Bio-Guided Isolation of Methanol-Soluble Metabolites of Common Spruce (Picea abies) Bark by-Products and Investigation of Their Dermo-Cosmetic Properties

Chemical profiling of botanical extracts obtained in NADES systems using centrifugal partition chromatography combined with 13 C NMR dereplication-Hypericum perforatum as a case study

INTRODUCTION

Natural deep eutectic solvents (NADES) have emerged as interesting extractants to develop botanical ingredients. They are nontoxic and biodegradable, nonflammable, easy to prepare, and able to solubilize a wide range of molecules. However, NADES extracts remain difficult to analyze because the metabolites of interest stay highly diluted in the nonvolatile viscous NADES matrix.

OBJECTIVE

This study presents a robust analytical workflow for the chemical profiling of NADES extracts. It is applied to Hypericum perforatum aerial parts extracted with the neutral mixture fructose/glycerol/water (3/1/1, w/w/w), and compared to the chemical profiling of a classical dry methanol extract.

METHODS

Exploiting polarity differences between metabolites, the H. perforatum NADES extract was partitioned in a liquid-liquid solvent system to trap the hydrophilic NADES constituents in the lower phase. The upper phase, containing a diversity of secondary metabolites from H. perforatum, was fractionated by centrifugal partition chromatography. All fractions were chemically investigated using a 13 C NMR dereplication method which involves hierarchical clustering analysis of the whole NMR dataset, a natural metabolite database for metabolite identification, and 2D NMR analyses for validation. Liquid chromatography-mass spectrometry (LC-MS) analyses were also performed to complete the identification process.

RESULTS

A range of 21 metabolites were unambiguously identified, including glycosylated flavonols, lactones, catechins, phenolic acids, lipids, and simple sugars, and 15 additional minor extract constituents were annotated by LC-MS based on exact mass measurements.

CONCLUSION

The proposed identification process is rapid and nondestructive and provides good prospects to deeply characterize botanical extracts obtained in nonvolatile and viscous NADES systems.

Rapid Chemical Profiling of Filipendula ulmaria Using CPC Fractionation, 2-D Mapping of 13C NMR Data, and High-Resolution LC-MS

Filipendula ulmaria, commonly known as meadowsweet, is a wild herbaceous flowering plant that is widely distributed in Europe. A range of salicylic acid derivatives and flavonol glycosides have been previously associated with the antirheumatic and diuretic properties of F. ulmaria. In the present work, a hydroalcoholic extract from F. ulmaria aerial parts was extensively profiled using an efficient NMR-based dereplication strategy. The approach involves the fractionation of the crude extract by centrifugal partition chromatography (CPC), 13C NMR analysis of the fractions, 2D-cluster mapping of the entire NMR dataset, and, finally, structure elucidation using a natural metabolite database, validated by 2D NMR data interpretation and liquid chromatography coupled with mass spectrometry. The chemodiversity of the aerial parts was extensive, with 28 compounds unambiguously identified, spanning various biosynthetic classes. The F. ulmaria extract and CPC fractions were screened for their potential to enhance skin epidermal barrier function and skin renewal properties using in vitro assays performed on Normal Human Epidermal Keratinocytes. Fractions containing quercetin, kaempferol glycosides, ursolic acid, pomolic acid, naringenin, β-sitosterol, and Tellimagrandins I and II were found to upregulate genes related to skin barrier function, epidermal renewal, and stress responses. This research is significant as it could provide a natural solution for improving hydration and skin renewal properties.

Tanshinone-I for the treatment of uterine fibroids: Molecular docking, simulation, and density functional theory investigations

Uterine fibroids (UF), most prevalent gynecological disorder, require surgery when symptomatic. It is estimated that between 25 and 35 percent of women wait until the symptoms have worsened like extended heavy menstrual bleeding and severe pelvic pain. These UF may be reduced in size through various methods such as medical or surgical intervention. Progesterone (prog) is a crucial hormone that restores the endometrium and controls uterine function. In the current study, 28 plant-based molecules are identified from previous literature and docked onto the prog receptors with 1E3K and 2OVH. Tanshinone-I has shown the best docking score against both proteins. The synthetic prog inhibitor Norethindrone Acetate is used as a standard to evaluate the docking outcomes. The best compound, tanshinone-I, was analyzed using molecular modeling and DFT. The RMSD for the 1E3K protein-ligand complex ranged from 0.10 to 0.42 Å, with an average of 0.21 Å and a standard deviation (SD) of 0.06, while the RMSD for the 2OVH protein-ligand complex ranged from 0.08 to 0.42 Å, with an average of 0.20 Å and a SD of 0.06 showing stable interaction. In principal component analysis, the observed eigen values of HPR-Tanshinone-I fluctuate between -1.11 to 1.48 and -1.07 to 1.25 for PC1 and PC2, respectively (1E3K), and the prog-tanshinone-I complex shows eigen values of -38.88 to -31.32 and -31.32 to 35.87 for PC1 and PC2, respectively (2OVH), which shows Tanshinone-I forms a stable protein-ligand complex with 1E3K in comparison to 2OVH. The Free Energy Landscape (FEL) analysis shows the Gibbs free energy in the range of 0 to 8 kJ/mol for Tanshinone-I with 1E3K and 0 to 14 kJ/mol for Tanshinone-I with the 2OVH complex. The DFT calculation reveals ΔE value of 2.8070 eV shows tanshinone-I as a stable compound. 1E3K modulates the prog pathway, it may have either an agonistic or antagonistic effect on hPRs. Tanshinone-I can cause ROS, apoptosis, autophagy (p62 accumulation), up-regulation of inositol requiring protein-1, enhancer-binding protein homologous protein, p-c-Jun N-terminal kinase (p-JNK), and suppression of MMPs. Bcl-2 expression can change LC3I to LC3II and cause apoptosis through Beclin-1 expression.

