Phloroglucinol Research Articles

Encapsulation of Phloroglucinol from Rosenvingea intricata Macroalgae with Zinc Oxide Nanoparticles against A549 Lung Cancer Cells

Background/Objectives: Phloroglucinol (PHL), a phenolic compound extracted from the brown alga Rosenvingea intricata, exhibits potent antioxidant and anticancer properties. This study aims to extract, purify, and characterize PHL, and further develop functionalized zinc oxide nanoparticles (ZnO NPs) loaded with PHL to enhance its therapeutic potential. Methods: PHL was extracted using acetone and purified through Sephadex LH-20 column chromatography, yielding a highly enriched fraction (F-3). The purified compound was characterized by FTIR, HPLC, NMR, and LC-MS. ZnO NPs were synthesized, PEGylated, and conjugated with PHL, forming ZnO-PEG-PHL NPs. Their characterization included DLS, zeta potential, XRD, SEM-EDAX, and encapsulation efficiency studies. Antioxidant assays (DPPH, FRAP, ABTS, RPA) were performed and in vitro cytotoxicity on A549 lung cancer cells were determined to evaluate the therapeutic efficacy of PHL. Results: The purified PHL fraction showed a high phenolic content (45.65 PHL mg/g), which was was confirmed by spectral analysis. The ZnO-PEG-PHL NPs increased in size from 32.36 nm to 46.68 nm, with their zeta potential shifting from −37.87 mV to −26.82 mV. The antioxidant activity was superior for the ZnO-PEG-PHL NPs in all assays, while the in vitro cytotoxicity tests showed an IC50 of 40 µg/mL compared to 60 µg/mL for the ZnO NPs and 70 µg/mL for PHL. Apoptotic studies revealed significant cell cycle arrest and apoptosis induction. Conclusions: The synthesized ZnO-PEG-PHL NPs demonstrated enhanced antioxidant and anticancer properties, making them promising candidates for cancer therapy and antioxidant applications.

New Application of an Old Drug: Anti-Diabetic Properties of Phloroglucinol.

Phloroglucinol (PHG), an analgesic and spasmolytic drug, shows promise in preventing high-fat-diet (HFD)-induced non-alcoholic fatty liver disease (NAFLD) and insulin resistance. In Wistar rats, 10 weeks of PHG treatment did not prevent HFD-induced weight gain but significantly mitigated fasting hyperglycemia, impaired insulin responses, and liver steatosis. This protective effect was not linked to hepatic lipogenesis or AMP-activated protein kinase (AMPK) activation. Instead, PHG improved mitochondrial function by reducing oxidative stress, enhancing ATP production, and increasing anti-oxidant enzyme activity. PHG also relaxed gastric smooth muscles via potassium channel activation and nitric oxide (NO) signaling, potentially delaying gastric emptying. A pilot intervention in pre-diabetic men confirmed PHG's efficacy in improving postprandial glycemic control and altering lipid metabolism. These findings suggest PHG as a potential therapeutic for NAFLD and insulin resistance, acting through mechanisms involving mitochondrial protection, anti-oxidant activity, and gastric motility modulation. Further clinical evaluation is warranted to explore PHG's full therapeutic potential.

Application of carbon dots synthesized with amino acid as precursor in the detection of phloroglucinol

Nitrogen doped carbon dots (CDs) were successfully applied in the detection of phloroglucinol. CDs were hydrothermally synthesized from L-phenylalanine (L-phe) and L-leucine (L-leu) in alkaline aqueous solution. The morphology, size and functional groups of CDs were characterized by transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The average size of CDs was 4.26 ± 1.77 nm. The main elements of CDs were C, N, O and functional groups were carboxyl, hydroxyl, pyridine and amino groups. CDs showed bright blue fluorescence with the quantum yield (QY) at 12.82 % (λex = 337 nm and λem = 437 nm). In the presence of phloroglucinol (PG), however, the fluorescence of CDs was quenched significantly. It could be ascribed from hydrogen bonds formed between PG and functional groups on the surface of CDs. There was a good linear response between the fluorescence quenching of CDs and the concentration of PG in the range of 0.5–150 μM with the limit of detection (LOD) at 12 nM. The strategy can be used to detect PG qualitatively and quantitatively with the advantages of low cost, high sensitivity, fast response and high specificity.

