Combined assessment of lysine and N-acetyl cadaverine levels assist as a potential biomarker of the smoker periodontitis.

Periodontitis is an inflammatory condition of supporting structures of teeth leading to attachment and bone loss. Cigarette smoking is the single most important and modifiable risk factor with 5 to 20-fold susceptibility for periodontal diseases. Reverse smoking is a peculiar habit of smoking where the lit end is kept inside the mouth, which is predominant in the northern coastal districts of Andhra Pradesh. Polyamines are biologically active amines involved in tissue regeneration and modulation of inflammation. The study aimed to evaluate polyamines and check their utility as a marker in detection of periodontitis among different groups. Total polyamine levels showed significant increase in reverse smokers with periodontitis when compared to the other groups. Qualitative analysis by thin layer chromatography showed three polyamine bands with varying intensity among the different groups. Mass spectrometric and NMR analyses of the three bands identified them as N1, N8-diacetyl spermidine, N-acetyl cadaverine and lysine. Most significantly elevated levels of lysine was observed in the smoker and reverse smoker periodontitis groups when compared to healthy and non-smoker periodontitis groups. The significantly elevated levels of N-acetyl cadaverine could be responsible for the more destruction of periodontium in the reverse smoker group. Antioxidant potential decreased significantly in different smoker periodontitis groups. The present study suggests that the quantitative analysis of salivary polyamines, lysine and N-acetyl cadaverine can aid as an easy noninvasive diagnostic method for assessing the periodontal status, especially in smokers.

Determination of toxic α-dicarbonyl compounds in sesame oils using dispersive liquid-liquid microextraction coupled with gas chromatography-mass spectrometry.

Glyoxal, methylglyoxal, and diacetyl are toxic α-dicarbonyl compounds found in heat-processed foods, including edible oils. Dispersive liquid-liquid microextraction was combined with gas chromatography mass spectrometry to determine the glyoxal, methylglyoxal, and diacetyl contents in sesame oil. Chloroform and methanol were selected as the optimal extraction and dispersive solvents, respectively. The maximum derivatization efficiency was obtained using 500 µg of the derivatization agent, o-phenylenediamine. The derivatization of glyoxal was completed in 1 h, whereas those of methylglyoxal and diacetyl were completed immediately. The optimized method was validated, and was found to exhibit a good linearity, recovery, intraday repeatability, and interday reproducibility. The α-dicarbonyl compound concentrations in the oils were dependent on the roasting temperature. The sesame oil concentrates contained 0-175.4, 0-990.5, and 0-220.9 ng g-1 of glyoxal, methylglyoxal, and diacetyl, respectively. For the perilla oils, the respective concentrations were 0-96.4, 0-410.8, and 0-197.5 ng g-1.

Determination of α-Dicarbonyl compounds in traditional Chinese herbal medicines.

α-DCs (α-dicarbonyls) have been proven to be closely related to aging and the onset and development of many chronic diseases. The wide presence of this kind of components in various foods and beverages has been unambiguously determined, but their occurrence in various phytomedicines remains in obscurity. In this study, we established and evaluated an HPLC-UV method and used it to measure the contents of four α-DCs including 3-deoxyglucosone (3-DG), glyoxal (GO), methylglyoxal (MGO), and diacetyl (DA) in 35 Chinese herbs after they have been derivatized with 4-nitro-1,2-phenylenediamine. The results uncover that 3-DG is the major component among the α-DCs, being detectable in all the selected herbs in concentrations ranging from 22.80 µg/g in the seeds of Alpinia katsumadai to 7032.75 µg/g in the fruit of Siraitia grosuenorii. The contents of the other three compounds are much lower than those of 3-DG, with GO being up to 22.65 µg/g, MGO being up to 55.50 µg/g, and DA to 18.75 µg/g, respectively. The data show as well the contents of the total four α-DCs in the herbs are generally in a comparable level to those in various foods, implying that herb medicines may have potential risks on human heath in view of the α-DCs.

Investigating the molecular mechanism of Qizhu anticancer prescription in inhibiting hepatocellular carcinoma based on high-resolution mass spectrometry and network pharmacology.