Antioxidative and Antimicrobial Evaluation of Bark Extracts from Common European Trees in Light of Dermal Applications

Plant species have developed effective defense strategies for colonizing diverse habitats and protecting themselves from numerous attacks from a wide range of organisms, including insects, vertebrates, fungi, and bacteria. The bark of trees in particular constitutes a number of components that protect against unwanted intruders. This review focuses on the antioxidative, dermal immunomodulatory, and antimicrobial properties of bark extracts from European common temperate trees in light of various skin pathogens, wound healing, and the maintenance of skin health. The sustainability aspect, achieved by utilizing the bark, which is considered a byproduct in the forest industry, is addressed, as are various extraction methods applied to retrieve extracts from bark.

Screening and Evaluation of Dermo-Cosmetic Activities of the Invasive Plant Species Polygonum cuspidatum

Polygonum cuspidatum (P. cuspidatum) is among the world's most problematic invasive plant species with negative ecological, socio-economic and security consequences. Management operations in areas invaded systematically generate a large quantity of plant waste, most often without outlets. Using this plant material could constitute a new alternative treatment for sustainable management. P. cuspidatum is well known to have numerous biological properties, containing notably stilbenes, quinones, flavonoids and phenolic acids. The present work proposes a reliable strategy using powerful techniques for the screening and the evaluation of the dermo-cosmetic potential of its aerial parts (AP) and root parts (RP). To the best of our knowledge, only antioxidant and anti-tyrosinase activities were previously evaluated on P. cuspidatum among the targets studied (superoxide dismutase, hyaluronidase, elastase, collagenase and tyrosinase). The results revealed strong antioxidant and anti-collagenase activities, moderate anti-hyaluronidase activity, while weak anti-elastase and anti-tyrosinase activities were observed for ethanolic extracts. Different standards selected and screened on the same targets made it possible to correlate the observed residual activities of produced extracts of P. cuspidatum from Savoie Mont Blanc and their chemical compositions. A structure-activity study was thus conducted on main molecular families, widely represented in the genus Polygonum.

In Vitro and In Silico Evaluations of Boswellia carterii Resin Dermocosmetic Activities

Boswellia carterii is a plant species belonging to the Burseraceae family. It grows up in trees or shrubs, and it is known for producing an aromatic resin commonly named frankincense or olibanum. This resin has been used in traditional medicine to treat various conditions such as inflammations, gastrointestinal disorders and traumatic injuries. Virtual screening and molecular docking are two in silico approaches used to predict potential interactions between ligands and the active site of a protein. These approaches are mainly used in natural product chemistry and pharmacology as a screening tool to select plant extracts or fractions for in vitro testing, as well as for the prediction of mechanisms of action. The aim of this research is the in silico and in vitro evaluations of the potential collagenase and elastase inhibitory activities of Boswellia carterii resin organic extracts (viz., methanol, n-hexane and ethyl acetate). The obtained results revealed that methanol and n-hexane exhibited the best collagenase inhibitory activity with values superior to 85%, whereas the methanol and ethyl acetate showed the highest elastase inhibition activity with inhibition values ranging between 40 and 60%. The molecular docking prediction confirmed the experimental results; moreover, the visualization of the ligand–protein interactions showed that the main compounds of the organic extracts may have mechanisms of action similar to the positive controls. Those findings are very promising and open new perspectives for the exploitation of Boswellia carterii resin as active agents for the development of anti-aging cosmeceuticals.

"Smart Extraction Chain" with Green Solvents: Extraction of Bioactive Compounds from Picea abies Bark Waste for Pharmaceutical, Nutraceutical and Cosmetic Uses

Secondary metabolites from the sawmill waste Picea abies bark were extracted using an innovative two-step extraction that includes a first step with supercritical CO₂ (SCO₂) and a second step using green solvents, namely ethanol, water, and water ethanol mixture. Maceration (M), ultrasound assisted extraction (UAE) and microwave assisted extraction (MAE) techniques were applied in the second step. A total of nineteen extract were obtained and yield were compared. Bark extracts were characterized by LC-DAD-MSⁿ and classes of compounds were quantified as abietane derivatives, piceasides, flavonoids, and phenolics to compare different extractions. Obtained extracts were studied by in vitro assay to evaluate potential pharmaceutical, nutraceutical and cosmetic uses assessing the antioxidant activity as well as the inhibitory activity on target enzymes. Results show that the “smart extraction chain” is advantageous in term of yield of extraction and phytoconstituent concentration. SCO₂ extract, presenting a unique composition with a large amount of abietane derivatives, exerted the best activity for amylase inhibition compared to the other extracts.