Ultrasound-assisted extraction of phenolics from Sargassum carpophyllum - A kinetics study.

The species of the brown macroalgal genus Sargassum are distributed globally and contain many bioactive compounds. In this study, ultrasound-assisted extraction (UAE) was applied to obtain phenolic compounds with strong antioxidant activity from Sargassum carpophyllum collected along the coastline of Weizhou Island in the South China Sea. The influence of different variables such as the solid-liquid ratio (1:5-1:30 g · mL-1), ultrasonic power (160-280 W), duty circle ratio (DCR, 1/3-1/1), and ethanol concentration (30% to ~90%) were studied using a single factor design. The extraction kinetics were investigated using the Peleg model and second-order kinetics model, and the second-order model described the extraction procedure better than the Peleg model. Total phenol content (TPC) values of 3.316, 2.964, 2.741, and 3.665 mg phloroglucinol (PHG) · g-1 algae were achieved at a higher solid-liquid ratio (1:30 g · mL-1), higher ultrasonic power (280 W), a higher DCR (1/1), and a moderate ethanol concentration (50%), respectively. However, a slightly different result was observed in the extract obtained, with total phenol contents (TPCextract) of 52.99, 65.00, 46.22, and 55.10 mg PHG · g-1 extract and DPPH radical scavenging activity (IC50) of 0.096, 0.066, 0.131, and 0.136 mg extract · mL-1 observed at 50% ethanol, 1:5 g m· mL-1, 2/3 DCR, and 200 W respectively. All variables studied influenced the extraction kinetics by altering the extraction rate and the TPC at equilibrium. As for the bioactivities in the extract, a larger solid-liquid ratio and greater ultrasonic power may not contribute because of their ability to extract non-phenolic components simultaneously, leading to reduced overall bioactivities. The results of the present study provide essential information for future UAE process design and optimization for extracting phenolics from S. carpophyllum through mathematical modeling and could be regarded as important reference for obtaining value-added products from other macroalgae species.

Phloroglucinol ameliorated methylglyoxal induced harmful effects in rats.

Glycation is among the underlying mechanisms attributed to ageing and associated morbidities. There is no drug available to combat this deleterious phenomenon. The present study aimed to explore phloroglucinol (PHL) for its anti-glycation potential at preclinical level. The rats were treated with methylglyoxal (MGO, 17.25 mg/kg, i.p. for 14 days) to induce glvcative stress. The treatment groups received additional administration of test drug (PHL; 0.25mg/kg, 0.5mg/kg, and 1mg/kg) or standard aminoguanidine (AG, 50 mg/kg) or saline (control, 5ml/kg). During 14 days, the weight and food intake was noted. Afterwards, the cognitive function was evaluated using Morris Water Maze (MWM) while hepatic and renal functions were assessed through liver function test (bilirubin, alkaline phosphatase, SGPT, and SGOT) and creatinine respectively, using chemical analyzer. The carboxymethyllysine (CML) levels were quantified in the blood using ELISA technique. Histopathological study was performed on the brain, liver, and kidney using H&E staining. Additionally, the qPCR was used to quantify the expression of TNF-α, RAGE and BACE-1 (brain), RAGE, TNF-α, and glyoxalase-I (liver) and RAGE, TNF-α, and VEGF (kidney), while glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as a reference housekeeping gene. The data regarding weight and food intake did not reveal significant alterations. In MWM, the MGO treatment caused significant increase in the time to reach target quadrant, while decrease in the time spent in target quadrant and number of crossings through platform position. All these effects were inhibited by both AG and PHL. The navigation maps also exhibit that the retention of spatial memory. Additionally, the MGO-induced alteration in hepatic and renal function indicators was ameliorated by both AG and PHL treatments. The plasma CML levels were found to be elevated following MGO treatment, while the concomitant administration of AG and PHL has resisted this raise. Histopathological assessment revealed no specific pathology in liver kidney and brain tissues. The qPCR data revealed enhanced expression of all genes, especially TNF-α and BACE, which were found to be reduced following both AG and PHL treatments. PHL prevented the brain, hepatic, and renal impairments caused by MGO induced glycative stress. Hence, the PHL, a clinically used anti-spasmodic drug, presents itself as a potential candidate to be repurposed as anti-glycation drug.

