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Three matrine-derived alkaloids, alopecuroidine A (1), alopecuroidine B (2a) and alopecuroidine C (2b) were isolated from the seeds of Sophora alopecuroides. Their structures were elucidated by extensive spectroscopic analyses and X-ray diffraction. Three compounds possess an unprecedented rearranged fused 7/6/5/6 tetracyclic skeleton with a diazacycloheptane structure. Their plausible biosynthetic pathway was also proposed. The anti-proliferative activities of compounds 1 and 2a were examined by the MTT assay. Compound 1 inhibited the viability of human lung cancer A549 cells, having a half maximal inhibitory concentration (IC50) of 7.58 ± 2.47 μmol/L at 72 h. The flow cytometric analysis suggested that 1 inhibited A549 cell growth by inducing apoptosis and cell-cycle arrest. Additionally, 1 induced the loss of mitochondrial membrane potential, elevated intracellular reactive oxygen species, increased the Bax/Bcl-2 ratio, stimulated cleaved-caspase-3 and P53 protein levels, and suppressed the pro-caspase-3 level. Thus, 1 appeared to induce A549 cells apoptosis through a mitochondria-mediated apoptotic pathway.

One pair of new amides enantiomers (1a and 1b) and two known amides were isolated from the rhizomes of Polygonum cuspidatum. Their structures were established using UV, IR, HRESIMS, and NMR data. Notably, compound 1 possesses unique C-C connection between feruloyltyramine and resveratrol. Their absolute configurations were determined by the ECD method. All compounds were evaluated for their α-glucosidase inhibitory activity and compounds 2 and 3 showed significant inhibitory activity with IC50 values of 2.82 and 13.06 μmol/L, respectively (positive control acarbose, IC50 385 μmol/L).

Oxygen isotopic analysis of aragonite by secondary ion mass spectrometry (SIMS) is of significance to reveal the high spatial resolution information correlated with microstructure which could not be achieved by conventional methods. Appropriate reference materials to calibrate instrumental mass fractionation of SIMS are vital to acquire accurate values. However, the scarcity of standards (as far as we know, there were just two in-house laboratory-based potential reference materials reported) limits the development of this field. Herein, an inorganically precipitated aragonite vein sample (VS001/1-A) being evaluated through several hundred SIMS oxygen isotopic analyses was ascertained to have homogeneous oxygen isotopic composition with an external reproducibility of 0.3‰ (1σ) and to be a potential SIMS reference material. The instrumental bias evident in the series of aragonites, decreased by ∼3.4‰ with decreasing aragonite Ca content. Corals, as biogenic carbonates, were used as examples for evaluating the application of the in situ SIMS analysis method, and processes involved in “vital effects” are described. The development of in situ oxygen isotopic microanalysis of aragonite is significant for the application of revealing possible biocarbonate mineralization mechanisms.

New phloroglucinol glycosides, aglycones, and oxidative dearomatized products of aglycones were discovered from Agrimonia pilosa, and the mechanism of the auto oxidative dearomatization was disclosed as a free radical chain reaction with 3O2.

Three new monocyclic monoterpenoid containing β-D-apiofuranosyl-(1→2)-O-β-D-glucopyranosyl moieties, together with three other known monocyclic monoterpenoid O-glycosides, were obtained from the roots of Glycyrrhiza uralensis for the first time. Their structures were determined by UV, IR, HRESIMS, and 1D and 2D NMR data.

Lithium garnets have been widely studied as promising electrolytes that could enable the next-generation all-solid-state lithium batteries. However, upon exposure to atmospheric moisture and carbon dioxide, insulating lithium carbonate forms on the surface and deteriorates the interfaces within electrodes. Here, we report a scalable solid sintering method, defined by lithium donor reaction that allows for complete decarbonation of Li6.4La3Zr1.4Ta0.6O12 (LLZTO) and yields an active LiCoO2 layer for each garnet particle. The obtained LiCoO2 coated garnets composite is stable against air without any Li2CO3. Once working in a solid-state lithium battery, the LiCoO2-LLZTO@LiCoO2 composite cathode maintains 81% of the initial capacity after 180 cycles at 0.1 C. Eliminating CO2 evolution above 4.0 V is confirmed experimentally after transforming Li2CO3 into LiCoO2. These results indicate that Li2CO3 is no longer an obstacle, but a trigger of the intimate solid-solid interface. This strategy has been extended to develop a series of LLZTO@active layer materials., Formation of insulating lithium carbonate on surface of lithium garnets hinders their application as solid electrolyte in lithium ion batteries. Here the authors explore a scalable sintering approach to utilize the undesired Li2CO3 and improve the active material-electrolyte interface within cathodes.

