Incorporating edible oil during cooking tailors the microstructure and quality features of brown rice following heat moisture treatment.

While brown rice (BR) has numerous nutritional properties, the consumption potential of which is seriously restricted since the poor cooking quality and undesirable flavor. Here, edible oils (pork lard and corn oil, 1-5 wt%) were incorporated during the cooking of BR following heat moisture treatment. Incorporating corn oil rather than lard significantly ameliorated the texture properties (e.g. hardness, cohesiveness, and chewiness) and sensory properties of cooked BR. Both lard- and corn oil-incorporated cooked BR showed obvious structural changes accompanied by the formation of amylose-lipid complexes during cooking. It was confirmed that the incorporation of lard and corn oil allowed a higher degree of short-range molecular order, more V-type starch crystallites, and elevated nano-structural arrangements. Additionally, a decreased hardness (from 559.04 g to 424.18 g and 385.91 g, respectively) and enriched resistant starch (RS) were also observed, the highest RS content (15.95 % and 16.32 %, respectively) was observed when 1 wt% of lard and corn oil were incorporated.

Effects of Bacillus subtilis subsp. on the microbial community and aroma components of flue-cured tobacco leaves based on metagenome analysis.

To improve the sensory quality of aged flue-cured tobacco (FCT), Bacillus subtilis subsp, H11 was inoculated on aged FCT leaves named Pingdingshan DCFB. The metagenome and thecharacteristic aroma substances of aged FCT with different fermentation times (0 h, 12 h, 24 h, and 36 h) were systematically analyzed. The results showed that the content of aroma components and sensory quality of aged FCT were significantly improved when the strain was treated at 35 °C with 25% moisture for 24 h. The inoculation of H11 had a strong influence on the microbial composition and metabolism of the aged FCT leaf surface. Five microorganisms Pantoea (35.04%, 20.12-56.95%), Enterobacter (22.16, 13.60-39.82%), Pseudomonas (12.12, 3.13-26.17%), Terribacillus (8.00%, 4.65-13.01%) and Bacillus (6.54%, 0.67-16.96%) accounted for the largest proportion during the process of fermentation. The content of most neutral flavor components such as ketones and aldehydes in FCT after fermentation was higher than that priorto fermentation. After 24 h fermentation, 3-furfural, 5-methylfurfural, dihydrokiwi lactone and megalotrienone increased by 71.42%, 49.19%, 21.09%, and 10.56%, respectively. Correlation analysis between groups showed that Pseudomonas was significantly correlated with (E, E)-2, 4-heptadienal (P < 0.05), Franconibacter was correlated with damascus ketone (P < 0.05), and Terribacillus was related to the production of ß-citral (P < 0.05). GH9 may be involved in the formation of damasone (P < 0.05), and 4-cyclopentene-1, 3-dione was significantly correlated with glycoside hydrolase family 5 (GH5) (P < 0.05). The correlation between 4-oxyisophorone and GH31, GH103, GH73, and GH3 was significant (P < 0.05). Microorganisms and GHs may play important roles in FCT fermentation.

An efficient turn-on fluorescence chemosensor system for Zn(II) ions detection and imaging in mitochondria.

Mitochondria-targetable fluorescent chemosensors, Rhodamine-B and rhodamine 6G bearing syringaldehyde based receptors were designed and synthesized for efficient chemosensing of Zinc(II) ions. The probes showed the very selective naked eye color change to pink from colorless upon addition of Zinc(II) ions, further these probes showing turn-on fluorescence enhancement with Zn(II) ions by opening of rhodamine spirolactam. The probes are very sensitive towards Zn(II) ions among other ions. These probes RBS and R6S will be applicable to detect zinc ions upto the low level concentration 0.18 and 0.19 nano molar respectively. The affinity of these sensors RBS and R6S for Zinc (II) ions was found to be in the range of 1.12 × 104 M-1 and 7.28 × 104 M-1 respectively. 1H-nmr titrations of the probes with Zn(II) ions clearly indicating the spiroring opening of the spirolactam. DFT calculations supporting that the perceived photophysical changes of the probes on appendage of the zinc ions. Probes RBS and R6S are useable for selective staining mitochondria. Both of the probes are applicable to reveal labile Zn(II) in live Hela and MCF-7 cells via fluorescence imaging. RBS and R6S are also finding application on quantification of Zinc(II) ions inside mitochondria via fluorescence imaging.

Adenosine triphosphate (ATP) and zinc(II) ions responsive pyrene based turn-on fluorescent probe and its application in live cell imaging.

A novel highly selective and sensitive turn-on fluorescent chemosensor PCE to recognize Zn2+ has been developed. The sensor PCE displays a remarkable fluorescent enhancement at 456 nm (λex = 340 nm) with Zn2+ without the interference of other biologically important relevant metal ions in aqueous acetonitrile solution. Job's plot and mass spectral studies divulge such the interaction of PCE by Zn2+ was 1:1 binding stoichiometry. The association constant and detection limit of PCE to recognize Zn2+ was found to be 0.948 × 104 M-1 and 4.82 × 10-7 M respectively. The nature of turn-on fluorescence sensor was supported by TD-DFT calculations. And the synthesized probe PCE was able to image intracellular Zn2+ in living cells using confocal imaging techniques. PCE-Zn ensemble showed the remarkable fluorescence enhancement with ATP selectively among other biologically important phosphates. 31P NMR experiments suggesting that the triphosphates unit of ATP is intact with the PCEZn. PCE-Zn ensemble can be utilized for monitoring ATP in live cells.

