Hydrostability, mechanical resilience, and biodegradability of paper straws fabricated through lignin-based polyurethane and chitosan binary emulsion bonding.

This study focuses on enhancing the strength and water stability of paper straws through a novel approach involving a binary emulsion of lignin-based polyurethane and chitosan. Kraft lignin serves as the raw material for synthesizing a blocked waterborne polyurethane, subsequently combined with carboxylated chitosan to form a stable binary emulsion. The resulting emulsion, exhibiting remarkable stability over at least 6 months, is applied to the base paper. Following emulsion application, the paper undergoes torrefaction at 155 °C. This process deblocks isocyanate groups, enabling their reaction with hydroxyl groups on chitosan and fibers, ultimately forming ester bonds. This reaction significantly improves the mechanical strength and hydrophobicity of paper straws. The composite paper straws demonstrate exceptional mechanical properties, including a tensile strength of 47.21 MPa, Young's modulus of 4.33 GPa, and flexural strength of 32.38 MPa. Notably, its water stability is greatly enhanced, with a wet tensile strength of 40.66 MPa, surpassing commercial paper straws by 8 folds. Furthermore, the composite straw achieves complete biodegradability within 120 days, outperforming conventional paper straws in terms of environmental impact. This innovative solution presents a promising and sustainable alternative to plastic straws, addressing the urgent need for eco-friendly products.

Lipid-Lowering Meroterpenoids Penihemeroterpenoids A-F from Penicillium herquei GZU-31-6 via Targeting the AMPK/ACC/SREBP-1c Signaling Pathway.

Penihemeroterpenoids A-C, the first meroterpenoids with an unprecedented 6/5/6/5/5/6/5 heptacyclic ring system, together with precursors penihemeroterpenoids D-F, were co-isolated from the fungus Penicillium herquei GZU-31-6. Among them, penihemeroterpenoids C-F exhibited lipid-lowering effects comparable to those of the positive control simvastatin by the activation of the AMPK/ACC/SREBP-1c signaling pathway, downregulated the mRNA levels of lipid synthesis genes FAS and PNPLA3, and increased the level of mRNA expression of the lipid export gene MTTP.

Meroterpenoids from the marine-derived fungus Aspergillus terreus GZU-31-1 exerts anti-liver fibrosis effects by targeting the Nrf2 signaling in vitro.

Six undescribed meroterpenoids aspertermeroterpenes A-F and four known analogues were isolated from the marine-derived fungus Aspergillus terreus GZU-31-1. Their structures were elucidated based on spectroscopic methods and electronic circular dichroism calculations. All meroterpenoids possessed the unique acetyl group at C-11, and also aspertermeroterpene A featured the rare C-14 decarboxylated in DMOA meroterpenoids. In the bioassays, aspermeroterpene B exhibited a potent inhibitory effect on the activation of hepatic stellate cells at the concentration of 5 µM via targeting the Nrf2 signaling. This is the first time reported that aspermeroterpene B as a previously undescribed carbon skeleton of meroterpenoid possessed anti-liver fibrosis effect.

Novel 6/7/6 ring system diterpenoids and cytochalasins from the fungus Eutypella scoparia GZU-4-19Y and their anti-inflammatory activity.

Two new compounds eutyditerpenoid A (1) and seco-phenochalasin B (5), together with seven known compounds diaporthein A (2), aspergillon A (3), phenochalasin B (4), cytochalasins Z24 and Z25 (6 and 7), scoparasins A and B (8 and 9) were isolated from marine-derived Eutypella scoparia GZU-4-19Y. Among them, eutyditerpenoid A (1) with a rare 6/7/6 ring system possesing an anhydride moiety was the first example in the pimarane-type diterpenoids. Their structures were determined based on spectroscopic methods and the electronic circular dichroism (ECD) calculations. In the bioassays, all of the isolates were evaluated for their inhibitory activity against NO production induced by lipopolysaccharide in RAW 264.7 cells. Compounds 3 and 7 showed potent NO inhibition activity with IC50 values of 2.1 and 17.1 µM respectively, and the former also significantly suppressed the protein expression of iNOS and COX-2 at the concentration of 2.5 µM.

