Investigating the synergistic antibacterial effects of chlorogenic and p-coumaric acids on Shigella dysenteriae.

Chlorogenic acid (CGA) is a well-known plant secondary metabolite exhibiting multiple physiological functions. The present study focused on screening for synergistic antibacterial combinations containing CGA. The combination of CGA and p-coumaric acid (pCA) exhibited remarkably enhanced antibacterial activity compared to that when administering the treatment only. Scanning electron microscopy revealed that a low-dose combination treatment could disrupt the Shigella dysenteriae cell membrane. A comprehensive analysis using nucleic acid and protein leakage assay, conductivity measurements, and biofilm formation inhibition experiments revealed that co-treatment increased the cell permeability and inhibited the biofilm formation substantially. Further, the polyacrylamide protein- and agarose gel-electrophoresis indicated that the proteins and DNA genome of Shigella dysenteriae severely degraded. Finally, the synergistic bactericidal effect was established for fresh-cut tomato preservation. This study demonstrates the remarkable potential of strategically selecting antibacterial agents with maximum synergistic effect and minimum dosage exhibiting excellent antibacterial activity in food preservation.

Anti-Melanogenic Potential of Malabar Spinach (Basella alba) in Human Melanoma Cells with Oxidative Stress Suppression and Anti-Inflammatory Activities.

Basella alba has been used in Thai remedies to treat skin disorders, but scientific evidence supporting its efficacy is currently limited. In this study, we investigated the inhibitory effects of B. alba extracts on melanin production using melanoma cells, as well as their impact on oxidative stress and inflammation in keratinocytes. The results demonstrate that B. alba extracts inhibited melanin content and cellular tyrosinase activity in 3-isobutyl-1-methylxanthine (IBMX)-induced melanoma cells by downregulating MITF and the pigmentary genes TYR, TRP-1, and DCT. Interestingly, the MITF regulator gene was inhibited by both the 50% and 95% ethanolic extracts of B. alba with levels of 0.97 ± 0.19 and 0.92 ± 0.09 of the control, respectively, which are comparable to those observed in the arbutin treatment group at 0.84 ± 0.05 of the control. Moreover, after hydrogen peroxide (H2O2) exposure, pretreatment with B. alba reduced lipid peroxidation byproducts and increased the levels of antioxidant-related genes, including SOD-1, GPX-1, and NRF2. Notably, the suppression of the POMC promoter gene in keratinocytes was observed, which may disrupt melanogenesis in melanocytes involving the MC1R signaling pathway. MC1R mRNA expression decreased in the treatments with 50% and 95% ethanolic extracts of B. alba, with relative levels of 0.97 ± 0.18 and 0.90 ± 0.10 of the control, respectively, similar to the arbutin-treated group (0.88 ± 0.25 of control). A significant reduction in nitric oxide was also observed in the B. alba-treated groups, along with a decrease in genes associated with pro-inflammatory cytokines, including IL-1ß, IL-6, and COX-2. These findings suggest that B. alba has potential in the prevention of skin-related problems.

Biochar regulates the functions of keystone taxa to reduce p-coumaric acid accumulation in soil.

Introduction: Applying biochar (BC) to reduce toxic substance accumulation in soil, either through direct adsorption or modulation of the microbial community, has received considerable attention. However, a knowledge gap exists regarding how BC regulates microbial community structure and functions to mitigate toxic substance accumulation. Methods: We previously identified p-coumaric acid (p-CA) as a representative autotoxin in tobacco rhizosphere soil. On this basis, this study simulated a soil environment with p-CA accumulation to investigate the impacts of BC on p-CA, soil physicochemical properties, and microbial community structure and function. Results: The results showed that p-CA could be directly adsorbed onto BC, which followed the pseudo-second-order kinetic model (R 2 = 0.996). A pot experiment revealed that BC significantly reduced soil p-CA, altered soil microbial composition, and enhanced bacterial community diversity. A weighted correlation network analysis showed a close association between taxon 1 in the microbial network and p-CA, suggesting a pivotal role for this taxon in reducing p-CA, with Devosia and Nocardioides identified as potential key contributors to this process. The prediction of possible keystone taxa functions showed that BC increased the relative abundances of aromatic compound degraders. Mantel tests indicated that soil organic matter exerted the greatest influence on keystone taxa functions and hub genera. Discussion: These findings suggest that BC may either directly chemisorb p-CA or indirectly facilitate p-CA degradation by regulating the functioning of keystone taxa. The results of this study provide a novel perspective for further investigation of the mechanisms through which BC reduces the accumulation of toxic substances in soil.

