[Separation, characterization, and antiviral activity of colloidal phase state of Maxing Shigan Decoction].

This study focused on the separation, characterization, content determination, and antiviral efficacy research on colloidal particles with different sizes in Maxing Shigan Decoction(MXSG). The mixed colloidal phase of MXSG was initially separated into small colloidal particle segment(S), medium colloidal particle segment(M), and big colloidal particle segment(B) using ultrafiltration. Further fine separation was performed using size-exclusion chromatography. Dynamic light scattering(DLS) and transmission electron microscopy(TEM) were employed to characterize the size and morphology of the separated colloidal particles. UPLC-MS/MS was used to determine the content of ephedrine, amygdalin, glycyrrhizic acid, and the EDTA complexometric titration was used to measure the calcium(Ca~(2+)) content in different colloidal phases. Finally, a respiratory syncytial virus(RSV) infection mouse model was established using intranasal administration. The experimental groups included a blank group, a model group, a ribavirin group, an MXSG group, an S group, an M group, and a B group. Oral administration was given for treatment, and pathological changes in mouse lung tissue and organ indices were evaluated. The results of the study showed that the distribution of ephedrine, amygdalin, glycyrrhizic acid, and Ca~(2+) content was not uniform among different colloidal segments. Among them, the B segment had the highest proportions of the three components, except for Ca~(2+), accounting for 46.35%, 53.72%, and 92.36%, respectively. Size-exclusion chromatography separated colloidal particles with uniform morphology in the size range of 100-500 nm. Compared to the S and M segments, the B segment showed an increased lung index inhibition rate(38.31%), spleen index, and thymus index in RSV-infected mice, and it improved the infiltration of inflammatory cells and lung injury in the lung tissue of mice. The complex components in MXSG form colloidal particles of various sizes and morphologies through heating, and small-molecule active components such as ephedrine, amygdalin, glycyrrhizic acid, and Ca~(2+) participate in the assembly to varying degrees. The main material basis for the antiviral effect of MXSG is the colloidal particles with certain particle sizes formed by the assembly of active components during the heating process.

Analysis of Bitter Almonds and Processed Products Based on HPLC-Fingerprints and Chemometry.

In the processing field, there is a saying that "seed drugs be stir-fried". Bitter almond (BA) is a kind of seed Chinese medicine. BA need be used after being fried. To distinguish raw bitter almonds (RBA) from processed products and prove the rationality of "seed drugs be stir-fried", we analyzed the RBA and five processed products (scalded bitter almonds, fried bitter almonds, honey fried bitter almonds, bran fried bitter almonds, bitter almonds cream) using RP-HPLC fingerprints and chemometric methods. The similarity between RBA and processed products was 0.733∼0.995. Hierarchically clustered heatmap was used to evaluate the changes in components. Principal component analysis (PCA) was used for classification, and all samples are distinguished according to RBA and five processing methods. Six chemical markers were obtained by partial least squares discriminant analysis (PLS-DA). The content and degradation rate of amygdalin and ß-glucosidase activity were determined. Compared with RBA, the content and degradation rate of amygdalin, and ß-glucosidase activity were increased in bitter almonds cream. The content and degradation rate were decreased, and ß-glucosidase was inactivated in other processed products. The above results showed that stir-frying had the best effect. The results showed that processing can ensure the stability of RBA quality, and the saying "seed drugs be stir-fried" is reasonable.

Study on the Correlation Between the Appearance Traits and Intrinsic Chemical Quality of Bitter Almonds Based on Fingerprint-Chemometrics.

Bitter almond is a well-known and commonly used traditional Chinese medicine (TCM) for relieving coughs and asthma. However, the bioactive chemical composition of bitter almonds, especially their amygdalin content, which determines their quality for TCM use, is variable and this can cause problems with formulating and prescribing TCMs based on bitter almonds. Therefore, a simple method was developed to evaluate the compositional quality of bitter almonds from their appearance traits, based on a combination of chromatographic fingerprinting and chemometrics. Bitter almonds were analyzed by high-performance liquid chromatography (HPLC). Hierarchical cluster analysis (HCA) and principal components analysis (PCA) were applied to classify bitter almonds, which split the samples into two independent clusters. Three chemical markers (amygdalin, prunasin, and one unidentified component) were found by partial least squares-discriminant analysis (PLS-DA). What's more, a new PLS-DA model was reconstructed to confirm the obtained chemical markers from PLS-DA. Additionally, the appearance trait indices and amygdalin content of bitter almond were determined and the classification was confirmed by one-way analysis of variance. This method can easily determine the quality of bitter almonds from their appearance alone, high quality correlated closely with kernels that were larger, oblong in shape and heavier.

