Optimization of Bioactive Phenolics Extraction and Cosmeceutical Activity of Eco-Friendly Polypropylene-Glycol-Lactic-Acid-Based Extracts of Olive Leaf.

Olive leaf is a rich source of phenolic compounds with numerous activities related to skin health and appearance. In this study, a green extraction method was developed using eco-friendly solvents: polypropylene glycol (PPG), lactic acid (LA), and water. The optimal extraction conditions were established, including solvent, extraction time, technique (magnetic stirrer vs. ultrasound-assisted extraction), and herbal material/solvent ratio. The composition of the solvent mixture was optimized using a mixture design. The content of phenolic compounds, including oleuropein and verbascoside, was determined using high-performance liquid chromatography (HPLC) and spectrophotometric methods. Using different extraction conditions, three extracts were prepared and their phytochemical compositions and antioxidant and skin-related bioactivities were investigated. The extracts were excellent inhibitors of elastase, collagenase, tyrosinase, and lipoxygenase. The best activity was shown by the extract richest in phenolics and prepared using magnetic-stirrer-assisted extraction for 20 min, with 0.8 g of herbal material extracted in 10 mL of PPG/LA/water mixture (28.6/63.6/7.8, w/w/w), closely followed by the extract prepared using the same extraction conditions but with 0.42 g of herbal material. The investigated PPG/LA/water mixtures contributed to the overall enzyme-inhibitory activity of the extracts. The prepared extracts were appropriate for direct use in cosmetic products, thus saving the time and energy consumption necessary for the evaporation of conventional solvents.

Monochloropropanediol in edible vegetable oils from Hangzhou market in China: occurrence and exposure risk assessment.

In this study, 241 vegetable-oil food samples were collected from the Hangzhou market in China and analysed for fatty acid esters of 3- and 2-monochloropropanediol (3-MCPD and 2-MCPD) using non-derivative gas chromatography tandem mass spectrometry (GC-MS/MS). Food consumption data were taken from a food consumption survey of urban and rural residents in Hangzhou city performed in 2010-2011. Levels of 3-MCPD esters in edible oil ranged from not detected to 7.98 mg/kg, and the highest mean levels were found in tea seed oil, with concentrations of 2.94 mg/kg. Esters of 2-MCPD levels ranged from not detected to 4.03 mg/kg, and the highest mean levels were also found in tea seed oil, containing 1.49 mg/kg. The range of mean dietary intake of 3-MCPD esters in different groups of edible oil was from 0.096 to 1.54 µg/kg body weight (bw) per day, which is lower than the tolerable daily intake (TDI) established by the European Food Safety Authority (EFSA) (2 µg/kg bw/day). For people aged above 6 years old, the dietary intake of 3-MCPD from edible oil was 0.42 µg/kg bw per day (mean) and 1.22 µg/kg bw per day (P97.5). The range of mean dietary intake of 2-MCPD esters in different groups of edible oil was from 0.025 to 0.79 µg/kg bw/day, and 2-MCPD esters intake was 0.20 µg/kg bw per day (mean) and 0.60 µg/kg bw per day (P97.5). In addition, the dietary intake exposure to 3-MCPD and 2-MCPD esters for urban residents was lower than that for rural residents. The findings indicate that the potential health risks caused by dietary 3-MCPD esters from edible oils were of low concern for most of the Hangzhou residents. However, the exposure risk for consumers with excessive consumption of certain kind of edible oil calls for attention.

Automated sample preparation and analysis by gas chromatography tandem mass spectrometry (GC-MS/MS) for the determination of 3- and 2-monochloropropanediol (MCPD) esters and glycidol esters in edible oils.