Phloroglucinol Derivatives Exert Anti-Inflammatory Effects and Attenuate Cognitive Impairment in LPS-Induced Mouse Model.

Neuroinflammation is an inflammatory immune response that arises in the central nervous system. It is one of the primary causes of neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease. Phloroglucinol (PG) is a natural product contained in extracts of plant, algae and microbe and has been reported to have antioxidant and anti-inflammatory properties. In this study, we synthesized PG derivatives to enhance antioxidant and anti-inflammatory activity. Among PG derivatives, 6 a suppressed pro-oxidative and inflammatory molecule nitric oxide (NO) production more effectively than PG. Moreover, 6 a dose-dependently reduced the expression of proinflammatory cytokines such as IL-6, IL-1β, TNF-α, and NO producing enzyme iNOS in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. Additionally, we confirmed that 6 a alleviated cognitive impairment and glial activation in mouse model of LPS-induced neuroinflammation. These findings suggest that novel PG derivative, 6 a, is a potential treatment for neurodegenerative diseases.

In Vitro Shoot Multiplication and Rooting of 'Kashan' and 'Hervy Azerbaijan' Damask Rose (Rosa damascena Mill.) Genotypes for Cosmetic and Ornamental Applications.

The damask rose (Rosa damascena Mill.) is an ornamental-medicinal plant from the Rosaceae family, and its aromatic compounds and essential oils are applied globally in the food, cosmetic, and pharmaceutical industries. Due to its economic value, this research aimed to establish a protocol for an efficient, rapid, and cost-effective method for in vitro shoot multiplication and rooting of the R. damascena 'Kashan' and 'Hervy Azerbaijan' genotypes. Nodal segments (as primary explants) were cultured on the Murashige and Skoog (MS) medium with combinations of various plant growth regulators (PGRs) such as gibberellic acid (GA3), 6-benzylaminopurine (BAP), and indole-3-butyric acid (IBA), as well as a PGR-like substance, phloroglucinol (PG), vitamins such as ascorbic acid (AA), and activated carbon in the form of active charcoal (AC). For the establishment stage, 0.1 mg·L-1 PG, 0.2 mg·L-1 GA3, and 1 mg·L-1 BAP were added to the media. Secondary explants (nodal segments containing axillary buds produced from primary explants) were obtained after 30 days of in vitro culture and transferred to the proliferation media supplemented with different concentrations of BAP (0, 0.5, 1, 1.5, 2, and 2.5 mg·L-1) and GA3 (0, 0.1, 0.2, 0.4, 0.8, and 1 mg·L-1) together with 0.1 mg·L-1 PG and 20 mg·L-1 of AA. The rooting media were augmented with different concentrations of BAP and GA3 with 0.1 mg·L-1 of IBA, PG and 20 mg·L-1 of AA and AC. The results showed that the highest regeneration coefficient (4.29 and 4.28) and the largest number of leaves (23.33-24.33) were obtained in the explants grown on the medium supplemented with 2 mg·L-1 BAP and 0.4 mg·L-1 GA3 for the 'Kashan' and 'Hervy Azerbaijan' genotypes, respectively. Likewise, this PGR combination provided the shortest time until bud break (approximately 6.5 days) and root emergence (approximately 10 days) in both genotypes. The highest number of shoots (4.78 per explant) and roots (3.96) was achieved in this medium in the 'Kashan' rose. Stem and root lengths, as well as stem and root fresh and dry weights, were also analyzed. In most measured traits, the lowest values were found in the PGRs-free control medium. Rooted plantlets were transferred to pots filled with perlite and peat moss in a 2:1 proportion and were acclimatized to ambient greenhouse conditions with a mean 90.12% survival rate. This research contributes significantly to our understanding of Damask rose propagation and has practical implications for the cosmetic and ornamental plant industries. By offering insights into the manipulation of regeneration processes, our study opens up new possibilities for the effective production of high-quality plant material.

