘Tijana' and adjustable color ‘Ravi Brent' of Hydrangea macrophylla were used as experimental materials. The extraction conditions were optimized and the components of H. macrophylla anthocyanins were measured. Their physical-chemical stabilities were also explored, aiming to explore the mechanism of flower color adjustability. The optimal extraction conditions of Hydrangea anthocyanins by the ultrasonic method were determined through L9(3³)orthogonal experiments. The anthocyanin components were separated and identified by UPLC-Q-TOF-MS. And the effects of temperature, light, metal ions and sugars on the physical-chemical stabilities of H. macrophylla anthocyanins were also explored in vitro conditions. The results were as follows:(1)The optimal conditions for extraction of H. macrophylla anthocyanins were that the ethanol concentration for ‘Tijana' and ‘Ravi Brent' were 70% and 80% respectively; the ratio of plant material to extraction solution was both 1:20; and the extraction time was both 20 m.(2)The main anthocyanin component of the two varieties was both Delphinidin 3-O-glucoside.(3)H. macrophylla anthocyanins were more stable when stored below 70 ℃ and in the dark.(4)Both Cu2+ and Al3+ change the color of the anthocyanin solution, and Cu2+ specifically improved the stability of the anthocyanin of ‘Tijana'. 10-90 mmol·L-1 Ca2+, Al3+ and 90 mmol·L-1 Mg2+ had significant effects on the stability of anthocyanin of both varieties. Glucose, maltose, sucrose, galactose and 8%-10% concentration of rhamnose increased the stability of the non-adjustable color ‘Tijana' Hydrangea macrophlla anthocyanins. While 4%-10% concentration of rhamnose promoted the stability of adjustable color ‘Ravi Brent' Hydrangea macrophylla anthocyanins. The non-adjustable color ‘Tijana' of H. macrophylla anthocyanins were more stable to light, sugars and most metal ions, compared with the adjustable color ‘Ravi Brent'. Only the anthocyanins of the adjustable color ‘Ravi Brent' of H. macrophylla turned from pink to blue, and its stability increased after adding low medium concentration(10-30 mmol·L-1)of Al3+. However, the non-adjustable color ‘Tijana' of H. macrophylla did not have this kind of color change, indicating that the difference in color adjustability of H. flowers is related to its physical-chemical stability. These results provide the theoretical reference for the extraction and observation of H. macrophlla anthocyanins, flower color improvement and dry flower color protection. [ABSTRACT FROM AUTHOR]

The first total synthesis of capsular polysaccharide (CPS) repeating unit [2)‐α‐l‐Rhap‐1→P→4‐β‐d‐ManpNAc‐(1→4)‐α‐d‐Glcp‐(1]n of streptococcus suis serotype 8 is reported. The key features of the synthesis are the formation of 1,2 cis glycosidic linkage between mannosamine and glucose derived monomers to get disaccharide which on coupling with rhamnose H‐phosphonate followed by oxidation of P−H bond and global debenzylation provide targeted trisaccharide repeating unit of streptococcus suis serotype 8. [ABSTRACT FROM AUTHOR]

The imbalance between energy intake and energy expenditure leads to the prevalence of obesity worldwide. A strategy to simultaneously limit energy intake and promote energy expenditure would be an important new obesity treatment. Here, we identified rhamnose as a nonnutritive sweetener to promote adipose thermogenesis and energy expenditure. Rhamnose promotes cAMP production and PKA activation through dopamine receptor D1 in adipose tissue. As a result, rhamnose administration promotes UCP1-dependent thermogenesis and ameliorates obesity in mice. Thus, we have demonstrated a rhamnose–dopamine receptor D1–PKA axis critical for thermogenesis, and that rhamnose may have a role in therapeutic molecular diets against obesity. [ABSTRACT FROM AUTHOR]