Phytochemical Screening, and In Vitro Evaluation of the Antioxidant and Dermocosmetic Activities of Four Moroccan Plants: Halimium antiatlanticum, Adenocarpus artemisiifolius, Pistacia lentiscus and Leonotis nepetifolia

In this study, four Moroccan plants, Halimium antiatlanticum, Adenocarpus artemisiifolius, Pistacia lentiscus and Leonotis nepetifolia, were evaluated for their phytoconstituents and biological activities. Methanolic extracts of these plants were obtained by Soxhlet apparatus, phytochemical screening was performed, and the total phenolic and flavonoid contents were determined. Then, the antioxidant and dermocosmetic activities of the methanolic extracts were evaluated. The obtained results revealed that the leaves and/or aerial parts contained tannins, polyphenols, flavonoids, coumarins, carotenoids, terpenoids and saponins. The higher total phenolic content values were recorded on Pistacia lentiscus and Halimium antiatlanticum with 396.64 ± 30.79 and 304.96 ± 55.61 mgGAE/gDW, respectively. The antioxidant activity was measured by DPPH, ABTS and FRAP assays, and showed that Pistacia lentiscus and Halimium antiatlanticum were the most active extracts, with, respectively, IC50 values of 3.705 ± 0.445 and 5.037 ± 0.122 µg/mL for DPPH. The same results were observed for the FRAP and ABTS assays. Those extracts also showed a strong collagenase inhibitory activity at 200 µg/mL, with 78.51 ± 2.27% for Pistacia lentiscus and 73.10 ± 8.52% for Halimium antiatlanticum. Adenocarpus artemisiifolius showed the highest elastase inhibition rate, with 76.30 ± 5.29%. This study disclosed the dermocosmetic potential of Halimium antiatlanticum and Adenocarpus artemisiifolius, two Moroccan endemic plants that can be traditionally used by local populations or exploited by the cosmetic industry.

Deciphering the Phytochemical Profile of an Alpine Rose (Rhododendron ferrugineum L.) Leaf Extract for a Better Understanding of Its Senolytic and Skin-Rejuvenation Effects

Rhododendron ferrugineum, commonly named Alpine rose, is an emblematic medicinal plant of European mountains. In this study, the chemical profile of a glycerol/water extract developed from this plant as a cosmetic ingredient is investigated to understand the extract constituent(s) that could mostly contribute to its senolytic activity and skin-rejuvenation effects. For this purpose, the dereplication method “CARAMEL”, which combines Centrifugal Partition Chromatography to Nuclear Magnetic Resonance data interpretation, was directly applied to the hydro-glycerinated extract, leading to the unambiguous identification of fourteen Alpine rose metabolites, despite the strong presence of the heavy solvent glycerol. Flavonoids derived from taxifolin, quercetin, and (+)-catechin were identified as significant constituents of the extract, followed by flavanones, orcinol derivatives, phloroacetophenone, and phenolic acids, as well as the pentacyclic triterpene lupeol. Given that senolytic molecules are known to selectively induce the death of senescent cells without affecting healthy proliferating cells, which can be achieved by the selective inhibition or downregulation of the anti-apoptotic Bcl-2 protein, and considering the well-recognized pro-apoptotic activity of hyperoside, taxifolin, naringenin and farrerol, the senolytic activity of the glycerol/water Alpine rose extract can be explained by the abundance of flavonoids present in the extract.

Molecular Docking, Tyrosinase, Collagenase, and Elastase Inhibition Activities of Argan By-Products

The argan tree (Argania spinosa (L.) Skeels) is one of the most important floristic resources in Morocco. This Moroccan endemic tree is known for its numerous therapeutic and medicinal uses. In addition to some medicinal and cosmetic uses, argan fruit pulp and press cake are traditionally used by the Berber population for heating and feeding livestock. Molecular docking is an in silico approach that predicts the interaction between a ligand and a protein. This approach is mainly used in chemistry and pharmacology of natural products as a prediction tool with the purpose of selecting plant extracts or fractions for in vitro tests. The aim of this research is to study the evaluation of potential tyrosinase, collagenase, and elastase inhibitory activities of argan fruit press-cake and pulp extracts. Extracts were evaluated for their total phenolic content (TPC), and the major polyphenols of both press-cake and pulp extracts were submitted to molecular docking in order to determine the mechanisms of action of these compounds. Obtained results revealed that fruit pulp had the strongest dermocosmetic activities, as well as the highest TPC, with values above 55 mg gallic-acid equivalent per gram of dry matter (mgeq AG/gDM). Moreover, those results were positively correlated with the docking findings, suggesting that the pulp lead compounds have higher affinity with tyrosinase, collagenase, and elastase action sites. The results here presented are very promising and open new perspectives for the exploitation of argan-tree by-products as cosmetic agents towards the development of new anti-aging products.

Wound healing potential of quercetin-3-O-rhamnoside and myricetin-3-O-rhamnoside isolated from Pistacia lentiscus distilled leaves in rats model

The development of bioproducts able to accelerate wound healing is an important topic in biomedicine. In the current study, Pistacia lentiscus distilled leaves (PDL) extract and its two isolated glycosylated flavonoids, myricetin-3-O-rhamnoside (MM) and quercetin-3-O-rhamnoside (QM), were evaluated for their wound healing activity, including evaluation of wound closure, revascularization, wound re-epithelialization, fibroblast proliferation, and collagen deposition on rat skin samples. Moreover, hydroxyproline content, C-reactive protein (CRP) level, and immunohistochemistry study were evaluated on blood and tissues collected from rats on day 14 post-wounding. Results showed that the topical application of PDL (at a concentration of 20 mg/ml) (PDL 20), MM, and QM increased wound healing and decreased inflammatory cells infiltration compared to the negative control group. Moreover, the cutaneous wound tissues treated with PDL 20, MM, and QM exhibited significantly higher hydroxyproline content than the negative control group, which means a high collagen biosynthesis in wound tissues. Indeed, the level of the inflammatory protein CRP is significantly lower in groups treated with MM and QM than in the negative control group. Also, the expression of the pro-inflammatory factor TNF-α and the angiogenesis marker CD-31 in PDL 20, MM, and QM treated groups is lower than in the negative control group. Moreover, MM, and QM induced a good elastase inhibition at 100 µg/ml compared to the standard epigallocatechin gallate. Therefore, PDL 20, MM, and QM could be used as effective cutaneous wound healing agents.

