RSS and ROS Sequentially Activated Carbon Monoxide Release for Boosting NIR Imaging-Guided On-Demand Photodynamic Therapy.

Carbon monoxide shows great therapeutic potential in anti-cancer. In particular, the construction of multifunctional CO delivery systems can promote the precise delivery of CO and achieve ideal therapeutic effects, but there are still great challenges in design. In this work, a RSS and ROS sequentially activated CO delivery system is developed for boosting NIR imaging-guided on-demand photodynamic therapy. This designed system is composed of a CO releaser (BOD-CO) and a photosensitizer (BOD-I). BOD-CO can be specifically activated by hydrogen sulfide with simultaneous release of CO donor and NIR fluorescence that can identify H2S-rich tumors and guide light therapy, also depleting H2S in the process. Moreover, BOD-I generates 1O2 under long-wavelength light irradiation, enabling both PDT and precise local release of CO via a photooxidation mechanism. Such sequential activation of CO release by RSS and ROS ensured the safety and controllability of CO delivery, and effectively avoided leakage during delivery. Importantly, cytotoxicity and in vivo studies reveal that the release of CO combined with the depletion of endogenous H2S amplified PDT, achieving ideal anticancer results. It is believed that such theranostic nanoplatform can provide a novel strategy for the precise CO delivery and combined therapy involved in gas therapy and PDT.

Designing nanohesives for rapid, universal, and robust hydrogel adhesion.

Nanoparticles-based glues have recently been shown with substantial potential for hydrogel adhesion. Nevertheless, the transformative advance in hydrogel-based application places great challenges on the rapidity, robustness, and universality of achieving hydrogel adhesion, which are rarely accommodated by existing nanoparticles-based glues. Herein, we design a type of nanohesives based on the modulation of hydrogel mechanics and the surface chemical activation of nanoparticles. The nanohesives can form robust hydrogel adhesion in seconds, to the surface of arbitrary engineering solids and biological tissues without any surface pre-treatments. A representative application of hydrogel machine demonstrates the tough and compliant adhesion between dynamic tissues and sensors via nanohesives, guaranteeing accurate and stable blood flow monitoring in vivo. Combined with their biocompatibility and inherent antimicrobial properties, the nanohesives provide a promising strategy in the field of hydrogel based engineering.

Manganese-enriched photonic/catalytic nanomedicine augments synergistic anti-TNBC photothermal/nanocatalytic/immuno-therapy via activating cGAS-STING pathway.

As the clinical efficacy of immunotherapy for triple-negative breast cancer (TNBC) remains limited, exploring new immunotherapy approaches is still indispensable. Mn2+ has been proven as a cGAS-STING agonist to remarkably enhance antitumor immunity. Here, we report a combined tumor-therapeutic strategy based on Prussian blue (PB)-mediated photothermal therapy with Mn2+-augmented immunotherapy by synergistically activating the cGAS-STING pathway. Mn-enriched photonic nanomedicine (MnPB-MnOx) were constructed by integrating MnOx onto the surface of Mn-doped PB nanoparticles. All components of MnPB-MnOx are biocompatible and biodegradable, wherein sufficient Mn are endowed through rational nanostructure design, conferring easier cGAS-STING activation. Additionally, tumor hyperthermia strengthened by MnPB under near-infrared light radiation, synergistic with the generation of reactive oxygen species catalyzed by MnOx, double hits cancer cells to release abundant tumor-associated antigens for further promoting immune response stimulation. The local anti-TNBC efficacy of photothermal/immuno-therapy has been proven effective in subcutaneous 4T1-bearing mice. Especially, it has been systematically demonstrated in bilateral orthotopic 4T1-bearing mice that the as-proposed treatment could successfully activate innate and adaptive immunity, and local therapy could engender systemic responses to suppress the distant tumors. Collectively, this work represents a proof-of-concept for a non-invasive Mn-based tumor-immunotherapeutic modality, providing a paradigm for the immunotherapy of metastatic-prone tumors.

