The formation mechanism and textural properties of a complex gel based on soybean glycinin-chitosan complex coacervates: Effects of pH, heat treatment temperature and centrifugation.

The soybean glycinin (11S)-chitosan (CS) complex gels with various textural properties were successfully constructed. The process involved the initial formation of 11S-CS coacervates through electrostatic interactions, followed by a heating treatment to obtain the final complex gels. The impacts of pH, heating temperature, and centrifugation on 11S-CS complex gel properties were investigated. The results indicated that the pore arrangement of the gel formed at pH 7.3 was more tightly and uniformly packed than those formed at pH 6.8 and 7.8. Centrifugation facilitated denser and more ordered gel structures at the three pH values, while increasing the heating temperature exhibited the opposite trend at pH 6.8 and 7.8. These structural differences were also reflected in the rheological and textural properties of the gel. The 11S-CS complex gels exhibited an elasticity-based gel property. The textural properties of gels formed at pH 6.8 were stronger compared to those formed at pH 7.3 and 7.8. However, when the 11S-CS coacervates were heated without centrifugation, the resulting gels were weak. This study emphasizes the potential of using protein/polysaccharide associative interactions during gel formation to alter the microstructure of the gel, meeting various production requirements.

Ultra High-Performance Liquid Chromatography-Mass Spectrometry and Self-established Database Analysis of Chinese Herbal Medicine Components.

Chinese herbal medicine is complex and has numerous unknown compounds, making qualitative research crucial. Ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) is the most widely used method in qualitative analysis of compounds. The method includes standardized and programmed protocols for sample pretreatment, MS tune, MS acquisition, and data processing. The sample pretreatments include collection, pulverization, solvent extraction, ultrasound, centrifugation, and filtration. Data post-processing was described in detail and includes data importing, self-established database construction, method establishment, data processing, and other manual operations. The above-ground part of the alpine yarrow herb, Achillea millefolium L., is used to treat inflammation, gastrointestinal disturbances, and pain and its 3-oxa-guaianolides could be useful leads for anti-inflammatory drug development. Three representative compounds in AML were identified, combining TOF-MS with a self-established database. Moreover, the differences from existing literature, liquid-phase parameter optimization, scan mode selection, ion source suitability, collision energy adjustment, isomer screening, method limitation, and possible solutions were discussed. This standardized analysis method is universal and can be applied to identify complex compounds in Chinese herbal medicine.

Simultaneous determination of four active compounds in Centella asiatica by supramolecular solvent-based extraction coupled with high performance liquid chromatography-tandem mass spectrometry.

In the present study, a new and rapid method for determining four bioactive compounds of Centella asiatica (C. asiatica) in herbs was developed based on high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). Supramolecular solvent (SUPRAS), formed by n-hexanol, tetrahydrofuran (THF) and water, was used for extracting madecassoside (MS), asiaticoside (AS), asiatic acid (AA) and madecassic acid (MA) from herbs. The sample was extracted with 4 mL of SUPRAS for 5 min. Then centrifugation was performed for phase separation followed by direct analysis by HPLC-MS/MS. Driving forces for the extraction of herbs in the SUPRAS involved both dispersion and hydrogen bond interactions. The effect of the parameters, including compounds of supramolecular solvents, dosage and vortex time, on the extraction efficiency was investigated. The recoveries were carried out at three levels with spiked samples and in the range of 91.6%-99.9%, with relative standard deviations between 1.7%-7.9%. The novel SUPRAS method, coupled with HPLC-MS/MS, was proved to be efficiency, green, and sensitive. It was applied for determination of four target compounds in herbs.

Influence of Centrifugation and Transmembrane Treatment on Determination of Polyphenols and Antioxidant Ability for Sea Buckthorn Juice.

