Preparation and characterization of a nanostructured lipid carrier for phenylethyl resorcinol

Phenylethyl resorcinol(PR)demonstrates inhibitory effects on multiple targets in the melanin synthesis pathway,resulting in a strong whitening effect.However,challenges such as limited solubility in water and susceptibility to oxidation and discoloration restrict its practical application in the cosmetics industry.In order to enhance stability and performance characteristics,a whitening nanostructured lipid carrier(NLC)was synthesized through high-pressure homogenization.This method entailed the incorporation of solid lipids,a liquid lipid,and a compound emulsifier,with deionized water fulfilling the roles of solid phase,liquid phase,and water phase,respectively.The NLC's particle size,Zeta potential,stability,encapsulation efficiency,and other parameters were assessed using techniques such as particle sizer,stability analyzer,and HPLC.The results showed that the NLC for phenylethyl resorcinol prepared by using the optimal formula(7.50%solid lipids,3.00%ethylhexyl palmitate,and 2.00%Tween 80 and soybean lecithin)has an encapsulation efficiency of 87.11%,a particle size of 157.2±0.70 nm,a kinetic instability of less than 1.2,and a greatly improved stability,thereby successfully solving the problems of unstable storage and poor solubility of phenylethyl resorcinol.

New 5-Alkenyl Resorcinols from <i>Lithraea molleoides</i>(Vell). Eng.

Lithraea molleoides (Anacardiaceae) is a tree that grows in South America including Southern Brazil, Southern, and Eastern Bolivia, Southern Paraguay, Northern, and Central Argentina. Infusions, decoctions, or tinctures from its aerial parts (leaves, buds, and young stems) are employed in ethnomedicine mainly against respiratory, and digestive inflammations and illnesses. Antibacterial, antiviral, antioxidant, anti-inflammatory, and antinociceptive activities, among others, have been reported for L. molleoides. Many of its biological activities have been associated with the reported presence of 5-alkenyl resorcinols. Alkyl/alkenyl catechols and alkyl/alkenyl resorcinols are very common in members of the Anacardiaceae family and several activities have been attributed to them. This work describes the isolation and the structural elucidation of three new 5-alkenyl resorcinols isolated from Lithraea molleoides reported in nature for the first time.

Vesicular carriers containing phenylethyl resorcinol for topical delivery system; liposomes, transfersomes and invasomes

Topical administration of phenylethyl resorcinol(PR) has attracted much attention as skin lightening agent with potent anti-tyrosinase activity. Two novel types of elastic carriers were developed to overcome the limitation of PR as topical delivery by increasing the solubility, stability and decreasing skin irritation compared to conventional liposomes. In addition, it also promotes skin penetration of PR to reach deep skin layer at the target site. The lead formulations were obtained from the invasomes containing 1%(w/v) d-limonene mixed with 10%(v/v) absolute ethanol as the skin enhancer, and transfersomes containing 15%(w/w) sodium deoxycholate(SDC) as edge activator. All formulations gave a vesicle size < 500 nm, polydispersity index(PDI) < 0.3, high zeta potential, entrapment efficiency > 50%, and good stability on storage at 30 °C at 75% RH for 4 months. Transfersomes have a lower degree of deformability(6.63%) than invasomes(25.26%). In contrast, the liposomes as rigid vesicles do not show a deformable property. This characteristic affects the skin permeation, and thus, transfersomes with high elastic property provided a significantly higher cumulative amount, steady state flux( J ss) and permeability coefficient( K p) compared to other formulations. However, in vitro PR accumulation in full-thickness newborn pig skin demonstrated that the application of elastic carrier formulations gave significantly higher accumulation than liposomes, and gave anti-tyrosinase activity up to 80%. These results are straightforwardly related to the results of cellular level study. Transfersomes and invasomes showed higher tyrosinase inhibition activity and melanin content reduction when compared to liposomes in B16 melanoma cells. In addition, acute irritation test in rabbits confirmed that these formulations are safe for skin application. Therefore, elastic vesicle carriers have theefficiency to deliver PR into the deep skin in both quantity and effectiveness which are better than conventional liposomes and appropriate for a skin lightening product.