Pistacia lentiscus L. Distilled Leaves as a Potential Cosmeceutical Ingredient: Phytochemical Characterization, Transdermal Diffusion, and Anti-Elastase and Anti-Tyrosinase Activities

The present work was performed to investigate the phenolic composition of P. lentiscus L. distilled leaves (PDL) and examine its potential against certain key enzymes related to skin aging. High-pressure liquid chromatography coupled to mass spectrometry (HPLC-MS) and various separation procedures combined with nuclear magnetic resonance (NMR) and MS analysis were performed to isolate and identify compounds present in the ethyl acetate extract (EAE) of PDL. A high amount of flavonol glycoside was detected in EAE. Indeed, quercetin-3-O-rhamnoside (FC), myricetin-3-O-rhamnoside (FM2), and kaempferol-3-O-rhamnoside (FB2) were isolated from EAE, and are present in high quantities of 10.47 ± 0.26, 12.17 ± 0.74, and 4.53 ± 0.59 mg/g dry weight, respectively. A transdermal diffusion study was carried out to determine the EAE-molecules that may transmit the cutaneous barrier and showed that FM2 transmits the membrane barrier with a high amount followed by FC. EAE, FM2, and FC were tested against tyrosinase and elastase enzymes. Moreover, intracellular tyrosinase inhibition and cytotoxicity on skin melanoma cells (B16) were evaluated. The results indicated that EAE, FC, and FM2 have important inhibitory activities compared to the well-known standards, at non-cytotoxic concentrations. Therefore, they could be excellent agents for treating skin pigmentation and elasticity problems.

Characterization and Evaluation of Antioxidant and Anti-Inflammatory Activities of Flavonoids from the Fruits of Lycium barbarum

The fruits of Lycium barbarum are rich in flavonoids, which may contribute to the health-promoting function of Lycium barbarum. However, the composition of flavonoids in the fruits of Lycium barbarum (LBFs) has received little attention. Thus, the goal of this work was to identify more kinds of flavonoids from fruits of Lycium barbarum by liquid chromatography–mass spectrometry. The potential antioxidant and anti-inflammatory activities of LBFs in vitro were also investigated. Thirteen flavonoid compounds were identified in LBFs, of which daphnetin, 6,7-dihydroxycoumarin, astragalin, taxifolin, eriodictyol, naringenin, and chrysoeriol were identified for the first time in the fruits of Lycium barbarum, which greatly enriched the variety of flavonoids in the fruits of Lycium barbarum. LBFs showed a similar superior antioxidant activity to vitamin C. Furthermore, LBFs exhibited an anti-inflammatory activity by suppressing the production of nitric oxide and pro-inflammatory cytokines, including tumor necrosis factor-alpha, interleukin-1β, and interleukin-6, in lipopolysaccharide-treated RAW264.7 macrophage cells. This study demonstrated the potential development of LBFs as functional foods.

The Bark of Picea abies L., a Waste from Sawmill, as a Source of Valuable Compounds: Phytochemical Investigations and Isolation of a Novel Pimarane and a Stilbene Derivative

In this work, the sawmill waste from Picea abies debarking was considered as source of valuable phytoconstituents. The extraction was performed using different ethanol/water mixtures, and characterization was obtained by LC-MSⁿ. This latter revealed flavonoid glycosides, lignans, and procyanidins. Extraction with organic solvents (dichloromethane and methanol) and chromatographic separations of the obtained extracts by silica column followed by semi-preparative HPLC led to the isolation of polyphenols and terpenoids such as 21α-metoxy-serrat-14-en-3-one, 21α-hydroxy-serrat-14-en-3-one, pinoresinol, dehydroabietic acid, 15-hydroxy-dehydroabietic acid, 7-oxo-dehydroabietic acid, pimaric acid, 9β-pimara-7,15-dien-19-ol, 13-epi-manoyl oxide, taxifolin-3'-O-glucopyranoside, trans-astringin, and piceasides. Piceaside V and 9β-pimara-7-keto-19β-olide, two novel compounds identified for the first time in P. abies bark, were isolated, and their structures were elucidated using 1D and 2D NMR and MS techniques. The polyphenolic composition of the methanolic portion was also investigated using LC-MSⁿ, and the piceaside content was estimated. To assess the antioxidant activity of main constituents, semi-preparative HPLC was performed on the methanolic extract, and the obtained fractions were assayed by using the DPPH test. Overall, this work shows the potential usefulness of P. abies bark as a source of valuable phytochemicals.