Rutinosides-derived from Sarocladium strictum 6-O-α-rhamnosyl-β-glucosidase show enhanced anti-tumoral activity in pancreatic cancer cells

BackgroundLow targeting efficacy and high toxicity continue to be challenges in Oncology. A promising strategy is the glycosylation of chemotherapeutic agents to improve their pharmacodynamics and anti-tumoral activity. Herein, we provide evidence of a novel approach using diglycosidases from fungi of the Hypocreales order to obtain novel rutinose-conjugates therapeutic agents with enhanced anti-tumoral capacity.ResultsScreening for diglycosidase activity in twenty-eight strains of the genetically related genera Acremonium and Sarocladium identified 6-O-α-rhamnosyl-β-glucosidase (αRβG) of Sarocladium strictum DMic 093557 as candidate enzyme for our studies. Biochemically characterization shows that αRβG has the ability to transglycosylate bulky OH-acceptors, including bioactive compounds. Interestingly, rutinoside-derivatives of phloroglucinol (PR) resorcinol (RR) and 4-methylumbelliferone (4MUR) displayed higher growth inhibitory activity on pancreatic cancer cells than the respective aglycones without significant affecting normal pancreatic epithelial cells. PR exhibited the highest efficacy with an IC50 of 0.89 mM, followed by RR with an IC50 of 1.67 mM, and 4MUR with an IC50 of 2.4 mM, whereas the respective aglycones displayed higher IC50 values: 4.69 mM for phloroglucinol, 5.90 mM for resorcinol, and 4.8 mM for 4-methylumbelliferone. Further, glycoconjugates significantly sensitized pancreatic cancer cells to the standard of care chemotherapy agent gemcitabine.ConclusionsαRβG from S. strictum transglycosylate-based approach to synthesize rutinosides represents a suitable option to enhance the anti-proliferative effect of bioactive compounds. This finding opens up new possibilities for developing more effective therapies for pancreatic cancer and other solid malignancies.

Construction of a grpE-based plasmid addiction system in Escherichia coli and its application in phloroglucinol biosynthesis.

Biotechnical processes in Escherichia coli often operate with artificial plasmids. However, these bioprocesses frequently encounter plasmid loss. To ensure stable expression of heterologous genes in E. coli BL21(DE3), a novel plasmid addiction system (PAS) was developed. This PAS employed an essential gene grpE encoding a cochaperone in the DnaK-DnaJ-GrpE chaperone system as the selection marker, which represented a chromosomal ΔgrpE mutant harboring episomal expression plasmids that carry supplementary grpE alleles to restore the deficiency. To demonstrate the feasibility of this system, it was implemented in phloroglucinol (PG) biosynthesis, manifesting improved host tolerance to PG and increased PG production. Specifically, PG titer significantly improved from 0.78±0.02 to 1.34±0.04 g l-1, representing a 71.8% increase in shake-flask fermentation. In fed-batch fermentation, the titer increased from 3.71±0.11 to 4.54±0.10 g l-1, showing a 22.4% increase. RNA sequencing and transcriptome analysis revealed that the improvements were attributed to grpE overexpression and upregulation of various protective chaperones and the biotin acetyl-CoA carboxylase ligase coding gene birA. This novel PAS could be regarded as a typical example of nonanabolite- and nonmetabolite-related PAS. It effectively promoted plasmid maintenance in the host, improved tolerance to PG, and increased the titer of this compound.

Agrobacterium-Mediated Transformation of the Dwarf Soybean MiniMax.

This study aims to establish an Agrobacterium-mediated transformation system for use with the 'MiniMax'soybean cultivar. MiniMax is a mutant soybean whose growth cycle is around 90 days, half that of most other soybean varieties, making it an optimal model cultivar to test genes of interest before investing in modification of elite lines. We describe an efficient protocol for Agrobacterium-mediated transformation using MiniMax seeds. It uses a modified 'half seed' regeneration protocol for transgenic soybean production, utilizing the rapid generation MiniMax variety to obtain T1 seeds in approximately 145 days. Addition of phloroglucinol (PG) to the regeneration protocol was key to obtaining high-efficiency rooting of the regenerated shoots. Transfer to soil was accomplished using an organic soil amendment containing nutrients and mycorrhiza for plants to thrive in the greenhouse. This combination of genotype and stimulants provides a transformation protocol to genetically engineer MiniMax seeds with a transgenic lab-to-greenhouse production efficiency of 4.0%. This is the first report of MiniMax soybean whole plant transformation and heritable T1 transmission. This protocol provides an ideal resource for enhancing the genetic transformation of any soybean cultivar.