Resorcinol-formaldehyde resin-based porous carbon spheres with high CO_2 capture capacities

Porous carbon spheres are prepared by direct carbonization of potassium salt of resorcinol-formaldehyde resin spheres, and are investigated as COadsorbents. It is found that the prepared carbon materials still maintain the typical spherical shapes after the activation, and have highly developed ultra-microporosity with uniform pore size, indicating that almost the activation takes place in the interior of the polymer spheres. The narrow-distributed ultra-micropores are attributed to the "in-situ homogeneous activation"effect produced by the mono-dispersed potassium ions as a form of -OK groups in the bulk of polymer spheres. The CS-1 sample prepared under a KOH/resins weight ratio of 1 shows a very high COcapture capacity of 4.83 mmol/g and good CO/Nselectivity of7-45. We believe that the presence of a welldeveloped ultra-microporosity is responsible for excellent COsorption performance at room temperature and ambient pressure.

Mechanistic insights into the selective hydrogenation of resorcinol to 1,3-cyclohexanedione over Pd/rGO catalyst through DFT calculation

In our previous work, graphene-supported Pd catalyst(Pd/rGO) exhibited higher activity and selectivity for the liquid phase selective hydrogenation of resorcinol to 1,3-cyclohexanedione compared with other catalysts. In the present study, further experimental and theoretical investigations were conducted to reveal the reaction mechanism and the catalytic mechanism of Pd/rGO for resorcinol hydrogenation. The effects of graphene nanosheet and the solvent on the reaction were investigated, and the pathway for resorcinol hydrogenation was proposed supported by density functional theory(DFT) calculations. The results showed that the excellent selectivity of Pd/rGO to 1,3-cyclohexanedione was attributed to the strong π–π and p–π interactions between the graphene nanosheet and the benzene ring as well as hydroxyl in resorcinol molecule, which was in agreement with our previous speculation. In weak polar aprotic solvents, solvation free energy had less impact to the π–π and p–π interactions mentioned above. In strong polar aprotic solvents and polar protic solvents,however, the influence of solvation free energy was much greater, which led to the decrease in the conversion of resorcinol and the selectivity to 1,3-cyclohexanedione.

Measurement and correlation of phase equilibrium data of the mixtures consisting of water, resorcinol, mesityl oxide at different temperatures

Liquid–liquid equilibrium(LLE) data were measured for the ternary system of water + resorcinol + mesityl oxide under atmospheric pressure at temperatures of(298.2, 323.2, 333.2, 343.2 and 353.2) K. The reliability of the experimental data was verified by the Hand and Bachman equations. The distribution coefficient and selectivity were calculated from the experimental LLE data, which showed high efficiency of mesityl oxide extracting resorcinol from the aqueous solution. The NRTL and UNIQUAC models were employed to fit the measured experimental LLE data and yield corresponding binary interaction parameters.

Induction of apoptosis on human hepatocarcinoma cell lines by an alkyl resorcinol isolated from Lithraea molleoides

AIM: To study the mechanism of cytotoxicity of a new active 5-alkyl resorcinol [1, 3-dihydroxy-5- (tridec-4’, 7’ -dienyl) benzene] isolated from Lithraea molleoides leaves on liver tumor cells. METHODS: Human hepatocarcinoma cell lines (HepG2 and Hep3B) in culture were treated with inhibitory concentrations, 50% of the compound, for 24 h. The induction of apoptosis was detected in treated cells by analysis of DNA fragmentation, DNA content, and acridine orange and propidium iodide staining. RESULTS: After 24 h of 5-alkyl resorcinol treatment, both cell lines showed: (1) the typical morphological alterations of apoptosis; (2) DNA fragmentation, detected by laddering and appearance of a subG0 population by flow cytometry; and (3) condensed and fragmented nuclei by acridine orange-propidium iodide staining. CONCLUSION: Based on the results, this compound exerts its cytotoxic effect in both hepatocellular cell lines through apoptotic cell death. For Hep3B, cells with mutated p53 and Fas, apoptosis would proceed by p53- or Fas-independent pathways.