The potentially carcinogenic process contaminant 3- and 2-monochloropropanediol esters (2-MCPD and 3-MCPD esters) and glycidyl esters (GEs) are under study in refined oils and foodstuffs. Legislation set recommended total daily intake (TDI) for 3-MCPD of 0.8 µg/kg and as low as reasonably achievable (ALARA) for glycidol. Usually, the so far adopted method for the determination of these contaminants relay on numerous and time-consuming steps for sample preparation (AOCS methods) and on GC-MS detection. The obtained sensitivities and the number of processable samples are thus limited. In this optic, new reliable methods that allow for the fast and sensitive determination of these contaminants in edible oils may be considered an improvement of the overall strategy of tackling the problem. In this paper a new automated method for sample preparation and detection by GC-MS/MS is presented and validated. Data on sensitivity (LOD at 1.5, 2.2 and 3 ng/g for 3-MCPD, 2-MCPD, 3-MBPD (deriving from glycidol), respectively), linearity across low and high calibration ranges and precision showed to be fit-for-purposes. Finally, the methodology was applied to ten extra virgin oil samples and one sample of sunflower seeds oil.

Optimization of Two Eco-Friendly Extractions of Black Medick (Medicago lupulina L.) Phenols and Their Antioxidant, Cosmeceutical, α-Glucosidase and α-Amylase Inhibitory Properties.

Medicago lupulina is an ancient edible plant from the Fabaceae family. In this work, two eco-friendly methods for extraction of bioactive phenolics from M. lupulina were developed using mixtures of water with two non-toxic, skin- and environmentally-friendly polyol solvents: glycerol and polypropylene glycol. Ultrasound-assisted extractions were optimized using a Box-Behnken design. The independent variables were the concentration of organic solvent in water (X1), extraction temperature (X2) and time (X3), while the response was phenolic content. The optimum conditions for extraction of polyphenols were (X1, X2, X3): (45%, 70 °C, 60 min) and (10%, 80 °C, 60 min) for glycerol and polypropylene glycol extraction, respectively. The extracts prepared at optimum conditions were rich in phenolic compounds, mainly derivatives of apigenin, kaempferol, luteolin, quercetin, caffeic and ferulic acid, as well as coumestrol. Their cosmeceutical and antidiabetic activity was tested. Both extracts demonstrated notable antioxidant, anti-lipoxygenase and anti-α-amylase activity. In addition to those activities, the glycerol extract efficiently inhibited protein coagulation, elastase and α-glucosidase activity. Glycerol present in the extract displayed enzyme-inhibiting activity in several assays and supported the action of the bioactive constituents. Thus, the optimized glycerol extract is a desirable candidate for direct incorporation in antidiabetic food supplements and cosmeceutical products.

Environmentally friendly processes from coffee wastes to trimethylolpropane esters to be considered biolubricants.

In this study, an eco-friendly renewable biodegradable alternative to petroleum-based oil lubricants was produced using espresso coffee wastes. Waste coffee oil used as raw material was extracted from Espresso coffee wastes by Soxhlet and conventional solvent extraction. Free fatty acids (FFA) were obtained by hydrolysis of the obtained waste oil using Lipozyme TL IM (Thermomyces lanuginosus). The byproduct, glycerol, was also separated from the reaction medium using a separatory funnel. The obtained FFA was used as a raw material in the production of TMP esters. Polyol esters of fatty acids were synthesized as a result of the esterification reaction between FFA and polyol alcohol (trimethylolpropane (TMP)) using Novozyme 435 (Candida antarctica). The amount of FFA in the medium and the FFA conversion was determined by titration with NaOH solution according to ASTM D 5555-95 standard and the FFA composition of espresso coffee oil by GC. The oil content of espresso coffee extract was found to be rich by 16% and the FFA composition was rich in palmitic acid (C16:0 43% by weight) and linoleic acid (C18:2 31% by weight). 31% of FFA was obtained from the coffee oil. Experimental studies have shown that the highest FFA conversion of 88% with 93% TMP tri-ester content was obtained at a temperature of 55°C, 5% enzyme (w/w), non-aqueous media, 3/1 FFA/TMP mole ratio, 500 rpm mixing speed and 24 hours. Implications: Filter coffee wastes, which have become one of the most important biological wastes with an annual production capacity of 6 million tons worldwide; It is targeted to be transformed into environmentally friendly products, as it is important in terms of economy and policies of many developing countries, it is a renewable resource and there is a high amount of waste accumulation day by day. Evaluation of waste filter coffees and oils with this research article; It is envisaged that the bio-lubricating oil used in many sectors will be synthesized and commercialized with an environmentally friendly process.

