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Due to channel noise and random atmospheric turbulence, retrieved satellite images are always distorted and degraded and so require further restoration before use in various applications. The latest quaternion-based weighted nuclear norm minimization (QWNNM) model, which utilizes the idea of low-rank matrix approximation and the quaternion representation of multi-channel satellite images, can achieve image restoration and enhancement. However, the QWNNM model ignores the impact of noise on similarity measurement, lacks the utilization of residual image information, and fixes the number of iterations. In order to address these drawbacks, we propose three adaptive strategies: adaptive noise-resilient block matching, adaptive feedback of residual image, and adaptive iteration stopping criterion in a new adaptive QWNNM model. Both simulation experiments with known noise/blurring and real environment experiments with unknown noise/blurring demonstrated that the effectiveness of adaptive QWNNM models outperformed the original QWNNM model and other state-of-the-art satellite image restoration models in very different technique approaches.

Conventional oxidation processes for alkyl aromatics to ketones employ oxidants that tend to generate harmful byproducts and cause severe equipment corrosion, ultimately creating critical environmental problems. Thus, in this study, a practical, efficient, and green method was developed for the synthesis of aromatic ketones by applying a bis(2-butoxyethyl) ether/O2 system under external catalyst-, additive-, and base-free conditions. This O2-mediated oxidation system can tolerate various functional groups and is suitable for large-scale synthesis. Diverse target ketones were prepared under clean conditions in moderate-to-high yields. The late-stage functionalization of drug derivatives with the corresponding ketones and one-pot sequential chemical conversions to ketone downstream products further broaden the application prospects of this approach.

Chinese herbs are a huge treasure trove of natural products and an important source of many active molecules. The theory of traditional Chinese medicine compatibility (TCMC) is widely applied in clinical practice, but its mechanism is still ambiguous. This study aims to open a new window for this predicament by studying the interaction between the main active ingredients from a drug pair. Carrier-free assembly of natural products improves the shortcomings of traditional nanodelivery systems and opens a new path for the development of new nanomaterials. The drug pair “Pueraria and Hedyotis diffusa” has been commonly used in clinical practice, with a predominant therapeutic effect. This study is devoted to the study of the binary small molecule co-assembly of the main active molecules from the drug pair. In this study, we introduce a carrier-free composite gel, formed by the co-assembly of puerarin (PUE) and deacetylasperulosidic acid (DAA) via non-covalent bonds including π–π packing, intermolecular hydrogen bonding, and C=O π interactions. With a strain point 7-fold higher than that of P gel, the P − D gel exhibited favorable rheological properties. The survival rate of SW1990 cells in the P − D group was only 21.39% when the concentration of administration reached 200 μM. It thus demonstrated activity in inhibiting SW1990 cells’ survival, suggesting potential in combating pancreatic cancer. Furthermore, this research offers a valuable concept for enhancing the mechanical properties and bioactivity of hydrogel materials through the utilization of a multi-component natural small molecule co-assembly approach. More importantly, this provides new ideas and methods for the treatment of pancreatic cancer and the analysis of traditional Chinese medicine compatibility theory.

The noise control of flank array sonar is a primary approach to enhance the sonar detection range. During submarine navigation, hydrodynamic noise is the main noise source in the platform region of the flank array sonar, which includes flow noise and flow-induced noise. Therefore, an in-depth investigation of hydrodynamic noise is necessary. In this paper, we firstly take the teardrop submarine as a computational model to validate the computational method. Afterwards, we numerically simulate the flow and flow-induced noise characteristics for the cylindrical shell model, and investigate differences in noise at different detection points along the X, Y, and Z axes. Finally, experiments are conducted to confirm the accuracy of the simulation results. The research findings reveal that, at the same frequency, flow-induced noise exceeds flow noise, and the noise decreases as the distance between the walls of the cylindrical shell increases. The experimental and simulation results are consistent, suggesting that the selected computational method can precisely simulate the submarine’s noise.

