The inhibitory effect and mechanism of theaflavins on fluoride transport and uptake in HIEC-6 cell model.

Fluoride (F-) is widely present in nature, while long-term excessive F- intake can lead to fluorosis. Theaflavins are an important bioactive ingredient of black and dark tea, and black and dark tea water extracts showed a significantly lower F- bioavailability than NaF solutions in previous studies. In this study, the effect and mechanism of four theaflavins (theaflavin, theaflavin-3-gallate, theaflavin-3'-gallate, theaflavin-3,3'-digallate) on F- bioavailability were investigated using normal human small intestinal epithelial cells (HIEC-6) as a model. The results showed that theaflavins could inhibit the absorptive (apical - basolateral) transport of F- while promote its secretory (basolateral - apical) transport in HIEC-6 cell monolayers in a time- and concentration-dependent (5-100 µg/mL) manner, and significantly reduce the cellular F- uptake. Moreover, the HIEC-6 cells treated with theaflavins showed a reduction in cell membrane fluidity and cell surface microvilli. Transcriptome, qRT-PCR and Western blot analysis revealed that theaflavin-3-gallate (TF3G) addition could significantly enhance the mRNA and protein expression levels of tight junction-related genes in HIEC-6 cells, such as claudin-1, occludin and zonula occludens-1 (ZO-1). Overall, theaflavins may reduce F- absorptive transport by regulating tight junction-related proteins, and decreasing intracellular F- accumulation by affecting the cell membrane structure and properties in HIEC-6 cells.

Effect and Mechanism of Theaflavins on Fluoride Transport and Absorption in Caco-2 Cells.

This paper investigated the effect and mechanism of theaflavins (TFs) on fluoride (F-) uptake and transport in the Caco-2 cell model through structural chemistry and transcriptome analysis. The results showed that the four major TFs (TF, TF3G, TF3'G and TFDG) at a 150 µg/mL concentration could all significantly decrease F- transport in Caco-2 cells after 2 h of treatment and, at 2 µg/mL F- concentration, the F- transport was more inclined to efflux. During transport, the F- retention in Caco-2 cells was significantly increased by TF3G while it was clearly decreased by TF. The interaction between TFs and F- was analyzed by Raman spectroscopy and isothermal titration calorimetry, and F- was shown to affect the π bond vibration on the benzene ring of TFs, thus influencing their stability. Additionally, F- showed weak binding to TF3G, TF3'G and TFDG, which may inhibit F- transport and absorption in the Caco-2 cell line. Transcriptome and RT-PCR analysis identified three key differentially expressed genes related to cell permeability, and TFs can be assumed to mediate F- transport by regulating the expression of permeability-related genes to change cell monolayer permeability and enhance cell barrier function; however, this needs to be further elucidated in future studies.

Reuse of composted food waste from rural China as vermicomposting substrate: effects on earthworms, associated microorganisms, and economic benefits.

ABSTRACTAerobic composting of food waste (FW) from rural China using a composting device results in a substantial financial burden on the government. This study aimed to assess the feasibility of mitigating this cost using vermicomposting of composted FW. The specific aims were to elucidate the effects of composted FW on earthworm growth and reproduction, reveal the changes in the physical and chemical properties of earthworm casts during vermicomposting, identify the microbial community structure associated with vermicomposting, and perform a financial analysis based on the yield of earthworms and earthworm casts. Mixing composted FW and mature cow dung in an equal ratio achieved the highest earthworm reproduction rate, where 100 adult earthworms produced 567 juvenile earthworms and 252 cocoons in 40 d. Earthworms reduce salt content of vermicomposting substrates by assimilating Na+ and promoting humification by transforming humin into humic and fulvic acid, thus producing earthworm casts with a high generation index > 80%. When composted FW was added to a vermicomposting substrate, a distinctive microbial community structure with alkaliphilic, halophilic, and lignocellulolytic microorganisms dominated the microflora. The dominant bacterial species was Saccharopolyspora rectivirgula, and the dominant fungal species changed from Kernia nitida to Coprinopsis scobicola. Furthermore, microbial genes for refractory organic matter and fat degradation were observed in Vibrio cholerae, Kernia nitida, and Coprinopsis scobicola. Financial analysis showed that vermicomposting has the potential to reduce the cost associated with FW disposal from $ 57 to $ 18/t.

A high-yielding strain of indole-3-acetic acid isolated from food waste compost: metabolic pathways, optimization of fermentation conditions, and application.