NaOH and Ba(OH)_2 Compound Catalyzed PhenolResorcinol-Formaldehyde Copolycondensation Resin Adhesive for Recombined Bamboo

In order to reduce the curing temperature, shorten the curing time of phenol-formaldehyde(PF) resin adhesive, and ensure the good water-solubility, NaOH and Ba(OH)_2 were used as compound catalysts. The influences of the adding time of Ba(OH)_2, the adding amount of NaOH, Ba(OH)_2 and resorcinol on the properties of adhesives were studied. The properties of NaOH catalyzed phenol-formaldehyde(PF) adhesive, NaOH and Ba(OH)_2 compound catalyzed PF adhesive, NaOH and Ba(OH)_2 compound catalyzed phenol-resorcinol-formaldehyde(PRF) adhesive, and the prepared recombinant bamboo with three kinds of adhesives were compared. The experimental results show that NaOH and Ba(OH)_2 compound catalyst not only shortens the curing time of PF adhesive, but also guarantees the suitable water solubility of adhesive. After copolycondensation with resorcinol, the curing time of adhesive is further shortened, the water solubility is improved obviously, and the highest bonding strength is obtained. Infrared spectrum analysis shows that the reaction activity point of NaOH and Ba(OH)_2 compound catalyzed PRF adhesive will increase, so that both the curing temperature and curing enthalpy decrease.

A NOVEL EOR POLYMER (Ⅰ)—STUDY ON GELATION OF RESORCINOL-FORMALDEHYDE SYSTEMS

Factors affecting the gelation of resorcinol-formaldehyde systems have been examined overvariable ranges applicable to oilfield use. Gelation of resorcinol-formaldehyde (RF) system wassensitive to pH,salinity and hardness. Generally,this gel system could be used in fresh water orlow salinity brine at pH higher than about 9. The application would require careful monitoring ofinjection fluids to avoid premature gelation or prolonged shut-in times,especially under conditionsof low salinity and high pH. Salinity and hardness compatibilities of the system were improved bysulfomethylation of resorcinol. Aqueous sulfomethylated resorcinol formaldehyde (SMRF)system could be used in brine with higher salinity and hardness and at a wider pH range of 5--10.

Simultaneous deternubation of the contents of phenol and resorcinol in compound resorcinol paint by linear combination method of absorbances

Linear combination method of absorbances was used for the simultaneous determinationof phenol and resorcinol whose absorption spectra overlap severely in the compound resorcinolpaint.The determination wavelengths were 265.0nm,270.0nm,273.4nm and 278.0nm.The averagerecoveries for phenol and resorcinol were 100.28±0.30% and 99.52±0.22%,respectively.

Study on CeO_2/CuFe_2O_4 Catalytic Ozonation of Resorcinol

In order to improve the catalytic ozonation effect of resorcinol, the spinel CuFe_2O_4 was modified by doped CeO_2, and X-ray diffraction(XRD) and scanning electron microscopy(SEM) were used for characterization analysis. The effects of composite catalyst CeO_2/CuFe_2O_4 dosage, ozone dosage, initial pH and reaction temperature on degradation were studied, and the stability of the catalyst was tested. The results showed that the composite effect of CeO_2/CuFe_2O_4 prepared by combustion method was good, and the catalyst presented a laminated structure, in which 30 wt% CeO_2/CuFe_2O_4 degradation effect was significant. The removal rate of resorcinol using CeO_2/CuFe_2O_4 composite catalyst was higher than that using ozone or CuFe_2O_4 separately by 41.8% and 11.9%, respectively. In a reaction with resorcinol concentration of 100 mg/L, the catalyst dosage of 1.0 g/L, the ozone dosage of 2.5 mg/(L·min), at pH=9, temperature of 20 ℃, for reaction time of 40 min, the resorcinol removal rate was 88.5%. The catalyst CeO_2/CuFe_2O_4 still showed good degradation effect after repeatedly using for 10 times, and the dissolution rate of metal ions was lower than that of CuFe_2O_4.