Carotid plaque score and ischemic stroke risk stratification through a combination of B-mode and contrast-enhanced ultrasound in patients with low and intermediate carotid stenosis.

Objective: The occurrence of ischemic stroke (IS) is closely related to the characteristics of carotid plaque (CP). Due to the effect of stroke risk stratification based on B-mode ultrasound (US) and contrast-enhanced ultrasound (CEUS) that has not been studied in patients with low and intermediate carotid stenosis, we construct and validate a CP score and ischemic stroke risk stratification (ISRS) using a combination of B-mode and CEUS, in order to provide new convenient strategies to stratify these patients to prevent stroke. Materials and methods: This retrospective study evaluated 705 patients with low and intermediate carotid stenosis who underwent B-mode and CEUS from November 2021 to April 2023. Qualitative B-mode and CEUS features of carotid plaques were analyzed using a univariable and multivariable logistic regression to construct the CP score. Then, we combined the CP score with Essen stroke risk score (ESRS) to develop ISRS. Results: This study included a total of 705 patients with low and intermediate carotid stenosis, of which 394 were symptomatic patients (with a mean age of 71.03 ± 10.48 years) and 311 were asymptomatic patients (with a mean age of 65.13 ± 10.31 years). Plaque echogenicity, plaque morphology, carotid intima-media thickness in B-mode US and intraplaque neovascularization grading and perfusion pattern in CEUS were significantly associated with IS. The ISRS incorporating these five predictors and ESRS showed good discrimination and calibration in both primary cohort [area under the curve (AUC), 0.91; Hosmer-Lemeshow test, p = 0.903] and validation cohort (AUC, 0.84; Hosmer-Lemeshow test, p = 0.886). Conclusion: We developed an effective and practical tool to identify and stratify patients with low and intermediate carotid stenosis, based on the CP score and ISRS estimation. Our study may provide new insights into managing patients with no indication of surgery.

Prognostic value of CD247 in patients with head and neck squamous cell carcinoma: bioinformatic analysis of TCGA database.

Background: Head and neck squamous cell carcinoma (HNSC) is the 7th most common type of cancer in the world. Through the advantages of The Cancer Genome Atlas (TCGA) large-scale sequencing-based genome analysis technology, we can explore the potential molecular mechanisms that can improve the prognosis of HNSC patients. Methods: The HNSC transcriptome and clinical data were downloaded from TCGA database. A univariate survival analysis and differential expression analysis were conducted to obtain the intersection gene set. A protein-protein interaction (PPI) analysis, modular analysis, and Gene Ontology (GO)/Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analysis were then conducted to identify the hub genes. Clinical correlation analysis, univariate and multivariate Cox regression analyses were performed on the identified hub genes to determine the prognostic impact of hub genes on HNSC patients. Results: In total, 601 intersecting gene sets were obtained. A modular analysis was conducted, and the highest scoring module was 19.304. Based on the GO/KEGG enrichment analysis results, CD247 molecule (CD247) was ultimately selected as the gene for this study. The CD247 were divided into a high-expression group and a low-expression group. The Kaplan-Meier survival curve analysis showed that there was a significant difference between the 2 groups (P<0.0001). The median survival time of the low-expression CD247 group was 30.9 months, and the 5-year survival rate was 36.4%. While the median survival time of the high-expression CD247 group was 68.8 months, and the 5-year survival rate was 52.3%. The clinical correlation analysis showed that CD247 was significantly negatively correlated with pathological tumor stage (pT) and pathological nodal extracapsular spread. Gene Set Enrichment Analysis (GSEA) showed that CD247 activating KEGG pathway hsa04650 and hsa04660. Conclusions: CD247 is an independent protective factor in the prognosis of HNSC patients. By activating the hsa04650 and hsa04660 pathways, the expression of interferon gamma, interleukin (IL)-2, and IL-10 is promoted, which in turn improves the tumor immune monitoring ability of the body, induces tumor cell apoptosis, and inhibits tumor cell growth. CD247 is a potential target for improving the clinical treatment effect of HNSC and the prognosis of patients.

