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Although the pathway and transcription factor regulation of anthocyanin biosynthesis in tea plants [Camellia sinensis (L.) O. Ktze] are known, post-transcriptional regulation mechanisms involved in anthocyanin accumulation have not been comprehensively studied. We obtained the full-length transcriptome of a purple cultivar (‘Zijuan’) and a normal green cultivar (‘Yunkang 10#) of C. sinensis var. asssamica (Masters) showing different accumulation of anthocyanins and catechins through PacBio isoform sequencing (Iso-Seq). In total, 577,557 mapped full-length cDNAs were obtained, and 2,600 average-length gene isoforms were identified in both cultivars. After gene annotations and pathway predictions, we found that 98 key genes in anthocyanin biosynthesis pathways could have undergone alternative splicing (AS) events, and identified a total of 238 isoforms involved in anthocyanin biosynthesis. We verified expression of the C4H, CHS, FLS, CCOM, F3′5’H, LAR, PAL, CCR, CYP73A13, UDP75L12, UDP78A15/UFGT, UDP94P1, GL3, MYB113, ANR, ANS, F3H, 4CL1, CYP98A3/C3H, CHI, DFR genes and their AS transcripts using qRT-PCR. Correlation analysis of anthocyanin biosynthesis and gene expression results revealed that C4H1, FLS1, PAL2, CCR2, UDP75L122 and MYB113-1 are crucial AS transcripts for regulating anthocyanin biosynthesis in C. sinensis var. assamica. Our results reveal post-transcriptional regulation of anthocyanin biosynthesis in tea plants, and provide more new insights into the regulation of secondary metabolism.

Tannase (E.C. 3.1.1.20) is hypothesized to be involved in the metabolism of gallates and gallic acid (GA) in pu-erh tea fermentation. In this work, we measured tannase in Aspergillus niger fermented tea leaves and confirmed the production of fungal tannase during pu-erh tea fermentation. A decrease in catechin and theaflavin gallates and a significant increase in GA content and the relative peak areas of ethyl gallate, procyanidin A2, procyanidin B2, procyanidin B3, catechin-catechin-catechin, epiafzelechin, and epicatechin-epiafzelechin [variable importance in the projection (VIP) > 1.0, p 1.5] were observed using high performance liquid chromatography (HPLC) and metabolomics analysis of tea leaves fermented or hydrolyzed by tannase. In vitro assays showed that hydrolysis by tannase or polymerization of catechins increased the antioxidant activity of tea leaves. In summary, we identified a metabolic pathway for gallates and their derivatives in tea leaves hydrolyzed by tannase as well as associated changes in gallate and GA concentrations caused by fungal tannase during pu-erh tea fermentation.

Tea is the second most widely consumed beverage and contains various bioactive compounds. A simple method to analyze these compounds is of great scientific and commercial interest. In this work, a 30 min HPLC method was developed using a simple gradient elution system, and the mobile phases and elution gradients were optimized. This method separated 17 polyphenols and three alkaloid compounds in tea extracts, including catechins, alkaloids, phenolic acids, flavonols, and flavone, which are responsible for the bioactivity and flavor of tea. Excellent linearity was observed for all standard calibration curves, and correlation coefficients were above 0.9994. Heatmap analysis demonstrated significant separation between green, black, and pu-erh tea samples. The method described here is accurate and sensitive enough for the determination of active components in tea and could potentially be applied to other food products for the comprehensive investigation of their quality.

One new Metal-Organic Frameworks, [Co4O(L)2]·(DMF)8·(H2O)8 (1, H3L = 4-[N,N-bis(4-methylbenzoic acid)amino]benzoic acid), had been successfully constructed under hydrothermal conditions, which firstly presents the [Co4O(COO)6] secondary-building unit similar to the typical [Zn4O(COO)6] one via single-crystal X-ray diffraction studies. All of the cobalt ions exhibit the four-coordinate environment, and possess more open metal sites. Heterogeneous catalytic experiments on allylic oxidation of cyclohexene indicate that 1 exhibits high catalytic activity by utilizing the tert-butylhydroperoxide (t-BuOOH) as the oxidant. The activation energy for the whole process of oxidation of cylcohexene had been calculated as 40.6 kJ mol−1, which indicate the important role of the special [Co4O(COO)6] cluster in the resulted heterogeneous catalyst.

Three new Metal-Organic Frameworks, Zn(L1)(H2O)·NMP (1), [Zn4O(L2)(NMP)(H2O)]·(NMP)2 and [Zn2(OH)(L3)(NMP)(H2O)]·NMP (3) (H2L1 = 1,4-Naphthalate, H2L2 = iso-Phthalic acid, H3L3 = 1,3,5-Benzenetricarboxylic acid), have been successfully constructed under the same reaction conditions. Although these ligands have been widely utilized for the construction of versatile MOFs by adjusting the reaction conditions, rare samples had been fabricated via the utilization of N-Methyl pyrrolidone (NMP). Different to the previous reported MOFs, the diversities of the title structures should be caused by the choice of pure solvent N-Methyl pyrrolidone and the configurations of the selected linkers. Guided by the synergistic effect between metal ions, the configuration of linkers and NMP, the different metal secondary building units (SBUs), porous structures and topological structures have been formed in these MOFs. In addition, all of these activated samples for these MOFs could reserve certain porosities and exhibit the corresponding gas adsorption for CO2 and H2.