Traditional Chinese medicine has been proven to be of great significance in cardioprotective effects. Clinopodium chinense (Lamiaceae) has unique advantages in the treatment and prevention of cardiovascular diseases. Tournefolic acid B (TAB) was proven to be a potent component against myocardial ischemia reperfusion injury (MIRI) from Clinopodium chinense (Lamiaceae). This article will attempt to establish a gram-scale synthesis method of TAB and discuss the structure-activity relationship of its analogs. The total synthesis of TAB was completed in 10 steps with an overall yield of 13%. In addition, analogs were synthesized, and their cardioprotective activity was evaluated on the hypoxia/reoxygenation of H9c2 cells. Amidation of the acid position is helpful to the activity, while methylation of phenolic hydroxyl groups greatly decreased the cardioprotective activity. The easily prepared azxepin analogs also showed cardioprotective activity. Most of the clogP values calculated by Molinspiration ranged from 2.5 to 5, which is in accordance with Lipinski’s rule of 5. These findings represent a novel kind of cardioprotective agent that is worthy of further study.

Four new meroterpenoids, Clavilactone M-P, possessing novel aminoglycoside moiety (1–4) and a 10-membered carbocycle fused with an α,β-epoxy-γ-lactone, were isolated from Clitocybe clavipes, a basidiomycete. Their structures with absolute configurations were determined by extensive analysis of their spectroscopic data, and the ECD method. All the isolated compounds (1–4) were evaluated for their antitumor activity against three human cancer cell lines using the MTT assay. Compound 1 and 2 exhibited a significant suppression of cell viability in the Hela (IC50 = 22.8 and 19.7 μM) cell line.

Indole diterpenes are a large class of secondary metabolites produced by fungi, possessing a cyclic diterpenoid backbone and an indole moiety. Novel structures and important biological activity have made indole diterpenes one of the focuses of synthetic chemists. Although the discovery, identification, structural diversity, biological activity and especially structure–activity relationship of indole diterpenes have been reported in some papers in recent years, they are absent of a systematic and comprehensive analysis, and there is no elucidation of enzymes related to this kind of natural product. Therefore, it is necessary to summarize the relevant reports to provide new perspectives for the following research. In this review, for the first time, the function of related synthases and the structure–activity relationship of indole diterpenes are expounded, and the recent research advances of them are emphasized.

Four new daphnane-type diterpenes named tianchaterpenes C-F (1–4) and six known ones were isolated from Stelleropsis tianschanica. Their structures were elucidated based on chemical and spectral analyses. The comparisons of calculated and experimental electronic circular dichroism (ECD) methods were used to determine the absolute configurations of new compounds. Additionally, compounds 1–10 were evaluated for their cytotoxic activities against HGC-27 cell lines; the results demonstrate that compound 2 had strong cytotoxic activities with IC50 values of 8.8 µM, for which activity was better than that of cisplatin (13.2 ± 0.67 µM).

From the dried vines of Aspidopterys obcordata Hemsl, five new polyoxypregnane glycosides, named obcordatas J–N (1–5), were obtained. Their structures were fully elucidated and characterized by HRESIMS and extensive spectroscopic data. In addition, all of the new compounds were screened for their antinephrolithiasis activity in vitro. The results showed that compounds 1–3 have prominent protective effects on calcium oxalate crystal-induced human kidney 2 (HK-2) cells, with EC50 values ranging from 6.72 to 14.00 μM, which is consistent with the application value of A. obcordata in folk medicine for kidney stones.

Five new compounds called Pestalotis A–E (1–5), comprising three monoterpene-lactone compounds (1–3), one tetrahydrobenzofuran derivative (4), and one sesquiterpene (5), were isolated from the EtOAc extract of Pestalotiopsis sp. The structures of the new compounds were elucidated by analysis of their NMR, HRMS, and ECD spectra, and the absolute configurations were established through the comparison of experimental and calculated ECD spectra. All compounds were tested for antitumor activity against SW-480, LoVo, HuH-7, and MCF-7. The results showed that compounds 2 and 4 exhibited potent antitumor activity against SW-480, LoVo, and HuH-7 cell lines. Furthermore, compound 4 was assessed against HuH-7, and the results indicated that the rate of apoptosis was dose-dependent.

Five new meroterpenoids, clavipols A−B (1−2) with a 12-membered ether ring and clavilactones G−I (3−5) having a 10-membered carbocycle connected to a hydroquinone and an α,β-epoxy/unsaturated lactone, were obtained from the fruiting bodies of the basidiomycete Clitocybe clavipes. Their structures were determined by comprehensive analysis of their spectroscopic data, and the absolute configuration of 1 was established by quantum chemical calculations of electronic circular dichroism (ECD). All the isolated compounds (1−5) were tested for their cytotoxic activity against three human tumor cell lines (Hela, SGC-7901, and SHG-44) in vitro after treatment for 48 h. Compound 4 exhibited moderate cytotoxic activity against Hela and SGC-7901 tumor cell lines, with IC50 values of 23.5 and 14.5 µM, respectively.