Design and synthesis of chromone-nitrogen mustard derivatives and evaluation of anti-breast cancer activity.

Chromone has emerged as one of the most important synthetic scaffolds for antitumor activity, which promotes the development of candidate drugs with better activity. In this study, a series of nitrogen mustard derivatives of chromone were designed and synthesised, in order to discover promising anti-breast tumour candidates. Almost all target derivatives showed antiproliferative activity against MCF-7 and MDA-MB-231 cell lines. In particular, methyl (S)-3-(4-(bis(2-chloroethyl)amino)phenyl)-2-(5-(((6-methoxy-4-oxo-4H-chromen-3-yl)methyl)amino)-5-oxopentanamido)propanoate showed the most potent antiproliferative activity with IC50 values of 1.83 and 1.90 µM, respectively, and it also exhibited certain selectivity between tumour cells and normal cells. Further mechanism exploration against MDA-MB-231 cells showed that it possibly induced G2/M phase arrest and apoptosis by generating intracellular ROS and activating DNA damage. In addition, it also inhibited MDA-MB-231 cells metastasis, invasion and adhesion. Overall, methyl (S)-3-(4-(bis(2-chloroethyl)amino)phenyl)-2-(5-(((6-methoxy-4-oxo-4H-chromen-3-yl)methyl)amino)-5-oxopentanamido)propanoate showed potent antitumor activities and relatively low side effects, and deserved further investigation.

A New Method for Syndrome Classification of Non-Small-Cell Lung Cancer Based on Data of Tongue and Pulse with Machine Learning.

OBJECTIVE: To explore the data characteristics of tongue and pulse of non-small-cell lung cancer with Qi deficiency syndrome and Yin deficiency syndrome, establish syndrome classification model based on data of tongue and pulse by using machine learning methods, and evaluate the feasibility of syndrome classification based on data of tongue and pulse. METHODS: We collected tongue and pulse of non-small-cell lung cancer patients with Qi deficiency syndrome (n = 163), patients with Yin deficiency syndrome (n = 174), and healthy controls (n = 185) using intelligent tongue diagnosis analysis instrument and pulse diagnosis analysis instrument, respectively. We described the characteristics and examined the correlation of data of tongue and pulse. Four machine learning methods, namely, random forest, logistic regression, support vector machine, and neural network, were used to establish the classification models based on symptom, tongue and pulse, and symptom and tongue and pulse, respectively. RESULTS: Significant difference indices of tongue diagnosis between Qi deficiency syndrome and Yin deficiency syndrome were TB-a, TB-S, TB-Cr, TC-a, TC-S, TC-Cr, perAll, and the tongue coating texture indices including TC-CON, TC-ASM, TC-MEAN, and TC-ENT. Significant difference indices of pulse diagnosis were t4 and t5. The classification performance of each model based on different datasets was as follows: tongue and pulse < symptom < symptom and tongue and pulse. The neural network model had a better classification performance for symptom and tongue and pulse datasets, with an area under the ROC curves and accuracy rate which were 0.9401 and 0.8806. CONCLUSIONS: It was feasible to use tongue data and pulse data as one of the objective diagnostic basis in Qi deficiency syndrome and Yin deficiency syndrome of non-small-cell lung cancer.

Interleukin-17A promotes the differentiation of bone marrow mesenchymal stem cells into neuronal cells.