When the total phenolic content (TPC) and antioxidant activity of sea buckthorn juice were assayed by spectrophotometry, the reaction solutions were not clarified, so centrifugation or membrane treatment was needed before determination. In order to find a suitable method for determining TPC and antioxidant activity, the effects of centrifugation and nylon membrane treatment on the determination of TPC and antioxidant activity in sea buckthorn juice were studied. TPC was determined by the Folin-Ciocalteau method, and antioxidant activity was determined by DPPH, ABTS, and FRAP assays. For Treatment Method (C): the sample was centrifuged for 10 min at 10,000 rpm and the supernatant was taken for analysis. Method (CF): The sample was centrifuged for 10 min at 4000 rpm, filtered by Nylon 66 filtration membranes with pore size of 0.22 µm, and taken for analysis. Method (F): the sample was filtered by Nylon 66 filtration membranes with pore size of 0.22 µm and taken for analysis. Method (N): after the sample of ultrasonic extract solution reacted completely with the assay system, the reaction solution was filtered by Nylon 66 filtration membranes with pore size of 0.22 µm and colorimetric determination was performed. The results showed that centrifugation or transmembrane treatment could affect the determination of TPC and antioxidant activity of sea buckthorn juice. There was no significant difference (p > 0.05) between methods (CF) and (F), while there was a significant difference (p < 0.05) between methods (C) (F) (N) or (C) (CF) (N). The TPC and antioxidant activity of sea buckthorn juice determined by the four treatment methods showed the same trend with fermentation time, and the TPC and antioxidant activity showed a significant positive correlation (p < 0.05). The highest TPC or antioxidant activity measured by method (N) indicates that method (N) has the least loss of TPC or antioxidant activity, and it is recommended for sample assays.

Centrifugation-Assisted Solid-Phase Extraction Coupled with UPLC-MS/MS for the Determination of Mycotoxins in ARECAE Semen and Its Processed Products.

Mycotoxins can occur naturally in a variety of agriculture products, including cereals, feeds, and Chinese herbal medicines (TCMs), via pre- and post-harvest contamination and are regulated worldwide. However, risk mitigation by monitoring for multiple mycotoxins remains a challenge using existing methods due to their complex matrices. A multi-toxin method for 22 mycotoxins (aflatoxin B1, B2, G1, G2, M1, M2; ochratoxin A, B, C; Fumonisin B1, B2, B3; 15-acetyldeoxynivalenol, 3-acetyldeoxynivalenol, diace-toxyscirpenol, HT-2, T-2, deepoxy-deoxynivalenol, deoxynivalenol, neosolaniol, zearalenone, and sterigmatocystin) using centrifugation-assisted solid-phase extraction (SPE) clean-up prior to ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis for Arecae Semen and its processed products was developed and validated. Several experimental parameters affecting the extraction and clean-up efficiency were systematically optimized. The results indicated good linearity in the range of 0.1-1000 µg/kg (r2 > 0.99), low limits of detection (ranging from 0.04 µg/kg to 1.5 µg/kg), acceptable precisions, and satisfactory recoveries for the selected mycotoxins. The validated method was then applied to investigate mycotoxin contamination levels in Areca catechu and its processed products. The mycotoxins frequently contaminating Areca catechu were aflatoxins (AFs), and the average contamination level and number of co-occurring mycotoxins in the Arecae Semen slices (Binlangpian) were higher than those in commercially whole Arecae Semen and Arecae Semen Tostum (Jiaobinlang). Sterigmatocystin was detected in 5 out of 30 Arecae Semen slices. None of the investigated mycotoxins were detected in Arecae pericarpium (Dafupi). The results demonstrated that centrifugation-assisted SPE coupled with UHPLC-MS/MS can be a useful tool for the analysis of multiple mycotoxins in Areca catechu and its processed products.

Role of pectin characteristics in orange juice stabilization: Effect of high-pressure processing in combination with centrifugation pretreatments.

