Generation of aroma in three-line hybrid rice through CRISPR/Cas9 editing of BETAINE ALDEHYDE DEHYDROGENASE2 (OsBADH2).

Aroma or fragrance in rice is a genetically controlled trait; Its high appreciation by consumers increases the rice market price. Previous studies have revealed that the rice aroma is controlled by a specific gene called BETAINE ALDEHYDE DEHYDROGENASE (OsBADH2), and mutation of this gene leads to the accumulation of an aromatic substance 2-acetyl-1-pyrroline (2-AP). The use of genetic engineering to produce aroma in commercial and cultivated hybrids is a contemporary need for molecular breeding. The current study reports the generation of aroma in the three-line hybrid restorer line Shu-Hui-313 (SH313). We created knock-out (KO) lines of OsBADH2 through the CRISPR/Cas9. The analysis of KO lines revealed a significantly increased content of 2AP in the grains compared with the control. However, other phenotypic traits (plant height, seed setting rate, and 1000-grain weight) were significantly decreased. These KO lines were crossed with a non-aromatic three-line hybrid rice male sterile line (Rong-7-A) to produce Rong-7-You-626 (R7Y626), R7Y627 and R7Y628. The measurement of 2-AP revealed significantly increased contents in these cross combinations. We compared the content of 2-AP in tissues at the booting stage. Data revealed that young spike stalk base contained the highest content of 2-AP and can be used for identification (by simple chewing) of aromatic lines under field conditions. In conclusion, our dataset offers a genetic source and illustrates the generation of aroma in non-aromatic hybrids, and outlines a straightforward identification under field conditions.

Allergen content of popular chemical hair relaxers: A product analysis.

BACKGROUND: Chemical hair relaxers are widely utilized by black women, yet little research exists on the allergens present in these products. OBJECTIVE: This study aims to investigate allergen prevalence in the most popular chemical hair relaxers. METHODS: We analysed 41 products from five major retailers, identifying allergens through ingredient lists and comparing them to the 2020 American Contact Dermatitis Group Core allergen series. RESULTS: The most common contact allergens in chemical relaxers include propylene glycol, cetyl steryl alcohol, fragrance, D/L-a-tocopherol, tea tree oil and cocamidopropyl betaine. CONCLUSION: Understanding allergen exposure in products used by individuals with textured hair is needed for managing contact dermatitis in diverse populations. This analysis underscores the presence of potential allergens in hair relaxers, emphasizing the importance of dermatologists' awareness and patient scrutiny of ingredient lists.

Elucidation of an anaerobic pathway for metabolism of l-carnitine-derived γ-butyrobetaine to trimethylamine in human gut bacteria.

Trimethylamine (TMA) is an important gut microbial metabolite strongly associated with human disease. There are prominent gaps in our understanding of how TMA is produced from the essential dietary nutrient l-carnitine, particularly in the anoxic environment of the human gut where oxygen-dependent l-carnitine-metabolizing enzymes are likely inactive. Here, we elucidate the chemical and genetic basis for anaerobic TMA generation from the l-carnitine-derived metabolite γ-butyrobetaine (γbb) by the human gut bacterium Emergencia timonensis We identify a set of genes up-regulated by γbb and demonstrate that the enzymes encoded by the induced γbb utilization (bbu) gene cluster convert γbb to TMA. The key TMA-generating step is catalyzed by a previously unknown type of TMA-lyase enzyme that utilizes a putative flavin cofactor to catalyze a redox-neutral transformation. We identify additional cultured and uncultured host-associated bacteria that possess the bbu gene cluster, providing insights into the distribution of anaerobic γbb metabolism. Lastly, we present genetic, transcriptional, and metabolomic evidence that confirms the relevance of this metabolic pathway in the human gut microbiota. These analyses indicate that the anaerobic pathway is a more substantial contributor to TMA generation from l-carnitine in the human gut than the previously proposed aerobic pathway. The discovery and characterization of the bbu pathway provides the critical missing link in anaerobic metabolism of l-carnitine to TMA, enabling investigation into the connection between this microbial function and human disease.