In-situ CBM3-modified bacterial cellulose film with improved mechanical properties.

Cellulose materials have poor wet strength and are susceptible to acidic or basic environments. Herein, we developed a facile strategy to modify bacterial cellulose (BC) with a genetically engineered Family 3 Carbohydrate-Binding Module (CBM3). To assess the effect of BC films, water adsorption rate (WAR), water holding capacity (WHC), water contact angle (WCA), and mechanical and barrier properties were determined. The results showed that CBM3-modified BC film exhibited significant strength and ductility improvement, reflecting improved mechanical properties of the film. The excellent wet strength (both in the acidic and basic environment), bursting strength, and folding endurance of CBM3-BC films were due to the strong interaction between CBM3 and fiber. The toughness of CBM3-BC films reached 7.9, 28.0, 13.3, and 13.6 MJ/m3, which were 6.1, 1.3, 1.4, and 3.0 folds over the control for conditions of dry, wet, acidic, and basic, respectively. In addition, its gas permeability was reduced by 74.3 %, and folding times increased by 56.8 % compared with the control. The synthesized CBM3-BC films may hold promise for future applications in food packaging, paper straw, battery separator, and other fields. Finally, the in situ modification strategy used to BC can be successfully applied in other functional modifications for BC materials.

Morphology-induced differences in adsorption behaviors and strength enhancement performance for fiber networks between quaternized amylose and amylopectin.

Cationic starch is the most widely used paper strength additive for papermaking wet end applications. However, it remains unclear how differently quaternized amylose (QAM) and amylopectin (QAP) are adsorbed on the fiber surface and their relative contribution to the inter-fiber bonding of papers. Herein, separated amylose and amylopectin were quaternized with different degrees of substitution (DS). After that, the adsorption behaviors of QAM and QAP on the fiber surface, the viscoelastic properties of the adlayers and their strength enhancement to fiber networks were comparatively characterized. Based on the results, the morphology visualizations of the starch structure displayed a strong impact on the adsorbed structural distributions of QAM and QAP. QAM adlayer with a helical linear or slightly branched structure was thin and rigid, while the QAP adlayer with a highly branched structure was thick and soft. In addition, the DS, pH and ionic strength had some impacts on the adsorption layer as well. Regarding the paper strength enhancement, the DS of QAM correlated positively to the paper strength, whereas the DS of QAP correlated inversely. The results provide a deep understanding of the impacts of starch morphology on performance and offer us some practical guidelines in starch selection.

New butanolide derivatives from the marine derived fungus Aspergillus terreus GZU-31-1 by chemical epigenetic manipulation.

Chemical epigenetic manipulation of Aspergillus terreus GZU-31-1 led to the discovery of five butanolide derivatives (1-5), including two new ones (1 and 2), and four known diphenyl ether derivatives (6-9). Compound 1 featured a Z-configuration double bond in the isoprenyl group was a potential anti-inflammatory bioactive group. Compound 2 was a new natural product. Moreover, compound 3 with a deacetylated group at C-4 was rarely reported as a butanolide analogue, which was isolated from the liquid culture treated with polyketide pathway inhibitor sodium citrate dihydrate. All of the isolates (1-9) were tested for their anti-inflammatory effects on the production of nitric oxide in lipopolysaccharide-induced microglial cells (RAW 264.7 cells). Compounds 1, 7, 8 and 9 exhibited more potent anti-inflammatory activity with IC50 values of 16.31, 20.16, 9.53 and 21.64 µM than the positive control (indomethacin, IC50, 24.0 µM).

Carbohydrate-Binding Modules of Potential Resources: Occurrence in Nature, Function, and Application in Fiber Recognition and Treatment.