Phytochemical investigation of the rhizome of Ligusticum chuanxiong Hort led to the isolation and identification of three new compounds, chuanxiongoside A, (2E,4E)-8-(6-O-inositolyl)-8-oxo-2,7-dimethyl-octadienoic acid (2), chuanxiongoside C (3). The structures of these compounds were unambiguously established by HR-ESI-MS, UV, IR, CD, NMR spectral data and comparison to reported data. All the isolated compounds (1-3) were investigated for their inhibitory effects on nitric oxide (NO) production in LPS-induced RAW 264.7 cells. All compounds showed excellent inhibition of NO production stronger than curcumin. [Formula: see text].

Dense and submicron-sized polycrystalline β-Si3N4 bulk samples with average grain size of 263 ± 68 nm have been synthesized using micron-sized α-Si3N4 powder (2 μm) as the starting material by simultaneously tuning the pressure and temperature conditions. The measured Vickers hardness HV of the submicron-sized polycrystalline β-Si3N4 could reach up to about 20 GPa, approaching the upper limit of the single crystal β-Si3N4. The measured fracture toughness KIC of the polycrystalline β-Si3N4 has been enhanced from 3.0 to 4.1 MPa m1/2, as much as 36%, while without sacrificing the hardness. This study demonstrates that using micron-sized powder as the starting material to synthesize submicron-sized polycrystalline bulks by phase transformation under extreme pressure conditions is an efficient pathway to break through the old paradigm—the higher the fracture toughness of a material, the lower the hardness.

Significance Reconstructing past extreme weather events, such as tropical cyclones and cold surges, using natural paleoclimate archives can lengthen the instrumental data and help us have a broader understanding of the range of weather variability not evident in instrumental record. However, the time resolution of current paleoarchives, from millennial to monthly at best, is usually too low to explore past weather events. Here we found that the Tridacna shells from South China Sea, western Pacific, have continuous daily growth bands, and several daily to hourly resolution biogeochemical proxy records were developed. Our results demonstrate that these records can record nearby tropical cyclones and cold surges, indicating that Tridacna shells have the potential to be an unprecedented ultra-high-resolution archive for paleoweather reconstructions., Paleoclimate research has built a framework for Earth’s climate changes over the past 65 million years or even longer. However, our knowledge of weather-timescale extreme events (WEEs, also named paleoweather), which usually occur over several days or hours, under different climate regimes is almost blank because current paleoclimatic records rarely provide information with temporal resolution shorter than monthly scale. Here we show that giant clam shells (Tridacna spp.) from the tropical western Pacific have clear daily growth bands, and several 2-y-long (from January 29, 2012 to December 9, 2013) daily to hourly resolution biological and geochemical records, including daily growth rate, hourly elements/Ca ratios, and fluorescence intensity, were obtained. We found that the pulsed changes of these ultra-high-resolution proxy records clearly matched with the typical instrumental WEEs, for example, tropical cyclones during the summer−autumn and cold surges during the winter. When a tropical cyclone passes through or approaches the sampling site, the growth rate of Tridacna shell decreases abruptly due to the bad weather. Meanwhile, enhanced vertical mixing brings nutrient-enriched subsurface water to the surface, resulting in a high Fe/Ca ratio and strong fluorescence intensity (induced by phytoplankton bloom) in the shell. Our results demonstrate that Tridacna shell has the potential to be used as an ultra-high-resolution archive for paleoweather reconstructions. The fossil shells living in different geological times can be built as a Geological Weather Station network to lengthen the modern instrumental data and investigate the WEEs under various climate conditions.

The 1,2-dibromoethane- and KI-mediated α-acyloxylation of ketones is reported in moderate to good yield without the use of transition metals and strong oxidants. Various acids are well tolerated with wide functional group compatibility. An 1,2-dibromoethane- and KI-catalysed reaction mechanism is proposed based on the results of control experiments.

The determination of the original boron (B) isotopic composition in altered basaltic glass is important to characterize magma generation and evolution in the mantle. Traditional whole-rock analysis of the B isotopic composition of basaltic glass requires time-consuming pretreatment for removing the altered section. Here, a protocol of in situ B isotopic analysis of basaltic glass by secondary ion mass spectrometry was developed using an accessible reference material BCR-2G which was first ascertained as a standard material for in situ B-isotopic analysis, whose B isotopic value (δ11B = −5.44‰; 2σ = 0.55‰) was determined by solution-based multi-collector-inductively coupled plasma-mass spectrometry in this study. Trans-sectional analysis of both slightly and extensively altered grains was performed from the cores outward to the rims (palagonite) by this in situ method to verify its ability in rapidly extracting information of the original (unaltered) B composition from natural samples. The δ11B values of the pristine (unaltered) melt ranging from −8.99‰ to −12.00‰ could be rapidly determined from the slightly altered grain, which is distinguishable from those of its transition (−3.14‰ to +9.56‰) and palagonite (+5.04‰ to +8.56‰) sections. Compared with the slightly altered one, the extensively altered grain has just the transition and palagonite sections without the pristine section. Therefore, in situ B isotopic profiling analysis of basaltic glass is beneficial for rapidly obtaining original magma B information from a single natural altered grain.