Food waste is a potential resource to prepare microbial fertilizer. However, functional microorganisms derived from the food waste compost (FWC) are relatively lacking. We have isolated, identified, characterized and optimized a high-yielding indole-3-acetic acid (IAA) strain from FWC and further evaluated its growth promoting effect on plants. A IAA high-yielding strain, Providencia sp.Y, with an initial IAA yield of 139.98 mg L-1, was obtained through high-throughput screening, and identified by 16S rRNA gene sequence. The novel strain Y may simultaneously involve the following three pathways from L-tryptophan to IAA, which were identified using liquid chromatography-tandem mass spectrometry: (1) L-tryptophan-indole-3-ethanol-indole-3-acetaldehyde-indole-3-acetic acid; (2) L-tryptophan-1-hydroxy-indole-3-ethanol-indole-3-acetic acid; (3) L-tryptophan-indole-3-acetamide-indole-3-acetic acid. The most suitable comprehensive conditions for IAA production, which were optimized by single factor experiment, were: culture time 12 h, inoculation amount 2% (v/v), NaCl concentration 4% (w/v), culture temperature 25℃, initial pH = 5, and L-tryptophan concentration 3.0 g L-1. The yield of IAA after optimization was increased by 590.48%, from 139.98 mg L-1 (before optimization) to 966.54 mg L-1. Diluted 200-fold microbial suspension could significantly improve the growth of pakchoi seedlings. The seedling plant height, root length, leaf width, leaf length, and fresh weight with microbial suspension increased by 17.39%, 107.35%, 77.98%, 37.75%, and 215.38%, respectively, compared with those without microbial suspension. The increase was greater than that of commercial bacterial agents. In conclusion, this isolated strain can be used as an economical microbial inoculant and provides a new germplasm resource for developing microbial fertilizers.

3-Phenyl-2-(pyrrolidin-1-yl)-5,6-dihydro-8H-thio-pyrano[4',3':4,5]thieno[2,3-d]pyrimidin-4(3H)-one.

In the title compound, C(19)H(19)N(3)OS(2), the thio-pyran ring adopts a twist-chair conformation and the pyrimidinone unit is essentially planar, with a mean deviation of 0.0497 Å. The thio-phene ring is essentially planar with a maximum deviation of 0.024 (2) Å, while the pyrrolidine ring exhibits an envelope conformation. The pyrimidinone and thio-phene rings are almost coplanar, forming a dihedral angle of 6.31 (15)°, while the dihedral angle between the mean planes of the phenyl ring and the pyrimidinone ring is 68.13 (10)°. In the crystal structure, adjacent mol-ecules are linked by C-H⋯O hydrogen bonds, forming a two-dimensional network in the ac plane.

N-Phenyl-morpholine-4-carboxamide.

In the title compound, C(11)H(14)N(2)O(2), the urea-type NC=ON moiety [planar to within 0.0002 (13) Å] is inclined to the phenyl ring by 42.88 (8) Å, and the morpholine ring has a chair conformation. In the crystal, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into infinite chains in [001].

Ethyl 2-amino-6-benzyl-4,5,6,7-tetra-hydro-thieno[2,3-c]pyridine-3-carboxyl-ate.

In the title compound, C(17)H(20)N(2)O(2)S, the tetra-hydro-pyridine ring adopts an envelope conformation with the N atom at the flap position; the phenyl ring makes a dihedral angle of 81.06 (10)° with the thio-phene ring. The amino group links with the carbonyl O atom via intra-molecular N-H⋯O hydrogen bonding, forming a six-membered ring. In the crystal, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into infinite chains running along the b axis.

Bis(acetyl-acetonato-κO,O')(methanol-κO)(thio-cyanato-κN)manganese(III).

In the title complex, [Mn(C(5)H(7)O(2))(2)(NCS)(CH(4)O)], the Mn(III) atom has a slightly distorted octa-hedral coordination formed by five O atoms and one N atom. The equatorial positions are occupied by four O atoms of two acetyl-acetonate ligands, while the axial positions are occupied by the N atom of the thio-cyanate anion and the O atom of the methanol mol-ecule. In the crystal structure, complex mol-ecules are linked by an inter-molecular O-H⋯S hydrogen bond, forming a chain running along [101].

catena-Poly[[(1,12,15,26-tetra-aza-5,8,19,22-tetra-oxa-3,4:9,10:17,18:23,24-tetra-benzocyclo-octa-cosane-κN,N,N,N)nickel(II)]-µ-terephthalato-κO:O].

In the title compound, [Ni(C(8)H(4)O(4))(C(36)H(44)N(4)O(4))](n), the Ni(II) atom is coordinated in a distorted octa-hedral geometry by the four N atoms of the 1,12,15,26-tetra-aza-5,8,19,22-tetra-oxa-3,4:9,10:17,18:23,24-tetra-benzocyclo-octa-cosane ligand and two O atoms from the terephthalate dianions. The Ni(II) atoms, which lie on inversion centres, are linked via terephthalate ligands to form a chain structure along [101]. The structure is stabilized by three intra-molecular and one inter-molecular N-H⋯O hydrogen bonds.

(E)-N'-(Furan-2-ylmethyl-ene)-4-(quinolin-8-yl-oxy)butanohydrazide.

In the title mol-ecule, C(18)H(17)N(3)O(3), the dihedral angle between the mean planes of the furan ring and the quinoline group is 77.4 (2)°. In the crystal structure, inter-molecular N-H⋯N hydrogen bonds link the mol-ecules into centrosymmetric dimers.

3-Phenyl-2-(piperidin-1-yl)-3,5,6,8-tetra-hydro-4H-thio-pyrano[3',4':2,3]thieno[5,4-d]pyrimidin-4-one.

In the title compound, C(20)H(21)N(3)OS(2), the piperidinyl ring has a distorted chair conformation. Weak inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into centrosymmetric dimers. The crystal packing exhibits short inter-molecular S⋯S distances of 3.590 (2) Å.