Rethinking the Esterquats: Synthesis, Stability, Ecotoxicity and Applications of Esterquats Incorporating Analogs of Betaine or Choline as the Cation in Their Structure.

Esterquats constitute a unique group of quaternary ammonium salts (QASs) that contain an ester bond in the structure of the cation. Despite the numerous advantages of this class of compounds, only two mini-reviews discuss the subject of esterquats: the first one (2007) briefly summarizes their types, synthesis, and structural elements required for a beneficial environmental profile and only briefly covers their applications whereas the second one only reviews the stability of selected betaine-type esterquats in aqueous solutions. The rationale for writing this review is to critically reevaluate the relevant literature and provide others with a "state-of-the-art" snapshot of choline-type esterquats and betaine-type esterquats. Hence, the first part of this survey thoroughly summarizes the most important scientific reports demonstrating effective synthesis routes leading to the formation of both types of esterquats. In the second section, the susceptibility of esterquats to hydrolysis is explained, and the influence of various factors, such as the pH, the degree of salinity, or the temperature of the solution, was subjected to thorough analysis that includes quantitative components. The next two sections refer to various aspects associated with the ecotoxicity of esterquats. Consequently, their biodegradation and toxic effects on microorganisms are extensively analyzed as crucial factors that can affect their commercialization. Then, the reported applications of esterquats are briefly discussed, including the functionalization of macromolecules, such as cotton fabric as well as their successful utilization on a commercial scale. The last section demonstrates the most essential conclusions and reported drawbacks that allow us to elucidate future recommendations regarding the development of these promising chemicals.

Green Extraction of Depsidones and Depsides from Hypogymnia physodes (L.) Nyl. Using Natural Deep Eutectic Solvents.

Various studies have shown that Hypogymnia physodes are a source of many biologically active compounds, including lichen acids. These lichen-specific compounds are characterized by antioxidant, antiproliferative, and antimicrobial properties, and they can be used in the cosmetic and pharmaceutical industries. The main aim of this study was to optimize the composition of natural deep eutectic solvents based on proline or betaine and lactic acid for the extraction of metabolites from H. physodes. The design of the experimental method and the response surface approach allowed the optimization of the extraction process of specific lichen metabolites. Based on preliminary research, a multivariate model of the experiment was developed. For optimization, the following parameters were employed in the experiment to confirm the model: a proline/lactic acid/water molar ratio of 1:2:2. Such a mixture allowed the efficient extraction of three depsidones (i.e., physodic acid, physodalic acid, 3-hydroyphysodic acid) and one depside (i.e., atranorin). The developed composition of the solvent mixtures ensured good efficiency when extracting the metabolites from the thallus of H. physodes with high antioxidant properties.

Not a "they" but a "we": The microbiome helps promote our well-being.

Anaerobic microbes in the human gut produce beneficial and harmful compounds, as well as neutral compounds like trimethylamine, which undergoes microbial metabolism or host-catalyzed transformation into proatherogenic trimethylamine-N-oxide. Ellenbogen et al. identified a microbiome-associated demethylase that short-circuits the production of trimethylamine-N-oxide from the metabolite γ-butyrobetaine and instead produces methyltetrahydrofolate, a key intermediate in the microbial production of beneficial small-chain fatty acids. This article highlights an example of how the microbiome is integrally involved in producing metabolites that support our health and in preventing the formation of compounds that promote disease.

The MttB superfamily member MtyB from the human gut symbiont Eubacterium limosum is a cobalamin-dependent γ-butyrobetaine methyltransferase.