Exogenous p-coumaric acid treatment improves phenolic compounds biosynthesis of postharvest cherry tomatoes by regulating physiological metabolism.

To investigate the effect of p-coumaric acid (p-CA) on postharvest cherry tomatoes, breaker stage fruits were treated with p-CA to analyze the physiological metabolism during storage. The results showed that exogenous p-CA treatment improved the sensory quality of tomato fruits. Transcriptomics results indicated that 782 genes (339 up-regulated and 443 down-regulated) were differentially expressed between p-CA treated and control fruits. Results suggested that p-CA treatment regulated the synthesis of phenolic compounds and inhibited the fruit ripening through the pathways of mangiferic acid biosynthesis and phenylalanine metabolism. Key enzymes activities of the phenylpropane metabolic pathway of tomato fruits were increased, including phenylalanine ammonia lyase (PAL), cinnamic acid 4-hydroxylase (C4H), and 4-coumarate-CoA ligase (4CL). In addition, the total phenols content, flavonoids content and antioxidant capacities of tomato fruits were improved with p-CA treatment. Overall, these findings showed that p-CA treatment could be a potential strategy for fruit and vegetable preservation.

Antihypertensive effect of a nanoemulsion of baccharis dracunculifolia leaves extract in sodium-dependent hypertensive rats.

Baccharis dracunculifolia (DC) is an important botanical source of Brazilian green propolis and have many compounds with potential antihypertensive activity. However, little is known about the specific antihypertensive properties of DC, or the mechanisms involved. Here we aimed to chemically characterise an ethanolic DC extract (eDC), test its antihypertensive properties and the involvement of neurogenic mechanisms using an animal model of salt-dependent hypertension. The chemical analysis of the eDC revealed the presence of many antihypertensive compounds. Administering the eDC in a nanoemulsion formulation (25 to 50 mg/kg) effectively normalised blood pressure in hypertensive rats. The result also suggested that neurogenic mechanisms are involved in the antihypertensive action of eDC. The treatment with p-coumaric acid (0.32 to 3 mg/kg), a polyphenol abundant in the eDC, produced no significant antihypertensive effect. The findings indicate that the eDC has antihypertensive properties, and that these effects may be mediated through neurogenic pressor mechanisms.

In vitro anthelmintic activity and colocalization analysis of hydroxycinnamic acids obtained from Chamaecrista nictitans against two Haemonchus contortus isolates.

This study assessed the in vitro anthelmintic activity of ethyl acetate extract (Cn-EtOAc) and its bioactive fractions (CnR3 and CnR5) obtained from Chamaecrista nictitans aerial parts against two Haemonchus contortus (Hc) isolates, one resistant (strain HcIVM-R) and another susceptible (strain HcIVM-S) to ivermectin. Ferulic acid and p-coumaric acid were identified in the bioactive fractions; therefore, their commercial standards were also assessed. A colocalization analysis between the ferulic acid commercial standard and eggs of the HcIVM-R strain was performed using confocal laser scanning microscopy and the ImageJ program. The ovicidal effects of the Cn-EtOAc extract, bioactive fractions and commercial compounds were tested through the egg hatching inhibition (EHI) assay on H. contortus isolates HcIVM-R and HcIVM-S. The Cn-EtOAc caused 88 % and 92 % EHI at 5000 µg/mL on HcIVM-R and HcIVM-S, respectively. Fractions CnR3 and CnR5 displayed the highest ovicidal activity against HcIVM-S, with effective concentrations (EC90) of 2134 and 601 µg/mL, respectively. Meanwhile, the commercial standards ferulic acid and p-coumaric acid also resulted in higher effectiveness on the same strain, with EC90 of 57.5 and 51.1 µg/mL. A colocalization analysis of ferulic acid and eggs of HcIVM-R revealed that this compound is localized to the cuticle surface of the embryo inside the egg parasite. The results demonstrated that both ferulic and p-coumaric acids interrupt the egg-hatching processes of the two Hc isolates. Both phenolic acids isolated from C. nictitans and commercial standards exhibited the best anthelmintic effect on HcIVM-S. These findings indicate that the phenolic acids were less effective in egg hatch inhibiting on the HcIVM-R strain compared to the HcIVM-S strain.