Determination of Amygdalin in Apricot Kernels and Almonds Using LC-MS/MS.

BACKGROUND: Cyanogenic glycosides are secondary metabolites in plants. In almonds and apricot kernels, amygdalin is an abundant cyanogenic glycoside. Upon consumption, amygdalin is enzymatically metabolized into hydrogen cyanide. Depending on the number of kernels consumed and the amygdalin concentration, ingestion of amygdalin-containing kernels may result in adverse effects. To better understand the US marketplace, the development and validation of analytical methods to reliably measure amygdalin in apricot kernels and almonds is needed to support the collection of occurrence and consumption data in retail products. OBJECTIVE: The aim of this study was to develop and validate a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantitation of amygdalin in apricot kernels and almonds following the U.S. Food and Drug Administration (FDA). Foods Program Guidelines for the Validation of Chemical Methods, 3rd Edition. METHODS: Apricot kernels and almonds were cryogenically homogenized and extracted using methanol containing an internal standard (IS), geniposide, followed by filtration, dilution, and LC-MS/MS analysis. Matrix effects were minimized using dilution. Quantitation was achieved using an external, solvent-based calibration. RESULTS: The amygdalin response was linear (r2 > 0.99) over a range of 0.05-50 µg/mL. The recovery of amygdalin spiked at 10-10 000 µg/g in sweet apricot kernels, raw almond, and dry-roasted almond ranged from 90 to 107% with RSDs ≤6%. The method limit of detection and limit of quantitation was 0.8 and 2.5 ng/g, respectively. Amygdalin concentrations in 18 market samples ranged from 2 to 24 000 µg/g. Corresponding estimates of cyanide concentration ranged from 0.2 to 1420 µg/g. CONCLUSIONS: Method performance meets the acceptance criteria defined by FDA guidelines and is fit for purpose for the analysis of amygdalin in apricot kernels and almonds. HIGHLIGHTS: An LC-MS/MS method is developed for the quantification of amygdalin in apricot kernels and almonds.

Amygdalin: A Review on Its Characteristics, Antioxidant Potential, Gastrointestinal Microbiota Intervention, Anticancer Therapeutic and Mechanisms, Toxicity, and Encapsulation.

Bioactive amygdalin, found in high concentrations in bitter almonds, has been recognized as a symbol of the cyanogenic glycoside chemical organic substance, which was initially developed as a pharmaceutical for treating cancer after being hydrolyzed to hydrogen cyanide (HCN). Regrettably, research has shown that HCN can also damage normal cells, rendering it non-toxic to the human body. Extreme controversy surrounds both in vivo and in vitro studies, making its use risky. This review provides an extensive update on characteristics, antioxidant potential, gastrointestinal microbiota intervention, anticancer therapeutic, mechanisms, toxicity, and encapsulation of amygdalin. Antioxidant, anti-tumor, anti-fibrotic, antiatherosclerosis, anti-inflammatory, immunomodulatory, and analgesic characteristics, and the ability to improve digestive and reproductive systems, neurodegeneration, and cardiac hypertrophy are just some of the benefits of amygdalin. Studies verified the HCN-produced amygdalin to be harmful orally, but only at very high doses. Although intravenous treatment was less effective than the oral method, the oral route has a dose range of 0.6 to 1 g daily. Amygdalin's toxicity depends heavily on the variety of bacteria in the digestive tract. Unfortunately, there is currently no foolproof method for determining the microbial consortium and providing a safe oral dosage for every patient. Amygdalin encapsulation in alginate-chitosan nanoparticles (ACNPs) is a relatively new area of research. Amygdalin has an enhanced cytotoxic effect on malignant cells, and ACNPs can be employed as an active drug-delivery system to release this compound in a regulated, sustained manner without causing any harm to healthy cells or tissues. In conclusion, a large area of research for a substance that might be the next step in cancer therapy is opened up due to unverified and conflicting data.