Advantages of Hyaluronic Acid and Its Combination with Other Bioactive Ingredients in Cosmeceuticals

This study proposes a review on hyaluronic acid (HA) known as hyaluronan or hyaluronate and its derivates and their application in cosmetic formulations. HA is a glycosaminoglycan constituted from two disaccharides (N-acetylglucosamine and D-glucuronic acid), isolated initially from the vitreous humour of the eye, and subsequently discovered in different tissues or fluids (especially in the articular cartilage and the synovial fluid). It is ubiquitous in vertebrates, including humans, and it is involved in diverse biological processes, such as cell differentiation, embryological development, inflammation, wound healing, etc. HA has many qualities that recommend it over other substances used in skin regeneration, with moisturizing and anti-ageing effects. HA molecular weight influences its penetration into the skin and its biological activity. Considering that, nowadays, hyaluronic acid has a wide use and a multitude of applications (in ophthalmology, arthrology, pneumology, rhinology, aesthetic medicine, oncology, nutrition, and cosmetics), the present study describes the main aspects related to its use in cosmetology. The biological effect of HA on the skin level and its potential adverse effects are discussed. Some available cosmetic products containing HA have been identified from the brand portfolio of most known manufacturers and their composition was evaluated. Further, additional biological effects due to the other active ingredients (plant extracts, vitamins, amino acids, peptides, proteins, saccharides, probiotics, etc.) are presented, as well as a description of their possible toxic effects.

Antimelanogenesis Effects of Leaf Extract and Phytochemicals from Ceylon Olive (Elaeocarpus serratus) in Zebrafish Model

The melanogenesis inhibition effect in zebrafish (Danio rerio) and antityrosinase activity of the ethanolic extract and its phytochemicals from Ceylon olive (Elaeocarpus serratus Linn.) leaves were investigated in this study. Among the leaf extract and four soluble fractions, the ethyl acetate soluble fraction exhibits the best antityrosinase and antimelanogenesis activities. One phenolic acid, gallic acid, and two flavonoids, myricetin and mearnsetin, are isolated from the active subfractions through the bioassay-guided isolation; their structures are elucidated based on the 1D and 2D NMR, FTIR, UV, and MS spectroscopic analyses. These compounds have significant antityrosinase activity whether using l-tyrosine or l-DOPA as the substrate; mearnsetin shows the optimal activity. In the enzyme kinetic investigation, both gallic acid and mearnsetin are the competitive-type inhibitors against mushroom tyrosinase, and myricetin acts as a mixed-type tyrosinase inhibitor. Leaf extract and an ethyl acetate soluble fraction show effective performance in the inhibition of melanin formation in zebrafish embryos. Mearnsetin also possesses a promising antimelanogenesis effect, which is superior to the positive control, arbutin. Results reveal that the Ceylon olive leaf extract and its phytochemicals, especially mearnsetin, have the potential to be used as antimelanogenesis and skin-whitening ingredients.

Taxifolin, an Inhibitor of Sortase A, Interferes With the Adhesion of Methicillin-Resistant Staphylococcal aureus

The evolution and spread of methicillin-resistant Staphylococcus aureus (MRSA) poses a significant hidden risk to human public health. The majority of antibiotics used clinically have become mostly ineffective, and so the development of novel anti-infection strategies is urgently required. Since Staphylococcus aureus (S. aureus) cysteine transpeptidase sortase A (SrtA) mediates the surface-anchoring of proteins to its surface, compounds that inhibit SrtA are considered potential antivirulence treatments. Herein, we report on the efficacy of the potent SrtA inhibitor taxifolin (Tax), a flavonoid compound isolated from Chinese herbs. It was able to reversibly block the activity of SrtA with an IC₅₀ of 24.53 ± 0.42 μM. Tax did not display toxicity toward mammalian cells or S. aureus at a concentration of 200 μM. In addition, Tax attenuated the virulence-related phenotype of SrtA in vitro by decreasing the adherence of S. aureus, reducing the formation of a biofilm, and anchoring of S. aureus protein A on its cell wall. The mechanism of the SrtA-Tax interaction was determined using a localized surface plasmon resonance assay. Subsequent mechanistic studies confirmed that Asp-170 and Gln-172 were the principal sites on SrtA with which it binds to Tax. Importantly, in vivo experiments demonstrated that Tax protects mice against pneumonia induced by lethal doses of MRSA, significantly improving their survival rate and reducing the number of viable S. aureus in the lung tissue. The present study indicates that Tax is a useful pioneer compound for the development of novel agents against S. aureus infections.

Isolation of Volatile Compounds with Repellent Properties against Aedes albopictus (Diptera: Culicidae) Using CPC Technology

The present work describes the use of Centrifugal Partition Chromatography (CPC) for the bio-guided isolation of repellent active volatile compounds from essential oils. Five essential oils (EOs) obtained from three Pinus and two Juniperus species were initially analyzed by gas chromatography–mass spectrometry (GC/MS) and evaluated for their repellent properties against Aedes albopictus. The essential oil from needles of P. pinea (PPI) presented the higher activity, showing 82.4% repellency at a dose of 0.2 μL/cm². The above EO, together with the EO from the fruits of J. oxycedrus subsp. deltoides (JOX), were further analyzed by CPC using the biphasic system n-Heptane/ACN/BuOH in ratio 1.6/1.6/0.2 (v/v/v). The analysis of PPI essential oil resulted in the recovery of (−)-limonene, guaiol and simple mixtures of (−)-limonene/β-pheladrene, while the fractionation of JOX EO led to the recovery of β-myrcene, germacrene-D, and mixtures of α-pinene/β-pinene (ratio 70/30) and α-pinene/germacrene D (ratio 65/45). All isolated compounds and recovered mixtures were tested for their repellent activity. From them, (−)-limonene, guaiol, germacrene-D as well the mixtures of (−)-limonene/β-pheladrene presented significant repellent activity (>97% repellency) against Ae. albopictus. The present methodology could be a valuable tool in the effort to develop potent mosquito repellents which are environmentally friendly.