The effect of plum extracts and antioxidants on reduction of ethyl carbamate in plum liqueur.

Stone-fruit liqueurs contain high contents of the carcinogen ethyl carbamate (EC). In this study, we investigated the effect of plum fruit extract and single antioxidants present in plum fruit extracts on the reduction in the EC content during the macerating process in a plum liqueur model system and authentic plum liqueur. 30% ethanol model plum liqueur treated with 0.2% plum extract showed the lowest EC content with 55% reduction rate after the macerating process compared to the content in the control. Interestingly, neither 0.1% ascorbic acid nor 0.1% p-coumaric acid lowered the EC contents in the model liqueur, while they decreased the EC contents in authentic plum liqueur. This was possibly attributed to the synergistic effect of the plum fruit phenolics with the ascorbic acid and p-coumaric acid antioxidants. Thus, plum extracts can be applied to plum liqueurs to reduce the rate of EC formation. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-024-01585-1.

Effects of grass species and harvest date on cell wall components and feed efficiency of dairy cows.

There is a balance between DM yield and feed value when choosing types of grasses on a farm depending on the acreages of farmland and types of ruminants to be fed. Therefore, optimisation of the harvest strategy for grass silage is important for profitable dairy farming. Tall fescue has high DM yield and can replace traditional grasses, such as timothy, in Northern Europe in a changing climate as it has been shown to be more drought tolerant. As differences in climate responses previously have been related to differences in cell wall structure between grass species and, consequently, in digestibility, it is highly relevant to compare these species at similar maturity stages and to investigate if a very early harvest date will diminish potential differences between the species. This study evaluated the effects of harvest date and forage species on the concentration of hydroxycinnamic acids in silages and its relationship to feed efficiency of dairy cows. Tall fescue and timothy were harvested at very early date on May 25 or at early date on May 31 in the spring growth cycle. Forty lactating dairy cows were used in a block design. Cows received 1 of 4 treatments: (1) tall fescue harvested at very early date, (2) timothy harvested at very early date, (3) tall fescue harvested at early date, and (4) timothy harvested at early date. Diets were formulated to have the same forage-to-concentrate ratio (49:51 on DM basis). Tall fescue silages showed greater concentrations of DM, ash, and CP than timothy silages. Grasses harvested at early date showed greater concentrations of NDF, ADL, and cell wall than grasses harvested at very early date. Tall fescue silages showed greater concentration of p-coumaric acid and lower in vitro organic matter digestibility (IVOMD) compared to timothy silages. Milk production and composition were not affected by treatments but cows fed tall fescue-based diets showed lower milk protein yield and greater milk urea nitrogen than when timothy-based diets were fed. Furthermore, cows receiving timothy-based diets showed greater feed efficiency compared to cows receiving tall fescue-based diets. Thus, the lower concentration of p-coumaric acid and the higher IVOMD was associated with greater feed efficiency of cows fed timothy-based diets compared to tall fescue-based diets.

Poly(p-coumaric acid) nanoparticles alleviate temporomandibular joint osteoarthritis by inhibiting chondrocyte ferroptosis.

Oxidative stress and inflammation are key drivers of osteoarthritis (OA) pathogenesis and disease progression. Herein we report the synthesis of poly(p-coumaric) nanoparticles (PCA NPs) from p-courmaic acid (p-CA), a naturally occurring phytophenolic acid, to be a multifunctional and drug-free therapeutic for temporomandibular joint osteoarthritis (TMJOA). Compared to hyaluronic acid (HA) that is clinically given as viscosupplementation, PCA NPs exhibited long-term efficacy, superior anti-oxidant and anti-inflammatory properties in alleviating TMJOA and repairing the TMJ cartilage and subchondral bone in a rat model of TMJOA. Notably, TMJ repair mediated by PCA NPs could be attributed to their anti-oxidant and anti-inflammatory properties in enhancing cell proliferation and matrix synthesis, while reducing inflammation, oxidative stress, matrix degradation, and chondrocyte ferroptosis. Overall, our study demonstrates a multifunctional nanoparticle, synthesized from natural p-coumaric acid, that is stable and possess potent antioxidant, anti-inflammatory properties and ferroptosis inhibition, beneficial for treatment of TMJOA.