Different fractions of organic matter in surface sediments from three transects along the eastern margin of the Arabian Sea (AS) were quantified to determine the sources of organic matter, and also to study its impact on microbial community structure. From the extensive analyses of different biochemical parameters, it was evident that the distribution of total carbohydrate (TCHO), total neutral carbohydrate (TNCHO), proteins, lipids, and uronic acids (URA) concentrations and yield (% TCHO-C/TOC) are affected by organic matter (OM) sources and microbial degradation of sedimentary OM. Monosaccharide compositions from surface sediment was quantified to assess the sources and diagenetic fate of carbohydrates, suggesting that the deoxysugars (rhamnose plus fucose) had significant inverse relationship (r = 0.928, n = 13, p < 0.001) with hexoses (mannose plus galactose plus glucose) and positive relationship (r = 0.828, n = 13, p < 0.001) with pentoses (ribose plus arabinose plus xylose). This shows that marine microorganisms are the source of carbohydrates and there is no influence of terrestrial OM along the eastern margin of AS. During the degradation of algal material, the hexoses seem to be preferentially used by heterotrophic organisms in this region. Arabinose plus galactose (glucose free wt %) values between 28 and 64 wt% indicate that OM was derived from phytoplankton, zooplankton, and non-woody tissues. In the principal component analysis, rhamnose, fucose, and ribose form one cluster of positive loadings while glucose, galactose, and mannose form another cluster of negative loadings which suggest that during OM sinking process, hexoses were removed resulting in increase in bacterial biomass and microbial sugars. Results indicate sediment OM to be derived from marine microbial source along the eastern margin of AS. [ABSTRACT FROM AUTHOR]

Aging is a complex physiological process that can be accelerated by chemical (high blood glucose levels) or physical (solar exposure) factors. It is accompanied by the accumulation of altered molecules in the human body. The accumulation of oxidatively modified and glycated proteins is associated with inflammation and the progression of chronic diseases (aging). The use of antiglycating agents is one of the recent approaches in the preventive strategy of aging and natural compounds seem to be promising candidates. Our study focused on the anti-aging effect of the flavonoid hesperetin, its glycoside hesperidin and its carbohydrate moieties rutinose and rhamnose on young and physiologically aged normal human dermal fibroblasts (NHDFs). The anti-aging activity of the test compounds was evaluated by measuring matrix metalloproteinases (MMPs) and inflammatory interleukins by ELISA. The modulation of elastase, hyaluronidase, and collagenase activity by the tested substances was evaluated spectrophotometrically by tube tests. Rutinose and rhamnose inhibited the activity of pure elastase, hyaluronidase, and collagenase. Hesperidin and hesperetin inhibited elastase and hyaluronidase activity. In skin aging models, MMP-1 and MMP-2 levels were reduced after application of all tested substances. Collagen I production was increased after the application of rhamnose and rutinose. [ABSTRACT FROM AUTHOR]

The most widely used and accessible monosaccharides have a number of stereogenic centers that have been hydroxylated and are challenging to chemically separate. As a result, the task of regioselective derivatization of such structures is particularly difficult. Considering this fact and to get novel rhamnopyranoside-based esters, DMAP-catalyzed di-O-stearoylation of methyl α-l-rhamnopyranoside (3) produced a mixture of 2,3-di-O- (4) and 3,4-di-O-stearates (5) (ratio 2:3) indicating the reactivity of the hydroxylated stereogenic centers of rhamnopyranoside as 3-OH > 4-OH > 2-OH. To get novel biologically active rhamnose esters, di-O-stearates 4 and 5 were converted into six 4-O- and 2-O-esters 6–11, which were fully characterized by FT-IR, 1H, and 13C NMR spectral techniques. In vitro antimicrobial assays revealed that fully esterified rhamnopyranosides 6–11 with maximum lipophilic character showed better antifungal susceptibility than antibacterial activity. These experimental findings are similar to the results found from PASS analysis data. Furthermore, the pentanoyl derivative of 2,3-di-O-stearate (compound 6) showed better antifungal functionality against F. equiseti and A. flavus, which were found to be better than standard antibiotics. To validate the better antifungal results, molecular docking of the rhamnose esters 4–11 was performed with lanosterol 14α-demethylase (PDB ID: 3LD6), including the standard antifungal antibiotics ketoconazole and fluconazole. In this instance, the binding affinities of 10 (−7.6 kcal/mol), 9 (−7.5 kcal/mol), and 7 (−6.9 kcal/mol) were better and comparable to fluconazole (−7.3 kcal/mol), indicating the likelihood of their use as non-azole type antifungal drugs in the future. [ABSTRACT FROM AUTHOR]