One new tanshinone derivative, which possesses an unusual 6/6/5/6 fused-ring skeleton system (1), together with four new five-membered lactone benzohexa-membered ring compounds (2, 3, 4A and 4B), and three new carboxyl substituted 5,5-spiroketal compounds (5–7), were isolated from the dried rhizomes of Salvia miltiorrhiza. The structures of these compounds were determined by multiple spectral analyses (UV, IR, NMR, and HR-ESI-MS). In addition, the absolute configurations were established by X-ray diffraction experiments, calculated and experimental circular dichroism spectra. Evaluation of antitumor activity showed that 1 had strong cytotoxicity to tumor-repopulating cells (TRCs) with an IC50 value of 2.83 μM. In the evaluation of neuroprotective activity, 4A and 6 showed a strong improvement in the survival rates of SK-N-SH cell injury induced by oxygen glucose deprivation (OGD).

Eight new geranylquinol derivatives (1-8) were purified from the roots of Arnebia euchroma. Compounds 1-6 possess an unprecedented dearomatic benzocogeijerene skeleton with a rare trans-fused hydronaphthalene moiety. Their structures and absolute configurations were elucidated by HRESIMS, NMR, ECD, and X-ray diffraction. A convenient strategy for rapid determination of the relative configuration of H-1/H-7/Me-16 and the absolute configuration at C-1 for 1-6 was summarized. Compound 2 exhibited cytotoxicity against all the tested cell lines, namely PC9, BGC823, HCT116, HepG2, HeLa, and U87-MG, with IC50 values ranging from 13.7 to 29.3 μM.

Three new macrocyclic trichothecenes possessing rare 6′-ketal moieties, roridoxins A–C (1–3), and five known compounds (4–8) were isolated from the insect-associated fungus Myrothecium roridum. Their structures were confirmed by a combination of NMR and HRESIMS data, while their absolute configurations were unambiguously determined by single-crystal X-ray analysis and electronic circular dichroism experiments. Trichothecenes 1 and 3 showed potent antifungal activities against four strains of phytopathogenic fungi. In addition, 1, 3, 5, and 6 were found to significantly inhibit the cell growth of Candida albicans with minimal inhibitory concentration values from 8.8 to 18.5 μg/mL. Moreover, they were able to inhibit the biofilm formation of C. albicans better than the positive control.

Four new phenolic acid derivatives, namely, 2,3-bis(4-hydroxy-3-methoxyphenyl)cyclopent-2-enone (1), 4,5-di-O-caffeoyldaucic acid methyl ester (2), (+)-ligusticumtone (3a), and (‒)-ligusticumtone (3b), and two known compounds were isolated from the rhizome of Ligusticum chuanxiong Hort. Among of them, compound 1 is an unusual norlignan. Additionally, compounds 3a and 3b are enantiomers that were obtained by chiral separation. Their structures were established using UV, IR, HRESIMS, NMR analysis. The absolute configurations of 3a and 3b were determined via quantum ECD calculations. All the isolates were evaluated for their hepatoprotective activity against N-acetyl-p-aminophenol-induced HepG2 cell injury. Compound 1 showed moderate hepatoprotective activity at a concentration of 10 μM (p

Two new lignans, wikstronoside B (1) and forsysesquinorlignan (2), were isolated from the fruits of Forsythia suspensa, along with two known sesquineolignans, hedyotol A and hedyotol C (3 and 4). The structures of new compounds were established via extensive spectroscopy techniques, including UV, IR, HRESIMS, NMR, and ECD. Compounds 3 and 4 were isolated from this plant for the first time. Their anti-inflammatory effects were evaluated via a detection model with LPS-induced murine macrophage RAW264.7 cells, and compound 3 showed a moderate activity.

Eight new triterpenoid saponins (1-8), were isolated from the roots of Glycyrrhiza uralensis Fisch., together with 10 known triterpenoid saponins (9-18). Their structures were determined by analysis of their spectroscopic data and comparison with the reference. All of the compounds were evaluated for their antioxidant effects in the in vitro assay. Compounds 2 and 8 showed significant antioxidant activities against Fe2+/cysteine-induced liver microsomal lipid peroxidation at 0.1 μM.

The determination of molecular configuration is usually a difficult and key point in the structure elucidation of natural products. However, due to the small number of available samples and the multiple chiral centers and complex structures of natural products, it is difficult to rapidly and accurately determine their relative configurations. In this paper, we use an NMR technique to comprehensively study 8,4′-oxyneolignan glucosides and find that the chemical shift difference between H-9a and H-9b can be used to accurately and rapidly determine the relative configuration of H-7 and H-8. Our finding can be directly applied to 8,4′-oxyneolignan glucosides without the need for hydrolysis.