A transparent p-coumaric acid-grafted-chitosan coating with antimicrobial, antioxidant and antifogging properties for fruit packaging applications.

The study aimed to develop a novel, transparent and non-toxic coating with antimicrobial, antioxidant, and antifogging properties. The p-coumaric acid-grafted chitosan (CS-PCA) was synthesized via a carbodiimide coupling reaction and then characterized. The CS-PCA coatings were further prepared using the casting method. The CS-PCA coatings obtained exhibited excellent transparency, UV-light barrier ability, and antifogging properties, as confirmed by spectroscopy and antifogging tests. The CS-PCA coatings showed stronger antioxidant capacity and antimicrobial properties against Escherichia coli, Staphylococcus aureus and Botrytis cinerea compared to CS. The multifunctional coatings were further coated on the polyethylene cling film and their effectiveness was confirmed through a strawberry preservation test. The decay of the strawberries was reduced by CS-PCA coated film at room temperature.

p-Coumaric Acid Differential Alters the Ion-Omics Profile of Chia Shoots under Salt Stress.

p-Coumaric acid (p-CA) is a phenolic compound that plays a crucial role in mediating multiple signaling pathways. It serves as a defense strategy against plant wounding and is also presumed to play a role in plant development and lignin biosynthesis. This study aimed to investigate the physiological and ionomic effect of p-CA on chia seedlings under salt stress. To this end, chia seedlings were supplemented with Nitrosol® containing 100 µM of p-CA, 100 of mM NaCI, and their combined (100 mM NaCI + 100 µM p-CA) solutions in 2-day intervals for a period of 14 days along with a control containing Nitrosol® only. The treatment of chia seedlings with 100 mM of NaCI decreased their growth parameters and the content of the majority of the essential macro-elements (K, P, Ca, and Mg), except for that of sodium (Na). The simultaneous application of p-CA and a salt stress treatment (p-CA + NaCI) alleviated the effect of salt stress on chia seedlings' shoots, and this was indicated by the increase in chia biomass. Furthermore, this combined treatment significantly enhanced the levels of the essential microelements Mg and Ca. In summary, this brief report is built on the foundational work of our previous study, which demonstrated that p-CA promotes growth in chia seedlings via activation of O2-. In this brief report, we further show that p-CA not only promotes growth but also mitigates the effects of salt stress on chia seedlings. This mitigation effect may result from the presence of Mg and Ca, which are vital nutrients involved in regulating metabolic pathways, enzyme activity, and amino acid synthesis.

p-Coumaric acid pronounced protective effect against potassium bromate-induced hepatic damage in Swiss albino mice.

Potassium bromate (KBrO3) is a common dietary additive, pharmaceutical ingredient, and significant by-product of water disinfection. p-coumaric acid (PCA) is a naturally occurring nutritional polyphenolic molecule with anti-inflammatory and antioxidant activities. The goal of the current investigation was to examine the protective effects of p-coumaric acid against the liver damage caused by KBrO3. The five groups of animals-control, KBrO3 (100 mg/kg bw), treatment with KBrO3 along with Silymarin (100 mg/kg bw), KBrO3, followed by PCA (100 mg/bw, and 200 mg/kg bw) were randomly assigned to the animals. Mice were slaughtered, and blood and liver tissues were taken for assessment of the serum biochemical analysis for markers of liver function (alanine transaminase, aspartate transaminase, alkaline phosphatase, albumin, and protein), lipid markers and antioxidant markers (TBARS), glutathione peroxidase [GSH-Px], glutathione (GSH), and markers of hepatic oxidative stress (CAT), (SOD), as well as histological H&E stain, immunohistochemical stain iNOS, and COX-2 as markers of inflammatory cytokines. PCA protects against acute liver failure by preventing the augmentation of blood biochemical markers and lipid profiles. In mice liver tissues, KBrO3 increases lipid indicators and depletes antioxidants, leading to an increase in JNK, ERK, and p38 phosphorylation. Additionally, PCA inhibited the production of pro-inflammatory cytokines and reduced the histological alterations in KBrO3-induced hepatotoxicity. Notably, PCA effectively mitigated KBrO3-induced hepatic damage by obstructing the TNF-α/NF-kB-mediated inflammatory process signaling system. Additionally, in KBrO3-induced mice, PCA increased the intensities of hepatic glutathione (GSH), SOD, GSH-Px, catalase, and GSH activities. Collectively, we demonstrate the molecular evidence that PCA eliminated cellular inflammatory conditions, mitochondrial oxidative stress, and the TNF-α/NF-κB signaling process, thereby preventing KBrO3-induced hepatocyte damage.