The production of lactic acid and value-added chemicals (such as hydroxypropanone, glycolic acid, and formic acid) directly from Ulva prolifera via one-step catalytic process was studied. The effect of different amounts of YCl3-derived catalysts on the hydrothermal conversion of carbohydrates in Ulva prolifera was explored, and the reaction conditions were optimized. In this catalytic system, rhamnose could be extracted from Ulva prolifera and converted in situ into lactic acid and hydroxypropanone at 160 °C, while all the glucose, xylose, and rhamnose were fractionated and completely converted to lactic acid at 220 °C or at a higher temperature, via several consecutive and/or parallel catalytic processes. The highest yield of lactic acid obtained was 31.4 wt% under the optimized conditions. The hydrothermal conversion of Ulva prolifera occurred rapidly (within 10 min) and showed promise to valorize Ulva prolifera. [ABSTRACT FROM AUTHOR]

Summary: This study investigated the structural changes of sesame kernel cellulosic polysaccharides during roasting and identified the volatile products produced from the degradation of cellulosic polysaccharides. The results showed that rhamnose and galacturonic acid of cellulosic polysaccharides were more susceptible to non‐enzymatic browning reaction than glucose. The degradation of cellulosic polysaccharides in the roasting temperature range of 180–220°C resulted in decreasing in their molecular weight from 163 270 to 125 477 Da. The crystallinity increased from 16.4% to 32.5% revealing that mainly the amorphous regions of cellulosic polysaccharides were degraded during roasting. In addition, the volatiles from degradation of the amorphous region were rich in aldehydes (10.17–33.33%) and furans (12.84–41.55%). This study provides a new perspective for improving the quality of sesame kernel products in the food industry. [ABSTRACT FROM AUTHOR]

The diversity of monosaccharides and glycosidic linkages of extracellular polysaccharide (EPS) of high molecular weight were studied in strains morphologically assigned to the genus Ankistrodesmus. EPSs of seven strains were similar in both monosaccharides and glycosidic linkages, but showed exclusive characteristics or enough differences in proportions to distinguish strains. Fucose, glucose, rhamnose, mannose and galactose occurred in relatively high percentages in all strains. The strain CCMA-UFSCar 423, excluded from the genus Ankistrodesmus by the molecular marker tufA, was the only one containing galacturonic acid. Arabinose was found only in one A. densus strain (CCMA-UFSCar 239). The species A. densus and A. stipitatus, which are known to have, respectively, stable mucilaginous capsules and pads in aqueous media, presented high percentages of the hydrophobic fucose and rhamnose on their polysaccharides. However, the strain CCMA-UFSCar 83, the only non-colonial A. densus, had low proportions of rhamnose. We also found variations in glycosidic linkages, and some of them were specific to one strain (e.g. 1-3 glucose in A. stipitatus). Conversely, the absence of common linkages was noteworthy for the strain outside the Ankistrodesmus clade, the CCMA-UFSCar 423. The data revealed important diversity in monosaccharides and linkages of the EPS within a single microalgae genus, and an important intraspecific diversity using a single growing condition. These differences could be useful as potential chemotaxonomic tools to help discriminating the Ankistrodesmus genus or species, but also for future studies on intraspecific diversity within the genus. Moreover, the results show the relevance of studying and conserving closely related strains to preserve biodiversity. The diverse composition of high molecular weight EPSs shows a great potential for prospecting EPSs of economic interest. [ABSTRACT FROM AUTHOR]