"High-pressure processing (HPP) plus" combined technologies are applied to overcome the limitation of single HPP and to produce juices with more stable quality during storage. This research explored the potential of HPP in combination with centrifugation to produce cloud stable orange juice during refrigerated storage. The results indicated that HPP combined processing technology significantly improved the cloud stability of orange juice, which was related to removed large particles, reduced viscosity, decreased protein contents, and inactivated pectin methylesterase activity induced by centrifugation (P < 0.05). Besides, chelator solubilized pectin (CSP) decreased but water solubilized pectin (WSP) maintained in the juice after centrifugation. During storage, the conversion of pectin fraction from WSP to CSP, resulting in sedimentation appeared in centrifugation treated orange juice when stored for 28 days. In general, pectin characteristics changes and pectin fractions conversion were the main driving forces affecting cloud stability of orange juice pasteurized by HPP in combination with centrifugation and during chilled storage.

Activity-Guided Characterization of COX-2 Inhibitory Compounds in Waltheria indica L. Extracts.

Inflammation is the body's response to infection or tissue injury in order to restore and maintain homeostasis. Prostaglandin E2 (PGE-2) derived from arachidonic acid (AA), via up-regulation of cyclooxygenase-2 (COX-2), is a key mediator of inflammation and can also be induced by several other factors including stress, chromosomal aberration, or environmental factors. Targeting prostaglandin production by inhibiting COX-2 is hence relevant for the successful resolution of inflammation. Waltheria indica L. is a traditional medicinal plant whose extracts have demonstrated COX-2 inhibitory properties. However, the compounds responsible for the activity remained unknown. For the preparation of extracts with effective anti-inflammatory properties, characterization of these substances is vital. In this work, we aimed to address this issue by characterizing the substances responsible for the COX-2 inhibitory activity in the extracts and generating prediction models to quantify the COX-2 inhibitory activity without biological testing. For this purpose, an extract was separated into fractions by means of centrifugal partition chromatography (CPC). The inhibitory potential of the fractions and extracts against the COX-2 enzyme was determined using a fluorometric COX-2 inhibition assay. The characterizations of compounds in the fractions with the highest COX-2 inhibitory activity were conducted by high resolution mass spectrometry (HPLC-MS/MS). It was found that these fractions contain alpha-linolenic acid, linoleic acid and oleic acid, identified and reported for the first time in Waltheria indica leaf extracts. After analyzing their contents in different Waltheria indica extracts, it could be demonstrated that these fatty acids are responsible for up to 41% of the COX-2 inhibition observed with Waltheria indica extract. Additional quantification of secondary metabolites in the extract fractions revealed that substances from the group of steroidal saponins and triterpenoid saponins also contribute to the COX-2 inhibitory activity. Based on the content of compounds contributing to COX-2 inhibition, two mathematical models were successfully developed, both of which had a root mean square error (RMSE) = 1.6% COX-2 inhibitory activity, demonstrating a high correspondence between predicted versus observed values. The results of the predictive models further suggested that the compounds contribute to COX-2 inhibition in the order linoleic acid > alpha linolenic acid > steroidal saponins > triterpenoid saponins. The characterization of substances contributing to COX-2 inhibition in this study enables a more targeted development of extraction processes to obtain Waltheria indica extracts with superior anti-inflammatory properties.

Isolation of N-Ethyl-2-pyrrolidinone-Substituted Flavanols from White Tea Using Centrifugal Countercurrent Chromatography Off-Line ESI-MS Profiling and Semi-Preparative Liquid Chromatography.