Surface grafting of resorcinol onto polyethylene film

Low density polyethylene film surface-grafted resorcinol was prepared by a sequential process.Firstly, acrylic acid was grafted to the surface of low density polyethylene by UV photo-grafting.Secondly, the carboxylic groups in poly（acrylic acid） chains were transferred to acyl chloride groups by the reaction of carboxylic groups with thionyl chloride.The stability of acyl chloride groups in several solvents（alcohol, water, acetone, aqueous NaOH and in N2 atmosphere） was investigated, and N2 atmosphere and acetone were appropriate media to protect acyl chloride groups from side reaction.Finally, resorcinol monomer reacted with acyl chloride to append to the poly（acrylic acid）chains at room temperature.FT-IR-ATR was used to characterize the change of carbonyl groups during each step of the grafting process.Furthermore, by the experimental data of gravimetric analysis the grafted resorcinol monomer on the surface of low density polyethylene film was verified to have undergone condensation with acetone further in the resorcinol/acetone solution at 56℃, which might be a useful feature for synthesizing a thermoplastic/thermosetting composition.

基于与间苯二酚的亚硝化反应光度法测定水中亚硝酸根

为拓宽光度法测定水中亚硝酸根的线性范围,文章提出了一种基于与间苯二酚的亚硝化反应测定水中亚硝酸根的新方法。在盐酸介质中,亚硝酸根与间苯二酚发生亚硝化反应生成对亚硝基间苯二酚,对亚硝基间苯二酚在pH值为9.97的碱性介质中快速异构化成橙黄色的邻羟基对苯醌单肟,采用分光光度计测定其在351 nm处的吸光度。结果表明,亚硝酸根浓度在0.08 mg/L~1.40 mg/L范围内与吸光度呈良好的线性关系,方法的检出限为0.02 mg/L,用于河水和池塘水中亚硝酸根的测定,回收率在96.3%~102.0%之间,相对标准偏差小于2.35%,测定值与标准方法的参考值吻合。该方法为环境水中亚硝酸根的测定提供了新方法和新思路。

比较两种常见的前驱物合成的聚合物及碳基微球材料

聚合物/碳基微球材料以其独特的骨架结构、优异的物理化学性能及广阔的应用前景,成为当下纳米材料研究和开发的热点领域之一。近年来,人们发展了两种常见的前驱物——间苯二酚/甲醛和多巴胺,来相对容易地在实验室合成制备聚合物/碳基微球材料。对这两种前驱物的不同的组成、化学结构、聚合反应机理等进行了系统的比较。此外,围绕合成与应用,对该领域研究存在的机遇与挑战进行了合理的展望。

新型供体-受体g-C_(3)N_(4)有机半导体光催化铀分离技术

从核废水中光催化提取铀是避免环境破坏和回收铀资源的一种可行方法,但设计具有快速迁移光生电荷和表面反应动力学的高效光催化剂用于去除含铀废水中的U(Ⅵ)仍然是一个重大挑战。采用无模板的自组装技术,成功构建了空心管状g-C_(3)N_(4)(TCN),并通过将间苯二酚引入TCN的骨架结构中,制备了管状供体-受体(D-A)有机半导体光催化剂B-TCN_(x),用于空气气氛下光催化去除U(Ⅵ)。分子内D-A体系的构建,使得电子和空穴分别聚集在受体和供体部分,这降低了电子-空穴对的复合。此外,电子和空穴在受体和供体部分的积累导致了内置电场的形成,从而促进了载流子的迁移。结果表明,B-TCN_(60)在120 min内对U(Ⅵ)的去除率达到96.8%,其动力学常数(0.031 14 min^(-1))是TCN (0.012 15 min^(-1))的2.58倍。并且在连续5次循环后变化不大,具有稳定性和可重复性。因此,D-A光催化剂具有很高的光催化铀分离效率。这项研究为深入了解光催化铀分离提供了启示和指导。

Adsorptive removal of resorcinol on a novel ordered mesoporous carbon(OMC) employing COK-19 silica scaffold:Kinetics and equilibrium study