Antimicrobial Effect of Honey Phenolic Compounds against E. coli-An In Vitro Study.

Growing concern over antimicrobial resistance in chronic wound patients necessitates the exploration of alternative treatments from natural sources. This study suggests that honey's phenolic compounds may offer antimicrobial benefits, warranting further investigation for therapeutic development. The main aim of this study was to investigate the antimicrobial activity of phenolic compounds and to determine the effects of their sub-inhibitory concentrations against Escherichia coli (E. coli). 3-phenyllactic acid (PLA), p-coumaric acid (PCA), and phloretin were tested against the bacterial strain of E. coli ATCC 25922. Comparison of the antimicrobial activity of honey constituents in vitro was performed using a broth culture assay. Measurement of the inhibitory properties of constituents in vitro was conducted using disc and well diffusion assays. The effects of sub-inhibitory concentrations of PCA on the susceptibility of E. coli ATCC 25922 to penicillin-streptomycin were tested. The results demonstrated that PLA was the most efficient antimicrobial agent, followed by PCA, whereas phloretin, at lower (2 mg/mL) concentrations, led to an increase in the growth of E. coli. Various modifications of the agar diffusion assay did not reveal the antibacterial properties of the studied phytochemicals. The enhancing effect of a sub-inhibitory concentration of PCA in cooperation with penicillin-streptomycin was shown. These findings might be helpful for the further investigation and development of new antimicrobial agents for the treatment of skin infections and wounds.

Chemical composition analysis and transcriptomics reveal the R2R3-MYB genes and phenol oxidases regulating the melanin formation in black radish.

Melanins are dark-brown to black-colored biomacromolecules which have been thoroughly studied in animals and microorganisms. However, the biochemical and molecular basis of plant melanins are poorly understood. We first characterized melanin from the black radish (Raphanus sativus var. niger) 'HLB' through spectroscopic techniques. p-Coumaric acid was identified as the main precursor of radish melanin. Moreover, a joint analysis of transcriptome and coexpression network was performed for the two radish accessions with black and white cortexes, 'HLB' and '55'. A set of R2R3-type RsMYBs and enzyme-coding genes exhibited a coexpression pattern, and were strongly correlated with melanin formation in radish. Transient overexpression of two phenol oxidases RsLAC7 (laccase 7) or RsPOD22-1 (peroxidase 22-1) resulted in a deeper brown color around the infiltration sites and a significant increase in the total phenol content. Furthermore, co-injection of the transcriptional activator RsMYB48/RsMYB97 with RsLAC7 and/or RsPOD22-1, markedly increased the yield of black extracts. Spectroscopic analyses revealed that these extracts are similar to the melanin found in 'HLB'. Our findings advance the understanding of structural information and the transcriptional regulatory mechanism underlying melanin formation in radish.

Development of a co-culture system for green production of caffeic acid from sugarcane bagasse hydrolysate.

Caffeic acid (CA) is a phenolic acid compound widely used in pharmaceutical and food applications. However, the efficient synthesis of CA is usually limited by the resources of individual microbial platforms. Here, a cross-kingdom microbial consortium was developed to synthesize CA from sugarcane bagasse hydrolysate using Escherichia coli and Candida glycerinogenes as chassis. In the upstream E. coli module, shikimate accumulation was improved by intensifying the shikimate synthesis pathway and blocking shikimate metabolism to provide precursors for the downstream CA synthesis module. In the downstream C. glycerinogenes module, conversion of p-coumaric acid to CA was improved by increasing the supply of the cytoplasmic cofactor FAD(H2). Further, overexpression of ABC transporter-related genes promoted efflux of CA and enhanced strain resistance to CA, significantly increasing CA titer from 103.8 mg/L to 346.5 mg/L. Subsequently, optimization of the inoculation ratio of strains SA-Ec4 and CA-Cg27 in this cross-kingdom microbial consortium resulted in an increase in CA titer to 871.9 mg/L, which was 151.6% higher compared to the monoculture strain CA-Cg27. Ultimately, 2311.6 and 1943.2 mg/L of CA were obtained by optimization of the co-culture system in a 5 L bioreactor using mixed sugar and sugarcane bagasse hydrolysate, respectively, with 17.2-fold and 14.6-fold enhancement compared to the starting strain. The cross-kingdom microbial consortium developed in this study provides a reference for the production of other aromatic compounds from inexpensive raw materials.