Chitosan hydrogels enriched with bioactive phloroglucinol for controlled drug diffusion and potential wound healing

We report a facile strategy to prepare chitosan (CS) hydrogels that eliminates the need for chemical crosslinking for advanced biomedical therapies. This approach gives controlled properties to the hydrogels by incorporating a natural bioactive phenolic compound, phloroglucinol (PG), into their microstructure. The adsorption of PG onto CS chains enhanced the hydrogels' antioxidant activity by up to 25 % and resulted in a denser, more entangled structure, reducing the pore size by 59 μm while maintaining porosity above 94 %. This allowed us to finely adjust pore size and swelling capacity. These structural properties make these hydrogels well-suited for wound healing dressings, promoting fibroblast proliferation and exhibiting excellent hemocompatibility. Furthermore, to ensure the versatility of these hydrogels, herein, we demonstrate their potential as drug delivery systems, particularly for dermal infections. The drug release can be controlled by a combination of drug diffusion through the swollen hydrogel and relaxation of the CS chains. In summary, our hydrogels leverage the synergistic effects of CS's antibacterial and antifungal properties with PG's antimicrobial and anti-inflammatory attributes, positioning them as promising candidates for biomedical and pharmaceutical applications, more specifically in advanced wound healing therapies with local drug delivery.

Phloroglucinol Enhances Anagen Signaling and Alleviates H2O2-Induced Oxidative Stress in Human Dermal Papilla Cells.

Phloroglucinol (PG) is one of the abundant isomeric benzenetriols in brown algae. Due to its polyphenolic structure, PG exhibits various biological activities. However, the impact of PG on anagen signaling and oxidative stress in human dermal papilla cells (HDPCs) is unknown. In this study, we investigated the therapeutic potential of PG for improving hair loss. A non-cytotoxic concentration of PG increased anagen-inductive genes and transcriptional activities of β-Catenin. Since several anagen-inductive genes are regulated by β-Catenin, further experiments were performed to elucidate the molecular mechanism by which PG upregulates anagen signaling. Various biochemical analyses revealed that PG upregulated β-Catenin signaling without affecting the expression of Wnt. In particular, PG elevated the phosphorylation of protein kinase B (AKT), leading to an increase in the inhibitory phosphorylation of glycogen synthase kinase 3 beta (GSK3β) at serine 9. Treatment with the selective phosphoinositide 3-kinase/AKT inhibitor, LY294002, restored the increased AKT/GSK3β/β-Catenin signaling and anagen-inductive proteins induced by PG. Moreover, conditioned medium from PG-treated HDPCs promoted the proliferation and migration of human epidermal keratinocytes via the AKT signaling pathway. Subsequently, we assessed the antioxidant activities of PG. PG ameliorated the elevated oxidative stress markers and improved the decreased anagen signaling in hydrogen peroxide (H2O2)-induced HDPCs. The senescence-associated β-galactosidase staining assay also demonstrated that the antioxidant abilities of PG effectively mitigated H2O2-induced senescence. Overall, these results indicate that PG potentially enhances anagen signaling and improves oxidative stress-induced cellular damage in HDPCs. Therefore, PG can be employed as a novel therapeutic component to ameliorate hair loss symptoms.

Synthesis and application of CoFe₂O₄@THAM@PHG‐SO₃H nanoparticles as a new and highly recyclable nanocatalyst in the one‐pot multicomponent synthesis of 3,4‐dihydropyranochromenes and chromeno[3,4‐b]quinoline‐6‐ones

In this study, we have developed a new environmentally‐friendly magnetic nanocatalyst by treating CoFe₂O₄ magnetic nanoparticles with chlorosulfonic acid, tris(hydroxymethyl)aminomethane (THAM), 1,2‐dichloroethane, and phloroglucinol (PHG). They confirmed the synthesis of the catalyst using various techniques such as FT‐IR, SEM, MAP, EDS, XRD, TGA, DTA, and VSM. The researchers then evaluated the catalytic efficiency of the nanocatalyst in two reactions: the synthesis of 3,4‐dihydropyranochromenes from the reaction among aromatic aldehydes, 4‐hydroxycoumarin, and malononitrile, and the synthesis of chromeno[3,4‐b]quinoline‐6‐ones from the reaction among aniline, 4‐hydroxycoumarin, and aromatic aldehydes.