N-Ethyl-2-pyrrolidinone-substituted flavanols (EPSF) are marker compounds for long-term stored white teas. However, due to their low contents and diasteromeric configuration, EPSF compounds are challenging to isolate. In this study, two representative epimeric EPSF compounds, 5'''R- and 5'''S-epigallocatechin gallate-8-C N-ethyl-2-pyrrolidinone (R-EGCG-cThea and S-EGCG-cThea), were isolated from white tea using centrifugal partition chromatography (CPC). Two different biphasic solvent systems composed of 1. N-hexane-ethyl acetate-methanol-water (1:5:1:5, v/v/v/v) and 2. N-hexane-ethyl acetate-acetonitrile-water (0.7:3.0:1.3:5.0, v/v/v/v) were used for independent pre-fractionation experiments; 500 mg in each separation of white tea ethyl acetate partition were fractionated. The suitability of the two solvent systems was pre-evaluated by electrospray mass-spectrometry (ESI-MS/MS) analysis for metabolite distribution and compared to the results of the CPC experimental data using specific metabolite partition ratio KD values, selectivity factors α, and resolution factors RS. After size-exclusion and semi-preparative reversed-phase liquid chromatography, 6.4 mg of R-EGCG-cThea and 2.9 mg of S-EGCG-cThea were recovered with purities over 95%. Further bioactivity evaluation showed that R- and S-EGCG-cThea possessed in vitro inhibition effects on α-glucosidase with IC50 of 70.3 and 161.7 µM, respectively.

New insights of phenolic compounds from optimized fruit extract of Ficus auriculata.

In this study, the extraction conditions extracted maximize amounts of phenolic and bioactive compounds from the fruit extract of Ficus auriculata by using optimized response surface methodology. The antioxidant capacity was evaluated through the assay of radical scavenging ability on DPPH and ABTS as well as reducing power assays on total phenolic content (TPC). For the extraction purpose, the ultrasonic assisted extraction technique was employed. A second-order polynomial model satisfactorily fitted to the experimental findings concerning antioxidant activity (R2 = 0.968, P < 0.0001) and total phenolic content (R2 = 0.961, P < 0.0001), indicating a significant correlation between the experimental and expected value. The highest DPPH radical scavenging activity was achieved 85.20 ± 0.96% at the optimum extraction parameters of 52.5% ethanol (v/v), 40.0 °C temperature, and 22 min extraction time. Alternatively, the highest yield of total phenolic content was found 31.65 ± 0.94 mg GAE/g DF at the optimum extraction conditions. From the LC-ESI-MS profiling of the optimized extract, 18 bioactive compounds were tentatively identified, which may regulate the antioxidant activity of fruits of F. auriculata.

Isolation of sesquiterpenoids from Matricaria chamomilla by means of solvent assisted flavor evaporation and centrifugal partition chromatography.

The (semi)volatile fraction of Matricaria chamomilla L., an annual herbal plant from the family of Asteraceae, contains high quantities of sesquiterpenes and sesquiterpenoids. A method was developed to achieve isolation and separation of these compounds, using a combination of solvent assisted flavor evaporation (SAFE) and solid support-free liquid-liquid chromatography. The biphasic liquid solvent system n-heptane/ethyl acetate/methanol/water, 5/2/5/2 v/v/v/v (Arizona S) was elaborated as a suitable solvent system for the simultaneous separation of the target compounds. The lab-scale liquid-liquid chromatography separation performed in a countercurrent chromatography (CCC) column was successfully transferred to a semi-preparative centrifugal partition chromatography (CPC) column, which enabled the isolation of artemisia ketone, artemisia alcohol, α-bisabolone oxide A, and (E)-en-yn-dicycloether. α-Bisabolol oxide A and (Z)-en-yn-dicycloether co-eluted, but were successfully separated by subsequent size-exclusion chromatography (SEC). Similarly, spathulenol and α-bisabolol oxide B were obtained as a mixture, and were separated by means of column chromatography using silica gel as stationary phase. The isolated compounds were characterized by means of nuclear magnetic resonance spectroscopy (NMR) and gas chromatography-mass spectrometry (GC-MS).

Polyphenolic Compounds Extracted and Purified from Buddleja Globosa Hope (Buddlejaceae) Leaves Using Natural Deep Eutectic Solvents and Centrifugal Partition Chromatography.