Effects of p-coumaric acid on probiotic properties of Lactobacillus acidophilus LA-5 and lacticaseibacillus rhamnosus GG.

Probiotics are defined as "live microorganisms that provide health benefits to the host when administered in adequate amounts." Probiotics have beneficial effects on human health, including antibacterial activity against intestinal pathogens, regulation of blood cholesterol levels, reduction of colitis and inflammation incidence, regulation of the immune system, and prevention of colon cancer. In addition to probiotic bacteria, some phenolic compounds found in foods we consume (both food and beverages) have positive effects on human health. p-coumaric acid (p-CA) is one of the most abundant phenolic compounds in nature and human diet. The interactions between these two different food components (phenolics and probiotics), resulting in more beneficial combinations called synbiotics, are not well understood in terms of how they will affect the gut microbiota by promoting the probiotic properties and growth of probiotic bacteria. Thus, this study aimed to investigate synbiotic relationship between p-CA and Lactobacillus acidophilus LA-5 (LA-5), Lacticaseibacillus rhamnosus GG (LGG). Probiotic bacteria were grown in the presence of p-CA at different concentrations, and the effects of p-CA on probiotic properties, as well as its in vitro effects on AChE and BChE activities, were investigated. Additionally, Surface analysis was conducted using FTIR. The results showed that treatment with p-CA at different concentrations did not exhibit any inhibitory effect on the growth kinetics of LA-5 and LGG probiotic bacteria. Additionally, both probiotic bacteria demonstrated high levels of antibacterial properties. It showed that it increased the auto-aggregation of both probiotics. While p-CA increased co-aggregation of LA-5 and LGG against Escherichia coli, it decreased co-aggregation against Staphylococcus aureus. Probiotics grown with p-CA were more resistant to pepsin. While p-CA increased the resistance of LA-5 to bile salt, it decreased the resistance of LGG. The combinations of bacteria and p-CA efficiently suppressed AChE and BChE with inhibition (%) 11.04-68.43 and 13.20-65.72, respectively. Furthermore, surface analysis was conducted using FTIR to investigate the interaction of p-coumaric acid with LA-5 and LGG, and changes in cell components on the bacterial surface were analyzed. The results, recorded in range of 4000 -600 cm-1 with resolution of 4 cm-1, demonstrated that p-CA significantly affected only the phosphate/CH ratio for both bacteria. These results indicate the addition of p-CA to the probiotic growth may enhance the probiotic properties of bacteria.

Systems engineering Escherichia coli for efficient production p-coumaric acid from glucose.

P-coumaric acid (p-CA), a pant metabolite with antioxidant and anti-inflammatory activity, is extensively utilized in biomedicine, food, and cosmetics industry. In this study, a synthetic pathway (PAL) for p-CA was designed, integrating three enzymes (AtPAL2, AtC4H, AtATR2) into a higher l-phenylalanine-producing strain Escherichia coli PHE05. However, the lower soluble expression and activity of AtC4H in the PAL pathway was a bottleneck for increasing p-CA titers. To overcome this limitation, the soluble expression of AtC4H was enhanced through N-terminal modifications. And an optimal mutant, AtC4HL373T/G211H, which exhibited a 4.3-fold higher kcat/Km value compared to the wild type, was developed. In addition, metabolic engineering strategies were employed to increase the intracellular NADPH pool. Overexpression of ppnk in engineered E. coli PHCA20 led to a 13.9-folds, 1.3-folds, and 29.1% in NADPH content, the NADPH/NADP+ ratio and p-CA titer, respectively. These optimizations significantly enhance p-CA production, in a 5-L fermenter using fed-batch fermentation, the p-CA titer, yield and productivity of engineered strain E. coli PHCA20 were 3.09 g/L, 20.01 mg/g glucose, and 49.05 mg/L/h, respectively. The results presented here provide a novel way to efficiently produce the plant metabolites using an industrial strain.

Engineering Yarrowia lipolytica as a Cellulolytic Cell Factory for Production of p-Coumaric Acid from Cellulose and Hemicellulose.