Herein, we report the use of reactive eutectic media from ammonium formate and monosaccharides to synthesize poly(hydroxyalkyl)pyrazines via microwave irradiation. This enabled unprecedented fast rates as well as better atom economy compared to previous methods. We investigated the influence of water on the reaction yield as well as the physical properties of the eutectic media and could thereby drastically reduce the viscosity, while preserving high reaction yields. The results were consistent for different monosaccharides, using fructose, glucose, rhamnose and fucose as reactants. Furthermore, the major reaction products were separated, chemically analyzed and tested for their antimicrobial activity via high-throughput screening. [ABSTRACT FROM AUTHOR]

This study is the first to isolate and purify the primary polysaccharide fraction (PPRR) from Rhizopogon rubescens (Tul.) Tul using ultrasonic-assisted hot water extraction. PPRR is a heteropolysaccharide composed of glucose, galactose, fucose, rhamnose, mannose, and xylose. After preliminary structural characterization, the main chain of PPRR is →3)- β - D -Glc p -(1→6)- β - D -Glc p -(1→. In vivo experiments showed that PPRR has significant therapeutic effects on the immune damage caused by cyclophosphamide (CPA). In a concentration range of 1–6 mg/mL, PPRR could augment the macrophage phagocytosis function and regulate the abnormal secretion of cytokines such as interleukin (IL)− 2 and interferon (IFN)- γ. Moreover, PPRR could reduce the inhibition of CPA on hematopoiesis of bone marrow and alleviate the damage caused by CPA to the thymus and spleen. These findings suggest that PPRR has the potential to be used as an immunomodulator in the future. [Display omitted] • Acidic polysaccharide component (named PPRR) was first isolated from Rhizopogon rubescens (Tul.) Tul. • The physicochemical properties and structural characteristics of PPRR were preliminarily characterized. • PPRR components exhibited good immunomodulatory activity in vivo. [ABSTRACT FROM AUTHOR]

Exopolysaccharide (EPS) from probiotic Enterococcus hirae WEHI01 was isolated and purified by anion exchange chromatography and gel chromatography, the results of which show that the EPS consists of four fractions, namely I01-1, I01-2, I01-3, and I01-4. As the main purification components, I01-2 and I01-4 were preliminarily characterized for their structure and their immunomodulatory activity was explored. The molecular weight of I01-2 was 2.28 × 104 Da, which consists mainly of galactose, and a few other sugars including glucose, arabinose, mannose, xylose, fucose, and rhamnose, while the I01-4 was composed of galactose only and has a molecular weight of 2.59 × 104 Da. Furthermore, the results of an evaluation of immunomodulatory activity revealed that I01-2 and I01-4 could improve the viability of macrophage cells, improve phagocytosis, boost NO generation, and encourage the release of cytokines including TNF-α and IL-6 in RAW 264.7 macrophages. These results imply that I01-2 and I01-4 could improve macrophage-mediated immune responses and might be useful in the production of functional food and medications. [ABSTRACT FROM AUTHOR]

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Copyright of Journal of Chinese Institute of Food Science & Technology is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Glycosyl phosphosaccharides represent a large and important family of complex glycans. Due to the distinct nature of these complex molecules, efficient approaches to access glycosyl phosphosaccharides are still in great demand. Here, we disclose a highly efficient and stereoselective approach to the synthesis of biologically important and complex α-glycosyl phosphosaccharides, employing direct gold(I)-catalyzed glycosylation of the weakly nucleophilic phosphoric acid acceptors. In this work, the broad substrate scope is demonstrated with more than 45 examples, including glucose, xylose, glucuronate, galactose, mannose, rhamnose, fucose, 2-N3-2-deoxymannose, 2-N3-2-deoxyglucose, 2-N3-2-deoxygalactose and unnatural carbohydrates. Here, we show the glycosyl phosphotriester prepared herein was successfully applied to the one-pot synthesis of a phosphosaccharide from Leishmania donovani, and an effective preparation of a trisaccharide diphosphate of phosphosaccharide fragments from Hansenula capsulate via iterative elongation strategy is realized. Glycosyl phosphosaccharides represent a large and important family of complex glycans, but are difficult to synthesize efficiently. Here, the authors disclose a stereoselective methodology to make α-glycosyl phosphosaccharides, via gold(I)-catalyzed glycosylation of phosphoric acid acceptors. [ABSTRACT FROM AUTHOR]