Phenolic compounds and their derivatives have been found in industrial wastewater, which pose threats to the natural environment. Ordered mesoporous carbon(OMC) has been identified as an ideal adsorbent possessing high specific surface area and large pore volume to alleviate these pollutants. A novel ordered mesoporous carbon was prepared using COK-19 template with the cubic Fm3 m structure for the first time. Ordered mesoporous silica COK-19 was synthesized and reported in 2015. Sucrose as the carbon precursor was impregnated into the mesopores of silica and converted to carbon through carbonization process using sulfuric acid as a catalyst. Ordered mesoporous carbon was obtained after the removal of silica framework using hydrofluoric acid. Boric acid was employed for the preparation of OMCs with tunable pore sizes in the range of 6.9–16.6 nm. Several characterization techniques such as nitrogen adsorption–desorption isotherms, transmission electron microscope(TEM), Fourier transform infrared spectroscopy, Boehm titration and elemental analysis were employed to characterize the OMCs. The pore size analysis and TEM images confirmed that OMC has replicated the mesostructure of the COK-19. Results obtained from adsorption kinetics and isotherms suggest that the Pseudo-second-order model and Langmuir isotherm well described the experimental data.

应用间苯三酚治疗分娩所致宫颈水肿的临床疗效评价

目的分析产妇分娩所致宫颈水肿采用间苯三酚治疗的作用效果。方法选取2022年4月—2023年4月寿光市人民医院收治的90例分娩导致宫颈水肿的产妇为研究对象。利用随机数表法将其分为两组,各45例。对照组采用利多卡因+阿托品治疗,观察组采用间苯三酚治疗。对比两组临床疗效、产程时间、分娩相关指标、宫颈水肿消退率与经阴道分娩率。结果观察组治疗总有效率为93.33%,高于对照组的77.78%,差异有统计学意义(χ^(2)=4.405,P=0.035)。观察组第1、2、3产程时间均短于对照组,差异有统计学意义(P均<0.05)。观察组宫口扩张速度、新生儿Apgar评分、宫口全开时间及产后2 h出血量优于对照组,差异有统计学意义(P均<0.05)。观察组宫颈水肿消退率和经阴道分娩率均高于对照组,差异有统计学意义(P均<0.05)。结论产妇分娩所致宫颈水肿采取间苯三酚治疗效果更优,可促进宫口扩张,缩短产程时间,利于提高新生儿Apgar评分与经阴道分娩率。

酚醛树脂基硬碳负极材料的性能

石墨负极有限的理论容量和倍率性能限制锂离子电池的发展,制备硬碳负极材料可提高理论容量。以间苯二酚和甲醛为前驱体,氨水为催化剂,通过水热法制备酚醛树脂基硬碳材料。采用SEM、高分辨透射电子显微镜(TEM)、XRD及N2吸-脱附对材料的形貌和结构进行分析,并以金属锂片为对电极组装扣式电池,测试电化学性能。硬碳样品具有典型的双电层电容和充放电可逆性,电极以50 mA/g电流在0.01~3.00 V循环,首次放电比容量达到311.22 mAh/g,首次库仑效率为60.07%,循环50次的容量保持率为75.7%,在经过不同电流循环后,基本能恢复到电流变化前的容量,表现出良好的循环稳定性和倍率性能。

Pd/TiO_(2)-C催化剂的制备及其对邻苯二甲酸酯苯环加氢的催化性能

以间苯二酚-甲醛树脂作为碳源、TiO_(2)为添加剂,采用浸渍法制备了Pd负载的二氧化钛-碳催化剂。通过XRD、TEM-EDS等表征手段发现Pd纳米粒子均匀地负载在二氧化钛-碳载体上。同时通过邻苯二甲酸二异辛酯(DOP)的加氢实验研究了该催化剂的加氢性能,考察了二氧化钛添加量、反应温度等条件对加氢性能的影响。结果表明:在TiO_(2)添加量为10%、反应温度为140℃条件下,DOP加氢的转化率为100%,目标产物选择性为91%,且该催化剂呈现出优异的重复使用性能。

橡胶用间苯二酚甲醛树脂的合成

以间苯二酚、苯乙烯和甲醛为原料合成间苯二酚甲醛树脂,考察不同催化剂和工艺条件对合成树脂性能的影响。结果表明,以对甲苯磺酸为催化剂,调整物质的量等反应条件,可制得软化点109℃的间苯二酚甲醛树脂,以间苯二酚甲醛树脂制备的硫化橡胶硫化性能和物理性能与采用间苯二酚制备的硫化橡胶相当,满足目前子午线轮胎粘合的需要。