Whole-genome analysis guided molecular mechanism of cyanogenic glucoside degradation by yeast isolated from Prunus mume fruit syrup.

Consumption of fermented Prunus mume fruit (maesil) sugar syrup raise a health concern due to the presence of the cyanogenic glucoside amygdalin. The goal of the present study was to investigate the amygdalin degradation potential and genome profile of the native microbes found in maesil syrup. The microbial profile analysis revealed that yeast is the predominant microorganism native to maesil syrup and that the isolated yeast cells showed a remarkable potential for amygdalin reduction (99.7%). Moreover, the reduction in amygdalin was inversely proportional to the growth of the isolated yeast. The whole-genome analysis revealed that the isolated yeast is Zygosaccharomyces rouxii (genome size 10 Mb, 39.25% of GC content). Of the 5250 genes (64.88%) predicted in the Z. rouxii genome, 5245 (99.90%) were annotated using NCBI Non-Redundant, UniProt, and InterProScan databases. The genome of the isolated Z. ruoxii harbored 2.03% of repeats and 0.68% of non-coding RNAs. Protein prediction indicated that ß-glycosidases and hydroxynitrile lyase may play a key role in amygdalin degradation. The predicted degradation initiated by ß-glycosidases that hydrolyze α-glucosidic bonds of amygdalin results in α-hydroxy nitriles (cyanohydrins) that are subsequently converted into carbonyl compounds (benzaldehyde) and hydrogen cyanide catalyzed by hydroxynitrile lyases. Present findings provide valuable data for constructing engineered microorganisms that can degrade amygdalin. Further analysis of Z. rouxii may elucidate the exact mechanism of amygdalin reduction in the production of maesil syrup.

Young honeybees show learned preferences after experiencing adulterated pollen.

Pollen selection affects honeybee colony development and productivity. Considering that pollen is consumed by young in-hive bees, and not by foragers, we hypothesized that young bees learn pollen cues and adjust their preferences to the most suitable pollens. To assess whether young bees show preferences based on learning for highly or poorly suitable pollens, we measured consumption preferences for two pure monofloral pollens after the bees had experienced one of them adulterated with a deterrent (amygdalin or quinine) or a phagostimulant (linoleic acid). Preferences were obtained from nurse-aged bees confined in cages and from nurse bees in open colonies. Furthermore, we tested the bees' orientation in a Y-maze using a neutral odour (Linalool or Nonanal) that had been previously associated with an amygdalin-adulterated pollen. Consumption preferences of bees, both in cages and in colonies, were reduced for pollens that had been adulterated with deterrents and increased for pollens that had been supplemented with linoleic acid. In the Y-maze, individuals consistently avoided the odours that they had previously experienced paired with the deterrent-adulterated pollen. Results show that nurse-aged bees associate pollen-based or pollen-related cues with either a distasteful/malaise experience or a tasty/nutritious event, leading to memories that bias their pollen-mediated response.

Inflammation, It's Regulation and Antiphlogistic Effect of the Cyanogenic Glycoside Amygdalin.

The inflammatory reaction accompanies in part or in full any disease process in the vascularized metazoan. This complicated reaction is controlled by regulatory mechanisms, some of which produce unpleasant symptomatic manifestations of inflammation. Therefore, there has been an effort to develop selective drugs aimed at removing pain, fever, or swelling. Gradually, however, serious adverse side effects of such inhibitors became apparent. Scientific research has therefore continued to explore new possibilities, including naturally available substances. Amygdalin is a cyanogenic glycoside present, e.g., in bitter almonds. This glycoside has already sparked many discussions among scientists, especially about its anticancer potential and related toxic cyanides. However, toxicity at different doses made it generally unacceptable. Although amygdalin given at the correct oral dose may not lead to poisoning, it has not yet been accurately quantified, as its action is often affected by different intestinal microbial consortia. Its pharmacological activities have been studied, but its effects on the body's inflammatory response are lacking. This review discusses the chemical structure, toxicity, and current knowledge of the molecular mechanism of amygdalin activity on immune functions, including the anti-inflammatory effect, but also discusses inflammation as such, its mediators with diverse functions, which are usually targeted by drugs.