Ex vitro rooting of micro-propagated intergeneric papaya through phloroglucinol

Micropropagation techniques of papaya have been optimized Worldwide. However, standard rapid multiplication technique of papaya at commercial level with economically viable is still lacking. Since establishment of in vitro culture pretty easy at the same time in vitro rooting of papaya is still difficult. However, in vitro rooting is costly and the roots initiated in vitro do not have lateral branches and root hairs, making them difficult to acclimatize. Hence ex vitro rooting induction of micro-propagated plantlets and acclimatization were conducted. In vitro cultures were established using shoot tips from seedlings of selected advanced intergeneric hybrid. They were inoculated onto Murashige and Skoog (MS) medium + 3% sucrose + 1 µM BAP + 1 µM GA3 + 0.1 µM IAA + 0.25% phytagel until plantlets were obtained. For ex vitro rooting, plantlets were cultured with various concentrations of phloroglucinol (PG) to investigate the appropriate condition of rooting. Direct rooting (82%) of papaya micro-cutting into potting medium (perlite + vermiculite + coco peat; in the ratio of 1:1:2) subsequent dipping into phloroglucinol was more effective than in vitro rooting and led to amended survival percentage (82%) of micro-cutting during acclimatization. PG at 1000 µM was extra effectual than IBA in encouraging root development. Sachet method was found to be the best appropriate for ex vitro rooting and hardening of papaya with single-step acclimatization.

Treatment of Staphylococcus aureus and Candida albicans polymicrobial biofilms by phloroglucinol-gold nanoparticles

The co-isolation of Staphylococcus aureus and Candida albicans from host tissues and organs and their in vitro and in vivo interaction studies suggest a synergistic relationship in forming polymicrobial biofilms. In particular, during polymicrobial biofilm formation, S. aureus becomes coated in the extracellular matrix secreted by C. albicans, leading to enhanced resistance to antibiotics. Accordingly, understanding the interactions between S. aureus and C. albicans in polymicrobial biofilms is of utmost importance in establishing treatment strategies for polymicrobial infections. As an alternate technique, nanoparticles were used in this investigation to suppress polymicrobial biofilm. The current study aims to manufacture gold nanoparticles (AuNPs) using phloroglucinol (PG), a natural chemical, and test their inhibitory capabilities against S. aureus and C. albicans biofilms in standard and host-mimicking media (like saliva and sputum). PG-AuNPs have a spherical form with an average size of 46.71 ± 6.40 nm. The minimum inhibitory concentration (MIC) values differed when PG-AuNPs were evaluated in the standard and host-mimicking artificial media. The MIC of PG-AuNPs against S. aureus and C. albicans was 2048 μg/mL in both the standard and artificial sputum media. However, the MIC in saliva was only 128 μg/mL. The initial stage polymicrobial biofilm of S. aureus and C. albicans was dramatically decreased at the sub-MIC of PG-AuNPs in both standard and host-mimicking media. S. aureus and C. albicans mature polymicrobial biofilms were more effectively eliminated by MIC and sub-MIC of PG-AuNPs. This study indicates that PG-AuNPs have the ability to limit the formation of polymicrobial biofilms caused by bacterial and fungal diseases.

Anti-skin glycation and collagen level stimulation of brown seaweed extracts and their compositional characteristics