Two new Metal-Organic Frameworks, [Zn3(tdc)3(H2O)2]·2.5(dioxane) (1) and [Mn3(H2O)3(tdc)3(dioxane)]·2(dioxane) (2), have been successfully constructed by the utilization of 2,5-thiophenedicarboxylate ligand (H2L) and Zn/Mn ions. Although trinuclear metal secondary building units (SBUs) have been stabilized in these two final frameworks, the different connection modes are exhibited due to the difference of coordination habits of metal ions. The trinuclear [Zn3(COO)6] SBU exhibits the 6-connected mode via six L ligands, whilst the trinuclear [Mn3(COO)6] SBU presents the 8-connected mode via six L ligands and two p-dioxane molecules. The different connection modes of two trinuclear SBUs lead to the formation of distinct topological structures (6-connected pcu for 1; 8-connected tsi for 2). Both of the activated samples for these two MOFs could reserve the certain porosities and exhibit the corresponding gas sorption for H2.

Morels (Morchella spp.) are highly prized for their culinary qualities and intensively collected worldwide by mycophiles. Morels are divided into three clades by phylogenetic analyses: black morels, yellow morels and the rufobrunnea clade. Morchella importuna, Mel-20 and M. sextelata are included in the black morel clade and are widely distributed in Yunnan province, China. M. importuna and M. sextelata have been artificially cultured in recent years, but their life cycles and reproductive systems are still poorly understood, which delays the progress of morel cultivation. In this study, the genomes of two ascospore isolates of M. importuna with opposite mating-type were sequenced and two idiomorphs, MAT1–1 and MAT1–2, were identified. The MAT1–2 idiomorph was 6.7 kb in length containing a single MAT1–2-1 gene, and the MAT1–1 idiomorph was 10.5 kb containing a MAT1–1-1 gene and two other open reading frames (ORFs), GME3123 and GME3124. These ORFs differed greatly from the homologues of previously published mating-type genes; therefore, we speculate that they are novel mating genes found only in morels. Single-ascospore populations of M. importuna, M. sextelata and Mel-20 were analysed, and the result indicated that the ratios of MAT1–1- and MAT1–2-harbouring idiomorphs were not significantly different from a 1:1 ratio. The results suggest that these three black morels are heterothallic.

Post-fermented Pu-erh tea (PFPT) is a microbially-fermented tea with distinct sensory qualities and multiple health benefits. Aspergillus are the dominant fungi in the fermentation and the main contributors to the characteristics of PFPT, so their underlying functions warrant detailed study. Here, tea leaves were fermented by Aspergillus niger, Aspergillus tamarii and Aspergillus fumigatus, and resulting samples (designated as Asn, Ast and Asf, respectively) were analyzed by proteomic and metabolomic methods. Changes to the composition of flavonoids, glycerophospholipids, organo-oxygen compounds and fatty acids resulting from Aspergillus fermentation were observed. Carbohydrate-active enzymes, e.g., endoglucanases and cellulases, for degradation of cellulose, starch, lignin, pectin, xylan and xyloglucan were identified. Glycoside hydrolase, glycosyltransferases, tannase, laccases, vanillyl-alcohol oxidases and benzoquinone reductase were identified and hypothesized to catalyze hydrolysis, oxidation, polymerization and degradation of phenolic compounds. Together, functions of Aspergillius were demonstrated as production of enzymes to change concentrations and compositions of metabolites in tea leaves.

Two coordination polymers (CPs) with novel tri-functional ligand, [Zn(H2O)(CH3OH)L]n (1) and [Cd(H2O)L]n (2), (H2L = 5-(1H-tetrazol-5-yl)nicotinic acid), have been synthesized and structurally characterized. Differently, 1 exhibits the 2D layer structure, while 2 exhibits the 3D structure due to the different connection modes between metal nodes and tri-functional ligand. The different coordination habit between metal ions and ligands must be responsible for the fabrication of versatile topologies. At room temperature, 1 exhibits an intense emission at around 367 nm, while 2 exhibits an intense emission at 358 nm. The different shift of the peak from free ligand, 1 and 2 must be assigned to the different configuration and π-bonding of L caused by the different coordination environments of metal ions.

A simple and efficient RP high-performance liquid chromatography method was developed for simultaneous analysis of eight small antihypertensive peptides with tyrosine at the C-terminal in Laminaria japonica hydrolysates (LHs). The chromatography was performed on an Xterra MS-C18 column at 45C, with an aqueous mobile phase (0.1% trifluoroacetic acid, pH 2.8) acetonitrile in a linear gradient at the flow rate of 0.7 mL/min, and detected at 218 nm. The detection limits ranged from 0.0624 to 0.2365 μM. Correlation coefficients were greater than 0.9997. The recovery ranged from 92.17 to 120.08%. The small peptides were successfully determined by this method in LHs and the structures were confirmed by ESI-MS/MS, and the structure–activity relationships were discussed. The results demonstrated that the proposed method could be used to determine the peptides with tyrosine at the C-terminal, and to characterize a widespread detection mode for small peptide analysis in easy operation and low cost. Practical Applications This study is the first to report that marine Laminaria japonica protein hydrolyzed by combined enzymes of the alcalase, trypsin and papain displayed high angiotensin-converting enzyme (ACE) inhibitory activity. An effective and efficient reverse phase (RP) high-performance liquid chromatography method was developed for simultaneous analysis of eight small antihypertensive peptides with tyrosine at the C-terminal. Adopting the proposed method, Laminaria japonica hydrolysates and the ACE inhibitory activities of small peptides will be successfully analyzed. The results also demonstrated that Laminaria japonica proteins would be a good source of hypotensive peptides.