An optimized preparation of nanofiber hydrogels derived from natural carbohydrate polymers and their drug release capacity under different pH surroundings.

Cellulose and chitin, as the two important natural carbohydrate polymers, have possibility to disassemble to biomass derived polysaccharide nanofibers. The 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) oxidized nanocellulose and nanochitin based hydrogel was fabricated via acid gas phase coagulation. It was observed that hydrogels began to form when the pH was lower than 3. When 0.1 mL of acetic acid coagulation bath was provided, 10 h were enough to form sufficient physical crosslinking. Moreover, the release time of amygdalin loaded in the hydrogel could be more than 60 h with a release amount of 80 % due to the uniform network and water-bearing structure. Meanwhile, the release capacity of hydrogels showed diversity at different pH surroundings, which was attributed to the existence of carboxyl groups on the oxidized nanofiber. The results suggested the possible application of the produced nanofiber hydrogels in some specific areas, such as drug delivery, wound dressing, and food packaging.

Amygdalin: Toxicity, Anticancer Activity and Analytical Procedures for Its Determination in Plant Seeds.

Amygdalin (d-Mandelonitrile 6-O-ß-d-glucosido-ß-d-glucoside) is a natural cyanogenic glycoside occurring in the seeds of some edible plants, such as bitter almonds and peaches. It is a medically interesting but controversial compound as it has anticancer activity on one hand and can be toxic via enzymatic degradation and production of hydrogen cyanide on the other hand. Despite numerous contributions on cancer cell lines, the clinical evidence for the anticancer activity of amygdalin is not fully confirmed. Moreover, high dose exposures to amygdalin can produce cyanide toxicity. The aim of this review is to present the current state of knowledge on the sources, toxicity and anticancer properties of amygdalin, and analytical methods for its determination in plant seeds.

Prunus Armeniaca L. Seed Extract and Its Amygdalin Containing Fraction Induced Mitochondrial-Mediated Apoptosis and Autophagy in Liver Carcinogenesis.

BACKGROUND: Despite significant advances in therapeutic interventions, liver cancer is the leading cause of cancer mortality in the world. Potential phytochemicals have shown to be promising agents against many life-threatening diseases because of their low toxicity and potential effectiveness. OBJECTIVE: The current study aims to conduct an in vitro investigation of the anticancer activity of Apricot Extract (AE) and Amygdalin Containing Fraction (ACF), additionally studying their therapeutic effects on DMBAinduced liver carcinogenesis mice model to highlight their related biochemical and molecular mechanisms. METHODS AND RESULTS: Amygdalin was isolated from the seeds of P. armeniaca L. Male mice received AE or ACF, DMBA, DMBA+AE, DMBA+ACF, and vehicles. The oxidative stress and antioxidant markers, cell proliferation by flow cytometric analysis of Proliferating Cell Nuclear Antigen (PCNA) expression, angiogenesis marker (VEGF), inflammatory marker (TNF-α), apoptotic, anti-apoptotic and autophagy genes expression (caspase-3, Bcl-2, and Beclin-1) were investigated. AE and ACF were found to stimulate the apoptotic process by up-regulating caspase-3 expression and down-regulating Bcl-2 expression. They also reduced VEGF and PCNA levels and increased the antioxidant defense system. Moreover, AE and ACF treatments also inhibited HepG2 and EAC cell proliferation and up-regulated Beclin-1 expression. CONCLUSION: This study provides evidence that, in DMBA-induced hepatocarcinogenesis, the key proteins involved in the proliferation, angiogenesis, autophagy, and apoptosis are feasible molecular targets for hepatotherapeutic potential using AE and ACF.

Analysis of Amygdalin in Various Matrices Using Electrospray Ionization and Flowing Atmospheric-Pressure Afterglow Mass Spectrometry.