A novel polysaccharide EtGIPL1a was purified from fruiting bodies of Echinodontium tinctorium, a fungus unique to western North America. EtGIPL1a has an estimated weight average molecular weight of 275 kDa and is composed of glucose (54.3%), galactose (19.6%), mannose (11.1%), fucose (10.3%), glucuronic acid (4%), and rhamnose (0.6%). It has multiple glycosidic linkages, with 3-Glcp (28.9%), 6-Glcp (18.3%), 3,6-Glcp (13%), 4-GlcpA (9.2%), 6-Galp (3.9%), 2,6-Galp (2.6%), 3-Fucp (2.5%), 6-Manp (2.4%) being the most prominent, and unsubstituted glucose (15.3%), mannose (1.3%) and fucose (0.9%) as major terminal sugars. EtGIPL1a has a backbone containing mostly 3-substituted β-glucopyranose with 4-substituted glucopyranosyluronic acid. EtGIPL1a showed anti-proliferative activity against multiple cancer cell lines, with IC50 ranging from 50.6 to 1446 nM. Flow cytometry analyses confirmed that apoptosis induction is one mechanism for its anti-proliferative activity. EtGIPL1a should be further investigated for its potential anti-cancer activity in animal models, and for its possible utility in differentiation cancer therapy. [ABSTRACT FROM AUTHOR]

Globotriaosylceramide (Gb3 or CD77) is a tumor-associated carbohydrate antigen implicated in several types of cancer that serves as a potential cancer marker for developing target-specific diagnosis and therapy. However, the development of Gb3-targeted therapeutics has been challenging due to its carbohydrate nature. In the present work, taking advantage of its natural pentamer architecture and Gb3-specific targeting of shiga toxin B subunit (StxB), we constructed a pentameric antibody recruiting chimera by site-specifically conjugating StxB with the rhamnose hapten for immunotherapy of colorectal cancer. The Sortase A-catalyzed enzymatic tethering of rhamnose moieties to the C terminus of Stx1B and Stx2B had very moderate effect on their pentamer architectures and thus the resultant conjugates maintained the potent ability to bind to Gb3 antigen both immobilized on an assay plate and expressed on colorectal cancer cells. All StxB-rhamnose constructs were capable of efficiently mediating the binding of rhamnose antibodies onto HT29 colorectal cancer cells, which was further shown to be able to induce cancer cell lysis by eliciting potent antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) in vitro. Finally, the best StxB-rhamnose conjugate, i.e. 1B-3R, was confirmed to be able to inhibit the colorectal tumor growth using a HT29-derived xenograft murine model. Taken together, our data demonstrated the potential of repurposing StxB as an excellent multivalent scaffold for developing Gb3-targeted biotherapeutics and StxB-rhamnose conjugates might be promising candidates for targeted immunotherapy of Gb3-related colorectal cancer. [Display omitted] • StxB-rhamnose conjugates were constructed as multivalent antibody-recruiting chimera. • StxB-rhamnose conjugates directed the binding of rhamnose antibodies to tumor cells. • StxB-rhamnose conjugates mediated tumor cells killing through ADCC and CDC. • StxB-rhamnose conjugates showed potential for Gb3-targeted cancer immunotherapy. [ABSTRACT FROM AUTHOR]