Ischemia or hemorrhagic stroke is one of the leading causes of death and permanent disability in the worldwide population. As a consequence of the potential increasing in stroke, stem cell therapy is currently an area of intense focus. However, there are less data available regarding the promotion of healing efficacy after stroke. The present study aimed to investigate whether the cytokine interleukin-17A (IL-17A) could have a role in promoting the neuronal differentiation of mesenchymal stem cells (MSCs) and to investigate the associated molecular mechanism. Firstly, different concentration of IL-17A at range from 5-40 ng/mL was applied to stimulate bone marrow MSCs (BMSCs) during the course of neurogenic differentiation. Then reverse transcription-PCR, histological analyses and immunofluorescence assays were used to determine the optimum concentration of IL-17A in promoting the neuronal differentiation of BMSCs, which was 20 ng/mL. Mechanistically, Wnt signaling pathway was activated and Notch signaling pathway was suppressed. In addition, there were antergic effect of these two signaling pathways modulating the neurogenic differentiation of BMSCs induced by IL-17A. The present study demonstrated the potential role of IL-17A-based BMSCs strategy for promoting neuronal differentiation in vitro. However, the treatment efficacy could be considerably confirmed in animals with ischemia stroke. Therefore, a more sophisticated strategy that addresses the complicated treatment associated with stroke is needed.

Destrin Contributes to Lung Adenocarcinoma Progression by Activating Wnt/ß-Catenin Signaling Pathway.

Lung cancer, especially lung adenocarcinoma, is one of the most common neoplasms worldwide. However, the mechanisms underlying its initiation, development, and metastasis are still poorly understood. Destrin (DSTN) is a member of ADF/cofilin family. Its detailed biological function remains unknown, although it is reported that DSTN is involved in cytoskeleton remodeling and regulation of actin filament turnover. Recent evidence has shown that high expression of cofilin-1 is associated with invasion and poor prognosis of several types of human tumors, but the detailed mechanism is still entirely unclear, particularly in lung cancer tumorigenesis and malignancy. Here, we report that DSTN was highly expressed in a mouse lung cancer model induced by urethane and in clinical lung adenocarcinoma tissue samples. Its expression level was positively correlated with cancer development, as well as metastasis to the liver and lymph nodes. Consistently, it was directly associated with the poor prognosis of lung adenocarcinoma patients. Furthermore, we also found that DSTN promotes cell proliferation, invasion, and migration in vitro, and facilitates subcutaneous tumor formation and lung metastasis via intravenous injection in vivo. Mechanically, DSTN associates with and facilitates nuclear translocation of ß-catenin, which promotes epithelial-to-mesenchymal transition (EMT). Taken together, our results indicated that DSTN enhances lung cancer malignancy through facilitating ß-catenin nuclear translocation and inducing EMT. Combined with multivariate analyses, DSTN might potentially serve as a therapeutic target and an independent prognostic marker of lung adenocarcinoma. IMPLICATIONS: This finding indicates that DSTN facilitates ß-catenin nuclear translocation and promotes malignancy in lung adenocarcinoma.

KIR3DL1 and HLA-Bw4 Interaction Showed a Favorable Role in Patients with Myelodysplastic Syndromes in Chinese Southern Han.

BACKGROUND: The association studies of killer cell immunoglobulin-like receptors (KIRs) with the occurrence of myelodysplastic syndromes (MDS) are limited worldwide; this study investigated the genetic risk/protective factors of MDS in KIR and human leucocyte antigen (HLA) systems to gain a better understanding of the role played by KIR and their cognate HLA ligands in MDS pathogenesis. METHODS: We genotyped a total number of 77 patients with MDS from Chinese Southern Han and 745 healthy controls for the KIR loci and HLA class I. The carrier frequencies of KIR genes, KIR genotypes, class I HLA ligands, and KIR-HLA combinations were calculated by direct counting. The effect of individual KIR genes and HLA ligands on MDS risk was evaluated by logistic regression analyses using SAS 9.2 software. RESULTS: We found that neither the KIR genes nor the KIR genotypes were associated with the occurrence of MDS. However, we observed that the frequencies for the strong inhibitory ligand HLA-Bw4 as well as KIR3DL1-HLA-Bw4 combination were significantly higher in healthy controls than those in the MDS patient group, respectively (73.42% vs. 62.34%, P = 0.038; 70.87% vs. 59.74%, P = 0.043). CONCLUSION: Our results showed that HLA-Bw4 ligand and KIR3DL1-HLA-Bw4 combination could confer a protective effect against MDS in Chinese Southern Han.