Chemical profiling of Buddleja globosa was performed by high-performance liquid chromatography coupled to electrospray ionization (HPLC-DAD-ESI-IT/MS) and quadrupole time-of-flight high-resolution mass spectrometry (HPLC-ESI-QTOF/MS). The identification of 17 main phenolic compounds in B. globosa leaf extracts was achieved. Along with caffeoyl glucoside isomers, caffeoylshikimic acid and several verbascoside derivatives (ß-hydroxyverbascoside and ß-hydroxyisoverbascoside) were identified. Among flavonoid compounds, the presence of 6-hydroxyluteolin-7-O-glucoside, quercetin-3-O-glucoside, luteolin 7-O-glucoside, apigenin 7-O-glucoside was confirmed. Campneoside I, forsythoside B, lipedoside A and forsythoside A were identified along with verbascoside, isoverbascoside, eukovoside and martynoside. The isolation of two bioactive phenolic compounds verbascoside and forsythoside B from Buddleja globosa (Buddlejaceae) was successfully achieved by centrifugal partition chromatography (CPC). Both compounds were obtained in one-step using optimized CPC methodology with the two-phase solvent system comprising ethyl acetate-n-butanol-ethanol-water (0.25:0.75:0.1:1, v/v). Additionally, eight Natural Deep Eutectic Solvents (NADESs) were tested for the extraction of polyphenols and compared with 80% methanol. The contents of verbascoside and luteolin 7-O-glucoside after extraction with 80% methanol were 26.165 and 3.206 mg/g, respectively. Among the NADESs tested in this study, proline- citric acid (1:1) and choline chloride-1, 2- propanediol (1:2) were the most promising solvents. With these NADES, extraction yields for verbascoside and luteolin 7-O-glucoside were 51.045 and 4.387 mg/g, respectively. Taken together, the results of this study confirm that CPC enabled the fast isolation of bioactive polyphenols from B. globosa. NADESs displayed higher extraction efficiency of phenolic and therefore could be used as an ecofriendly alternative to classic organic solvents.

Centrifugal ultrafiltration preconcentration for studying the colloidal phase of a uranium-containing soil suspension.

The objective of this work was to explore centrifugal ultrafiltration (UF) to separate and / or preconcentrate natural colloidal particles for their characterization. A soil suspension obtained by batch leaching was used as a laboratory reference sample. It was preconcentrated with concentration factors (CF) varying from 10 to 450. The dimensional analysis of the colloidal phase was carried out by Asymmetric Flow Field-Flow Fractionation (AF4)-multidetection. The colloidal masses were estimated by mass balance of the initial suspension, its concentrates and filtrates. The size-dependent distribution (expressed in gyration radius) and total colloidal mass (especially recovery), as well as chemical composition and concentration (including species partitioning between dissolved and colloidal phases) were determined to assess the effects of UF preconcentration on colloidal particles. The gyration radius of the colloidal particles recovered in these concentrated suspensions ranged from about 20 nm to over 150 nm. Neither de-agglomeration nor agglomeration was observed. However, only (64 ± 4) % (CF = 10) of the colloidal particles initially in the soil suspension were found in the recovered concentrated suspensions, and this percentage decreased as CF increased. The filter membrane trapped all other particles, mainly the larger ones. Whatever the CF, the centrifugal UF did not appear to change the dissolved-colloidal partitioning of certain species (Al, organic carbon); whereas it led to an enrichment of the colloidal phase for others (Fe, U). The enrichment rate was specific to each species (15% for Fe; 100% for U). By fitting the observed trends (i.e. conservation, depletion or enrichment of the colloidal phase in the concentrate) as a function of CF, the colloidal concentrations (total and species) were assessed without bias. This methodology offers a new perspective for determining physicochemical speciation in natural waters, with a methodology applicable for environmental survey or site remediation studies.

Target-Guided Isolation of O-tigloylcyclovirobuxeine -B from Buxus sempervirens L. by Centrifugal Partition Chromatography.