The production of trimethylamine (TMA) from quaternary amines such as l-carnitine or γ-butyrobetaine (4-(trimethylammonio)butanoate) by gut microbial enzymes has been linked to heart disease. This has led to interest in enzymes of the gut microbiome that might ameliorate net TMA production, such as members of the MttB superfamily of proteins, which can demethylate TMA (e.g., MttB) or l-carnitine (e.g., MtcB). Here, we show that the human gut acetogen Eubacterium limosum demethylates γ-butyrobetaine and produces MtyB, a previously uncharacterized MttB superfamily member catalyzing the demethylation of γ-butyrobetaine. Proteomic analyses of E. limosum grown on either γ-butyrobetaine or dl-lactate were employed to identify candidate proteins underlying catabolic demethylation of the growth substrate. Three proteins were significantly elevated in abundance in γ-butyrobetaine-grown cells: MtyB, MtqC (a corrinoid-binding protein), and MtqA (a corrinoid:tetrahydrofolate methyltransferase). Together, these proteins act as a γ-butyrobetaine:tetrahydrofolate methyltransferase system, forming a key intermediate of acetogenesis. Recombinant MtyB acts as a γ-butyrobetaine:MtqC methyltransferase but cannot methylate free cobalamin cofactor. MtyB is very similar to MtcB, the carnitine methyltransferase, but neither was detectable in cells grown on carnitine nor was detectable in cells grown with γ-butyrobetaine. Both quaternary amines are substrates for either enzyme, but kinetic analysis revealed that, in comparison to MtcB, MtyB has a lower apparent Km for γ-butyrobetaine and higher apparent Vmax, providing a rationale for MtyB abundance in γ-butyrobetaine-grown cells. As TMA is readily produced from γ-butyrobetaine, organisms with MtyB-like proteins may provide a means to lower levels of TMA and proatherogenic TMA-N-oxide via precursor competition.

Antifouling Surface Coating on Various Substrates by Inducing Tyrosinase-Mediated Oxidation of a Tyrosine-Conjugated Sulfobetaine Derivative.

Inspired by the melanogenesis occurring in nature, we report tyrosinase-mediated antifouling surface coating by synthesizing a tyrosine-conjugated sulfobetaine derivative (Tyr-SB). Synthetic Tyr-SB contains zwitterionic sulfobetaine and tyrosine, whose phenolic amine group acts as a dormant coating precursor. In contrast to catecholamine derivatives, tyrosine derivatives are stable against auto-oxidation and are enzymatically oxidized only in the presence of tyrosinase to initiate melanin-like oxidation. When the surface of interest was applied during the course of Tyr-SB oxidation, a superhydrophilic poly(Tyr-SB) film was coated on the surfaces, thereby showing antifouling performance against proteins or adherent cells. Because the oxidation of Tyr-SB occurred under mild aqueous conditions (pH 6-7) without the use of any chemical oxidants, such as sodium periodate or ammonium persulfate, we anticipate that the coating method described herein will serve as a biocompatible tool in the field of biosensors, cell surface engineering, and medical devices, whose interfaces differ in chemistry.

Zwitterionic surface chemistry enhances detachment of bacteria under shear.

The ubiquitous nature of microorganisms, especially of biofilm-forming bacteria, makes biofouling a prevalent challenge in many settings, including medical and industrial environments immersed in liquid and subjected to shear forces. Recent studies have shown that zwitterionic groups are effective in suppressing bacteria and protein adhesion as well as biofilm growth. However, the effect of zwitterionic groups on the removal of surface-bound bacteria has not been extensively studied. Here we present a microfluidic approach to evaluate the effectiveness in facilitating bacteria detachment by shear of an antifouling surface treatment using (3-(dimethyl;(3-trimethoxysilyl)propyl)ammonia propane-1-sulfonate), a sulfobetaine silane (SBS). Control studies show that SBS-functionalized surfaces greatly increase protein (bovine serum albumin) removal upon rinsing. On the same surfaces, enhanced bacteria (Pseudomonas aeruginosa) removal is observed under shear. To quantify this enhancement a microfluidic shear device is employed to investigate how SBS-functionalized surfaces promote bacteria detachment under shear. By using a microfluidic channel with five shear zones, we compare the removal of bacteria from zwitterionic and glass surfaces under different shear rates. At times of 15 min, 30 min, and 60 min, bacteria adhesion on SBS-functionalized surfaces is reduced relative to the control surface (glass) under quiescent conditions. However, surface-associated bacteria on the SBS-functionalized glass and control show similar percentages of live cells, suggesting minimal intrinsic biocidal effect from the SBS-functionalized surface. Notably, when exposed to shear rates ranging from 104 to 105 s-1, significantly fewer bacteria remain on the SBS-functionalized surfaces. These results demonstrate the potential of zwitterionic sulfobetaine as effective antifouling coatings that facilitate the removal of bacteria under shear.