Mitigating the formation of monochloropropanediol diesters in vegetable oils by removing their residual sediments.

This study investigates whether the formation of monochloropropane diol fatty acid esters (MCPDE) can be mitigated by removing the residual sediments from vegetable oils. Settling and centrifugation were conducted in crude sunflower and palm oil and the purified oils and their sediment-rich fractions were heated and analyzed for their MCPDE content. Increased MCPDE levels by factors of x2 to x6 were found in the sediment-rich fractions of settled sunflower oils compared to the sediment-free oil. The sediment-containing fraction could be however purified by ultracentrifugation resulting in the mitigation of MCPDE levels by a factor of 10. The effect of residual sediment on the MCPDE formation was also confirmed in the case of palm oil showing x2 to x10 more MCPDE formation in the sediment containing fractions compared to the purified oil. These results confirm that the mechanical removal of the trace sediments from crude vegetable oils results in reduced MCPDE levels.

Binary and ternary solid dispersions of an anticancer preclinical lead, IIIM-290: In vitro and in vivo studies.

The objective of this study was to formulate an anticancer preclinical lead, IIIM-290, loaded in solid dispersions to enhance its solubility, dissolution, and oral pharmacokinetics. IIIM-290 is an in-house preclinical anticancer lead prepared by semisynthetic modification of the natural product rohitukine. It is an orally bioavailable Cdk inhibitor showing efficacy in xenograft models of pancreatic, colon and leukemia cancer. It demonstrated in vivo efficacy at a relatively higher dose owing to its poor aqueous solubility (~8.6 µg/mL). Binary and ternary solid dispersions containing PVP K-30, xanthan gum, and PEG-PPG-PEG were selected after solubility screening of various hydrophilic polymers. Several formulations with varying ratios of polymers, alone and in combination, were prepared and investigated for their effects on the solubility enhancement of IIIM-290. The binary solid dispersion VKB-SD75, prepared with PVP K-30 at the ratio of 1:4 w/w, was identified as the optimized composition that displayed 17-fold improvement in the aqueous solubility of IIIM-290. VKB-SD75 was scaled up to a 100-g scale. IIIM-290 and VKB-SD75 were evaluated for DSC, p-XRD, FTIR, 1H NMR, SEM, in vitro dissolution, and oral pharmacokinetics, as well as for in vivo anticancer activity in the Ehrlich solid tumor model. The oral administration of VKB-SD75 in BALB/c mice resulted in a 1.9-fold improvement in plasma exposure. These findings also correlated well when the formulation was administered to mice in the Ehrlich solid tumor model. The newly developed solid dispersion is expected to reduce the dose of IIIM-290 by ~40-50% in preclinical and clinical studies.

Tacrolimus-loaded lecithin-based nanostructured lipid carrier and nanoemulsion with propylene glycol monocaprylate as a liquid lipid: Formulation characterization and assessment of dermal delivery compared to referent ointment.

Nanostructured lipid carriers (NLC) and nanoemulsions (NE) are colloid carriers which could improve dermal delivery of tacrolimus. The aims of this study were to evaluate effects of different formulation and process parameters on physicochemical characteristics and stability of lecithin-based NLC with glyceryl palmitostearate as solid and propylene glycol monocaprylate as liquid lipid and to compare the influence of different inner structure of tacrolimus-loaded NLC and corresponding NE on physicochemical characteristics, stability, entrapment efficiency, in vitro drug release and overall skin performance. Solid/liquid lipid ratio, total amount of lipids, homogenization pressure and cooling after the preparation were identified as critical variables in NLC development. Moreover, tacrolimus-loaded NLC emerged as more stabile carrier than NE. Differential stripping performed on porcine ear skin revealed significantly higher tacrolimus amount in stratum corneum from nanocarriers compared to referent ointment (Protopic®). Similarly the highest amount of tacrolimus in hair follicles was obtained using NLC (268.54 ±â€¯92.38 ng/cm2), followed by NE (128.17 ±â€¯48.87 ng/cm2) and Protopic® (77.61 ±â€¯43.25 ng/cm2). Contrary, the highest permeation rate through full-thickness porcine ear skin was observed for Protopic®, implying that the selection of experimental setup is critical for reliable skin performance assessment. Overall, developed NLC could be suggested as promising carrier in a form of lotion for tacrolimus dermal delivery.