Amygdalin is a natural cyanogenic compound that plants produce in the fight against insects and herbivores. Excessive amounts of amygdalin by animals and humans can potentially lead to fatal intoxication. However, studies confirm that amygdalin has antitumor properties, including the ability to inhibit the proliferation of cancer cells and to induce their apoptosis. The analysis of amygdalin in various matrices is an important analytical problem today. The publication presents the methodology of direct determination of amygdalin in water, sewage, and biological materials using electrospray ionization mass spectrometry (ESI-MS) and a new analytical method using flowing atmospheric-pressure afterglow mass spectrometry (FAPA-MS). The methods of analyte pre-concentration using a magnetic, molecularly imprinted polymer (mag-MIP) and the influence of interferents on the recorded spectra were discussed. Analytical parameters in ESI-MS and FAPA-MS methods were established. The linearity range was 4.5 µg L-1-45 mg L-1 in positive mode ESI-MS and FAPA-MS. The limit of detection (LOD) for ESI-MS was 0.101 ± 0.003 µg L-1 and the limit of quantification (LOQ) was 0.303 ± 0.009 µg L-1. In FAPA-MS, the LOD was 0.050 ± 0.002 µg L-1 and the LOQ was 0.150 ± 0.006 µg L-1. The content of amygdalin in various matrices was determined.

Amygdalin based G-6-P synthase inhibitors as novel preservatives for food and pharmaceutical products.

G-6-P synthase enzyme has been involved in the synthesis of the microbial cell wall, and its inhibition may lead to the antimicrobial effect. In the present study, we designed a library of amygdalin derivatives, and two most active derivatives selected on the basis of various parameters viz. dock score, binding energy, and ADMET data using molecular docking software (Schrodinger's Maestro). The selected derivatives were synthesized and evaluated for their antioxidant and antimicrobial potential against several Gram (+ ve), Gram (-ve), as well as fungal strains. The results indicated that synthesized compounds exhibited good antioxidant, antimicrobial, and better preservative efficacy in food preparation as compared to the standard compounds. No significant differences were observed in different parameters as confirmed by Kruskal-Wallis test (p < 0.05). Docking results have been found in good correlation with experimental wet-lab data. Moreover, the mechanistic insight into the docking poses has also been explored by binding interactions of amygdalin derivative inside the dynamic site of G-6-P synthase.

Discovery of a Cryptic Depsipeptide from Streptomyces ghanaensis via MALDI-MS-Guided High-Throughput Elicitor Screening.

Microbial genomes harbor an abundance of biosynthetic gene clusters, but most are expressed at low levels and need to be activated for characterization of their cognate natural products. In this work, we report the combination of high-throughput elicitor screening (HiTES) with matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) for the rapid identification of cryptic peptide natural products. Application to Streptomyces ghanaensis identified amygdalin as an elicitor of a novel non-ribosomal peptide, which we term cinnapeptin. Complete structural elucidation revealed cinnapeptin as a cyclic depsipeptide with an unusual 2-methyl-cinnamoyl group. Insights into its biosynthesis were provided by whole genome sequencing and gene deletion studies, while bioactivity assays showed antimicrobial activity against Gram-positive bacteria and fission yeast. MALDI-HiTES is a broadly applicable tool for the discovery of cryptic peptides encoded in microbial genomes.

Bitter apricot ethanolic extract induces apoptosis through increasing expression of Bax/Bcl-2 ratio and caspase-3 in PANC-1 pancreatic cancer cells.

Pancreatic cancer is the fourth common cause of cancer death. Surgery and chemotherapy are the common treatment strategies for pancreatic cancer patients; however, the response rate is less than 20% at advanced stages. In recent years, growing interest has been dedicated to natural products. Bitter apricot seeds possess a number of pharmacological properties including antitumor activity and amygdalin from bitter apricot seeds can induce apoptosis. In this study, we investigated the cyto/genotoxic effects of bitter apricot ethanolic extract (BAEE) and amygdalin on human pancreatic cancer PANC-1 and normal epithelial 293/KDR cells. BAEE was assessed using high-performance liquid chromatography for the confirmation of the structure. The biological impacts of BAEE and amygdalin on PANC-1 and 293/KDR cells were evaluated by MTT assay, DAPI staining, AnnexinV/PI and Real-time qPCR analysis. BAEE and amygdalin inhibited cancer cell growth in a dose- and time-dependent manner. DAPI staining and flow cytometric analysis revealed fragmented nuclei and elevated numbers of early and late apoptotic cells, respectively. Also, increased Bax/Bcl-2 ratio and upregulation of caspase-3 further confirmed the occurrence of apoptosis in PANC-1 cells, but not in non-cancerous 293/KDR cells. These results indicate that BAEE could mediate apoptosis induction in cancer cells through a mitochondria dependent pathway. These findings suggest that BAEE functions as a potent pro-apoptotic factor for human pancreatic cancer cells without a significant effect on 293/KDR cells. Though, the potent anti-cancer components of BAEE should be further identified. Moreover, in vivo investigations are required to confirm bitter apricot ethanolic extract's clinical value as an anti-tumor drug.