Great interests have recently been aroused in the independent associative domain of glycoside hydrolases that utilize insoluble polysaccharides-carbohydrate-binding module (CBM), which responds to binding while the catalytic domain reacts with the substrate. In this mini-review, we first provide a brief introduction on CBM and its subtypes including the classifications, potential sources, structures, and functions. Afterward, the applications of CBMs in substrate recognition based on different types of CBMs have been reviewed. Additionally, the progress of CBMs in paper industry as a new type of environmentally friendly auxiliary agent for fiber treatment is summarized. At last, other applications of CBMs and the future outlook have prospected. Due to the specificity in substrate recognition and diversity in structures, CBM can be a prosperous and promising 'tool' for wood and fiber processing in the future.

Linderasesterterpenoids A and B: Two 7-Cyclohexyldecahydroazulene Carbon Skeleton Sesterterpenoids Isolated from the Root of Lindera glauca.

Two novel sesterterpenoids linderasesterterpenoids A (1) and B (2) with an unprecedented 7-cyclohexyldecahydroazulene carbon skeleton isolated from the root of Lindera glauca. Their structures were elucidated by X-ray diffraction, quantum chemical calculations, and spectroscopic methods. The biogenetic pathway for 1 and 2 is proposed. In the bioassay, linderasesterterpenoids A and B showed good inhibitory activities against LPS-induced NO production in RAW 264.7 cells compared to a positive control.

Furanaspermeroterpenes A and B, two unusual meroterpenoids with a unique 6/6/6/5/5 pentacyclic skeleton from the Marine-derived fungus Aspergillus terreus GZU-31-1.

Furanaspermeroterpenes A (1) and B (2), with a unique 6/6/6/5/5 pentacyclic skeleton, and five new congeners aspermeroterpenes D-H (3-7) were co-isolated from the marine-derived fungus Aspergillus terreus GZU-31-1. Among them, compounds 1 and 2 with rare five-membered D/E coupling rings were the first example of DMOA-derived meroterpenoids. Moreover, compound 3 was the first reported 6/6/6/6/5 pentacyclic meroterpenoid featuring an unusual cis-fused A/B ring. In the bioassays, all of the isolates were evaluated on the inhibitory activities against lipopolysaccharide-induced nitric oxide production in RAW 264.7 cells, and compounds 3-7 exhibited significant anti-inflammatory activity with IC50 values ranging from 6.74 to 29.59 µM than positive control (Indomethacin, IC50 30.98 µM).

Furanasperterpenes A and B, two meroterpenoids with a novel 6/6/6/6/5 ring system from the marine-derived fungus Aspergillus terreus GZU-31-1.

Furanasperterpenes A (1) and B (2) with a novel 6/6/6/6/5 pentacyclic skeleton and a new 11-acetoxy-terretonin E (3), were isolated from the marine-derived Aspergillus terreus GZU-31-1. Their structures were elucidated based on spectroscopic methods, and the absolute configurations were determined by X-ray diffraction and electronic circular dichroism (ECD) calculations. A possible biogenetic pathway was proposed. These compounds were evaluated for their lipid-lowering effects in 3T3-L1 adipocytes. Furanasperterpene A (1) showed the equivalent activity in reducing TG levels to positive control (berberine) at the concentration of 5 µM.

Aspermeroterpenes A-C: Three Meroterpenoids from the Marine-Derived Fungus Aspergillus terreus GZU-31-1.

Aspermeroterpene A (1) with an unprecedented and highly congested 5/3/6/6/6/5 hexacyclic skeleton, together with two precursors aspermeroterpenes B (2) and C (3), were isolated from the marine-derived fungus Aspergillus terreus GZU-31-1. Their structures were elucidated by quantum chemical calculations, X-ray diffraction, and spectroscopic methods. The biogenetic pathway for 1-3 is proposed. Aspermeroterpenes A-C (1-3) showed significant inhibitory activities against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 cells compared to positive control.

Cytochalasins and polyketides from the fungus Diaporthe sp. GZU-1021 and their anti-inflammatory activity.