Synthesis and Optical Properties of Excited-State Intramolecular Proton Transfer (ESIPT) Emitters with Sulfobetaine Fragments.

This article describes the synthetic efforts towards the solubilization of organic fluorescent emitters based on a 2-(2'-hydroxybenzofuranyl)benzazole (HBBX) scaffold in aqueous media under physiological conditions (PBS, pH 7.4). These dyes are well-known to display the excited-state intramolecular proton transfer (ESIPT) process which leads to a Stokes-shifted fluorescence with enhanced photostability and strong environment dependent features. Organic dyes are hydrophobic by nature and their vectorization into aqueous media usually necessitates amphiphilic polymers. In this study, we show that the incorporation of one or two sulfobetaine fragments, a highly biocompatible zwitterionic unit leads to the vectorization in buffer solution at pH 7.4 while keeping a reasonable ESIPT fluorescence emission. The photophysical properties of all dyes were studied in multiple solvents and showed that, depending on structure and environment, different excited-state species are observed: normal or tautomeric species, as well as a competitive anionic fluorescent derivative. This study shows that it is not only possible to solubilize fluorescent ESIPT dyes in water using sulfobetaine(s) but also that the optical properties can be finely tuned depending on small structural inputs.

Structural investigation of sulfobetaines and phospholipid monolayers at the air-water interface.

Mixtures of sulfobetaine based lipids with phosphocholine phospholipids are of interest in order to study the interactions between zwitterionic surfactants and the phospholipids present in cell membranes. In this study we have investigated the structure of mixed monolayers of sulfobetaines and phosphocholine phospholipids. The sulfobetaine used has a single 18-carbon tail, and is referred to as SB3-18, and the phospholipid used is DMPC. Surface pressure-area isotherms of the samples were used to determine whether any phase transitions were present during the compression of the monolayers. Neutron and X-ray reflectometry were then used to investigate the structure of these monolayers perpendicular to the interface. We found that the average headgroup and tail layer thickness was reasonably consistent across all mixtures, with a variation of less than 3 Å reported in the total thickness of the monolayers at each surface pressure. However, by selective deuteration of the two components of the monolayers, it was found that the two components have different tail layer thicknesses. For the mixture with equal compositions of DMPC and SB3-18 or with a higher composition of DMPC the tail tilts were found to be constant, resulting in a greater tail layer thickness for SB3-18 due to its longer tail. For the mixture higher in SB3-18 this was not the case, the tail tilt angle for the two components was found to be different and DMPC was found to have a greater tail layer thickness than SB3-18 as a result.

Patch testing with the European baseline series and 10 added allergens: Single-centre study of 748 patients.