ETHNOPHARMACOLOGICAL RELEVANCE: Of all primary liver cancer cases, hepatocellular carcinoma (HCC) accounts for about 90%. Most patients with HCC receive a diagnosis in the medium-to-late stages or with chronic liver disease, have lost the opportunity for radical treatment, such as surgical resection, and their 5-year survival rate is low. Qizhu Anticancer Prescription (QZACP) is an empirical formula composed of traditional Chinese herbs that can clinically relieve HCC symptoms, inhibit the progression of HCC, reduce recurrence rate, and prolong survival; however, its exact mode of action remains unknown. AIM OF THE STUDY: This study's purpose was to investigate the mode of action of QZACP in the prevention and treatment of HCC. MATERIALS AND METHODS: Initially, drug components in the QZACP decoction were analyzed using high-resolution mass spectrometry. A subcutaneous tumor xenograft model in nude mice was constructed to further analyze the active components of QZACP that had entered tumor tissues through oral administration. Potential targets of QZACP in the prevention and treatment of HCC were identified and then confirmed in vivo via network pharmacology and molecular docking. In addition, regulatory effects of QZACP on HCC cell proliferation and the cell cycle were detected using a CCK-8 assay and flow cytometry. RESULTS: High-resolution mass spectrometry revealed that the QZACP decoction contained deacetyl asperulosidic acid methyl ester (DAAME), paeoniflorin, calycosin-7-glucoside, liquiritin, glycyrrhizic acid, astragaloside IV, saikosaponin A, curdione, and atractylenolide II. In nude mice, QZACP could effectively inhibit the growth of subcutaneous tumors, where DAAME, paeoniflorin, liquiritin, and glycyrrhizic acid could enter liver cancer tissues after oral administration. Among these, DAAME was the most highly expressed in HCC tissues and may be an important active component of QZACP for inhibiting HCC. Utilizing network pharmacology, the targets of action of these four drug components were identified. After verification using western blotting, STAT3, VEGFA, JUN, FGF2, BCL2L1, AR, TERT, MMP7, MMP1, ABCB1, CA9, and ESR2 were identified as targets of QZACP inhibition in HCC. In vitro experiments revealed that QZACP inhibited the proliferation of HCC cells while inducing G0/G1 phase cell cycle arrest. In vivo experiments demonstrated that DAAME significantly inhibited HCC growth. After intersection of the 24 DAAME targets predicted using network pharmacology with the 435 HCC disease targets, only CA9 was identified as a DAAME-HCC crossover target. Molecular docking results revealed that the binding site of DAAME and CA9 had good stereo-complementarity with a docking score of -8.1 kcal/mol. Western blotting and immunohistochemical results also confirmed that DAAME significantly decreased CA9 protein expression in HCC. CONCLUSIONS: QZACP inhibits HCC by reducing the expression of STAT3, VEGFA, JUN, FGF2, BCL2L1, AR, TERT, MMP7, MMP1, ABCB1, CA9, and ESR2. DAAME may be an important active component of QZACP for the prevention and treatment of HCC, inhibiting it by targeting the expression of CA9.

Single-cell resolution of human airway epithelial cells exposed to bronchiolitis obliterans-associated chemicals.