Twelve phenolics, including the three new compounds balanophonin C (1), balanophonin D (2), balanophonin E (3), were isolated from the seeds of Lithocarpus pachylepis. Their structures were elucidated by various spectroscopic techniques (UV, IR, MS, 1D and 2D NMR). Compounds 1–9 were evaluated for their anti-inflammatory activities on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 and showed moderate inhibitory activities, with IC50 values ranging from 10.9 to 34.7 μM.

A new prenylated naphthoquinoid, named (3R,4aR,10bR)-3,10-dihydroxy-2,2-dimethyl-3,4,4a,10b-tetrahydro-2H-naphtho[1,2-b]-pyran-5H-6-one (1), was isolated from the aerial parts of Clinopodium chinense (Benth.) O. Kuntze, together with six known compounds: apigenin (2), luteolin (3), neoeriocitrin (4), naringenin (5), narirutin (6), and didymin (7). Neoeriocitrin was isolated for the first time from the species C. chinense. Their structures were elucidated by spectroscopic methods, including 1D, 2D (1H-1H-COSY, HSQC, HMBC and NOESY) NMR, HR-ESI-MS. The absolute configuration of 1 was determinated using the CD method. We highlight that the structure of 1 is characterized by a rarely seen prenylated naphthoquinoid framework.

Phenolic acid derivatives are typical constituents of Clerodendranthus spicatus which were considered to the active principles of this medicinal plant. These chemical constituents with their interesting frameworks and biological significance attracted our attention. As part of our ongoing chemical investigation of C. spicatus using various column chromatography techniques, a new phenolic compound, named clerodendranoic acid (1), was isolated from the aerial parts of C. spicatus together with five known ones, including rosmarinic acid (2), methyl rosmarinate (3), caffeic acid (4), methyl caffeate (5), ethyl caffeate (6). Their structures, including stereochemical configurations, were completely established by extensive spectroscopic methods, mainly inclvolving 1D, 2D NMR, as well as HRESIMS.

From the whole plant of Sarcandra glabra, a new phenolic acid glycoside, benzyl 2-β-glucopyranosyloxybenzoate (1), together with seven known compounds including eleutheroside B1 (2), 5-O-caffeoylshikimic acid (3), (–)-(7S, 8R)-dihydrodehydro-diconiferyl alcohol (4), (–)-(7S, 8R)-dihydrodehydrodiconiferyl alcohol 9-, 9′- and 4-O-â-D-glucopyranoside (5–7), and (–)-(7S, 8R)-5-methoxydihydrodehydrodiconiferyl alcohol 4-O-β-D-glucopyranoside (8) was isolated. Their structures were elucidated by spectral analysis including 1D-, 2D-NMR and HR-ESI-MS. Compound 2 was found to exhibit potent cytotoxic activity against BGC-823 and A2780 cancer cell lines using MTT method with IC50 value of 2.53 and 1.85 µM, respectively.

On our ongoing investigation, a new oleanolic triterpene, 3β,6β,19α-trihydroxy-12-oleanen-28-oic acid (1) was obtained from the chloroform-soluble portion of the 90% alcohol-water extract of the stem bark of Uncaria macrophylla. Its structure was elucidated by extensive spectroscopic methods, including 1D and 2D (1H-1H COSY, HSQC and HMBC) NMR and HR-ESI-MS. The cytotoxicities of the compound was evaluated against two cancer cell lines of MCF-7 and HepG2 by the MTT method, and the compound exhibited weak activities with the IC50 values of 78.2 µg/mL and 73.9 µg/mL.

Our ongoing investigations on the stem bark of Uncaria macrophylla afforded a new ursolic triterpene, 3β,6β,19α-trihydroxy-urs-12-en-28-oic acid-24-carboxylic acid methyl ester (1), named uncariursanic acid, and three known ursolic triterpenes including 3β,6β,19α-trihydroxy-23-oxo-urs-12-en-28-oic acid (2), 3β,6β,19α-trihydroxy-urs-12-en-28-oic acid (3) and ursolic acid (4). Their structures were elucidated by extensive spectral methods, including 1D and 2D NMR and HR-ESI-MS. The cytotoxicities of the four compounds were evaluated against two cancer cell lines (MCF-7 and HepG2) by the MTT method, and only compound 4 exhibited potent activity.