De novo biosynthesis of high-value added food additive p-coumaric acid (p-CA) direct from cellulose/hemicellulose is a more sustainable route compared to the chemical route, considering the abundant cellulose/hemicellulose resources. In this study, a novel factory was constructed for the production of p-CA in Yarrowia lipolytica using cellulose/hemicellulose as the sole carbon source. Based on multicopy integration of the TAL gene and reprogramming the shikimic acid pathway, the engineered strain produced 1035.5 ± 67.8 mg/L p-CA using glucose as a carbon source. The strains with overexpression of cellulases and hemicellulases produced 84.3 ± 2.4 and 65.3 ± 4.6 mg/L p-CA, using cellulose (carboxymethyl-cellulose) or hemicellulose (xylan from bagasse) as the carbon source, respectively. This research demonstrated the feasibility of conversion of cost-effective cellulose/hemicellulose into a value-added product and provided a sustainable cellulolytic cell factory for the utilization of cellulose/hemicellulose.

Engineered Zea mays phenylalanine ammonia-lyase for improve the catalytic efficiency of biosynthesis trans-cinnamic acid and p-coumaric acid.

Phenylalanine ammonia-lyase (PAL) plays a pivotal role in the biosynthesis of phenylalanine. PAL from Zea mays (ZmPAL2) exhibits a bi-function of direct deamination of L-phenylalanine (L-Phe) or L-tyrosine(-L-Tyr) to form trans-cinnamic acid or p-coumaric acid. trans-Cinnamic acid and p-coumaric acid are mainly used in flavors and fragrances, food additives, pharmaceutical and other fields. Here, the Activity of ZmPAL2 toward L-Phe or L-Tyr was improved by using semi-rational and rational designs. The catalytic efficiency (kcat/Km) of mutant PT10 (V258I/I459V/Q484N) against L-Phe was 30.8 µM-1 s-1, a 4.5-fold increase compared to the parent, and the catalytic efficiency of mutant PA1 (F135H/I459L) to L-tyrosine exhibited 8.6 µM-1 s-1, which was 1.6-fold of the parent. The yield of trans-cinnamic acid in PT10 reached 30.75 g/L with a conversion rate of 98%. Meanwhile, PA1 converted L-Tyr to yield 3.12 g/L of p-coumaric acid with a conversion rate of 95%. Suggesting these two engineered ZmPAL2 to be valuable biocatalysts for the synthesis of trans-cinnamic acid and p-coumaric acid. In addition, MD simulations revealed that the underlying mechanisms of the increased catalytic efficiency of both mutant PT10 and PA1 are attributed to the substrate remaining stable within the pocket and closer to the catalytically active site. This also provides a new perspective on engineered PAL.

Application of Poloxamer for In Situ Eye Drop Modeling by Enrichment with Propolis and Balsam Poplar Buds Phenolic Compounds.

In situ poloxamer-based gels are increasingly being explored as ocular drug delivery carriers to extend the release of active substances, thereby enhancing bioavailability. The objective of this study was to develop thermally stable in situ gels incorporating balsam poplar bud extract, propolis extract, and p-coumaric acid solution and to evaluate the physicochemical parameters of these gelified eye drops. This research assessed the compatibility of poloxamer-based eye drops with active components, their physicochemical properties, stability post-sterilization and during storage, and the release profiles of the active compounds. Fifteen eye drop formulations were prepared and categorized into three groups based on active components. One of the active components was propolis extract. As an alternative to propolis, eye drops containing the plant precursor, balsam poplar bud extract, were developed. The third group's active component was p-coumaric acid, a dominant phenolic acid in propolis and balsam poplar bud extracts. The study reported phenolic contents of 76.63 CAE mg/g for propolis and 83.25 CAE mg/g for balsam poplar bud aqueous extracts, with balsam poplar bud extracts showing higher SPF values (14.0) compared to propolis (12.7), while p-coumaric acid solution exhibited the highest SPF values (25.5). All eye drops were transparent, with pH values meeting the requirements for ocular drops. Formulations containing 8-10% poloxamer 407 met the criteria for in situ gels. All formulations remained stable for 90 days. Conclusion: The study results indicate that the formulated gels possess suitable physicochemical properties, are resistant to applied autoclaving conditions, and exhibit an extended release of active compounds with an increase in poloxamer content.