Exploitation of Vitis vinifera, Foeniculum vulgare, Cannabis sativa and Punica granatum By-Product Seeds as Dermo-Cosmetic Agents

In the current study, by-product seed pastes (VSPs) from Vitis vinifera, Foeniculum vulgare, Cannabis sativa and Punica granatum, generated during the oil production process, were investigated for their potential exploitation as dermo-cosmetic agent. The extraction pipeline of all the raw materials was developed with emphasis on green methodologies and employed on laboratory scale based on industry-adopted techniques. Two different protocols were applied, Supercritical Fluid Extraction (SFE) and Ultrasound Assisted Extraction (UAE); the by-product pastes were defatted with supercritical CO2 and n-Hexane, respectively. Then, two SFE extracts (CO2 with 10% and 20% of ethanol as co-solvent) and two UAE extracts (with ethanol and ethanol/water 1:1 v/v) were obtained from each raw material. The providing yield range was between 2.6 to 76.3 mg/g raw material. The extracts were analyzed with High-Performance Liquid Chromatography coupled with Diode Array Detector (HPLC-DAD) and Liquid Chromatography coupled with High-Resolution Mass Spectrometer (LC-HRMS), and the major compounds, were identified. All the extracts were evaluated for their antioxidant and inhibition activity against collagenase, elastase and tyrosinase enzymes. Grapevine by-product extracts found rich in proanthocyanidins and presented the higher inhibition activity. A holistic green experimental methodology is proposed for the obtainment of extracts from significant medicinal plants by-products that provides us with promising results concerning dermo-cosmetic properties, especially for grape seeds extracts.

Dereplication of Natural Extracts Diluted in Propylene Glycol, 1,3-Propanediol and Glycerin. Comparison of Leontopodium alpinum Cass. (Edelweiss) Extracts as a Case Study

Many natural extracts used as cosmetic ingredients are available as solutions prepared in high-boiling-point solvents, called carrier solvents, such as propylene glycol (1,2-propanediol), propanediol (1,3-propanediol) and glycerin. The upstream chemical profiling of these extracts represents a major asset for the cosmetic industry, because it accelerates product development. A new workflow for the rapid characterization of the main metabolites present in natural extracts diluted in propylene glycol and 1,3-propanediol is presented here as an extension of previous works on glycerin-containing extracts. This method is an optimized version of a well-established dereplication procedure and consists of a fractionation by centrifugal partition chromatography followed by 13C nuclear magnetic resonance analysis and dedicated data processing. The concentration by evaporation under reduced pressure was considered as a pertinent preliminary step, particularly adapted to the analysis of highly diluted extracts. A dried hydro-ethanolic extract of Leontopodium alpinum Cass. was prepared at laboratory scale and used for method validation. Three solutions at 5% wt. of dry extract were prepared with propylene glycol/water (1:1), 1,3-propanediol/water (1:1) and glycerin/water (1:1) as carrier solvents. The dereplication workflow was applied to the three resulting L. alpinum extracts. Each study led to the quick identification of 26 metabolites including five flavonoids (luteolin and its derivatives), five hydroxycinnamic acids (among which are leontopodic acids), sugars and organic acids.

Dereplication of Natural Extracts Diluted in Glycerin: Physical Suppression of Glycerin by Centrifugal Partition Chromatography Combined with Presaturation of Solvent Signals in 13C-Nuclear Magnetic Resonance Spectroscopy

For scientific, regulatory, and safety reasons, the chemical profile knowledge of natural extracts incorporated in commercial cosmetic formulations is of primary importance. Many extracts are produced or stabilized in glycerin, a practice which hampers their characterization. This article proposes a new methodology for the quick identification of metabolites present in natural extracts when diluted in glycerin. As an extension of a 13C nuclear magnetic resonance (NMR) based dereplication process, two complementary approaches are presented for the chemical profiling of natural extracts diluted in glycerin: A physical suppression by centrifugal partition chromatography (CPC) with the appropriate biphasic solvent system EtOAc/CH3CN/water 3:3:4 (v/v/v) for the crude extract fractionation, and a spectroscopic suppression by presaturation of 13C-NMR signals of glycerin applied to glycerin containing fractions. This innovative workflow was applied to a model mixture containing 23 natural metabolites. Dereplication by 13C-NMR was applied either on the dry model mixture or after dilution at 5% in glycerin, for comparison, resulting in the detection of 20 out of 23 compounds in the two model mixtures. Subsequently, a natural extract of Cedrus atlantica diluted in glycerin was characterized and resulted in the identification of 12 metabolites. The first annotations by 13C-NMR were confirmed by two-dimensional NMR and completed by LC-MS analyses for the annotation of five additional minor compounds. These results demonstrate that the application of physical suppression by CPC and presaturation of 13C-NMR solvent signals highly facilitates the quick chemical profiling of natural extracts diluted in glycerin.

Renewable sources: applications in personal care formulations

A global tendency for products considered environmentally sustainable, and ecologically obtained led the industry related to personal care formulations to fund the research and the development of personal care/cosmetics containing ingredients from natural resources. Furthermore, consumers are aware of environmental and sustainability issueans, thus not harming the environment represents a key consideration when developing a new cosmetic ingredient. In this study we review some examples of active ingredients or raw materials used in cosmetics/personal care/biomedical products that are coming from either through biotechnological systems, or as byproducts of several industries. A skin formulation containing biosynthetic actives, prepared by us and the study regarding its dermocosmetic properties are also described. The need for the standardization processes, the safety assessment tools, the improvement of the exploitation methods of these renewable sources in order the production to be ecologically and economically better are also discussed.