MFAP2 is overexpressed in gastric cancer and promotes motility via the MFAP2/integrin α5ß1/FAK/ERK pathway.

Gastric cancer (GC) is one of the most common malignancies and its prognosis is extremely poor. This study identifies a novel oncogene, microfibrillar-associated protein 2 (MFAP2) in GC. With integrative reanalysis of transcriptomic data, we found MFAP2 as a GC prognosis-related gene. And the aberrant expression of MFAP2 was explored in GC samples. Subsequent experiments indicated that silencing and exogenous MFAP2 could affect motility of cancer cells. The inhibition of silencing MFAP2 could be rescued by another FAK activator, fibronectin. This process is probably through affecting the activation of focal adhesion process via modulating ITGB1 and ITGA5. MFAP2 regulated integrin expression through ERK1/2 activation. Silencing MFAP2 by shRNA inhibited tumorigenicity and metastasis in nude mice. We also revealed that MFAP2 is a novel target of microRNA-29, and miR-29/MFAP2/integrin α5ß1/FAK/ERK1/2 could be an important oncogenic pathway in GC progression. In conclusion, our data identified MFAP2 as a novel oncogene in GC and revealed that miR-29/MFAP2/integrin α5ß1/FAK/ERK1/2 could be an important oncogenic pathway in GC progression.

Comparison of antioxidant capacity of 4-vinylguaiacol with catechin and ferulic acid in oil-in-water emulsion.

The product of ferulic acid decarboxylation, 4-vinylguaiacol (4-VG), is an important antioxidant and is reported to have an antioxidant capacity comparable to α-tocopherol. In this study, evaluation on antioxidant capacities of ferulic acid, catechin, and 4-VG was performed when 200 ppm of each compound was added in a 10% O/W emulsion for 50 days. Peroxide value (POV) results of the O/W emulsion containing 4-VG were noteworthy. The POV was 1.9 meq/L of emulsion after 29 days, which was no different to the initial value (day 0). Even when the oxidation was allowed to advance to day 50, the POV remained at 2.2 meq/L of emulsion, representing only a tiny increase relative to the initial value on day 0. 1H-NMR results also showed that the lowest conjugated forms and no aldehydes were detected in emulsion of 4-VG stored for 50 days, proving the excellent antioxidant capacity in the O/W emulsion.

Antioxidant capacity of decarboxylated rice bran extract in bulk oil.

Decarboxylation of ferulic acid would increase the solubility in oils. Rice bran extract (RBE) containing 29 mg ferulic acid/g RBE was decarboxylated to obtain decarboxylated rice bran extract (DRBE), and its antioxidant capacity in oil system was studied. After addition of DRBE (500 ppm), oxidation was monitored for 20 days at 60 °C under the dark. To compare the oxidation degree, 500 ppm of ferulic acid and well-known lipid soluble antioxidant, α-tocopherol, were used. Contents of conjugated dienes and aldehydes were measured using 1H NMR as well as peroxide value (POV). On 7 days of oxidation, DRBE (539.0 meq/kg oil) showed lower POV than the control (819.7 meq/kg oil). Also, contents of total conjugated form and aldehydes were 194.60, and 5.94 mmol/L oil, which were lower than those of control (323.63 and 15.94 mmol/L oil). However, after 10 days of oxidation, antioxidant capacity of DRBE was not observed.

Influence of In-Gap States on the Formation of Two-Dimensional Election Gas at ABO3/SrTiO3 Interfaces.

We explored in-gap states (IGSs) in perovskite oxide heterojunction films. We report that IGSs in these films play a crucial role in determining the formation and properties of interfacial two-dimensional electron gas (2DEG). We report that electron trapping by IGSs opposes charge transfer from the film to the interface. The IGS in films yielded insulating interfaces with polar discontinuity and explained low interface carrier density of conducting interfaces. An ion trapping model was proposed to explain the physics of the IGSs and some experimental findings, such as the unexpected formation of 2DEG at the initially insulating LaCrO3/SrTiO3 interface and the influence of substitution layers on 2DEG.