In the filamentous cyanobacterium, Anabaena sp. PCC 7120, single heterocysts differentiate at semi-regular intervals in response to nitrogen stepdown. HetR is a principal regulator of heterocyst differentiation, and hetP and hetZ are two genes that are regulated directly by HetR. In a hetR mutant generated from the IHB (Institute of Hydrobiology) substrain of PCC 7120, heterocyst formation can be restored by moderate expression of hetZ and hetP. The resulting heterocysts are located at terminal positions. We used a tandem promoter, PrbcLPpetE, to express hetZ and hetP strongly in the hetR mutant. Co-expression of hetZ and hetP enabled the hetR mutant to form multiple contiguous heterocysts at both terminal and intercalary positions. Expression of hetZ, alone resulted in terminally located heterocysts, whereas expression of hetP, alone produced enlarged cells in strings. In the absence of HetR, formation of heterocysts was insensitive to the peptide inhibitor, RGSGR.

The authors wish to make the following correction to their paper [...]

In this study, an improved UPLC-MS (Ultra-high performance liquid chromatography-tandem mass spectrometry) method for simultaneously quantifying twelve major components belonging to two chemical types was developed and validated, and was applied to quantitatively compare the quality of sulfur-fumigated Astragali Radix of different durations and of the fresh reference sample. The results showed that the contents of triterpenes astragaloside III and astragaloside IV decreased moderately, while the flavonoids calycosin, formononetin, and 7,2′-dihydroxy-3′,4′-dimethoxyisoflavane decreased significantly. The corresponding flavonoid glycosides increased accordingly, which indicated the occurrence of chemical transformation of flavonoids and glycosides in the process of sulfur-fumigation. These transformations were further confirmed by the synthesis of flavonoid glycosides under simulated sulfur-fumigation circumstances. Furthermore, the sulfur-fumigated duration varied in proportion with the contents of compounds 7, 11, and 12. These results suggest that the established method was precise, accurate and sensitive enough for the global quality evaluation of sulfur-fumigated Astragali Radix. Further, sulfur-fumigation not only changes the proportions of bioactive components, but also causes chemical transformation in Astragali Radix.

Ischemic stroke is a clinically common cerebrovascular disease whose main risks include necrosis, apoptosis and cerebral infarction, all caused by cerebral ischemia and reperfusion (I/R). Ischemia and reperfusion-induced injury or apoptosis inhibition in human brain tissue may exert an irreplaceable protective effect on ischemic nerves. This process has particular significance for the treatment of stroke patients. However, the development of neuroprotective drugs remains challenging. Radix Scrophulariae, traditionally considered a valuable medicine, has been discovered to have neuroprotective effects. To explore the neuroprotective effects of an aqueous extract of Radix Scrophulariae (RSAE) on cerebral ischemia/reperfusion and their underlying mechanisms, oxygen-glucose deprivation and reperfusion (OGD/R)-induced PC12 cells were used, and a middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model was established. In vitro results showed that 12.5 μg/mL RSAE markedly improved cell viability; inhibited LDH leakage; increased SOD, GSH-Px and CAT enzyme activity; stabilized the mitochondrial membrane potential; and reduced OGD-induced cell injury and apoptosis. Additionally, in vivo results preliminarily suggested that in MCAO/R model mice, RSAE treatments attenuated infarct volume; reduced brain water content and nitric oxide (NO) and malondialdehyde (MDA) concentrations; inhibited I/R-induced neurological deficits; reduced the levels of lactate dehydrogenase (LDH) leakage release; improved antioxidant capacity by upregulating SOD, GSH-Px and CAT enzyme activity; and reduced neuronal apoptosis, necrosis and loss of neurons. Moreover, it was found that RSAE upregulated the expression of Bcl-2 and downregulated the expression of Bax. In addition, the phosphorylation levels of MAPK signal pathways were elucidated via western blot analysis and immunohistochemical evaluation. In summary, this study investigated the neuroprotective effects and potential mechanisms of RSAE on focal cerebral I/R injury in mice. Radix Scrophulariae has been previously identified as a potential neuroprotective natural plant. Hence, our results may offer insight into discovering new active compounds or drugs for the treatment of ischemic stroke. Many new natural active chemicals in this extract may be discovered by chemical separation and identification and may provide new insights into therapeutic targets in stroke patients.