Four new compounds: diaporthichalasins A-C (1-3) and biatriosporin N (7), along with six known compounds (4-6 and 8-10) were separated from the culture of the fungus Diaporthe sp. GZU-1021. The absolute configurations of 1-3 were determined by quantum chemical calculations, X-ray diffraction, and spectroscopic analysis. The structure of 4 was analyzed by X-ray crystallography analysis for the first time. All of the isolates were evaluated on the production of nitric oxide in lipopolysaccharide-induced microglial cells (RAW 264.7 cells). Compounds 5-10 exhibited significant inhibitory effects against nitric oxide production with IC50 values from 1.94 to 16.5 µM than positive control (indomethacin, IC50 = 29.7 µM). This is the first time tetrahydroxanthone dimer (10), as a novel carbon skeleton possessing NO inhibitory activity, was reported.

Diaporindenes A-D: Four Unusual 2,3-Dihydro-1 H-indene Analogues with Anti-inflammatory Activities from the Mangrove Endophytic Fungus Diaporthe sp. SYSU-HQ3.

Diaporindenes A-D (1-4), four unusual 2,3-dihydro-1 H-indene isomers, a novel isoprenylisobenzofuran A (5), two new isoprenylisoindole alkaloids diaporisoindoles D and E (6 and 7), and a new benzophenone derivative tenellone D (11), together with four known biogenetic agents (8-10 and 12), were all separated from the endophytic fungus Diaporthe sp. SYSU-HQ3 guided by ultraperformance liquid chromatography high-resolution mass spectrometry. The absolute configurations of 1-7 and 11 were defined by X-ray diffraction, quantum chemical calculations, and spectroscopic analysis. Diaporindenes A-D (1-4) possessed an unprecedented chemical skeleton featuring a 2,3-dihydro-1 H-indene ring and a 1,4-benzodioxan moiety. All of the isolates (1-12) were tested for their inhibitory effects on the production of nitric oxide in lipopolysaccharide-induced microglial cells (RAW 264.7 cells). Compounds 1-5, 8, and 9 were found to exhibit significant inhibitory effects against nitric oxide production with IC50 values from 4.2 to 9.0 µM and SI values from 3.5 to 6.9. In addition, the structure-activity relationships of all compounds were summarized.

Angucycline Glycosides from Mangrove-Derived Streptomycesdiastaticus subsp. SCSIO GJ056.

Nine new angucycline glycosides designated urdamycins N1⁻N9 (1⁻9), together with two known congener urdamycins A (10) and B (11), were obtained from a mangrove-derived Streptomycesdiastaticus subsp. SCSIO GJ056. The structures of new compounds were elucidated on the basis of extensive spectroscopic data analysis. The absolute configurations of 6⁻9 were assigned by electronic circular dichroism calculation method. Urdamycins N6 (6) and N9 (9) represent the first naturally occurring (5R, 6R)-angucycline glycosides, which are diastereomers of urdamycins N7 (7) and N8 (8), respectively.

Ethylnaphthoquinone derivatives as inhibitors of indoleamine-2, 3-dioxygenase from the mangrove endophytic fungus Neofusicoccum austral SYSU-SKS024.

Bioassay-guided fractionation of the dichloromethane extract of the fungus Neofusicoccum austral SYSU-SKS024 led to the isolation of three new ethylnaphthoquinone derivatives, neofusnaphthoquinone A (1), 6-(1-methoxylethy1)-2,7-dimethoxyjuglone (2), (3R,4R)-3-methoxyl-botryosphaerone D (6), together with six known analogs (3-5 and 7-9). Their structures were elucidated by spectroscopic analysis and single crystal X-ray diffraction analysis. Neofusnaphthoquinone A (1) is the third example of the unsymmetrical naphthoquinone dimer, which is rarely found in natural source. All of the isolates were evaluated for their indoleamine 2, 3-dioxygenase (IDO) inhibitory activity, compounds 1-6 showed in vitro inhibitory effects against IDO with IC50 values ranging from 0.11 to 10.92µM. This is the first time naphthoquinone dimer (1), as a novel carbon skeleton possessing IDO inhibitory activity, was reported.