Iron oxide nanoclusters for T 1 magnetic resonance imaging of non-human primates.

Iron-oxide-based contrast agents for magnetic resonance imaging (MRI) had been clinically approved in the United States and Europe, yet most of these nanoparticle products were discontinued owing to failures to meet rigorous clinical requirements. Significant advances have been made in the synthesis of magnetic nanoparticles and their biomedical applications, but several major challenges remain for their clinical translation, in particular large-scale and reproducible synthesis, systematic toxicity assessment, and their preclinical evaluation in MRI of large animals. Here, we report the results of a toxicity study of iron oxide nanoclusters of uniform size in large animal models, including beagle dogs and the more clinically relevant macaques. We also show that iron oxide nanoclusters can be used as T 1 MRI contrast agents for high-resolution magnetic resonance angiography in beagle dogs and macaques, and that dynamic MRI enables the detection of cerebral ischaemia in these large animals. Iron oxide nanoclusters show clinical potential as next-generation MRI contrast agents.

The Synthesis and Evaluation of Arctigenin Amino Acid Ester Derivatives.

The use of arctigenin (ARG), a traditional medicine with many pharmacological activities, has been restricted due to its poor solubility in water. Five amino acid derivatives of ARG have been synthesized using glycine, o-alanine, valine, leucine, and isoleucine, which have t-butyloxy carbonyl (BOC) as a protective group. In this study, we examined the effects of removing these protective groups. The results showed that the amino acid derivatives have better solubility and nitrite-clearing ability than ARG. Among the compounds tested, the amino acid derivatives without protective group were the best. Based on these results, ARG and its two amino acid derivatives without protective group (ARG8, ARG10) were selected to evaluate their anti-tumor activity in vivo at a dosage of 40 mg/kg. The results indicated that ARG8 and ARG10 both exhibit more anti-tumor activity than ARG in H22 tumor-bearing mice. The tumor inhibition rates of ARG8 and ARG10 were 69.27 and 43.58%, which was much higher than ARG. Furthermore, the mice treated with these compounds exhibited less damage to the liver, kidney and immune organs compared with the positive group. Furthermore, ARG8 and ARG10 improved the serum cytokine levels significantly compared to ARG. In brief, this study provides a method to improve the water solubility of drugs, and we also provide a reference basis for new drug development.

[Cone-beam CT study of bone septa during maxillary sinus lift among Changzhou population].

PURPOSE: To observe the incidence, location, morphological characteristics of sinus septa among Changzhou population, and to investigate the relationship between maxillary posterior teeth loss and bony septum, and the guiding significance for sinus lift. METHODS: One hundred and twenty-four subjects were selected, the preoperative cone-beam CT (CBCT) data was analyzed by NNT software, which provided a three-dimensional measurement of the maxillary sinus septa. SPSS 13.0 software package was used for statistical analysis. RESULTS: 33.87%（42/124）subjects had sinus septa, 27.42%（68/248）sinus had septa. 66.18% (45/68) of the septa were located in the middle region, 22.06% （15/68）in the posterior region, 11.76%（8/68） in the anterior region. The occurrence of sinus septa had no relation with gender, age and loss of teeth. CONCLUSIONS: The sinus septa can be observed by CBCT for the position, pattern, to predict the difficulty of the surgery, and enhance the success rate.

A New Method for Discriminating between Bronchial and Pulmonary Arterial Phases using Contrast-Enhanced Ultrasound.