This study aimed to investigate anti-skin aging potential of the extracts from three Southern Australian brown seaweeds: Ecklonia radiata (ER), Cystophora moniliformis (CM), and Cystophora siliquosa (CS). These extracts and two positive controls (Aminoguanidine (AG), a drug candidate for anti-glycation, and phloroglucinol (PG)) were tested for their inhibition of glycation reaction using in vitro non-cellular bovine serum albumin (BSA)-glucose and methylglyoxal (MGO) models. The safe doses were also established by toxicity test with human skin fibroblast cell by MTT assay. Among three extracts studied, ER showed the highest toxic, but far less than both positive controls. The CM and CS extracts at 500 μg/mL showed inhibition of glycation activity, approximately 65–90 % compared to AG (15–40 %) and PG (15–20 %) at 20 μg/mL. In addition, the stimulation of collagen and elastin levels using an in vitro cell-based assay was evaluated. Relative to the control (water without samples), the CM and CS extracts at concentration greater than or equal to 250 μg/mL significantly increased the collagen levels of human skin fibroblast cells up to ∼16.5 folds, while there was no significant increase in elastin levels by most seaweed extracts. Furthermore, compositions of all extracts were characterized. Apart from high polysaccharide contents, phlorotannin which accounts for 17–23 % of CM and CS might be responsible for their anti-skin aging benefits. These findings demonstrate that the brown seaweed extracts CM and CS have high potential to be used as skin anti-aging supplements with anti-glycation and collagen stimulation benefits, worthy of further in vivo studies.

In vitro propagation of oil-bearing Rosa damascena using phloroglucinol: A protocol for rapid and high-quality shoot multiplication and rooting

Damask rose (Rosa damascena Mill.), of the family Rosaceae, is an important ornamental-medicinal, essential oil-bearing species. Due to its economic value, the aim of this study was to establish a new protocol for the in vitro propagation of R. damascena ‘Isfahan' using phloroglucinol. Axillary bud explants, Murashige and Skoog (MS) medium, and combinations of various plant growth regulators (PGRs) were used for the development of an effective method for rapid and high-quality shoot multiplication and in vitro rooting of Damask rose ‘Isfahan’. In the establishment step, 0.1 mg·L–1 phloroglucinol (PG), 0.2 mg·L–1 gibberellic acid (GA3), 0.1 mg·L–1 indole-3-butyric acid (IBA) and 1 mg·L–1 6-benzylaminopurine (BAP) were used. Secondary explants (nodal segments containing an axillary bud), obtained after 30 days of culture, were transferred to the proliferation media enriched with different concentrations of PG (0, 0.1, 0.2 and 0.3 mg·L–1), BAP (0, 1, 2 and 3 mg·L–1) and IBA (0, 0.1, 0.2 and 0.3 mg·L–1). A total of 64 combinations of these PGRs were investigated as a factorial experiment on the basis of a completely randomized design. Results showed that the shortest time until bud break (4.3 days), the highest number of green leaves (13.3) and lowest number of yellow leaves (1.3) were obtained in the explants grown on the medium containing 0.3 mg·L–1 PG + 2 mg·L–1 BAP + 0.2 mg·L–1 IBA. The largest number of shoots (4.8), and the highest fresh (5.9 g) and dry (1.2 g) weight of roots per explant were produced in the medium supplemented with 0.2 mg·L–1 PG + 2 mg·L–1 BAP + 0.3 mg·L–1 IBA. The highest regeneration coefficient (2.53), stem length (6.47 cm), fresh (2.32 g) and dry (0.51 g) weight of stem were obtained in the medium with 0.2 mg·L–1 PG + 2 mg·L–1 BAP + 0.2 mg·L–1 IBA. On the other hand, the highest number of roots (4.7) per explant were produced in the media supplemented with 0.3 mg·L–1 PG + 2 mg·L–1 BAP + 0.3 mg·L–1 IBA. None of the shoots regenerated roots in the absence of IBA. In most measured traits, the lowest values of the measured traits were obtained in the control medium without PGRs. Rooted plantlets were transferred to pots containing perlite and peat moss in 2:1 proportion and acclimatized in a greenhouse with a mean 82% survival rate. The positive role of PG in micropropagation was confirmed. The obtained results are more efficient than the previously established ones. Therefore, this cost-effective protocol can be used for the in vitro mass propagation of R. damascena Mill.