Phytochemical analysis of olive flowers' hydroalcoholic extract and in vitro evaluation of tyrosinase, elastase and collagenase inhibition activity

Olea europaea L. is historically one of the most important trees of the Mediterranean countries. Increasing scientific interest regarding its fruits, leaves and olive oil has led to the elucidation of several phytochemical and biological characteristics. However, the phytochemical and biological studies regarding olive flowers remain limited. The aim of the present study was the phytochemical characterization of olive flowers' hydroalcoholic extract from Greek variety Lianolia, the effective isolation of the major secondary metabolites and evaluation of their inhibition activity against tyrosinase, elastase and collagenase. UPLC-HRMS/MS analysis was used to investigate the chemical composition of hydroalcoholic extract resulting in the identification of sixty-three secondary metabolites witch mainly belong to phenilethanoids, triterpenoids, flavonoids and secoiridoids. The orthogonial combination of Centrifugal Partition Chromatography and preparative HPLC in the same purification process led to the isolation of nine major compounds of the extract including two triterpenic acids, two flavonoid glycosides and five secoiridoid derivatives. From them, oleofloside A and oleofloside B are new natural products. Although, the hydroalcoholic extract and isolated secoiridoids exhibited weak or no inhibition activity towards tyrosinase and elastase, they exhibit remarkable anti-collagenase activity with 2΄-ethoxyoleuropein being the most active compound.

Separation and isolation of major polyphenols from maritime pine (Pinus pinaster) knots by two-step centrifugal partition chromatography monitored by LC-MS and NMR spectroscopy

Pine knots are a rich source of lignans, flavonoids, and stilbenes. These bioactive compounds are widely known for their roles to combat human disorders but also to protect plants against pathogens. In order to gain knowledge inside their potential activities, a suitable isolation and purification of these high-added value compounds is required. To this end, centrifugal partition chromatography, as a rapid and useful methodology of separation, was employed and developed. The coefficient partition values (K_D ) of six major compounds in nine biphasic solvent systems were determined to evaluate the most appropriate system. Two-step centrifugal partition chromatography was required to separate lignans using ARIZONA system K (n-heptane/ethyl acetate/methanol/water 1:2:1:2, v:v) and to isolate stilbenes and flavonoids using ARIZONA system P (n-heptane/ethyl acetate/methanol/water 6:5:6:5, v:v). Eight one-compound enriched-fractions were obtained as follows: nortrachelogenin (70.1%), secoisolariciresinol (53.7%), isolariciresinol (61.1%), taxifolin (48.4%), pinocembrin (91.3%), pinobanksin (91.1%), pinosylvin (91.4%), and pinosylvin monomethyl ether (91.1%). Additionally, the centrifugal partition chromatography allowed to unravel the composition of pine knot owing to the several fractions generated. Twenty-two compounds were characterized by liquid chromatography-mass spectrometry and NMR spectroscopy, some of which are described for the first time in literature.

Absolute Configuration of Mycosporine-Like Amino Acids, Their Wound Healing Properties and In Vitro Anti-Aging Effects

Mycosporine-like amino acids (MAAs) are water-soluble metabolites, reported to exhibit strong UV-absorbing properties. They have been found in a wide range of marine organisms, especially those that are exposed to extreme levels of sunlight, to protect them against solar radiation. In the present study, the absolute configuration of 14 mycosporine-like-amino acids was determined by combining the results of electronic circular dichroism (ECD) experiments and that of advanced Marfey's method using LC-MS. The crystal structure of a shinorine hydrate was determined from single crystal X-ray diffraction data and its absolute configuration was established from anomalous-dispersion effects. Furthermore, the anti-aging and wound-healing properties of these metabolites were evaluated in three different assays namely the inhibition of collagenase, inhibition of advanced glycation end products (AGEs) and wound healing assay (scratch assay).

Antimicrobial Effect of Picea abies Extracts on E. coli Growth

This study aims to investigate the effect of essential oils extracted from wood residues of Picea abies on the growth of Escherichia coli. The essential oils were extracted by supercritical carbon dioxide, leading to a yield of 3.4 ± 0.5% (w/w) in 120 min. The antimicrobial effect was tested at 37 °C by isothermal calorimetry. The heat-flow (dq/dt vs. time) was integrated to give a fractional reaction curve (α vs. time). Such curves were fitted by a modified Gompertz function to give the lag-time (λ) and the maximum growth rate (µmax) parameters. The results showed that λ was linearly correlated with E. coli concentration (λ = 1.4 h/log (CFU/mL), R² = 0.997), whereas µmax was invariant. Moreover, the overall heat was nearly constant to all the dilutions of E. coli. Instead, when the essential oil was added (with concentrations ranging from 1 to 5 mg/L) to a culture of E. coli (10⁴ CFU/mL), the lag-time increased from 14.1 to 33.7 h, and the overall heat decreased from 2120 to 2.37 J. The results obtained by the plate count technique were linear with the lag-time (λ), where (λ = −7.3 × log (CFU/mL) + 38.3, R² = 0.9878). This suggested a lower capacity of E. coli to metabolize the substrate in the presence of the essential oils. The results obtained in this study promote the use of essential oils from wood residues and their use as antimicrobial products.