Saffloneoside (1), a structurally unusual p-hydroxycinnamylcyclopentenone C-glucoside obtained from the florets of Carthamus tinctorius, was synthesized on a gram scale in seven steps. A stereospecific acyloin ring contraction controlled by the chirality of glucose moiety at the C5 position of highly substituted cyclohexadienones was discovered. The possible β-orientation hydrogen migration mechanism in the transformation of C5(sp2) into C5(sp3) was proposed.

Accurately locating the video target in the process of occlusion and recurrence will be very important for effective follow-up of the target. For the problem of poor applicability of Mean Shift and its improved algorithm when the target is heavily occluded, this paper proposes an anti-occlusion video target tracking algorithm based on prediction and re-matching strategy. Firstly, dynamically combining the Mean Shift algorithm with the Kalman filter, this paper achieves stable tracking of un-occluded target. Secondly, when the target is occluded, Kalman filter is combined with the target prior information to predict the position of the occluded target. Finally, in the recurrence process of occluded targets, the target is re-matched through the normalized cross-correlation method to obtain target optimal position, and then the target can be quickly and accurately located. The simulation results show that the proposed method has strong anti-occlusion and reliability tracking in the video target tracking process.

Neuroinflammation is emerging as a crucial reason of major neurodegenerative diseases in recent years. Increasingly evidences have supported that bioactive natural products from traditional Chinese medicines have efficiency for neuroinflammation. Forsythia suspensa, a typical medicinal herb, showed potential neuroprotective and anti-inflammatory properties in previous pharmacological studies. In our research to obtain neuroprotective and anti-inflammatory natural products, three unprecedented C6–C7′/C6–C16′ linked phenylethanoid glycoside dimers (1–3), three new phenylethanoid glycosides (4–6), and six known compounds (7–12) were isolated from the fruits of Forsythia suspensa. Their structures were determined by comprehensive spectroscopic data and comparison to the literature data. All isolated compounds were evaluated their neuroprotective and anti-inflammatory activities. Compounds 1 and 10 exhibited significant neuroprotective activities with the cell viability values of 75.24 ± 8.05% and 93.65 ± 10.17%, respectively, for the serum-deprivation and rotenone induced pheochromocytoma (PC12) cell injury. Meanwhile, compound 1 exhibited excellent anti-inflammatory activity against tumor necrosis factor (TNF)-α expression in LPS induced RAW264.7 cells with the IC50 value of 1.30 μM. This study revealed that the bioactive phenylethanoid glycosides may attenuate neuroinflammation through their neuroprotective and anti-inflammatory activities.

Four new compounds including two new phenylpropanoid esters of sucrose, polygonusucroside A (1) and B (2); two new anthraquinones, 8-O-β- d -(6′-galloyl)-glucopyranoside (3) and polyanthraquinoside A (4), together with six known compounds were isolated from Polygonum cuspidatum. Their structures were established using UV, IR, HRESIMS, and NMR data. All compounds were evaluated for their α-glucosidase inhibitory activities and neuroprotective effects. Compounds 5, 7 and 9 showed significant α-glucosidase inhibitory activities with IC50 values of 27.30, 5.51, and 1.09 μmol/L, respectively (acarbose as positive control, IC50 = 6.17 μmol/L). In addition, the assessment of neuroprotective effect showed that compound 3 exhibited remarkable effect against PC12 cells injured by serum-deprivation and compounds 2, 7, and 9 exhibited moderate effects against PC12 cells injured by rotenone.

Ligusticum chuanxiong Hort is a famous health promoting plant cultivated in China, and widely consumed due to its various curative effects. To study the potential bioactive constituents from the rhizome of L. chuanxiong, a chemical investigation was thus performed. In present study, we report the isolation and identification of ten new compounds, including two coumarins (1-2), four lignans (3-6), and four phenols (7-10), along with five known compounds (11-15) from the rhizome of L. chuanxiong. The structures of these compounds were unambiguously established by HR-ESI-MS, UV, IR, CD, NMR spectral data and comparison to reported data. Meanwhile, the anti-inflammation and hepatoprotective activities of all these compounds were evaluated. The results show that compounds 5, 6 and 7 showed excellent inhibition of NO production in LPS-induced RAW 264.7 cells stronger than curcumin, and compounds 5, 7 and 9 exhibited greater hepatoprotective effect than that of bicyclol.

Three new compounds named tanshinoic acid A (1), tanshinoic acid B (2), and tanshinoic acid C (3) were isolated from the rhizomes of Salvia miltiorrhiza, together with two known compounds methyl salvianolate A (4) and methyl salvianolate C (5). Their structures were determined on the basis of spectroscopic data (UV, IR, HRESIMS, 1 D and 2 D NMR). The in vitro assay indicated that 4 and 5 could improve the survived rate of cells on oxygen glucose deprivation (OGD) induced neurons damage model and glutamate-induced neurons damage model at a concentration of 10 μM.