3-Arylisoindolinone and sesquiterpene derivatives from the mangrove endophytic fungi Aspergillus versicolor SYSU-SKS025.

A pair of 3-arylisoindolinone enantiomers: (+)-asperglactam A (1), (-)-asperglactam A (1) and a pair of nor-bisabolane enantiomers: (+)-1-hydroxyboivinianic acid (2), (-)-1-hydroxyboivinianic acid (2), along with seven known compounds (3-8) were obtained from the mangrove endophytic fungus Aspergillus versicolor SYSU-SKS025. Their structures were determined on the basis of HRESIMS and NMR spectroscopic data, and X-ray diffraction. (+)-Asperglactam A (1) and (-)-asperglactam A (1) are the first optically pure examples in the 3-arylisoindolinone family, which are rarely found in natural sources. All isolated compounds were evaluated for α-glucosidase inhibitory activity. The enantiomers of 1-3 showed moderate inhibitory activity against α-glucosidase with IC50 values ranging from 50 to 190µM. Compound 7 exhibited significant inhibitory activity against α-glucosidase with IC50 value of 7.5µM. In addition, compound 7 was found to inhibit nitric oxide production in RAW 264.7 macrophages with IC50 value of 12.5µM.

A Novel Heterodimer from Crotalaria ferruginea.

A new compound was isolated from the traditional Chinese folk herb Crotalaria ferruginea. The structure of the new compound was identified as (±)-crotaferruphenol (1) based on analyses of its spectroscopic data including NMR, MS, and specific rotation values. (±)-Crotaferruphenol was a novel heterodimer characteristic of a unique spiroketal moiety, which was produced by the condensation reaction of a chromanone and a 2-isopropenybenzofuran. (±)-Crotaferruphenol exhibited inhibitory activity (IC50 = 6.57 µM.) against phosphodiesterase-4 (PDE4), a drug target for the treatment of chronic obstructive pulmonary disease and asthma.

Natural phosphodiesterase-4 (PDE4) inhibitors from Crotalaria ferruginea.

Bioassay-guided fractionation of the ethanol extract of the Chinese folk medicine Crotalaria ferruginea led to the isolation of a new isoflavonoid, 4'-hydroxy-2'-methylalpinum-isoflavone (1), and eight known analogs (2-9). Their structures were elucidated by spectroscopic analysis. Compounds 1, 2, 5, and 8 showed inhibitory activities against phosphodiesterase-4 (PDE4), a therapeutic target of asthma, with IC50 values ranging from 2.57 to 8.94 µM. The possible action mechanism and the structure-activity relationship (SAR) of the active isoflavonoids were explored by using molecular docking and molecular dynamics (MD) simulation methods. Our study herein may explain the anti-inflammatory function of this plant in Chinese folk medicine.

Extracellular signal-regulated kinases (ERK) inhibitors from Aristolochia yunnanensis.

Six new sesquiterpenoids, aristoyunnolins A-F (1-6), an artifact of isolation [7-O-ethyl madolin W (7)], and 12 known analogues were isolated from stems of Aristolochia yunnanensis. The structures were determined by combined chemical and spectral methods, and the absolute configurations of compounds 2, 3, 5-7, 9, 14, and 17 were determined by the modified Mosher's method and CD analysis. Compounds 1-19 were screened using a bioassay system designed to evaluate the effect on mitogen-activated protein kinases (MAPKs) signaling pathways. Among three MAPKs (ERK1/2, JNK, and p38), compounds 1, 4, 10-13, 16, 18, and 19 exhibited selective inhibition of the phosphorylation of ERK1/2. Compounds 16 and 19 were more active than the positive control PD98059, a known inhibitor of the ERK1/2 signaling pathway.