Alhagi pseudalhagi is a well-known herbal remedy in traditional medicine. The current study aims to isolate and characterize the polysaccharides of A. pseudalhagi , as well as assess their antioxidative and hypoglycemic effects in vitro. Using DEAE-52 and Sephadex G-100 chromatographic columns, obtained one neutral (APs-1) and two acidic (APs-2, APs-3) polysaccharides. HPGPC, GC–MS, UV, FT–IR, Congo red, CD, and SEM analyses were used to characterize their physicochemical properties. The major monosaccharides in APs-1 and APs-2 were rhamnose, mannose, glucose and galactose, while in APs-3 was only rhamnose and galactose. They were heteropolysaccharides with average molecular weights of 57.8 kDa, 630 kDa, and 707 kDa, respectively. All three polysaccharides were in α-glycosidic linkage and had a triple-helical conformation with varying degrees of asymmetry. APs-1and APs-2 exhibited relatively loose, curly, honeycomb-like texture, whereas APs-3 was cross-linked filamentous with a smooth surface. In vitro , all three polysaccharides demonstrated remarkable antioxidant effects on the DPPH and ABTS radicals, with, APs-3 demonstrating excellent α-glucosidase inhibiting capacity of the three polysaccharides. showed better ABTS scavenging and α-glucosidase inhibiting capacity compared to APs-1 and APs-2. These findings suggest that A. pseudalhagi polysaccharides have the potential to act as an antioxidant and a hypoglycemic agent. [Display omitted] • Three heteropolysaccharides were obtained from the aerial parts of Alhagi pseudalhagi. • The polysaccharides possessed various molecular weights and monosaccharides compositions. • The polysaccharides have triple-helix structure, and different morphological properties. • All three polysaccharides exhibited desirable antioxidant and hypoglycemic activities in vitro. • This study provides structural characterization to the future use of Alhagi polysaccharides. [ABSTRACT FROM AUTHOR]

The physicochemical properties of cyanidin-3-O-glucoside (C3G) were investigated after binding with pectin from different sources (apple and peach) and fractions (water-soluble fraction (WSF), chelator soluble fraction (CSF) and sodium carbonate soluble fraction (NSF)). Apple WSF and peach CSF were high esterification degree pectin (DE) (63.23% and 55.66%). CSF of both AP and PP was abundant in HG and exhibited a much more linear structure than WSF and NSF. The maximum binding percentage was obtained at pH 2.0 for apple pectin (AP) (46%–50%) and at pH 3.5 for peach pectin (PP) (50%–54%). Binding with both pectins increased the color stability of C3G at pH 2.0. High DE pectin increased C3G light stability by reducing the degradation rate (0.03 h−1) compared to C3G alone (0.05 h−1). All the pectins reduced the thermal degradation rate of C3G, thus exhibiting a protective effect. A negative correlation was found between the relative RG I area and the particle size of the pectin-C3G complexes. Pectin played a leading role in the ζ-potential change. • The maximum binding percentage was obtained at pH 2.0 for apple pectin and pH 3.5 for peach pectin. • Pectin played a leading role in the ζ-potential change. • Pectin could reduce the thermal degradation rate of cyanidin-3-O-glucoside (C3G). • High degree of esterification pectin could reduce the C3G light degradation rate. • The contents of rhamnose and glucose were positively correlated with pectin particle size. [ABSTRACT FROM AUTHOR]

Phytochemical investigation on aerial parts of Lysimachia atropurpurea L. (Myrsinaceae), guided by NMR methods, resulted in the isolation and characterization of three previously undescribed triterpenoid saponins named stralysaponins A-C along with five known compounds. Their structures were elucidated by 1D and 2D NMR spectroscopy and HR-ESI-MS. Stralysaponins A-C were categorized into 13 β -28-epoxyoleanane-type triterpenoid saponins, reaffirming their prevalent presence of this type in the Myrsinaceae family and the genus Lysimachia. The identified derivatives share a common four-unit branched sugar chain, with rhamnose as the terminal sugar linked at C-3 of the aglycone. The presence of triterpenoid saponins in L. atropurpurea is reported herein for the first time. This study enriched the chemical diversity of triterpenoid saponins of the genus Lysimachia. Additionally, it demonstrates the effectiveness of NMR-profiling in isolating previously undescribed triterpenoid saponins from Lysimachia spp. [Display omitted] • Three undescribed oleanane-type triterpenoid saponins from Lysimachia atropurpurea L. • First time that triterpenoid saponins were reported from Lysimachia atropurpurea L. • The structures of the undescribed compounds were determined by NMR and HRMS. [ABSTRACT FROM AUTHOR]