Two new benzoic acid derivatives, sophophenoside A (1) and sophophenoside B (2), were isolated from Sophora flavescens. Their structures were elucidated by detailed spectroscopic analysis and chemical methods. Compounds 1 and 2 were assayed for their hepatoprotective activity on the cytotoxic effect of D-galactosamine on HL-7702 cells, and compound 1 exhibited a moderate hepatoprotective activity at a concentration of 10 μM.

Two new quinochalcone glycosides, hydroxysafflor yellow A-4'-O-β-D-glucopyranoside (1) and 3'-hydroxyhydroxysafflor yellow A (2), were isolated from the safflower yellow pigments of Carthamus tinctorius. The structures of new compounds were elucidated by a detailed spectroscopic analysis (UV, IR, HR-ESI-MS, 1D and 2D NMR, ECD). The in vitro assay indicated that compound 1 could improve the survived rate of primary mouse cortical neurons on glutamate-induced neurons damage model at a concentration of 10 μM.

The generation of Miocene–Pliocene post-collisional magmatic rocks in northern Tibet was coeval with surface uplift, meaning that understanding the petrogenesis of these rocks should provide clues to the mechanism of uplift of the Tibetan Plateau. However, the nature of the source(s) of Miocene–Pliocene post-collisional rocks is unresolved, especially for potassic–ultrapotassic rocks. This study focuses on 16 Ma olivine leucitites in the Hoh Xil Basin of northern Tibet, which display the lowest SiO2 (43·4–48·8 wt%) contents of all Miocene–Pliocene magmatic rocks in northern Tibet and have high MgO (4·85–8·57 wt%) contents and high K2O/Na2O (>1) ratios. Whole-rock geochemical compositions suggest that the olivine leucitites did not undergo significant fractional crystallization or crustal assimilation. All samples are enriched in large ion lithophile elements relative to high field strength elements, and they exhibit uniform whole-rock Sr–Nd isotope [(87Sr/86Sr)i = 0·7071–0·7077 and εNd(t) = −3·1 to −3·9] and olivine O isotope (5·8–6·6 ‰, mean of 6·2 ± 0·2 ‰, n = 21) compositions. We propose that the olivine leucitites were derived by low-degree partial melting of phlogopite-lherzolite in garnet-facies lithospheric mantle. Given the tectonic evolution of the Hoh Xil Basin and adjacent areas, we suggest that southward subduction of Asian (Qaidam block) lithosphere after India–Asia collision transferred potassium and other incompatible elements into the lithospheric mantle, forming the K-enriched mantle source of the Miocene–Pliocene potassic–ultrapotassic rocks. Removal of lower lithospheric mantle subsequently induced voluminous Miocene–Pliocene magmatism and generated >1 km surface uplift in the Hoh Xil Basin.

Three new thionic compounds, (S)-2-(2-carboxyl-2-hydroxyethylthio)-ferulic acid (1), (E)-2-methoxy-4-(3-(methylsulfonyl)prop-1-en-1-yl)phenol (2), and thiosenkyunolide C (3), together with two new aromatic glycosides (4 and 5) were isolated from the rhizome of Ligusticum chuanxiong Hort. Two known compounds (6 and 7) were also obtained. Their structures were elucidated based on extensive spectroscopic data (UV, IR, 1D and 2D NMR, and HR-ESI-MS). Furthermore the absolute configurations were established by comparison of their calculated and experimental circular dichroism spectra and by a dimolybdenum tetraacetate [Mo2(AcO)4]-induced circular dichroism procedure. All compounds were evaluated against lipopolysaccharide (LPS)-induced NO production in BV2 cells, and compounds 4 and 5 showed strong inhibitory activities with IC50 values of 2.03 and 3.09 µmol/L, respectively (positive control curcumin, IC50 = 6.17 µmol/L). In addition, compound 1 showed weak proteintyrosine phosphatase-1B (PTP1B) inhibitory activity. KEY WORDS: Ligusticum chuanxiong Hort., Thionic compounds, Aromatic glycosides, Anti-inflammatory, Natural products

In our ongoing investigation of the bioactive compounds from the extract of the roots of Sophora flavescens, two novel prenylated flavanones, named sophoflavanones A (1) and B (2), each with an unusual pyran ring were isolated. Their structures, as well as their absolute configurations, were elucidated based on spectroscopic data including a comparison of their experimental and calculated electronic circular dichroism (ECD) spectra. Additionally, compounds 1 and 2 showed moderate antioxidant activities against Fe2+/cysteine-induced toxicity at a concentration of 0.1 µM (inhibition values of 71.65% and 72.49%, respectively, using vitamin C as a positive control (87.83%)).

Four new sesquiterpene compounds, (5R,7R,10S)-3-O-β- d -glucopyranosylisopterocarpolone-11-O-β- d -apiofuranosyl-(1 → 6)-β- d -glucopyranoside (1), (5R,7R,10S)-14-carboxylisopterocarpolone-11-O-β- d -glucopyranoside (2), (1R,7R,10R)-1-hydroxylcarissone-11-O-β- d -glucopyranoside (3), and (1R,7R,10S)-10,11-dihydroxy-4-guaien-3-one 11-O-β- d - glucopyranoside (4), were isolated from the Atractylodes lancea by high-performance liquid chromatography. The compounds’ structures were elucidated through detailed spectroscopic methods.