Recovery of Sesamin, Sesamolin, and Minor Lignans From Sesame Oil Using Solid Support-Free Liquid-Liquid Extraction and Chromatography Techniques and Evaluation of Their Enzymatic Inhibition Properties

In this study, an integrated process for the recovery of sesamin and sesamolin, two high added-value lignans of sesame oil (SO) was developed, using synchronous extraction and chromatography techniques. The extraction of SO phenolic content was studied using two different extraction techniques: Annular centrifugal extraction (ACE) and centrifugal partition extraction (CPE). The derived data of each experiment were compared in terms of revealing the yields, time, and solvents consumption showing that CPE is the most effective technique, concerning the solvent consumption. The isolation of lignans was achieved using centrifugal partition chromatography (CPC) both on semi-preparative and preparative scale. The biphasic system used for this purpose consisted of the following solvents: n-Hex/EtOAc/EtOH/H₂O in proportion 2:3:3:2 (v/v/v/v) and direct recovery of the two major lignans sesamin and sesamolin was achieved. In parallel the CPC analysis resulted in the isolation of four minor lignans of sesame oil, i.e., samin, sesamol, sesaminol, and episesaminol. Structure elucidation of isolated lignans was based on HRMS/MS and NMR experiments. High-performance liquid chromatography (HPLC) was employed for quantitative analysis of the obtained extracts to determine the purity of the isolated compounds as well. The results of this study demonstrated that sesamin and sesamolin were recovered in purity higher than 95%, verifying the effectiveness of the purposed separation methodology. Finally, due to the general application of sesame oil in cosmetic industry, all the pure compounds were evaluated for their tyrosinase, elastase, collagenase, and hyaluronidase inhibition activity.

Rapid isolation and characterization of crocins, picrocrocin, and crocetin from saffron using centrifugal partition chromatography and LC-MS

This study demonstrates a simple method for one-step isolation of the main secondary metabolites of a hydroalcoholic extract of Crocus sativus stigmas (saffron) using step-gradient centrifugal partition chromatography. The analysis was performed in dual and elution-extrusion mode, using five biphasic systems of the solvents heptane/ethyl acetate/butanol/ethanol/water in ratios of 4:10:0:4:10, 1:13:0:4:10, 1:12:1:4:10, 1:10:3:4:10, and 1:7:6:4:10. Five major crocins, picrocrocin, and crocetin were directly isolated in one step. Scaling up to preparative level, allowed the recovery of significantly high quantities of pure compounds, especially trans-crocin-4, saffron's principal crocin. Comparing dual-mode and elution-extrusion, in dual-mode, the trans-crocin-4 containing fractions were co-eluted with a high amount of free β-d-glucose. In contrast, absence of free β-d-glucose was observed in the corresponding trans-crocin-4 fractions obtained by the second method denoting its superiority against dual-mode. Initiating analysis with the 4^th solvent-system afforded selective isolation of trans-crocin-4, with reduction in experimental time and solvent consumption. Structure elucidation was performed by nuclear magnetic resonance spectroscopy, liquid chromatography with mass spectrometry, and high-resolution tandem mass spectrometry. The proposed methodology comprises an integrated approach for the purification and characterization of biologically active saffron components in a fast, selective, and environmentally friendly manner.

Assessment of the antioxidant activity of an olive oil total polyphenolic fraction and hydroxytyrosol from a Greek Olea europea variety in endothelial cells and myoblasts

Olive oil (OO) constitutes the basis of the Mediterranean diet, and it seems that its biophenols, such as hydroxytyrosol (HT) may scavenge free radicals, attracting distinct attention due to their beneficial effects in many pathological conditions, such as cancer. To the best of our knowedge, this is the first study in which the functional properties of an OO total polyphenolic fraction (TPF) and pure HT were examined in order to determine their antioxidant effects at a cellular level in endothelial cells and myoblasts. The test compounds were isolated using a green gradient-elution centrifugal partition chromatography-based method that allows the isolation of large volumes of OO in a continuous extraction procedure and with extremely low solvent consumption. For the isolation of HT, a combination of two chromatographic techniques was used, which is effective for the recovery of pure compounds from complex natural extracts. Moreover, TPF and HT exhibited potent free radical scavenging activity in vitro. The cells were treated with non-cytotoxic concentrations and their redox status [in terms of glutathione (GSH) and reactive oxygen species (ROS) levels] was assessed. TPF extract was less cytotoxic than HT, and the observed differences between the two cell lines used suggest a tissue-specific activity. Finally, flow cytometric analysis revealed that both TPF and HT improved the redox status by increasing the levels of GSH, one of the most important antioxidant molecules, in both endothelial cells and myoblasts, while the ROS levels were not significantly affected.

Computer-aided Dereplication and Structure Elucidation of Natural Products at the University of Reims

Natural product chemistry began in Reims, France, in a pharmacognosy research laboratory whose main emphasis was the isolation and identification of bioactive molecules, following the guidelines of chemotaxonomy. The structure elucidation of new compounds of steadily increasing complexity favored the emergence of methodological work in nuclear magnetic resonance. As a result, our group was the first to report the use of proton-detected heteronuclear chemical shift correlation spectra for the computer-assisted structure elucidation of small organic molecules driven by atom proximity relationships and without relying on databases. The early detection of known compounds appeared as a necessity in order to deal more efficiently with complex plant extracts. This goal was reached by an original combination of mixture fractionation by centrifugal partition chromatography, analysis by ¹³ C NMR, digital data reduction and alignment, hierarchical data clustering, and computer database search.