Magnetically Actuated Degradable Microrobots for Actively Controlled Drug Release and Hyperthermia Therapy.

Microrobots facilitate targeted therapy due to their small size, minimal invasiveness, and precise wireless control. A degradable hyperthermia microrobot (DHM) with a 3D helical structure is developed, enabling actively controlled drug delivery, release, and hyperthermia therapy. The microrobot is made of poly(ethylene glycol) diacrylate (PEGDA) and pentaerythritol triacrylate (PETA) and contains magnetic Fe3 O4 nanoparticles (MNPs) and 5-fluorouracil (5-FU). Its locomotion is remotely and precisely controlled by a rotating magnetic field (RMF) generated by an electromagnetic actuation system. Drug-free DHMs reduce the viability of cancer cells by elevating the temperature under an alternating magnetic field (AMF), a hyperthermic effect. 5-FU is released from the proposed DHMs in normal-, high-burst-, and constant-release modes, controlled by the AMF. Finally, actively controlled drug release from the DHMs in normal- and high-burst-release mode results in a reduction in cell viability. The reduction in cell viability is of greater magnitude in high-burst- than in normal-release mode. In summary, biodegradable DHMs have potential for actively controlled drug release and hyperthermia therapy.

Evaluation of miscibility and polymorphism of synthetic and natural lipids for nanostructured lipid carrier (NLC) formulations by Raman mapping and multivariate curve resolution (MCR).

Nanostructured lipid carriers (NLC) belong to youngest lipid-based nanocarrier class and they have gained increasing attention over the last ten years. NLCs are composed of a mixture of solid and liquid lipids, which solubilizes the active pharmaceutical ingredient, stabilized by a surfactant. The miscibility of the lipid excipients and structural changes (polymorphism) play an important role in the stability of the formulation and are not easily predicted in the early pharmaceutical development. Even when the excipients are macroscopically miscible, microscopic heterogeneities can result in phase separation during storage, which is only detected after several months of stability studies. In this sense, this work aimed to evaluate the miscibility and the presence of polymorphism in lipid mixtures containing synthetic (cetyl palmitate, Capryol 90®, Dhaykol 6040 LW®, Precirol ATO5® and myristyl myristate) and natural (beeswax, cocoa and shea butters, copaiba, sweet almond, sesame and coconut oils) excipients using Raman mapping and multivariate curve resolution - alternating least squares (MCR-ALS) method. The results were correlated to the macroscopic stability of the formulations. Chemical maps constructed for each excipient allowed the direct comparison among formulations, using standard deviation of the histograms and the Distributional Homogeneity Index (DHI). Lipid mixtures of cetyl palmitate/Capryol®; cetyl palmitate/Dhaykol®; myristyl myristate/Dhaykol® and myristyl myristate/coconut oil presented a single histogram distribution and were stable. The sample with Precirol®/Capryol® was not stable, although the histogram distribution was narrower than the samples with cetyl palmitate, indicating that miscibility was not the factor responsible for the instability. Structural changes before and after melting were identified for cocoa butter and shea butter, but not in the beeswax. Beeswax + copaiba oil sample was very homogenous, without polymorphism and stable over 6 months. Shea butter was also homogeneous and, in spite of the polymorphism, was stable. Formulations with cocoa butter presented a wider histogram distribution and were unstable. This paper showed that, besides the miscibility evaluation, Raman imaging could also identify the polymorphism of the lipids, two major issues in lipid-based formulation development that could help guide the developer understand the stability of the NLC formulations.