To evaluate the suitability of domestic polyvinyl alcohol (PVA) fiber for preparing high ductility cementitious composites (HDCC), single PVA fiber pullout tests were conducted. The tests were carried out with four matrices having a water-to-cement ratio of 0.25 or 0.30, and fly ash replacement level 60% or 80%. The micromechanical behavior of single PVA fiber pullout from the matrix was monitored using a fiber tensile testing machine. Micromorphology of the pulled fiber was subsequently investigated using scanning electron microscopy (SEM). The results indicated that the slip-hardening coefficient is greater than zero and that the fiber therefore meets the micromechanical requirements for preparing HDCC. The chemical bonding energy and frictional bond strength were determined to decrease with the increasing fly ash content and/or water-to--cement ratio. SEM images indicate a significant number hydration products attached to the fiber surface, associated with an increase friction force during fiber pullout. After the pullout test, a complete tunnel containing fiber fragments was observed in the matrix, indicative of matrix cutting.

An efficient 1H NMR spectroscopic approach for determining the relative configurations of lignans with a 7,9′:7′,9-diepoxy moiety has been established. Using the chemical shift differences of H2-9 and H2-9′ (ΔδH-9 and ΔδH-9′), the configurations of 8-H and 8-OH furofuran lignans can be rapidly and conveniently determined. The rule is applicable for data acquired in DMSO-d6, methanol-d4, or CDCl3. Notably, the rule should be applied carefully when the C-2 or C-6 substituent of the aromatic rings may alter the dominant conformers of the furofuran moiety.

Four new ferulic acid derivatives ligusticumacid A-C (1-3) and ligusticumaldehyde A (4), one new dimer ligusticumacid D (5), and two novel 8-8' lignans ligusticumacid E-F (6-7) were isolated from the rhizome of Ligusticum chuanxiong Hort. In particular, compounds 1-2, 5 were rarely phenylpropanoid phenolic acid dimers through different polymerization action in natural products. Their structures were established using UV, IR, HRESIMS, NMR data. The absolute configurations of 3 was determined by quantum ECD calculation and 4, 6-7 were determined by the ECD exciton chirality method. In addition, all compounds were evaluated for their neuroprotective effects on human neuroblastoma SH-SY5Y cell injury induced by H2O2. Compound 2 had a moderate neuroprotective activity and 7 had a weak neuroprotective activity on human neuroblastoma SH-SY5Y cell injury induced by H2O2 respectively.

Eight new amino acid derivatives (1–8) and two known compounds (9–10) were isolated from the rhizome of Ligusticum chuanxiong Hort. Their structures were established using UV, IR, HRESIMS, and NMR data. Notably, phenylpropanoid–amino acid adducts 1–6 are the first reported natural products, which possess a unique adduct structure. In addition, their analogues (1–5) were successfully synthesized by nucleophilic substitution and hydrolysis. The absolute configurations of 1–5 were determined by comparison of the specific rotations with those of their analogues and the natural amino acid methyl ester hydrochloride in acetic acid. In addition, these compounds were all evaluated for their neuroprotective effects, and compound 9 showed a moderate protective effect towards human neuroblastoma SH-SY5Y cell injury induced by H2O2.

Six new phenylethanoid glycosides possessing dioxane moieties, named forsyoxasides A−F ( 1–6 ), together with four known such compounds ( 7–10 ) were isolated from the fruits of Forsythia suspensa . These structures were illustrated by extensive NMR spectroscopic techniques and by comparing their NMR data with the related literatures. Notably, forsyoxaside A ( 1 ) is a novel dioxane phenylethanoid glycoside with an axial aromatic ring, which is rare in the natural sources. Compounds 1 , 4 , 7 and 8 showed remarkable bioactivities against rotenone induced PC12 cell damage. Furthermore, 1 and 7 displayed strong activities against serum deprivation induced damage on the same cells.

Five new heterocyclic compounds, 5-α-d-fructofuranosylmethyl-furfural (1), 5-β-d-fructofuranosylmethyl-furfural (2), 5-β-d-fructopyranosylmethyl-furfural (3), 4-(2-((2S-2,3-dihydroxypropoxy)methyl)-5-formyl-1H-pyrrol-1-yl)butanoic acid (4), and 3S,4S-4,5,8-trihydroxy-3-(prop-1-en-2-yl)isochroman-1-one (5), were obtained from the root of Ranunculus ternatus Thunb., which is a traditional Chinese anti-tuberculosis medicine. Their structures were elucidated by UV, IR, HRESIMS, NMR data, and the comparison of experimental and calculated electronic circular dichroism (ECD) spectra. Notably, compounds 1-3 are rarely occurring furfural fructosides in natural sources. These heterocyclic compounds could be further studied for the synthetic chemists and pharmacologists due to the source and structural properties.

