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An annulation of phthalide-derived activated alkenes is initially disclosed in this work. Specifically, we have developed an unprecedented [5 + 2] cycloaddition/ring-contraction tandem process of activated tetrasubstituted alkenes derived from phthalides or butyrolactone with vinylethylene carbonates under Pd(0) catalysis. Differing from the traditional spirolactonization strategy, this method renders an efficient and mechanistically distinct approach to benzo-[5,5]-spiroketal lactones and [5,5]-spiroketal lactones bearing two vicinal tetrasubstituted centers with high diastereoselectivity.

Here, we present palladium-catalyzed regiodivergent asymmetric annulations of vinyl indoloxazolidones, which can act as 1,5-carbodipoles or 1,3-carbodipoles by tuning the chiral ligands and conditions, in the assemblies with sulfamate-derived cyclic imines and even activated alkenes. A diversity of polycyclic products are generally constructed with high regio- and enantioselectivity.

Drynaria roosii is a traditional medicinal fern, whose rhizome is particularly valued for its effective flavonoid components of naringin/neoeriocitrin. UV irradiation can induce flavonoid accumulation in plants, however the molecular mechanism of UVC-mediated naringin/neoeriocitrin synthesis in D. roosii has never been reported. Our HPLC-tandem mass spectrometry (MS/MS) results showed that UVC irradiation increased naringin/neoeriocitrin contents (NNCs) based on irradiation dosage in D. roosii. According to the NGS data, DEG-based heat map analysis revealed up-regulation of naringin/neoeriocitrin synthetic genes was more obvious in 12h UVC irradiation (UV dose = 81.648 kJ m−2) when compared with 24h (UV dose = 163.296 kJ m−2), especially for PAL, C3’H and HCT in old rhizomes. Through systems biology method of modular organization analysis, we clustered 15,678 DEGs into 19 modules, and calculated correlation coefficients between modules and samples, as well as modules and NNCs. Four significant naringin-related modules were achieved and displayed high correlations with specific samples. Moreover, weighted gene co-expression network analysis results discovered that 4CL, CHS and HCT, C3H acted as the hub responsive genes to UVC irradiation involved in naringin and neoeriocitrin synthesis respectively, and presented high co-expression with MYB/bHLH-regulated DEGs. Overall, we demonstrated that UVC irradiation up-regulated the naringin/neoeriocitrin related gene expression in separate new and old rhizomes to enhance NNCs in a dose-dependent manner. Hormetic UVC dose ranges improving NNCs in D. roosii were established for the first time. Our work also provided new insights into the study of secondary metabolites in medicinal plants.

Gingival crevicular fluid (GCF) is a promising biofluid for disease identification and biomarker searching in periodontology. This study aimed to investigate the possible influencing factors, including tooth site, sex and age, on the normal GCF proteome. Forty periodontal healthy adults were randomly divided into a training group and a testing group. In the training group, GCF samples from 12 adults were analyzed using the iTRAQ 2D LC-MS/MS method. The influencing factors, tooth site (including periodontitis-susceptible and -insusceptible tooth sites), sex and age, and related differential proteins were defined and functionally annotated. The important differential proteins from 28 adults in the testing group were then validated by PRM analysis. An average of approximately 5 differential proteins were found between tooth sites of periodontitis-susceptible and -insusceptible sites. Eighty-five differentially expressed proteins were obtained between sexes in the young group, while only 7 sex-associated proteins were found in the old group. A total of 203 and 235 age-associated proteins were found in the male and female groups, respectively. The differential protein functional annotation showed that sex-related proteins were mainly related to immune function and metabolism, and age-related proteins were primarily associated with inflammation, lipid metabolism and immune function. In the testing group, a total of 4 sex-related proteins and 12 age-related proteins were validated by PRM analysis. Significance The influences of tooth site, sex and age in GCF proteomics in periodontal health were firstly analyzed using LC-MS/MS. Tooth site showed a small influence on the GCF proteome. The sex effect was significant in young adults, but its influence in old adults is small. Age is an important impact factor for the GCF proteome. These findings enrich the knowledge about the normal GCF proteome and might benefit future disease analyses.

An asymmetric α-regioselective allenylation reaction of activated ketimines with 3-butynoates is disclosed under Cu(I) catalysis, probably via the generation of nucleophilic γ-allenylcopper species in the presence of diisopropylethylamine. A broad range of imines, derived from diverse ketones such as isatins, pyrazolediones, isoquinoline-1,3,4-triones, and even trifluoromethyl alkynyl ketones, can be utilized, generally affording the corresponding α-allenyl amine derivatives in high yields (≤97%) with excellent enantioselectivities (≤99% ee).

A cascade vinylogous 1,6-Michael addition/1,4-proton shift/aza-Michael addition/hemiaminal formation sequence of 1,2-diaza-1,3-dienes and β-substituted 2-butenals has been developed under the influence of dienamine activation of a chiral secondary amine. This method exhibits high regio- and chemoselectivity and provides an efficient and straightforward approach to bicyclic l,8-diazabicyclo[3.3.0]octane skeletons with a tetrasubstituted stereogenic center with fair to excellent enantioselectivity.

Zwitterionic dienolates generated from Morita-Baylis-Hillman carbonates of cyclohexen-2-one and a phenolic tertiary amine catalyst underwent divergent cyclization reactions with isatylidene malononitriles. A new [4 + 2] stepwise cyclization process was disclosed to deliver complex bridged spirooxindoles after the initial δ'-regioselective Rauhut-Currier-type reaction with N-methyl electrophiles by the catalysis of β-isocupreidine, while spirooxindoles incorporating an aromatic chromene motif were generated with N-MOM acceptors in the presence of α-isocupreine through different domino transformations.

In the present work, the performances of high-solids enzymatic hydrolysis of rice straw were experimentally studied. Moreover, the heat flow and weight loss of the pre- and post-hydrolysis of rice straw were measured by the simultaneous thermogravimetric analyzer. It is found that the output and yield of reducing sugar initially increased and then reduced with an increase of supplied water, hydrolysis temperature and substrate mesh, while the cellulose content in residual substrate had an opposite trends. Furthermore, a high enzyme loading resulted in a constant saccharification efficiency of cellulose. The output and yield of the sugar, 77.7 mg/(g substrate) and 0.44 g/g, were respectively achieved under the optimal conditions of the supplied water of 1.0 ml/(g substrate), enzymolysis temperature of 50 °C, rice straw of 60 mesh and the cellulase dosage of 2.0 mg/(g substrate). Simultaneous thermogravimetric analysis on the rice straw indicates that the chemical compositions of rice straw changed after enzymolysis.