BACKGROUND: The European baseline series (EBS) of contact allergens is subject to change. An allergen is considered for inclusion when routine patch testing of patients with suspected contact dermatitis results in ≥0.5% prevalence rate. OBJECTIVES: We aimed to determine the frequency of sensitizations to 30 EBS allergens and 10 locally added allergens. Additionally, we assessed the strength and evolution of reactions to all tested allergens and co-reactivity of additional allergens. METHODS: Patch testing with our baseline series of 40 allergens was done in 748 consecutive adults. Tests were applied to the upper back and removed by patients after 48 h. Readings were done on Day 3 (D3) and D6 or D7 (D6/7). Positive reactions fulfilled the criteria of at least one plus (+) reaction. A retrospective analysis was done. RESULTS: Eight allergens not listed in the EBS had ≥0.5% prevalence rate (i.e., cocamidopropyl betaine, thiomersal, disperse blue mix 106/124, 2-bromo-2-nitropropane-1,3-diol, diazolidinyl urea, propylene glycol, Compositae mix II and dexamethasone-21-phosphate), and 16.6% of positive reactions would have been missed without D6/7 readings. CONCLUSION: We propose further studies to evaluate whether cocamidopropyl betaine, disperse blue mix 106/124, 2-bromo-2-nitropropane-1,3-diol, diazolidinyl urea and Compositae mix II need to be added to the EBS.

Structure-Activity Relationship of the Thiacalix[4]arenes Family with Sulfobetaine Fragments: Self-Assembly and Cytotoxic Effect against Cancer Cell Lines.

Regulating the structure of macrocyclic host molecules and supramolecular assemblies is crucial because the structure-activity relationship often plays a role in governing the properties of these systems. Herein, we propose and develop an approach to the synthesis of the family of sulfobetaine functionalized thiacalix[4]arenes with regulation of the self-assembly and cytotoxic effect against cancer cell lines. The dynamic light scattering method showed that the synthesized macrocycles in cone, partial cone and 1,3-alternate conformations form submicron-sized particles with Ag+ in water, but the particle size and polydispersity of the systems studied depend on the macrocycle conformation. Based on the results obtained by 1H and 1H-1H NOESY NMR spectroscopy and transmission electron microscopy for the macrocycles and their aggregates with Ag+, a coordination scheme for the Ag+ and different conformations of p-tert-butylthiacalix[4]arene functionalized with sulfobetaine fragments was proposed. The type of coordination determines the different shapes of the associates. Cytotoxic properties are shown to be controlled by the shape of associates, with the highest activity demonstrated by thiacalix[4]arenes in partial cone conformation. This complex partial cone/Ag+ is two times higher than the reference drug imatinib mesylate. High selectivity against cervical carcinoma cell line indicates the prospect of their using as components of new anticancer system.

Association of gut-related metabolites with outcome in acute heart failure.

BACKGROUND: Trimethylamine N-oxide (TMAO), a gut-related metabolite, is associated with heart failure (HF) outcomes. However, TMAO is the final product of a complex metabolic pathway (ie, choline/carnitine) that has never been entirely investigated in HF. The present study investigates a panel of metabolites involved in the TMAO-choline/carnitine metabolic pathway for their associations with outcome in acute HF patients. METHODS: In total, 806 plasma samples from acute HF patients were analyzed for TMAO, trimethyllysine, L-carnitine, acetyl-L-carnitine, γ-butyrobetaine, crotonobetaine, trimethylamine, betaine aldehyde, choline, and betaine using a developed liquid chromatography-tandem mass spectrometry method. Associations with outcome of all-cause mortality (death) and a composite of all-cause mortality and/or rehospitalization caused by HF (death/HF) at 30 days and 1 year were investigated. RESULTS: TMAO, trimethyllysine, L-carnitine, acetyl-L-carnitine, and γ-butyrobetaine were associated with death and death/HF at 30 days (short term; hazard ratio 1.30-1.49, P≤ .021) and at 1 year (long term; hazard ratio 1.15-1.25, P≤ .026) when adjusted for cardiac risk factors. L-carnitine and acetyl-L-carnitine were superior for short-term outcomes whereas TMAO was the superior metabolite for association with long-term outcomes. Furthermore, acetyl-L-carnitine and L-carnitine were superior for in-hospital mortality and improved risk stratification when combined with current clinical risk scores (ie, Acute Decompensated HEart Failure National REgistry, Organized Program To Initiate Lifesaving Treatment In Hospitalized Patients With Heart Failure, and Get With The Guidelines-Heart Failure; odds ratio (OR) ≥ 1.52, P≤ .020). CONCLUSIONS: Carnitine-related metabolites show associations with adverse outcomes in acute HF, in particular L-carnitine and acetyl-L-carnitine for short-term outcomes, and TMAO for long-term outcomes. Further studies are warranted to investigate the role and implications of carnitine metabolites including intervention in the pathogenesis of HF.