Two new compounds, named lyciumlignan D ( 1 ) and lyciumphenyl propanoid A ( 2 ), along with seven known compounds, were isolated from the root bark of Lycium chinense . Their structures were elucidated using spectroscopic data (UV, IR, HR-ESI-MS, 1D and 2D NMR, CD), as well as by comparison with those of the literature. Compounds 3 9 were isolated from this genus for the first time. In the in vitro assay, compounds 3 , 6 , and 7 exhibited stronger anti-inflammatory effects than the positive control curcumin at a concentration of 10 μmol/L.

Four new and rare iridoid glucosides, cornusfuroside A-D (1-4), containing the furan ring were identified from water extract of the fruit of Cornus officinalis. These new chemical structures were determined through extensive spectroscopic analysis, including 1D and 2D NMR, IR, HRESIMS, experimental and calculated electronic circular dichroism (ECD). Notably, this study is the first report on the isolation of four iridoid glucoside structures with acetal functions in the sugar moiety. The neuroprotective effects of these compounds were also evaluated in vitro.

Three new caffeoylquinic acid derivatives, chrysanthemorimic acids A-C (1-3), and 11 known compounds (4-14) were isolated and characterized from the flowers of Chrysanthemum morifolium. Their structures were confirmed by spectroscopic data as well as by comparison of the experimental and calculated electronic circular dichroism spectra. Chrysanthemorimic acids A-C possess a rare 8-oxa-bicyclo[3.2.1]oct-3-en-2-one ring that is formed through a [5+2] cycloaddition of caffeoylquinic acid with a d-glucose derivative. Compounds 1-3, 6-8, 12, and 13 displayed significant effects against hydrogen peroxide-induced neurotoxicity in SH-SY5Y cells at 10 μM.

Four new glycosides including a eudesmane-type sesquiterpenoid (1), a guaiane-type sesquiterpenoid (2), and two C14-polyacetylenes (3, 4) were isolated from the rhizomes of Atractylodes lancea. Their structures were elucidated by means of spectroscopic and spectrometric analyses (UV, IR, 1D and 2D NMR, and HR-ESIMS). The absolute configurations of their aglycones were established based on the experimental and calculated electronic circular dichroism (ECD), whereas those of monosaccharide moieties were determined by the GC method after chiral derivatization. Compound 4 showed weak anti-inflammatory effects on the LPS-induced NO production in microglia BV2 cells at a concentration of 10 μmol L−1.

An approach for discriminating the threo and erythro configurations of polyacetylene glycosides by 1H NMR spectroscopy was developed. Using acetic acid-d4/D2O as the solvent, a relatively larger 3JHH value (7.0 Hz) for the acyclic vicinal diol group was unambiguously assigned to the threo configuration, whereas the smaller value (3.5 Hz) was assigned to the erythro configuration. This convenient method requires no hydrolysis or derivatization and is suitable for micromolar concentrations of polyacetylene glycosides. The underlying mechanism is discussed via visualized conformations.

Lycium chinense Mill. is a deciduous shrub in the Solanaceae family that is known for its fruits (Lycii fructus) and root bark (Lycii cortex). In our ongoing search for α-glucosidase inhibitors from the root bark of L. chinense, lyciumflavane A, one new flavane with an unusual benzofuran unit, one new amide possessing a naphthalene skeleton, one new sesquiterpene, three new lignan glucosides, and three new phenolic glucosides were isolated along with eight known compounds. Their structures were elucidated using NMR, HRESIMS, UV, ECD, and IR spectroscopic data. Their α-glucosidase inhibitory activity was screened using acarbose as a positive control (IC50 = 385 μM). Compound 1 showed strong inhibitory activity against α-glucosidase (IC50 = 20.89 μM).

Eleven new phthalide derivatives (1–11) have been isolated from the rhizome of Ligusticum chuanxiong. In particular, 1 and 2 contain a mercaptopropionic acid moiety in the phthalide derivatives. All the structures, including their absolute configurations, were determined by UV, IR, HRESIMS, 1D and 2D NMR spectroscopic measurements, and by a comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. Results of a bioassay showed that compound 4 has a moderate neuroprotective activity on human neuroblastoma SH-SY5Y cell injury induced by H2O2 and oxygen glucose deprivation (OGD).

Forsythenethosides A (1) and B (2), two new phenylethanoid glycosides with an unprecedented 15-membered carbon scaffold ring, were isolated from the fruits of Forsythia suspensa. Their structures, including their geometric configurations, were determined via extensive NMR spectroscopy techniques, especially using 2D NMR data combined with systematic conformational analysis. Forsythenethosides A and B showed strong neuroprotective activities against serum-deprivation-induced PC12 cell damage. Furthermore, they were active on rotenone-induced PC12 cell damage.