Bronchiolitis obliterans (BO) is a fibrotic lung disease characterized by progressive luminal narrowing and obliteration of the small airways. In the nontransplant population, inhalation exposure to certain chemicals is associated with BO; however, the mechanisms contributing to disease induction remain poorly understood. This study's objective was to use single-cell RNA sequencing for the identification of transcriptomic signatures common to primary human airway epithelial cells after chemical exposure to BO-associated chemicals-diacetyl or nitrogen mustard-to help explain BO induction. Primary airway epithelial cells were cultured at air-liquid interface and exposed to diacetyl, nitrogen mustard, or control vapors. Cultures were dissociated and sequenced for single-cell RNA. Differential gene expression and functional pathway analyses were compared across exposures. In total, 75,663 single cells were captured and sequenced from all exposure conditions. Unbiased clustering identified 11 discrete phenotypes, including 5 basal, 2 ciliated, and 2 secretory cell clusters. With chemical exposure, the proportion of cells assigned to keratin 5+ basal cells decreased, whereas the proportion of cells aligned to secretory cell clusters increased compared with control exposures. Functional pathway analysis identified interferon signaling and antigen processing/presentation as pathways commonly upregulated after diacetyl or nitrogen mustard exposure in a ciliated cell cluster. Conversely, the response of airway basal cells differed significantly with upregulation of the unfolded protein response in diacetyl-exposed basal cells, not seen in nitrogen mustard-exposed cultures. These new insights provide early identification of airway epithelial signatures common to BO-associated chemical exposures.NEW & NOTEWORTHY Bronchiolitis obliterans (BO) is a devastating fibrotic lung disease of the small airways, or bronchioles. This original manuscript uses single-cell RNA sequencing for identifying common signatures of chemically exposed airway epithelial cells in BO induction. Chemical exposure reduced the proportion of keratin 5+ basal cells while increasing the proportion of keratin 4+ suprabasal cells. Functional pathways contributory to these shifts differed significantly across exposures. These new results highlight similarities and differences in BO induction across exposures.

IL-17A neutralization fails to attenuate airway remodeling and potentiates a proinflammatory lung microenvironment in diacetyl-exposed rats.

Bronchiolitis obliterans (BO) is a devastating lung disease that can develop following inhalation exposure to certain chemicals. Diacetyl (DA) is one chemical commonly associated with BO development when inhaled at occupational levels. Previous studies in rats have shown that repetitive DA vapor exposures increased lung CD4+CD25+ T cells and bronchoalveolar (BAL) interleukin-17A (IL-17A) concentrations concurrent with the development of airway remodeling. We hypothesized that IL-17A neutralization would attenuate the severity of airway remodeling after repetitive DA vapor exposures. Sprague-Dawley rats were exposed to 200 parts-per-million DA vapor or filtered air (RA) for 6 h/day × 5 days and monitored for 2 wk postexposure. Treatment with IL-17A neutralization (αIL-17A) or IgG (control) began immediately following exposures and continued twice weekly until study's end. Lungs were harvested for histology, flow cytometry, and BAL analyses. Survival, oxygen saturations, and percent weight change decreased significantly in DA-exposed versus RA-exposed rats, but did not differ significantly between DA + αIL-17A versus DA + IgG. Similarly, the number nor severity of airway lesions did not differ significantly between DA + αIL-17A versus DA + IgG rats despite the percentage of lung regulatory T cells increasing with decreased BAL IL-17A concentrations. Ashcroft scoring of the distal lung parenchyma suggested worse parenchymal remodeling in DA + αIL-17A versus DA + IgG rats with increased expression of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1ß), and nuclear factor-kappa B (NF-κB). Collectively, IL-17A neutralization in DA-exposed rats failed to attenuate airway remodeling with increased expression of pro-inflammatory cytokines TNF-α, IL-1ß, and NF-κB.NEW & NOTEWORTHY Interleukin-17A (IL-17A) neutralization has shown benefit previously in preclinical models of transplant-associated bronchiolitis obliterans (BO), yet it remains unknown whether IL-17A neutralization has similar benefit for other forms of BO. Here, IL-17A neutralization fails to prevent severe airway remodeling in rats exposed repetitively to the flavoring chemical diacetyl, and instead, promotes a proinflammatory microenvironment with increased expression of TNF-α, IL-1ß, and NF-κB within the lung.

Evaluation of the cytotoxicity and genotoxicity potential of synthetic diacetyl food flavoring in silico, in vivo, and in vitro.