Evaluation of amygdalin-loaded alginate-chitosan nanoparticles as biocompatible drug delivery carriers for anticancerous efficacy.

Amygdalin, despite possessing anticancerous properties, has been viewed as a controversial choice due to the presence of the cyanide group. Here, we synthesise and investigate the potential of alginate-chitosan nanoparticles (ACNPs) as drug delivery agents for amygdalin encapsulation and its delivery to cancer cells. Amygdalin loaded ACNPs were made with both anionic and cationic outer layer to further investigate charge dependency on drug delivery and cytotoxicity. ACNPs encapsulating amygdalin were monodisperse, colloidally stable with ~90% drug encapsulation efficiency and were entirely made from natural materials. The nanoparticles exhibited sustained drug release for a duration of 10 h and significant swelling rates in neutral and slightly acidic environments. The ACNPs successfully adhered to porcine mucin type II when assessed for its mucoadhesion and shown to transmigrate with an average velocity of 1.68 µm/s in uncoated channels, under biomimicked flow conditions. To investigate charge dependency on drug delivery and cytotoxicity, amygdalin loaded ACNPs were made with both anionic and cationic outer layer and assessed. ACNPs demonstrated greater yet sustained anti-cancerous effect on H1299 cell lines in a dose-dependent manner than free amygdalin suggesting greater cellular uptake of the former. In conclusion, biocompatible and biodegradable alginate-chitosan nanoparticles can be used as an effective drug delivery system for sustained and controlled amygdalin release with its improved cytotoxic effect on cancerous cells while protecting normal cells and tissues.

Anticancer Effect of Amygdalin (Vitamin B-17) on Hepatocellular Carcinoma Cell Line (HepG2) in the Presence and Absence of Zinc.

BACKGROUND: Amygdalin (Vitamin B-17) is a naturally occurring vitamin found in the seeds of the fruits of Prunus Rosacea family including apricot, bitter almond, cherry, and peach. OBJECTIVE: The purpose of this study was to examine the effect of amygdalin with and without zinc on hepatocellular carcinoma (HepG2) cell line. METHODS: MTT assay was used to evaluate the cytotoxicity of amygdalin without zinc, amygdalin + 20µmol zinc, and amygdalin + 800µmol zinc on HepG2 cell lines. The cell cycle distribution assay was determined by flow cytometry. Apoptosis was confirmed by Annexin V-FITC/PI staining assay. Moreover, the pathway of apoptosis was determined by the percentage of change in the mean levels of P53, Bcl2, Bax, cytochrome c, and caspase-3. RESULTS: Amygdalin without zinc showed strong anti-HepG2 activity. Furthermore, HepG2 cell lines treatment with amygdalin + 20µmol zinc and amygdalin + 800µmol zinc showed a highly significant apoptotic effect than the effect of amygdalin without zinc. Amygdalin treatment induced cell cycle arrest at G2/M and increased the levels of P53, Bax, cytochrome c, and caspase-3 significantly, while it decreased the level of anti-apoptotic Bcl2. CONCLUSION: Amygdalin is a natural anti-cancer agent, which can be used for the treatment of hepatocellular carcinoma. It promotes apoptosis via the intrinsic cell death pathway (the mitochondria-initiated pathway) and cell cycle arrest at G/M. The potency of amygdalin in HepG2 treatment increased significantly by the addition of zinc.

A "turn off-on" fluorescent nanoprobe consisting of CuInS2 quantum dots for determination of the activity of ß-glucosidase and for inhibitor screening.