A comparison of different surfactants on foam stability in foam sclerotherapy in vitro.

OBJECTIVE: This article compares the effect of different surfactants on foam stability and determines the foam decay relationship, so that the suitability of surfactants in a clinical setting can be evaluated. METHODS: Five different surfactants were used to prepare sclerosing foam at room temperature using a liquid:gas ratio of 1:4 in vitro. Foam decay experiments were performed for each sample using a laboratory-made foaming apparatus, and the process was recorded using a video camera. The stability indices used included the drainage time, drainage rate, half-life, foam half-life volume, surfactant stability index, and foaming index. RESULTS: The sodium morrhuate foam was relatively more stable than the polidocanol foam, but exhibited weak foaming. After the addition of the surfactants, the foam half-life was less than 300 seconds. The effect of the surfactants on the stability of the sodium morrhuate foam was more pronounced. The surfactant stability indices could be arranged as follows: poloxamer 188 > Tween 80 > macrogol 4000 > propanediol > lecithin. However, the differences in the foaming indices were small. CONCLUSIONS: Of the five surfactants tested, poloxamer 188 has best performance to enhance sclerosing foam stability. The addition of the surfactants improved the stability of the sclerosing foams. It was observed that the relationships between the foam half-life and the surfactant stability index and the surfactant concentration follow the power law.

Novel application of pluronic lecithin organogels (PLOs) for local delivery of synergistic combination of docetaxel and cisplatin to improve therapeutic efficacy against ovarian cancer.

The synergistic combination of docetaxel (DTX) and cisplatin (CIS) by local drug delivery with a pluronic lecithin organogel (PLO) to facilitate high drug concentrations at tumor sites and less nonspecific distribution to normal organs is thought to be beneficial in chemotherapy. In this study, using Capryol-90 (C90) with the addition of lecithin as the oil phase was developed to carry DTX, which was then incorporated into a PLO-containing CIS to formulate a dual-drug injectable PLO for local delivery. An optimal PLO composite, P13L0.15O1.5, composed of PF127:lecithin:C90 at a 13:0.15:1.5 weight ratio was obtained. The sol-gel transition temperature of P13L0.15O1.5 was found to be 33 °C. Tumor inhibition studies illustrated that DTX/CIS-loaded P13L0.15O1.5 could efficiently suppress tumor growth by both intratumoral and peritumoral injections in SKOV-3 xenograft mouse model. Pharmacokinetic studies showed that subcutaneous administration of P13L0.15O1.5 was able to sustain the release of DTX and CIS leading to their slow absorption into the systemic circulation resulting in lower area under the plasma concentration curve at 0-72 h (AUC0-72) and maximum concentration (Cmax) values but longer half-life (T1/2) and mean residence time (MRT) values. An in vivo biodistribution study showed lower DTX and CIS concentrations in organs compared to other treatment groups after IT administration of the dual drug-loaded P13L0.15O1.5. It was concluded that the local co-delivery of DTX and CIS by PLOs may be a promising and effective platform for local anticancer drug delivery with minimal systemic toxicities.

Multifractal and mechanical analysis of amorphous solid dispersions.

The formulation of lipophilic and hydrophobic compounds is a challenge for the pharmaceutical industry and it requires the development of complex formulations. Our first aim was to investigate hot-melt extrudate microstructures by means of multifractal analysis using scanning electron microscopy imaging. Since the microstructure can affect solid dosage form performance such as mechanical properties, a second objective was to study the influence of the type of adsorbent and of the presence of an amorphous compound on extrudate hardness. ß-Carotene (BC) was chosen as poorly water-soluble model compound. Formulations containing a polymer, a lipid and two different silica based inorganic carriers were produced by hot-melt extrusion. Based on scanning electron microscopy/energy dispersive X-ray spectroscopy, the obtained images were analyzed using multifractal formalism. The breaking force of the strands was assessed by a three point bending test. Multifractal analysis and three point bending results showed that the nature of interparticle interactions in the inorganic carrier as well as the presence of amorphous BC had an influence on the microstructure and thus on the mechanical performance. The use of multifractal analysis and the study of the mechanical properties were complementary to better characterize and understand complex formulations obtained by hot-melt extrusion.