The marine environment is a rich source of biodiversity, including microorganisms that have proven to be prolific producers of bioactive secondary metabolites. Arctic seas are less explored than warmer, more accessible areas, providing a promising starting point to search for novel bioactive compounds. In the present work, an Arctic marine Pseudomonas sp. belonging to the Pseudomonas (P.) fluorescence group was cultivated in four different media in an attempt to activate biosynthetic pathways leading to the production of antibacterial and anticancer compounds. Culture extracts were pre-fractionated and screened for antibacterial and anticancer activities. One fraction from three of the four growth conditions showed inhibitory activity towards bacteria and cancer cells. The active fractions were dereplicated using molecular networking based on MS/MS fragmentation data, indicating the presence of a cluster of related rhamnolipids. Six compounds were isolated using HPLC and mass-guided fractionation, and by interpreting data from NMR and high-resolution MS/MS analysis; the structures of the compounds were determined to be five mono-rhamnolipids and the lipid moiety of one of the rhamnolipids. Molecular networking proved to be a valuable tool for dereplication of these related compounds, and for the first time, five mono-rhamnolipids from a bacterium within the P. fluorescence group were characterized, including one new mono-rhamnolipid.

Bispecific antibodies (BsAbs) are next‐generation therapeutics for complex cancer treatment. Herein, we developed a dual‐targeting non‐IgG format of bsAbs by using a bispecific nanobody (bsNb) that can simultaneously target EGFR and HER2 on tumor cells. Site‐specific modification of the anti‐EGFR‐HER2 bsNb was conducted using the rhamnose (Rha) hapten via sortase A‐mediated ligation to reconstitute the missing crystallizable fragment (Fc) effector biological functions. Functionally similar to bsAbs, bsNb‐Rha conjugates retained dual‐targeting activity and exerted potent anticancer effects via the Fc‐domain‐mediated engagement of endogenous anti‐Rha antibodies. Further, an optimized bsNb‐Rha conjugate exhibited markedly improved pharmacokinetics and efficient inhibitory effects against xenograft tumor growth in vivo. Our strategy provides a general and cost‐effective platform to generate a new bsAb format for cancer immunotherapy. [ABSTRACT FROM AUTHOR]

Anthocyanins, vital metabolites in plants, are formed by anthocyanidins combined with various monosaccharides, including glucose, rhamnose, and arabinose. Rhamnose contributes greatly to the glycosylation of anthocyanidins. There are two kinds of rhamnose synthase (RS): rhamnose biosynthesis (RHM), and nucleotide‐RS/epimerase‐reductase (UER1). Nevertheless, no RS isoform was reported to be involved in anthocyanin synthesis. Here, three homologous PhRHM genes, namely PhRHM1, PhRHM2, and PhRHM3, and one PhUER1 gene from petunia were cloned and characterized. Green fluorescent protein fusion protein assays revealed that PhRHMs and PhUER1 are localized in the cytoplasm. We obtained PhRHM1 or/and PhRHM2 or PhUER1 silenced petunia plants and did not attempt to obtain PhRHM3 silenced plants since PhRHM3 mRNA was not detected in petunia organs examined. PhRHM1 and PhRHM2 (PhRHM1‐2) silencing induced abnormal plant growth and decreased the contents of l‐rhamnose, photosynthetic pigments and total anthocyanins, while PhUER1 silencing did not cause any visible phenotypic changes. Flavonoid metabolome analysis further revealed that PhRHM1‐2 silencing reduced the contents of anthocyanins with rhamnose residue. These results revealed that PhRHMs contribute to the biosynthesis of rhamnose and that PhRHMs participate in the anthocyanin rhamnosylation in petunia, while PhUER1 does not. [ABSTRACT FROM AUTHOR]