Microbial community and metabolic function analysis of cigar tobacco leaves during fermentation.

Cigar tobacco leaves (CTLs) contain abundant bacteria and fungi that are vital to leaf quality during fermentation. In this study, artificial fermentation was used for the fermentation of CTLs since it was more controllable and efficient than natural aging. The bacterial and fungal community structure and composition in unfermented and fermented CTLs were determined to understand the effects of microbes on the characteristics of CTLs during artificial fermentation. The relationship between the chemical contents and alterations in the microbial composition was evaluated, and the functions of bacteria and fungi in fermented CTLs were predicted to determine the possible metabolic pathways. After artificial fermentation, the bacterial and fungal community structure significantly changed in CTLs. The total nitrate and nicotine contents were most readily affected by the bacterial and fungal communities, respectively. FAPROTAX software predictions of the bacterial community revealed increases in functions related to compound transformation after fermentation. FUNGuild predictions of the fungal community revealed an increase in the content of saprotrophic fungi after fermentation. These data provide information regarding the artificial fermentation mechanism of CTLs and will inform safety and quality improvements.

Coumarin-fused coumarin: antioxidant story from N,N-dimethylamino and hydroxyl groups.

Two coumarin skeletons can form chromeno[3,4-c]chromene-6,7-dione by sharing with the C ═ C in lactone. The aim of the present work was to explore the antioxidant effectiveness of the coumarin-fused coumarin via six synthetic compounds containing hydroxyl and N,N-dimethylamino as the functional groups. The abilities to quench 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS(+•)), 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH), and galvinoxyl radical revealed that the rate constant for scavenging radicals was related to the amount of hydroxyl group in the scaffold of coumarin-fused coumarin. But coumarin-fused coumarin was able to inhibit DNA oxidations caused by (•)OH, Cu(2+)/glutathione (GSH), and 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH) even in the absence of hydroxyl group. In particular, a hydroxyl and an N,N-dimethylamino group locating at different benzene rings increased the inhibitory effect of coumarin-fused coumarin on AAPH-induced oxidation of DNA about 3 times higher than a single hydroxyl group, whereas N,N-dimethylamino-substituted coumarin-fused coumarin possessed high activity toward (•)OH-induced oxidation of DNA without the hydroxyl group contained. Therefore, the hydroxyl group together with N,N-dimethylamino group may be a novel combination for the design of coumarin-fused heterocyclic antioxidants.

Coumarin sharing the benzene ring with quinoline for quenching radicals and inhibiting DNA oxidation.

Fifteen 8-substituted-phenyl-6-ferrocenyl-4-methyl-2H-pyrano[3,2-g]quinolin-2-ones were synthesized via Povarov three-component reaction, in which the substituted aromatic aldehydes reacted with ferrocenylacetylene and 7-amino-4-methylcoumarin in the presence of Ce(OTf)3 as the catalyst. The obtained coumarin-fused quinolines were applied to quench 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS(+)) and 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH) and to inhibit 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH)-induced oxidation of DNA. It was found that the ferrocenyl group attaching to pyrano[3,2-g]quinolin-2-one scaffold can trap radicals and inhibit DNA oxidation even in the absence of phenolic hydroxyl group. The inhibitory effects on radicals and DNA oxidation can be further enhanced by the electron-donating groups such as p-(N,N-dimethyl amino)phenyl, ferrocenyl, and furan-2-yl group at 8-position. Therefore, ferrocenyl-substituted pyrano[3,2-g]quinolin-2-one skeleton together with electron-donating groups became a novel structural style for antioxidants.

Coumestan inhibits radical-induced oxidation of DNA: is hydroxyl a necessary functional group?

Coumestan is a natural tetracycle with a C═C bond shared by a coumarin moiety and a benzofuran moiety. In addition to the function of the hydroxyl group on the antioxidant activity of coumestan, it is worth exploring the influence of the oxygen-abundant scaffold on the antioxidant activity as well. In this work, seven coumestans containing electron-withdrawing and electron-donating groups were synthesized to evaluate the abilities to trap 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS(•+)), 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH), and galvinoxyl radical, respectively, and to inhibit the oxidations of DNA mediated by (•)OH, Cu(2+)/glutathione (GSH), and 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH), respectively. It was found that all of the coumestans used herein can quench the aforementioned radicals and can inhibit (•)OH-, Cu(2+)/GSH-, and AAPH-induced oxidations of DNA. In particular, substituent-free coumestan exhibits higher ability to quench DPPH and to inhibit AAPH-induced oxidation of DNA than Trolox. In addition, nonsubstituted coumestan shows a similar ability to inhibit (•)OH- and Cu(2+)/GSH-induced oxidations of DNA relative to that of Trolox. The antioxidant effectiveness of the coumestan can be attributed to the lactone in the coumarin moiety and, therefore, a hydroxyl group may not be a necessary functional group for coumestan to be an antioxidant.