The increasing drug resistance of malaria parasites challenges the treatment of this life-threatening disease. Consequently, the development of innovative and effective antimalarial drugs is inevitable. O-tigloylcyclovirobuxeine-B, a nor-cycloartane alkaloid from Buxussempervirens L., has shown promising and selective in vitro activity in previous studies against Plasmodiumfalciparum (Pf), causative agent of Malaria tropica. For further investigations, it is indispensable to develop an advanced and efficient isolation procedure of this valuable natural product. Accordingly, we used liquid-liquid chromatography including centrifugal partition chromatography (CPC) to obtain the pure alkaloid on a semi-preparative scale. Identification and characterization of the target compound was accomplished by UHPLC/+ESI-QqTOF-MS/MS, 1H NMR and 13C NMR. In conclusion, this work provides a new and efficient method to obtain O-tigloylcyclovirobuxeine-B, a valuable natural product, as a promising antiplasmodial lead structure for the development of innovative and safe medicinal agents.

Salting-out strategy for speciation of selenium in aqueous samples using centrifuge-less dispersive liquid-liquid microextraction.

The centrifuge-less dispersive liquid-liquid microextraction (DLLME) technique was used to separate selenium species in aqueous samples. According to the salting-out effect, a simple approach was used to eliminate the centrifugation step. The optimization of the independent variables was performed using chemometric methods. Under optimal conditions, this methodology was statistically validated. The linearity was between 20 and 300 µg L-1. The limit of detection and quantification were calculated 3.4 µg L-1 and 10.4 µg L-1, respectively. The values of reproducibility and repeatability were determined ≤ 9.5% and ≤ 6.4, respectively. The possibility of the method was successfully assessed by analyzing the analytes in real samples clarified satisfactory recoveries (98.1-101.4% for Se (IV) and 98.4-101.5% for Se (VI)).

A highly-efficient and cost-effective pretreatment method for selective extraction and detection of perchlorate in tea and dairy products.

In view of the high polarity and ubiquitous occurrence of perchlorate, achieving an ultra-trace analysis has become a challenging task. The present study aimed to develop a simple and generic pretreatment protocol based on cold-induced liquid-liquid extraction to efficiently extract perchlorate from tea and dairy products and remarkably decrease potential matrix interferences and laborious cleanup. By optimizing the pretreatment conditions, the enrichment factor of perchlorate increased by 7.79 times under the compromise between the matrix effect and extraction recovery. The validated method presented satisfactory selectivity, linearity, accuracy, precision, and matrix effect, providing recoveries of 78.2%-106.2% with RSDr ranging from 1.2% to 7.9% and RSDR less than 10.7% for tea and dairy products. This pretreatment protocol depended only on shaking, freezing, and centrifugation in one step, without additional equipment or tedious operations, which will be explored to a greater extent in complex biological or food matrices.

New protocol to separate llama sperm without enzymatic treatment using Androcoll-E™.

The objective of this study was to design a protocol to separate spermatozoa from seminal plasma of raw llama semen without prior enzymatic treatment using a single-layer centrifugation with Androcoll-E™ (AE). Two experiments were performed: (a) samples were divided into three aliquots (1 ml) that were deposited on the top of 4, 5 or 6 ml of AE and were centrifuged at 800g for 20 min and (b) samples were divided into two aliquots (1 ml) that were deposited on the top of 4 ml of AE and were centrifuged at 600g or 1,000g for 20 min. Columns of 5 and 6 ml of AE showed a total sperm motility (TM) significantly lower, while in the 4 ml column, this parameter was not different from the TM of samples before the AE treatment. The percentage of spermatozoa with intact and functional membranes, normal morphology and intact acrosomes, as well as the percentages of sperm with highly condensed chromatin, was conserved (p Ëƒ .05) in the three column heights and in the two centrifugation speeds evaluated. In conclusion, the different column heights of AE (4, 5 and 6 ml) and the different centrifugation speeds used (600, 800 and 1,000g) allow separating spermatozoa of raw llama semen without enzymatic treatment, preserving the evaluated sperm characteristics. However, of all the studied treatments, centrifugation in the 4 ml column of AE at 800g would be the method of choice to process raw llama semen samples destined for reproductive biotechnologies.

Membrane Extracts from Plant Tissues.