Structure/property comparisons of chemistries based on renewable 1,3-propanediol and petroleum-derived alkylene oxides.

Structure/property comparisons were made of chemistries based on renewable 1,3-propanediol (PDO)- versus petroleum-based alkylene oxides as well as comparisons of the respective polyethers, emulsifiers, and cosmetic formulations based on these feedstocks. Green Chemistry Principles were applied in the manufacture of polyethylene glycol (PEG)-free renewable PDO-based oligomers and PDO-based fatty acid ester emulsifiers. Sustainable cosmetic products formulated with renewable PDO-based emulsifiers gave equivalent performance in sensory and moisturization evaluations compared to those formulated with the petroleum-derived PEG-based emulsifiers.

Two natural compounds - a benzofuran and a phenylpropane - from Artemisia dracunculus.

The structure elucidation of three metabolites herniarin (7-methoxy-2H-chromen-2-one, 1), phytoalexin (5-acetyl-6-hydroxy-2-(1-hydroxy-1-methylethyl)benzofuran, 2), and prestragol (3-(4'-methoxyphenyl)-prop-1,2-diol, 3) isolated from Artemisia dracunculus was determined on the basis of 1D, 2D NMR methods and by an X-ray crystallographic determination.

Omega 3 fatty acid-enriched nanoemulsion of thiocolchicoside for transdermal delivery: formulation, characterization and absorption studies.

Thiocolchicoside (TCC) is an effective therapeutic agent against the orthopaedic, traumatic and rheumatologic disorders but it suffer from the drawback of poor bioavailability due to extensive first pass metabolism and low permeability via the oral route. The aim of the present study was to evaluate the potential of nanoemulsion (NE) for bioavailability enhancement of TCC through the transdermal route. The NEs were developed using Linseed: sefsol in 1:1 ratio as the oil phase, span 80, Transcutol P and distilled water as surfactant, co-surfactant and aqueous phase. Furthermore, selected formulations were subjected to physical stability and consequently evaluated for in vitro permeation using porcine skin. The optimized formulation had small average globule diameter of 117 nm with polydispersity index of 0.285. The globules were spherical in shape as observed by transmission electron microscopy. The in vitro skin permeation profile of optimized NE was compared with aqueous solution of TCC. Significant increase in permeability parameters were observed in NEs formulation (p < 0.05) as compared to aqueous solution of TCC. The steady-state flux (Jss) and permeability coefficient (Kp) for optimized NE formulation (C1) were found to be 30.63 ± 4.18 µg/cm(2)/h and 15.21 × 10(-3) ± 2.81cm(2)/h, respectively. The results of enhanced permeation through transdermal route suggest that water-in-oil NEs which are compatible with the lipophilic sebum environment of the hair follicle facilitate the transport of TCC, and such transport might be predominantly transfollicular in nature. Overall, these results suggested that water-in-oil NEs are good carriers for transdermal delivery of TCC.

Integrated method of thermosensitive triblock copolymer-salt aqueous two phase extraction and dialysis membrane separation for purification of lycium barbarum polysaccharide.

A polymer-salt aqueous two-phase system (ATPS) consisting of thermosensitive copolymer ethylene-oxide-b-propylene-oxide-b-ethylene-oxide (EOPOEO) and NaH2PO4 was employed in deproteinization for lycium barbarum polysaccharide (LBP). The effects of salt type and concentration, EOPOEO concentration, amount of crude LBP solution and temperature were studied. In the primary extraction process, LBP was preferentially partitioned to the bottom (salt-rich) phase with high recovery ratio of 96.3%, while 94.4% of impurity protein was removed to the top (EOPOEO-rich) phase. Moreover, the majority of pigments could be discarded to top phase. After phase-separation, the LBP in the bottom phase was further purified by dialysis membrane to remove salt and other small molecular impurities. The purity of LBP was enhanced to 64%. Additionally, the FT-IR spectrum was used to identify LBP. EOPOEO was recovered by a temperature-induced separation, and reused in a new ATPS. An ideal extraction and recycle result were achieved.