Theoretical calculation guided molecularly imprinted polymer for selective adsorption of phloroglucinol

Effective adsorption of phloroglucinol (PG) is a method that kills two birds with one stone, which can not only reduce the harm of phenolic wastewater to the environment but also bring considerable economic benefits. In this work, the optimal functional monomer N-Vinyl imidazole (VIM) that possesses the strongest affinity with PG among 11 phenolic monomers was quantitatively selected by DFT calculation. The key factors that influence the adsorption capacity (Qe) and imprinting effect (α) were systematically researched. And the physicochemical property and morphology of the obtained VIM-MIP with the best adsorption performance were explored by a series of characterization methods. The adsorption tests were carried out, indicating that the VIM-MIP exhibited a large adsorption capability (Qe = 81.34 mg/g), which exceeded 78.97 % of the existing optimal absorbents for PG. What’s more, the adsorption data for PG fit in with the Freundlich model (R2 > 0.99). More notably, the excellent PG selectivity of the VIM-MIP was confirmed by competitive adsorption experiments under binary systems (relative selectivity coefficient, 2.014), which was attributed to the existence of imprinted cavities. The molecular simulation, X-ray photoelectron spectroscopy (XPS) analysis, and Zeta potential analysis were employed to reveal the adsorption mechanism, indicating the hydrogen bond was the main driving force.

Investigation of the dual role of acyl phloroglucinols as a new hope for antibacterial and anti-SARS-CoV-2 agents employing integrated in vitro and multi-phase in silico approaches

With the rapid spread of multi-drug-resistant bacteria and more infectious or aggressive variants of SARS-CoV-2, it is critical to develop drugs that can quickly adapt to evolving bacterial and viral mutations. In this study, encouraged by nature, we synthesized a series of phloroglucinol (PG) derivatives, acyl phloroglucinols (ACPLs) 2a-4c by mimicking the structure of the natural antifungal 2,4-diacetylphloroglucinol 3a (2,4-DAPG). According to the quantum chemical calculation, these compounds were expected to be exceptionally favourable for intermolecular interaction with protein receptors. Intriguingly, the in vitro study of Staphylococcus aureus (S. aureus) ATCC 25923 and Escherichia coli (E. coli) ATCC 25922, showed that the four ACPLs 3a–4a had good antibacterial activity and selectivity against gram-positive bacteria, S. aureus. These results were then supported by in silico molecular docking and molecular dynamics simulations (MDs) between these potent compounds and the S. aureus FtsA protein (PDB ID: 3WQU). Furthermore, with the aid of the knowledge base Virus-CKB along with the molecular docking study, it was found that the three ACPLs 4a–4c showed potential inhibitors against SARS-CoV-2 PLpro (PDB ID: 7CMD). Additionally, 100 ns of MDs was carried out in order to assess the stability behaviour of ACPLs at the docked site. Moreover, in silico ADME/T and drug likeness of all studied ACPLs were also predicted. Finally, shape-based screening of FDA-approved drugs was performed using the most prominent synthesized ACPLs as a template, enabling us to include several medications that could be utilized as antibacterial and antiviral drug candidates. Communicated by Ramaswamy H. Sarma

Biomass derived carbon quantum dots embedded PEDOT/CFP electrode for the electrochemical detection of phloroglucinol

Carbon nanocomposites have garnered a lot of attention among various nanomaterials due to their distinct characteristics, such as large surface area, biocompatibility, and concise synthetic routes. They are also a viable contender for electrochemical applications, notably sensing, due to their intriguing electrochemical features, which include large electroactive surface area, outstanding electrical conductivity, electrocatalytic activity, and high porosity and adsorption capability. Herein, an electrochemical sensor for phloroglucinol (PL) was designed using a CFP electrode modified with biomass-derived carbon quantum dots (S-CQD) doped on conducting organic polymer poly(3,4-ethylene dioxythiophene) (PEDOT) via electrodeposition method. The obtained nanocomposite (S-CQD+PEDOT) on the CFP electrode possesses a high surface area. The higher electrocatalytic activity of S-CQD and significant conductivity of PEDOT- modified electrode enhance the electrocatalytic activity for the phloroglucinol oxidation. The oxidation peak current of PL shows a higher response on the finally modified electrode than the other electrodes. The developed electrochemical sensor for the selective and sensitive detection of PL showed a good linear range of 36 -360 nM and a detection limit of 11 nM. The modified electrodes were characterized using Transmission electron spectroscopy (TEM), Fourier Transform infrared spectroscopy (FT-IR), and X-ray photon spectroscopy (XPS). Finally, the developed method was successfully used to detect Phloroglucinol from industrial effluents with RSD (0.84–1.02%) and (98.5–101.2%) of recovery.