A fluorescent "turn off-on" nanoprobe is described for highly sensitive and selective determination of the activity of the enzyme ß-glucosidase (ß-Glu). Firstly, cysteine modified CuInS2 quantum dots (Cys-CuInS2 QDs) were prepared from indium(III) and copper(II) salts and the presence of thiourea. The red fluorescence of the Cys-CuInS2 QDs, with excitation/emission maxima at 590/656 nm, is quenched by Cu(II). However, in the presence of ß-Glu and the cyanogenic glycoside, enzymatic hydrolysis leads to the formation of cyanide. The latter competitively binds to Cu(II) owing to its high affinity for cyanide. This restores the fluorescence of the Cys-CuInS2 QDs. Under the optimum conditions, fluorescence increases linearly in the 0.5-700 U·L-1 ß-Glu activity range. The detection limit is 0.2 U·L-1. The nanoprobe was applied to analyze spiked soil samples, and satisfactory results were obtained. The average recoveries of ß-Glu were in the range of 96-103%, and the RSD was lower than 4.0%. The fluorescent probe can also be used to screen for ß-Glu inhibitors as demonstrated for castanospermine as an example. Graphical abstractSchematic representation of the fluorescent nanoprobe for ß-glucosidase activity detection and inhibitor screening by taking advantage of the fluorescence (FL) "turn-off" and "turn-on" feature of cysteine capped CuInS2 quantum dots (Cys-CuInS2 QDs).

In vitro and in silico anticancer activity of amygdalin on the SK-BR-3 human breast cancer cell line.

In spite of several studies that have shown the cytotoxic effects of amygdalin on the different cancer cell lines, however, the chemopreventive potential of amygdalin on the breast cancer cell line is not completely understood. We investigated the effect of amygdalin on the cell death and the level of pro-apoptotic Bax protein and anti-apoptotic Bcl-2 protein in SK-BR-3 human breast cancer cell line. The cell viability of SK-BR-3 cells was evaluated by MTT assay in different concentration of amygdalin. The level of Bax and Bcl-2 in SK-BR-3 cells were measured by western blot analysis. For statistical analysis, One-way ANOVA was used for the comparison of Bax and Bcl-2 protein level and percent of cell viability between groups. The molecular docking studies of amygdalin within the Bcl-2 (PDB ID: 4LVT) and HER2 (PDB ID: 3RCD) active site, were performed using AutoDock 4.2.5. Amygdalin induced a significant reduction of cell viability in SK-BR-3 after 24-h treatment in a dose-dependent manner. Also, amygdalin causes an increase in pro-apoptotic Bax protein and a decrease in anti-apoptotic Bcl-2 protein expression in the SK-BR-3 cells. Molecular docking studies showed that amygdalin interacts with the active site amino acids of Bcl-2 and HER2 through hydrogen bonding and some hydrophobic interactions. Amygdalin can induce apoptotic death in SK-BR-3 cells by increasing pro-apoptotic Bax protein and decreasing anti-apoptotic Bcl-2 protein expression. The results suggest that amygdalin may be a valuable candidate for the treatment of breast cancer, especially in HER2 positive cells.

Changes of amygdalin and volatile components of apricot kernels during the ultrasonically-accelerated debitterizing.

Ultrasound has been regarded as an efficient novel technique for debitterizing of the apricot kernels, but its influence is severely concerned on the possible epimerization of d-amygdalin to the l-amygdalin, a more potentially toxigenic compound. Considering this, the experiments were conducted to investigate the epimerization of d-amygdalin and the volatile components in the debitterizing water, which were separated and identified by the high performance liquid chromatography (HPLC) and gas chromatography with a mass spectrometer (GC-MS), respectively. The results indicate that the ultrasonically-debitterizing did not cause the epimerization of d-amygdalin to the l-amygdalin, while the procedure can be greatly accelerated due to the rapid mass transfer and degradation of d-amygdalin induced by ultrasound irradiation. In addition, the water from the ultrasonically-debitterizing of apricot kernels exerted more aromas compared with that of the conventional debitterizing, which might have more applications about this kind of water. In a word, ultrasound can be safely applied in the debitterizing industry of apricot kernels.