During our continuing study on the fruits of Forsythia suspensa, one new heterodimer (forsythoneoside E) containing a flavonoid and a phenethanoid glycoside formed through a pyran ring, one new phenylethanoid glycoside dimer (forsythoneoside F) with a C–O bond, along with a pair of flavonoid glycoside dimers (forsythobiflavone A and B) possessing different axial chirality, were obtained. Their chemical structures, including absolute configurations, were established by NMR, HRESIMS, UV, IR, and ECD spectroscopic data and comparison of experimental and calculated electronic circular dichroism (ECD) spectra. All of the compounds were evaluated for their neuroprotective effects against rotenone-induced neurotoxicity in PC12 cells at 1 μM.

Zircon is probably the most important mineral used in the dating formation of high-pressure (HP) and ultrahigh-pressure (UHP) metamorphic rocks. The origin of zircon, i.e., magmatic or metamorphic, is commonly assessed by its external morphology, internal structure, mineral inclusions, Th/U ratios and trace element composition. In this study, we present an unusual case of metamorphic zircon from the Qiangtang eclogite, north-central Tibet. The zircon grains contain numerous eclogite-facies mineral inclusions, including omphacite, phengite, garnet and rutile; hence, they are clearly of metamorphic origin. However, they display features similar to common magmatic zircon, including euhedral crystal habit, high Th/U ratios and enriched heavy rare earth elements pattern. We suggest that these zircon grains formed from a different reservoir from that for garnet where no trace elements was present and trace element equilibrium between zircon and garnet was achieved. U–Pb dating of zircon gave an age of 232–237 Ma for the eclogite, and that of rutile yielded a slightly younger age of ca. 217 Ma. These ages are consistent with the reported Lu–Hf mineral isochron and phengite Ar–Ar ages. The zircon U–Pb and mineral Lu–Hf isochron ages are interpreted as the time of the peak eclogite-facies metamorphism, whereas the rutile U–Pb and phengite Ar–Ar ages represent the time of exhumation to the middle crust. Thus, the distinction between metamorphic and magmatic zircons cannot be made using only Th/U ratios and heavy REE compositions for HP–UHP metamorphic rocks of oceanic derivation.

An ongoing phytochemical investigation of the rhizomes of Atractylodes lancea resulted in the isolation of four new C10-type polyacetylene glycosides (1-4). Their structures were elucidated on the basis of extensive spectroscopic data (UV, IR, 1D and 2D NMR, and HRESIMS). The absolute configurations of compounds 2-4 were determined by comparing the specific rotations of their aglycones. Notably, compounds 2 and 3 exhibited significant hepatoprotective activities against APAP-induced HepG2 cell injury at a concentration of 10 μM. Compounds 2 and 3 showed weak anti-inflammatory effects on LPS-induced NO production in microglia BV2 cells at a concentration of 10 μM.

Well-characterized matrix-matched natural mineral references of known age are an important prerequisite for SIMS (secondary ion mass spectrometry) U–Th–Pb dating. We have characterized RW-1, a 44 g yellowish-brown single monazite specimen from a Norwegian pegmatite as an excellent hi-Th reference material for secondary ion mass spectrometric U–Th–Pb dating. A total of 206 secondary ion mass spectrometric analyses over six analytical sessions were performed on different monazite fragments of RW-1. The analyses resulted in 207Pb-based common lead corrected 206Pb/238U ages and Th–Pb ages with overall 2 % (2 SD = standard deviation) variations, indicating the good U–Th–Pb system homogeneity. The homogeneity of Th content of 11.8 ± 1.0 wt% (2 SD) and Th/U of 42 ± 3 (2 SD) make this crystal also a good compositional reference material. We used the combined ID–TIMS(Pb)/ID–MC–ICP–MS(U) technique (i.e. isotope dilution thermal ionization mass spectrometry for Pb, and isotope dilution multi-collector inductively-coupled plasma mass spectrometry for U) to determine U–Pb ages of the monazite samples studied. The mean 207Pb/235U age of 904.15 ± 0.26 Ma (95 % confidence level) is recommended as the best estimate crystallization age for RW-1 monazite. Considering that the most commonly distributed U–Pb monazite reference materials have rather low ThO2, we suggest that this RW-1 monazite with its ThO2 of 13.5 wt% is a suitable reference material providing investigators more confidence when dating high-Th monazite unknowns.

As part of our ongoing investigation of the bioactive constituents from the roots of Glycyrrhiza uralensis Fisch., seven new flavonoid glycosides (1–7) were obtained along with 19 known compounds (8–26). All of the isolates possessed one or more sugar moieties. Their structures, as well as the absolute configurations, were elucidated on the basis of spectroscopic data (UV, IR, HRESIMS, 1D and 2D NMR, and CD). In the in vitro assay, compounds 3 and 7 showed moderate antioxidant activities at a concentration of 0.1 μM; compound 2 showed hepatoprotective activity at a concentration of 10 μM.