Diacetyl is a common ingredient that creates a buttery flavor in baked goods and other food products. The cytotoxic impact of diacetyl on a normal human liver cell line (THLE2) indicated an IC50 value of 41.29 mg/ml through MTT assay and a cell cycle arrest in the G0/G1 phase relative to the control. Administration of diacetyl at two-time points (acute-chronic) led to a significant increase in DNA damage indicated by the increase in tail length, tail DNA%, and tail moment. The mRNA and protein expression levels of genes in the rats' livers were then measured using real-time PCR and western blotting. The results showed an activation of the apoptotic and necrosis mechanism, with an upregulation of p53, Caspase 3, and RIP1 and a downregulation of Bcl-2 at the mRNA level. The ingestion of diacetyl disrupted the liver's oxidant/antioxidant balance, as evidenced by alterations in levels of GSH, SOD, CAT, GPx, GR, MDA, NO, and peroxynitrite. Additionally, heightened levels of inflammatory cytokines were shown. Histopathological examinations revealed necrotic foci and congested portal areas in the rats' liver cells after treatment with diacetyl. Diacetyl may interact moderately with Caspase, RIP1, and p53 core domain through In-silico, possibly resulting in upregulated gene expression.

Combination of four bacterial strains isolated from Yamahai-shubo in traditional Japanese sake brewing.

This study investigated the interactions of four bacteria strains isolated from Yamahai-shubo, the source of yeast used to produce a Japanese traditional rice wine, Yamahai-shikomi sake. The bacterial strains were nitrate-reducing Pseudomonas sp. 61-02, Leuconostoc mesenteroides LM-1, Lactiplantibacillus plantarum LP-2, and Latilactobacillus sakei LS-4. We examined fermentation factors for Yamahai-shubo and Yamahai-shikomi sake samples to compare the suitability of their bacterial combination (16 variations). As a result of principal component analysis, we found that two major groups were formed; one containing strain LP-2 and the other containing strain LS-4, and that strains LP-2 and LS-4 were important in the Yamahai-shikomi sake in the presence of strains 61-02 and LM-1. Then, we investigated the effects of strains LP-2 and LS-4 on the concentration of organic acids (pyruvic acid, citric acid, succinic acid, malic acid, and lactic acid) in Yamahai-shikomi sake. Only in lactic acid, a tendency to decrease with a smaller proportion of LS-4 strains in Yamahai-shubo was observed. Subsequently, their effect on the concentration of diacetyl, crucial for aroma, was investigated between the LP-2 and LS-4 strains. The sample prepared in the absence of strain LS-4 exhibited the lowest concentration of diacetyl. This result was supported by the statistical analysis for the sensory scores performed for aroma of each Yamahai-shikomi sake sample. In conclusion, strain LP-2 plays a more significant role in improving Yamahai-shikomi sake quality with strains LM-1 and 61-02 rather than strain LS-4 in Yamahai-shubo preparation and Yamahai-shikomi sake brewing.

Molecular and Electronic Structures of Macrocyclic Compounds Formed at Template Synthesis in the M(II)-Thiocarbohydrazide-Diacetyl Triple Systems: A Quantum-Chemical Analysis by DFT Methods.

Using density functional theory (DFT) B3PW91/TZVP, M06/TZVP, and OPBE/TZVP chemistry models and the Gaussian09 program, a quantum-chemical calculation of geometric and thermodynamic parameters of Ni(II), Cu(II), and Zn(II) macrotetracyclic chelates, with (NNNN)-coordination of ligand donor centers arising during template synthesis between the indicated ions of 3d elements, thiocarbohydrazide H2N-HN-C(=S)-NH-NH2 and diacetyl Me-C(=O)-C(=O)-Me, in gelatin-immobilized matrix implants was performed. The key bond lengths and bond angles in these coordination compounds are provided, and it is noted that in all these complexes the MN4 chelate sites, the grouping of N4 atoms bonded to the M atom, and the five-membered and six-membered metal chelate rings are practically coplanar. NBO analysis of these compounds was carried out, on the basis of which it was shown that all these complexes, in full accordance with theoretical expectations, are low-spin complexes. The standard thermodynamic characteristics of the template reactions for the formation of the above complexes are also presented. Good agreement between the data obtained using the above DFT levels is noted.

Sensory Specificities Involving Acetaldehyde and Diacetyl in Wines Produced without Added Sulfur Dioxide.