The mortality of gastric cancer (GC) is increasing due to its high rates of recurrence and metastasis. Zeylenone (Zey), a type of naturally occurring cyclohexene oxide, was demonstrated to be effective in cancer patients. The aim of this study is to explore the anti-cancer effect of Zey against gastric cancer both in vitro and in vivo, as well as the underlying mechanisms. We found that Zey inhibited gastric tumor growth, as demonstrated by in vitro gastric cancer cell lines and in a human gastric cancer xenograft mouse model. Furthermore, Zey induced substantial apoptosis through a mitochondrial apoptotic pathway, involving mitochondrial transmembrane potential loss, caspase-3 activation, anti-apoptotic protein downregulation, and pro-apoptotic protein upregulation. Notably, we revealed for the first time that Zey suppressed invasion and migration by wound healing and transwell chamber assays. Through Western blotting, we further explored the potential mechanism of Zey’s anti-cancer activity. We found that Zey downregulated the expression of matrix metalloproteinase 2/9 (MMP 2/9) and inhibited the phosphorylation of AKT and ERK. In short, Zey, which induced mitochondrial apoptosis and inhibited proliferation, migration, and invasion, may be developed as a novel drug for the treatment of gastric cancer.

Seven pyrrole alkaloids, three of which are novel (phlebopines A–C (1–3)), were isolated from the fruiting bodies of the edible mushroom Phlebopus portentosus. Their structures were determined on the basis of spectroscopic data. All the isolated compounds were tested for their neuroprotective properties and acetylcholine esterase (AChE) inhibition activities. Compound 7 displayed remarkable neuroprotective effects against hydrogen peroxide (H2O2)-induced neuronal-cell damage in human neuroblastoma SH-SY5Y cells.

The potential applications of multilayer graphene in many fields, such as superconductivity and thermal conductivity, continue to emerge. However, there are still many problems in the growth mechanism of multilayer graphene. In this paper, a simple control strategy for the preparation of interlayer-coupled multilayer graphene on a liquid Cu substrate was developed. By adjusting the flow rate of a carrier gas in the CVD system, the effect for finely controlling the carbon source supply was achieved. Therefore, the carbon could diffuse from the edge of the single-layer graphene to underneath the layer of graphene and then interlayer-coupled multilayer graphene with different shapes were prepared. Through a variety of characterization methods, it was determined that the stacked mode of interlayer-coupled multilayer graphene conformed to AB-stacking structure. The small multilayer graphene domains stacked under single-layer graphene was first found, and the growth process and growth mechanism of interlayer-coupled multilayer graphene with winged and umbrella shapes were studied, respectively. This study reveals the growth mechanism of multilayer graphene grown by using a carbon source through edge diffusion, paving the way for the controllable preparation of multilayer graphene on a liquid Cu surface.

Three phosphine sulfide-based bipolar host materials, viz CzPhPS, DCzPhPS, and TCzPhPS, were facilely prepared through a one-pot synthesis in excellent yields. The developed hosts exhibit superior thermal stabilities with the decomposition temperatures (Td) all exceeding 350 °C and the melting temperatures (Tm) over 200 °C. In addition, their triplet energy (ET) levels are estimated to be higher than 3.0 eV, illustrating that they are applicable to serve as hosts for blue phosphorescent organic light-emitting diodes (PhOLEDs). The maxima luminance, current efficiency (CE), power efficiency (PE), and external quantum efficiency (EQE) of 17,223 cd m−2, 36.7 cd A−1, 37.5 lm W−1, and 17.5% are achieved for the blue PhOLEDs hosted by CzPhPS. The PhOLEDs based on DCzPhPS and TCzPhPS show inferior device performance than that of CzPhPS, which might be ascribed to the deteriorated charge transporting balance as the increased number of the constructed carbazole units in DCzPhPS and TCzPhPS molecules would enhance the hole-transporting ability of the devices to a large extent. Our study demonstrates that the bipolar hosts derived from phosphine sulfide have enormous potential applications in blue PhOLEDs, and the quantity of donors should be well controlled to exploit highly efficient phosphine sulfide-based hosts.