Effect of the drug cyclophosphamide on the activity of porcine kidney betaine aldehyde dehydrogenase.

The enzyme betaine aldehyde dehydrogenase (BADH EC 1.2.1.8) catalyzes the synthesis of glycine betaine (GB), an osmolyte and osmoprotectant. Also, it participates in several metabolic pathways in humans. All BADHs known have cysteine in the active site involved in the aldehyde binding, whereas the porcine kidney enzyme (pkBADH) also has a neighborhood cysteine, both sensitive to oxidation. The antineoplastic and immuno-suppressant pre-drug cyclophosphamide (CTX), and its bioactivation products, have two highly oxidating chlorine atoms. This work aimed to analyze the effect of CTX in the activity of porcine kidney betaine aldehyde dehydrogenase. PkBADH was incubated with varying CTX concentration (0 to 2.0 mM) at 25 °C and lost 50 % of its activity with 2.0 mM CTX. The presence of the coenzyme NAD+ (0.5 mM) decreased 95% the activity in 2.0 mM CTX. The substrate betaine aldehyde (0.05 and 0.4 mM, and the products NADH (0.1-0.5 mM) and GB (1 and 10 mM) did not have an effect on the enzyme inactivation by CTX. The reducing agents, dithiothreitol and ß-mercaptoethanol, reverted the pkBADH inactivation, but reduced glutathione (GSH) was unable to restore the enzyme activity. Molecular docking showed that CTX could enter at the enzyme active site, where its chlorine atoms may interact with the catalytic and the neighboring cysteines. The results obtained show that CTX inactivates the pkBADH due to oxidation of the catalytic cysteine or because it oxidizes catalytic and neighborhood cysteine, forming a disulfide bridge with a concomitant decrease in the activity of the enzyme.

A proposed antioxidation mechanism of ergothioneine based on the chemically derived oxidation product hercynine and further decomposition products.

Ergothioneine (ERGO), a thiohistidine betaine, exists in various fungi, plants, and animals. Humans take in ERGO from their diet. ERGO is a strong biological antioxidant, but there are only a limited number of reports about its redox mechanism. The purpose of this study was to clarify the oxidation mechanism of ERGO. Reactions of ERGO with chemical oxidants were performed. The oxidation products of ERGO were analyzed by nuclear magnetic resonance and liquid chromatography-mass spectrometry (LC-MS). The major product of oxidation of ERGO by hydrogen peroxide in physiological conditions was identified as hercynine (histidine betaine). One molecule of ERGO was able to reduce 2 molecules of hydrogen peroxide. Hercynine was found to react with the more potent oxidant hypochlorite. One unstable decomposition product was detected by LC-MS. As a result, a mechanism of oxidation of ERGO, and hence its physiological antioxidant activity, was developed.

Influence of Zwitterionic CAPB on Flocculation of the Aqueous Cationic Guar Gum/Glauconite Suspensions at Various pH.

The influence of the pseudoamphoteric zwitterionic surfactant cocamidopropylbetaine (CAPB) on the stabilizing flocculating properties of the aqueous suspensions of glauconite (GT) with cationic guar gum (CGG) at various pH values was investigated. The following techniques were used: turbidimetry, UV-VIS spectrophotometry, tensiometry, electrophoretic mobility measurements, SEM, CHN, XRD, and FT-IR. It was established that CGG is an effective glauconite flocculant. Moreover, the most probable mechanism that is responsible for flocculation is bridge flocculation resulting from polymer adsorption on the glauconite surface. The adsorption process is caused by electrostatic interactions between the negatively charged glauconite surface and the positively charged polymer. The amount of CGG adsorption increases with the increase of the pH, which was confirmed by the adsorption and zeta potential measurements. The addition of CAPB increases the amount of the polymer adsorption due to the formation of intermolecular polymer-surfactant complexes; however, it reduces flocculation effectiveness.