Nowadays, the development of naturality concept is illustrated in the oenological field by the development of wine produced without the addition of SO2. Among its chemical properties, SO2 is able to react with carbonyl compounds to form carbonyl bisulfites. Acetaldehyde and diacetyl are the main carbonyl compounds of red wines, which could influence product perception. The goal of this paper was to evaluate their chemical and sensory impact in red wines produced without any addition of SO2. A first quantification approach revealed a lower concentration of these compounds in wines without added SO2 than in those produced with SO2. A sensory approach involving aromatic reconstitutions in wines in the presence or absence of SO2 revealed that analytical differences observed for acetaldehyde and diacetyl were able to impact wine freshness, with diacetyl being, moreover, involved in wine fruity aroma changes.

Assessment of Chemosensory Response to Volatile Compounds in Healthy, Aged, and Neurodegenerative Caenorhabditis elegans Models.

A basic function of the nervous system is to confer the ability to detect external stimuli and generate appropriate behavioral and physiological responses. These can be modulated when parallel streams of information are provided to the nervous system and neural activity is appropriately altered. The nematode Caenorhabditis elegans utilizes a simple and well characterized neural circuit to mediate avoidance or attraction responses to stimuli, such as the volatile odorant octanol or diacetyl (DA), respectively. Aging and neurodegeneration constitute two important factors altering the ability to detect external signals and, therefore, changing behavior. Here, we present a modified protocol to assess avoidance or attraction responses to diverse stimuli in healthy and worm models associated with neurodegenerative diseases.

[Two cases of airway dysfunction related to diacetyl exposure].

Occupational exposure to diacetyl can lead to bronchiolitis obliterans. In this paper, two patients with severe obstructive ventilation disorder who were exposed to diacetyl at a fragrance and flavours factory were analyzed. The clinical manifestations were cough and shortness of breath. One of them showed Mosaic shadows and uneven perfusion in both lungs on CT, while the other was normal. Field investigation found that 4 of the 8 workers in the factory were found to have obstructive ventilation disorder, and 2 had small airway dysfunction. This paper summarizes the diagnostic process of patients in order to improve the understanding of airway dysfunction caused by occupational exposure to diacetyl and promote the development of relevant standards.

Topical Delivery of Diacetyl Boldine in a Microemulsion Formulation for Chemoprotection against Melanoma.

This study aimed to develop a microemulsion formulation for topical delivery of Diacetyl Boldine (DAB) and to evaluate its cytotoxicity against melanoma cell line (B16BL6) in vitro. Using a pseudo-ternary phase diagram, the optimal microemulsion formulation region was identified, and its particle size, viscosity, pH, and in vitro release characteristics were determined. Permeation studies were performed on excised human skin using Franz diffusion cell assembly. The cytotoxicity of the formulations on B16BL6 melanoma cell lines was evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) assay. Two formulation compositions were selected based on the higher microemulsion area of the pseudo-ternary phase diagrams. The formulations showed a mean globule size of around 50 nm and a polydispersity index of <0.2. The ex vivo skin permeation study demonstrated that the microemulsion formulation exhibited significantly higher skin retention levels than the DAB solution in MCT oil (Control, DAB-MCT). Furthermore, the formulations showed substantially higher cytotoxicity toward B16BL6 cell lines than the control formulation (p < 0.001). The half-maximal inhibitory concentrations (IC50) of F1, F2, and DAB-MCT formulations against B16BL6 cells were calculated to be 1 µg/mL, 10 µg/mL, and 50 µg/mL, respectively. By comparison, the IC50 of F1 was 50-fold lower than that of the DAB-MCT formulation. The results of the present study suggest that microemulsion could be a promising formulation for the topical administration of DAB.

Technological Characterization of Lactic Acid Bacteria Strains for Potential Use in Cheese Manufacture.