In this work, we reported an in situ exopolysaccharide (in situ -EPS1) containing rare fucose produced by Lactobacillus helveticus MB2-1 in Sayram ketteki yoghurt, which made it unique. Its fine structure was characterized by GPC, HPLC, FT-IR, GC–MS,1HNMR and 13CNMR together with two-dimensional (2D) NMR spectra. The results revealed that in situ -EPS1 was a new heteropolysaccharide with molecular weight of 1.06 × 105 Da, and was composed of mannose, rhamnose, glucose, galactose and fucose with the following repeating units. [Display omitted] Furthermore, the in situ -EPS1 exhibited significant antibiofilm effect against Methicillin-resistant Staphylococcus aureus (MRSA). Notably, the in situ -EPS1 did not interfere with the planktonic growth of MRSA strain, whereas inhibited its cell metabolic activity and the transcription of genes related to biofilm formation. This unique antibiofilm but non-antibacterial mechanism supposedly prevented the development of bacterial drug resistance, which may open a new door to fight against these drug-resistant microorganisms. [Display omitted] • Three purified exopolysaccharides were obtained from Sayram ketteki yoghurt. • The fine structure of the most abundant fraction in situ -EPS1 was elucidated. • The purified in situ -EPS1 presented strong antibiofilm activities on MRSA. • The purified in situ -EPS1 was non-interfered with planktonic growth of MRSA. [ABSTRACT FROM AUTHOR]

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Rhamnose-associated molecules are attracting attention because they are present in bacteria but not mammals, making them potentially useful as antibacterial agents. Additionally, they are also valuable for tumor immunotherapy. Thus, studies on the functions and biosynthetic pathways of rhamnose-containing compounds are in progress. In this paper, studies on the biosynthetic pathways of three rhamnose donors, i.e., deoxythymidinediphosphate-L-rhamnose (dTDP-Rha), uridine diphosphate-rhamnose (UDP-Rha), and guanosine diphosphate rhamnose (GDP-Rha), are firstly reviewed, together with the functions and crystal structures of those associated enzymes. Among them, dTDP-Rha is the most common rhamnose donor, and four enzymes, including glucose-1-phosphate thymidylyltransferase RmlA, dTDP-Glc-4,6-dehydratase RmlB, dTDP-4-keto-6-deoxy-Glc-3,5-epimerase RmlC, and dTDP-4-keto-Rha reductase RmlD, are involved in its biosynthesis. Secondly, several known rhamnosyltransferases from Geobacillus stearothermophilus, Saccharopolyspora spinosa, Mycobacterium tuberculosis, Pseudomonas aeruginosa, and Streptococcus pneumoniae are discussed. In these studies, however, the functions of rhamnosyltransferases were verified by employing gene knockout and radiolabeled substrates, which were almost impossible to obtain and characterize the products of enzymatic reactions. Finally, the application of rhamnose-containing compounds in disease treatments is briefly described. [ABSTRACT FROM AUTHOR]

Highlights: The multiple fingerprints of 10 batches of Saposhnikoviae Radix polysaccharide(SP) were prepared and chemometrics analysis was carried out. The anti-allergic activity of the SPs was evaluated. The spectrum-effect relationship of SPs was establishedd. PMP-HPLC, FT-IR, and HPSEC fingerprints of 10 batches of polysaccharides from Saposhnikoviae Radix with different production areas and harvest times have been prepared, and the chemometrics analysis was performed. The anti-allergic activity of 10 batches of Saposhnikoviae Radix polysaccharide (SP) was evaluated, and the spectrum-effect relationship of the 10 batches of SP was analyzed by gray correlation degree with the chromatographic fingerprint as the independent variable. The results showed that the PMP-HPLC, HPSEC, and FT-IR fingerprints of 10 batches of SP had a high similarity. Two monosaccharides (rhamnose and galactose), the polysaccharide fragment Mn = 8.67 × 106~9.56 × 106 Da, and the FT-IR absorption peak of 892 cm−1 can be used as the quality control markers of SPs. All 10 batches of SP could significantly inhibit the release of β-HEX in RBL-231 cells, and the polysaccharides harvested from Inner Mongolia in the winter had the best anti-allergic activity. The spectrum-effect relationship model showed that the monosaccharide composition and molecular weight were related to the anti-allergic activity of the SPs. Multiple fingerprints combined with spectrum-effect relationship analysis can evaluate and control the quality of SPs from the aspects of overall quality and efficacy, which has more application value. [ABSTRACT FROM AUTHOR]