Effect of Polyhexamethylene Biguanide in Combination with Undecylenamidopropyl Betaine or PslG on Biofilm Clearance.

Hospital-acquired infection is a great challenge for clinical treatment due to pathogens' biofilm formation and their antibiotic resistance. Here, we investigate the effect of antiseptic agent polyhexamethylene biguanide (PHMB) and undecylenamidopropyl betaine (UB) against biofilms of four pathogens that are often found in hospitals, including Gram-negative bacteria Pseudomonas aeruginosa and Escherichia coli, Gram-positive bacteria Staphylococcus aureus, and pathogenic fungus, Candida albicans. We show that 0.02% PHMB, which is 10-fold lower than the concentration of commercial products, has a strong inhibitory effect on the growth, initial attachment, and biofilm formation of all tested pathogens. PHMB can also disrupt the preformed biofilms of these pathogens. In contrast, 0.1% UB exhibits a mild inhibitory effect on biofilm formation of the four pathogens. This concentration inhibits the growth of S. aureus and C. albicans yet has no growth effect on P. aeruginosa or E. coli. UB only slightly enhances the anti-biofilm efficacy of PHMB on P. aeruginosa biofilms. However, pretreatment with PslG, a glycosyl hydrolase that can efficiently inhibit and disrupt P. aeruginosa biofilm, highly enhances the clearance effect of PHMB on P. aeruginosa biofilms. Meanwhile, PslG can also disassemble the preformed biofilms of the other three pathogens within 30 min to a similar extent as UB treatment for 24 h.

The Study of Derivatization Prior MALDI MSI Analysis-Charge Tagging Based on the Cholesterol and Betaine Aldehyde.

Mass spectrometry imaging is a powerful tool for analyzing the different kinds of molecules in tissue sections, but some substances cannot be measured easily, due to their physicochemical properties. In such cases, chemical derivatization could be applied to introduce the charge into the molecule and facilitate its detection. Here, we study cholesterol derivatization with betaine aldehyde from tissue slices and evaluate how different sample preparation methods influence the signal from the derivatization product. In this study, we have tested different solutions for betaine aldehyde, different approaches to betaine aldehyde deposition (number of layers, deposition nozzle height), and different MALDI matrices for its analysis. As a result, we proved that the proposed approach could be used for the analysis of cholesterol in different tissues.

Soapwort (Saponaria officinalis L.) Extract vs. Synthetic Surfactants-Effect on Skin-Mimetic Models.

Our skin is continuously exposed to different amphiphilic substances capable of interaction with its lipids and proteins. We describe the effect of a saponin-rich soapwort extract and of four commonly employed synthetic surfactants: sodium lauryl sulfate (SLS), sodium laureth sulfate (SLES), ammonium lauryl sulfate (ALS), cocamidopropyl betaine (CAPB) on different human skin models. Two human skin cell lines were employed: normal keratinocytes (HaCaT) and human melanoma cells (A375). The liposomes consisting of a dipalmitoylphosphatidylcholine/cholesterol mixture in a molar ratio of 7:3, mimicking the cell membrane of keratinocytes and melanoma cells were employed as the second model. Using dynamic light scattering (DLS), the particle size distribution of liposomes was analyzed before and after contact with the tested (bio)surfactants. The results, supplemented by the protein solubilization tests (albumin denaturation test, zein test) and oil emulsification capacity (using olive oil and engine oil), showed that the soapwort extract affects the skin models to a clearly different extent than any of the tested synthetic surfactants. Its protein and lipid solubilizing potential are much smaller than for the three anionic surfactants (SLS, ALS, SLES). In terms of protein solubilization potential, the soapwort extract is comparable to CAPB, which, however, is much harsher to lipids.