A total of 26 lactic acid bacteria isolates from both Italian and Brazilian cheeses were tested for their use in cheesemaking. Isolates were screened for salt tolerance, exopolysaccharide and diacetyl production, lipolytic, acidifying, and proteolytic activities. In addition, the aminopeptidase (Pep N and Pep X) activities, were evaluated. Most of the strains demonstrated salt tolerance to 6% of NaCl, while only two L. delbruekii (P14, P38), one L. rhamnosus (P50) and one L. plantarum (Q3C4) were able to grow in the presence of 10% (w/v) of NaCl. Except for 2 L. plantarum (Q1C6 and Q3C4), all strains showed low or medium acidifying activity and good proteolytic features. Furthermore, lipolytic activity was revealed in none of the strains, while the production of EPS and diacetyl was widespread and variable among the tested strains. Finally, regarding aminopeptidase activities, 1 L. delbrueckii (P10), 1 L. rhamnosus (P50), and 1 L. lactis (Q5C6) were considered as the better performing, showing high values of both Pep N and Pep X. Based on data presented here, the aforementioned strains could be suggested as promising adjunct cultures in cheesemaking.

Diacetyl Inhibits the Browning of Fresh-Cut Stem Lettuce by Regulating the Metabolism of Phenylpropane and Antioxidant Ability.

Enzymatic browning is the main quality issue of fresh-cut stem lettuce (Lactuca sativa L. var. angustana Irish). In this research, the effect of diacetyl on the browning and browning-related mechanisms of fresh-cut stem lettuce was explored. The data showed that diacetyl treatment with 10 µL L-1 inhibited the browning of fresh-cut stem lettuce and extended the shelf life by over 8 d at 4 °C compared with the control. Diacetyl treatment repressed gene expression and decreased the activities of PAL (phenylalanine ammonia-lyase), C4H (cinnamate-4-hydroxylase) and 4CL (4-coumarate-CoA ligase), which thus reduced the accumulation of individual and total phenolic compounds. Moreover, diacetyl enhanced the antioxidant ability and reduced ROS accumulation, improving the anti-browning ability and indirectly suppressing the biosynthesis of phenolic compounds. These results indicated that diacetyl treatment repressed the browning of fresh-cut stem lettuce by regulating the phenylpropanoid metabolism pathway and antioxidant ability. This study is the first to report that diacetyl has an effective anti-browning role for fresh-cut stem lettuce.

Two Fast GC-MS Methods for the Measurement of Nicotine, Propylene Glycol, Vegetable Glycol, Ethylmaltol, Diacetyl, and Acetylpropionyl in Refill Liquids for E-Cigarettes.

The use of e-cigarettes (ECs) has become increasingly popular worldwide, even though scientific results have not established their safety. Diacetyl (DA) and acetylpropionyl (AP), which can be present in ECs, are linked with lung diseases. Ethyl maltol (EM)-the most commonly used flavoring agent-can be present in toxic concentrations. Until now, there is no methodology for the determination of nicotine, propylene glycol (PG), vegetable glycerin (VG), EM, DA, and acetylpropionyl in e-liquids that can be used as a quality control procedure. Herein, gas chromatography coupled with mass spectrometry (GC-MS) was applied for the development of analytical methodologies for these substances. Two GC-MS methodologies were developed and fully validated, fulfilling the standards for the integration in a routine quality control procedure by manufacturers. As proof of applicability, the methodology was applied for the analysis of several e-liquids. Differences were observed between the labeled and the experimental levels of PG, VG, and nicotine. Three samples contained EM at higher concentrations compared to the other samples, while only one contained DA. These validated methodologies can be used for the quality control analysis of EC liquid samples regarding nicotine, PG, and VG amounts, as well as for the measurement of the EM.

A New Essential Oil from the Leaves of Gynoxys rugulosa Muschl. (Asteraceae) Growing in Southern Ecuador: Chemical and Enantioselective Analyses.