The comparison of isolated plant cell membranous enclosures can be hampered if their extraction method differs, e.g., in regard to the utilized buffers, the tissue, or the developmental stage of the plant. Thus, for comparable results, different cellular compartments should be isolated synchronously in one procedure. Here, we devise a workflow to isolate different organelles from one tissue, which is applicable to different eudicots such as Medicago x varia and Solanum lycopersicum. We describe this method for the isolation of different organelles from one plant tissue for the example of Arabidopsis thaliana. All compartments are retrieved by utilizing differential centrifugation with organelle-specific parameters.

Development of a scalable procedure by a discontinuous crossflow DF/UF to obtain a concentrate of chenopodin from a dead-end centrifugal UF at bench scale.

The aim of this study was to develop a scalable crossflow diafiltration/ultrafiltration procedure for quinoa 11S globulin purification starting at the bench scale using Ultra15 centrifugal filter devices. The electrophoretic profiles of centrifugal ultrafiltration fractions showed a high heterogeneity in the bands, while crossflow ultrafiltration reduced the phenomena of protein sticking to the membrane, avoiding aggregate formation. In the crossflow protein concentration, flux decline curves were studied according to Hermia's fouling mechanisms and the resistance in a series model. High reversible resistance was related to external mechanisms due to complete blockage of the membrane surface followed by cake formation. The crossflow ultrafiltration was the most efficient technique for obtaining 57 kDa chenopodin isolate with higher processing capacity, purity and protein yield. The diafiltration/ultrafiltration process proved to be adequate and easy to handle to scale up the production of the 11S quinoa globulin.

Lower facial regeneration with a combination of platelet-rich fibrin liquid matrices based on the low speed centrifugation concept-Cleopatra technique.

BACKGROUND: Autologous blood concentrates are increasingly being applied in esthetic medicine and dentistry due to their safety and their potential beneficial properties. Platelet-rich fibrin based on the low speed centrifugation, a newly described blood product, seems to convey additional properties in several in vitro and ex vivo studies. Its clinical significance however in relation to facial regeneration remains anecdotal. OBJECTIVE: The aim of this study was to assess a specific combination of PRF liquid matrices utilized for lower facial regeneration (Cleopatra technique). PATIENTS/METHODS: Cleopatra technique was applied in 32 patients. In addition to recording of all patients' complaints and adverse events, a photographical study was performed. Possible positive effects were assessed by asking twenty-three independent reviewers to distinguish initial and later photographs of each patient. RESULTS: A statistically significant percentage of true answers by the reviewers was noted upon completion of the treatment (U = 110.5, P < .001), which indicates a clinically significant effect of Cleopatra technique. Moreover, only few minor, self-limited adverse events were recorded. CONCLUSIONS: Cleopatra technique is a well-tolerated and effective method of lower facial rejuvenation that deserves further attention from dentists and other health professional who utilize conservative methods in facial esthetics.

Purification of thonningianins A and B and four further derivatives from Thonningia sanguinea by one- and two-dimensional centrifugal partition chromatography.

Thonningia sanguinea is a parasitic herb widely used in traditional African medicine. Dihydrochalcone glucosides (unsubstituted, substituted with hexahydroxydiphenoyl or galloyl moieties) are the main constituents in the subaerial parts of this plant. In the present study, purification of the six major compounds from a methanol extract of the plant's subaerial parts was achieved by centrifugal partition chromatography. A first dimension centrifugal partition chromatography separation with the solvent system methyl tert-butyl ether/1,2-dimethoxyethane/water (1:2:1) in the ascending mode enabled the isolation of the two major bioactive compounds thonningianin A and B from 350 mg of methanol extract within only 16 min with respectable yields (25.7 and 21.1 mg), purities (87.1 and 85%), and recoveries (71.2 and 70.4%). Using a multiple heart-cutting strategy, the remaining four major dihydrochalcone glucosides of the extract were further separated in a second dimension centrifugal partition chromatography with the solvent system ethyl acetate/1,2-dimethoxyethane/water (2:1:1) in the descending mode with high purities (88.9-98.8%).