This study aimed to explore the value of a real-time comparative observation method using contrast-enhanced ultrasound (CEUS) for discriminating between bronchial and pulmonary arterial phases in diagnosing lung diseases. Forty-nine patients with 50 pulmonary lesions (45 peripheral lesions and five central lesions with obstructive atelectasis, including 36 malignant tumors, five tuberculomas, four inflammatory pseudotumors and five pneumonia lesions) detected via computed tomography and visible on ultrasonography were enrolled in this study. The arterial phases were determined by comparing contrast agent arrival time (AT) in the peripheral lung lesion with that in adjacent lung tissue, referred to as a real-time comparative observation method. Detection rates of this observation method were 100% (50/50) for pulmonary arterial phase and 88% (44/50) for bronchial arterial phase. Using the instrument's built-in graphing and analysis software, a time-intensity curve was constructed based on a chosen region of interest within the lesion where enhancement was the most obvious. Commonly used perfusion indicators in CEUS, such as AT, time-to-peak and peak intensity, were obtained from the time-intensity curve. Percutaneous puncture biopsies were performed under ultrasound guidance, and specimens of all 50 lesions were examined pathologically. AT was significantly shorter in patients with pneumonia than in those with malignant tumors or chronic inflammation (p < 0.05), whereas no difference was seen between those with malignant tumors and those with chronic inflammation. No significant differences in time-to-peak or peak intensity were seen among those with various lung diseases (p > 0.05). This is the first description of a real-time comparative observation method using CEUS for determining the arterial phases in the lungs. This method is accurate, simple to perform and provides a direct display. It is expected to become a practical and feasible tool for diagnosing lung diseases.

Antioxidant Properties of Caffeic acid Phenethyl Ester and 4-Vinylcatechol in Stripped Soybean Oil.

Caffeic acid was used to synthesize 4-vinylcatechol (4-VC) by thermal decarboxylation and to prepare caffeic acid phenethyl ester (CAPE) by esterification reaction. The identities of synthesized products were confirmed by (1)H NMR. Antioxidative activities of 4-VC and CAPE were compared with α-tocopherol and BHT in stripped soybean oil at 60 °C under the dark. To evaluate the degrees of oxidation at different concentrations and combinations, peroxide value (PV) and (1)H NMR were performed. From the results of PV, the formation of primary oxidation products (i.e., hydroperoxides) in stripped soybean oil containing 200 ppm CAPE was the slowest. The relative oxidation degree of 200 ppm CAPE (9.5%) was lower than other samples on 9 d. Similar results were obtained by (1)H NMR analysis. After 15 d of storage, levels of conjugated diene forms and aldehydes of 200 ppm CAPE sample (57.3 and 0.9 mmol/mol oil) were also lower than other treatments. In addition, 4-VC and α-tocopherol were found to have a synergistic antioxidant effect.

Effects of Caffeic Acid Phenethyl Ester and 4-Vinylcatechol on the Stabilities of Oil-in-Water Emulsions of Stripped Soybean Oil.

Caffeic acid phenethyl ester (CAPE) and 4-vinylcatechol (4-VC) were prepared for studying their antioxidative activities in emulsion. Oil-in-water emulsions of stripped soybean oil containing 200 ppm of CAPE, 4-VC, or α-tocopherol were stored at 40 °C in the dark for 50 days, and proton nuclear magnetic resonance ((1)H NMR) was used to identify and quantify the oxidation products. Emulsion droplet sizes, peroxide values, and levels of primary oxidation products (i.e., hydroperoxides) and secondary oxidation products (i.e., aldehydes) were determined. The results showed that CAPE (200 ppm) and 4-VC (200 ppm) had significantly greater antioxidant activities on the oxidation of stripped soybean oil-in-water emulsions than α-tocopherol (200 ppm). The peroxide values of CAPE (8.4 mequiv/L emulsion) and 4-VC (15.0 mequiv/L emulsion) were significantly lower than that of α-tocopherol (33.4 mequiv/L emulsion) (p < 0.05) on 36 days. In addition, the combinations of CAPE + α-tocopherol (100 + 100 ppm) or 4-VC + α-tocopherol (100 + 100 ppm) had better antioxidant activities than α-tocopherol (200 ppm). For CAPE + α-tocopherol, 4-VC + α-tocopherol, and α-tocopherol, the amounts of conjugated diene forms were 16.67, 13.72, and 16.32 mmol/L emulsion, and the concentrations of aldehydes were 2.15, 1.13, and 4.26 mmol/L emulsion, respectively, after 50 days of storage.