An essential oil, distilled from the leaves of the Andean species Gynoxys rugulosa Muschl., is described in the present study for the first time. The chemical composition was qualitatively and quantitatively determined by GC-MS and GC-FID, respectively. On the one hand, the qualitative composition was obtained by comparing the mass spectrum and the linear retention index of each component with data from literature. On the other hand, the quantitative composition was determined by calculating the relative response factor of each constituent, according to its combustion enthalpy. Both analyses were carried out with two orthogonal columns of nonpolar and polar stationary phases. A total of 112 compounds were detected and quantified with at least one column, corresponding to 87.3-93.0% of the whole oil mass. Among the 112 detected components, 103 were identified. The main constituents were α-pinene (5.3-6.0%), (E)-ß-caryophyllene (2.4-2.8%), α-humulene (3.0-3.2%), germacrene D (4.9-6.5%), δ-cadinene (2.2-2.3%), caryophyllene oxide (1.6-2.2%), α-cadinol (3.8-4.4%), 1-nonadecanol (1.7-1.9%), 1-eicosanol (0.9-1.2%), n-tricosane (3.3-3.4%), 1-heneicosanol (4.5-5.8%), n-pentacosane (5.8-7.1%), 1-tricosanol (4.0-4.5%), and n-heptacosane (3.0-3.5%). Furthermore, an enantioselective analysis was carried out on the essential oil, by means of two cyclodextrin-based capillary columns. The enantiomers of α-pinene, ß-pinene, sabinene, α-phellandrene, ß-phellandrene, linalool, α-copaene, terpinen-4-ol, α-terpineol, and germacrene D were detected, and the respective enantiomeric excess was calculated.

Nonlinear viscoelasticity and crystallization behavior of anhydrous milk fat/palm stearin/oleogel blends.

The crystallization behavior of anhydrous milk fat (AMF)/palm stearin (POs)/diacetyl tartaric acid ester of mono(di)glycerides (DATEM) oleogel blends was investigated, moreover, the linear and nonlinear rheological behavior of systems was analyzed by small amplitude oscillatory shear (SAOS) and large amplitude oscillatory shear (LAOS). The addition of DATEM oleogels inhibited the growth rate of crystals of blends at 4 °C and reduced the average size of crystalline nanoplatelet. Moreover, the DATEM oleogels promoted the transition of blends to more stable ß polymorphism. The nonlinear rheological response of blends was qualitatively analyzed by normalized Lissajous-Bowditch curves. The addition of DATEM oleogels made blends more resistant to large deformations and slowed down viscous losses while reducing the rearrangement behavior of the crystal microstructure under high strain. These findings could open up the possibility of developing low-saturated fat products and further broaden the application of oleogels.

Enzymes and pathways in microbial production of 2,3-butanediol and 3-acetoin isomers.

2,3-Butanediol (BD) and acetoin (AC) are products of the non-oxidative metabolism of microorganisms, presenting industrial importance due to their wide range of applications and high market value. Their optical isomers have particular applications, justifying the efforts on the selective bioproduction. Each microorganism produces different isomer mixtures, as a consequence of having different butanediol dehydrogenase (BDH) enzymes. However, the whole scene of the isomer bioproduction, considering the several enzymes and conditions, has not been completely elucidated. Here we show the BDH classification as R, S or meso by bioinformatics analysis uncovering the details of the isomers production. The BDH was compared to diacetyl reductases (DAR) and the new enoyl reductases (ER). We observed that R-BDH is the most singular BDH, while meso and S-BDHs are similar and may be better distinguished through their stereo-selective triad. DAR and ER showed distinct stereo-triads from those described for BDHs, agreeing with kinetic data from the literature and our phylogenetic analysis. The ER family probably has meso-BDH like activity as already demonstrated for a single sequence from this group. These results are of great relevance, as they organize BD producing enzymes, to our known, never shown before in the literature. This review also brings attention to nontraditional enzymes/pathways that can be involved with BD/AC synthesis, as well as oxygen conditions that may lead to the differential production of their isomers. Together, this information can provide helpful orientation for future studies in the field of BD/AC biological production, thus contributing to achieve their production on an industrial scale.

Two cases of airway dysfunction related to diacetyl exposure / 中华劳动卫生职业病杂志

Occupational exposure to diacetyl can lead to bronchiolitis obliterans. In this paper, two patients with severe obstructive ventilation disorder who were exposed to diacetyl at a fragrance and flavours factory were analyzed. The clinical manifestations were cough and shortness of breath. One of them showed Mosaic shadows and uneven perfusion in both lungs on CT, while the other was normal. Field investigation found that 4 of the 8 workers in the factory were found to have obstructive ventilation disorder, and 2 had small airway dysfunction. This paper summarizes the diagnostic process of patients in order to improve the understanding of airway dysfunction caused by occupational exposure to diacetyl and promote the development of relevant standards.