Palm oil derived trimethylolpropane triesters synthetic lubricants and usage in industrial metalworking fluid.

Trimethylolpropane triesters are biodegradable synthetic lubricant base oil alternative to mineral oils, polyalphaolefins and diesters. These oils can be produced from trimethylolpropane (TMP) and fatty acid methyl esters via chemical or enzymatic catalyzed synthesis methods. In the present study, a commercial palm oil derived winter grade biodiesel (ME18) was evaluated as a viable and sustainable methyl ester source for the synthesis of high oleic trimethylolpropane triesters (HO-TMPTE). ME18 has fatty acid profile containing 86.8% oleic acid, 8.7% linoleic acid with the remaining minor concentration of palmitic acid, stearic acid and linolenic acid. It's high oleic property makes it superior to produce synthetic lubricant base oil that fulfills both the good low temperature property as well as good oxidative stability. The synthetic base oil produced had a viscosity of 44.3 mm(2)/s at 40°C meeting the needs for ISO 46 oils. It also exhibited an excellent viscosity index of 219 that is higher than some other commercial brands of trimethylolpropane trioleate. Properties of base oil such as cloud point, density, acid value, demulsibility and soap content were also examined. The oil was then used in the formulation of tapping oil and appraised in term of adaptability, stability and field test performance.

Molecularly imprinted polymer for specific extraction of hypericin from Hypericum perforatum L. herbal extract.

The molecularly imprinted polymers (MIPs) were prepared by an oxidation-reduction polymerization system using a non-covalent molecularly imprinting strategy with hypericin as the template, acrylamide as the functional monomer and pentaerythritol triacrylate as the cross-linker in the porogen of acetone. The UV spectrum revealed that a cooperative hydrogen-bonding complex between hypericin and acrylamide might be formed at the ratio of 1:6 in the prepolymerized system. Two classes of the binding sites were produced in the resulting hypericin-imprinted polymer with the dissociation constants of 16.61µgL(-1) and 69.35µgL(-1), and the affinity binding sites of 456.53µgg(-1) and 603.06µgg(-1), respectively. The synthesized MIPs were characterized by scanning electron microscope, thermogravimetric and differential thermal analysis. High-performance liquid chromatography was used to investigate the adsorption and recognition properties of the MIPs. Selective binding of the template molecule was demonstrated in comparison to the analog pseudohypericin. After the Hypericum perforatum L. plant being air dried and finely ground, an extract was prepared by shaking the powder in a methanol-water solution (80:20, v/v), vacuum filtration though a Büchner funnel, liquid-liquid extraction with ethyl ether and ethyl acetate, and evaporating on a rotary evaporator until dry. With the sorbents of the optimized MIPs, a molecularly imprinted solid-phase extraction (MISPE) procedure was developed for enrichment and separation of hypericin from the Hypericum extract in the presence of interfering substances. The selective extraction of hypericin from herbal medicine was achieved with the recovery of 82.30%. The results showed that MISPE can be a useful tool for specific isolation and effective clean-up of target compounds from natural products.

Structure-property relationships and biocompatibility of carbohydrate crosslinked polyurethanes.

Biocompatible and biodegradable polyurethanes (PUs) based on castor oil and polypropylene glycols (PPGs) were prepared using various carbohydrate crosslinkers: monosaccharide (glucose), disaccharide (sucrose) and polysaccharides (starch and cellulose). The mechanical and thermal properties were investigated and interpreted on the basis of SEM study. The advantage of incorporating various carbohydrates is to have tunable mechanical properties and biodegradability due to variety in their structure. The glass transition temperature and sorption behavior were dominated by the type of polyol than by the type of crosslinker. All the PUs were observed to be biodegradable as well as non-cytotoxic as revealed by MTT assay in normal lung cell line L132. The study supports the suitability of carbohydrates as important components of biocompatible PUs for development of biomedical devices.