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Abstract Metal-organic framework (MOF) glasses are an emerging class of glasses which complement traditional inorganic, organic and metallic counterparts due to their hybrid nature. Although a few zeolitic imidazolate frameworks have been made into glasses, how to melt and quench the largest subclass of MOFs, metal carboxylate frameworks, into glasses remains challenging. Here, we develop a strategy by grafting the zwitterions on the carboxylate ligands and incorporating organic acids in the framework channels to enable the glass formation. The charge delocalization of zwitterion-acid subsystem and the densely filled channels facilitate the coordination bonding mismatch and thus reduce the melting temperature. Following melt-quenching realizes the glass formation of a family of carboxylate MOFs (UiO-67, UiO-68 and DUT-5), which are usually believed to be un-meltable. Our work opens up an avenue for melt-quenching porous molecular solids into glasses.

In this study, low-cost siderite was used to activate peroxydisulfate (PDS, S2O82-)-inactivated Enterococcus faecalis to study the inactivation characteristics and mechanism of siderite/PDS. The results showed that the siderite/PDS had a better inactivation effect on Enterococcus faecalis at pH 3. The sterilization effect increases with the increase of siderite dosage, PDS concentration and temperature. The inactivation rate is decreased with the increase of initial bacterial concentration. Inorganic ions and natural organic matter (NOM) can inhibit the inactivation effect of this technology, and the inhibition intensity is NOM > HCO3− > NO3−. The free radical quenching test shows that HO• is the main oxidizing substance in the sterilization process of siderite/PDS technology. In addition, the main disinfection mechanism is highly reactive oxygen species destroying the cell wall of bacteria and releasing organic compounds in cells. After siderite was reused for four times, simply washing siderite would recover almost 80% of the removal of Enterococcus faecalis in siderite/PDS, indicating that siderite has the potential of recycling. HIGHLIGHTS Enterococcus faecalis (Gram-positive bacteria), a typical disinfection residue bacteria, was used as the indicator microorganism.; The economic and efficient natural siderite was used as the activator of persulfate, and the reusability and structural stability of the recovered siderite are also analyzed.;

Four new polyhydroxylated steroids lobophysterols E–H (1–4), together with three known compounds (5–7), were isolated from the soft coral Lobophytum pauciflorum collected at Xisha Island, China. The structures of the new compounds were elucidated by extensive spectroscopic analysis and comparison with NMR data of structurally related compounds reported in the literature. The absolute configuration of 1–3 was determined by X-ray diffraction. All the compounds have assessed the cytotoxicity against HL-60, K562, and Hela cells. Compound 1 showed weak cytotoxicity against K562 cells with an IC50 value of 19.03 μM. In addition, compound 1 also showed a moderate anti-inflammatory effect in zebrafish.

Abstract Background The immunoregulatory functions of regulatory T cells (Tregs) in the development and progression of some chronic infectious diseases are mediated by immune checkpoint molecules and immunosuppressive cytokines. However, little is known about the immunosuppressive functions of Tregs in human brucellosis, which is a major burden in low-income countries. In this study, expressions of immune checkpoint molecules and Treg-related cytokines in patients with acute and chronic Brucella infection were evaluated to explore their impact at different stages of infection. Methods Forty patients with acute brucellosis and 19 patients with chronic brucellosis admitted to the Third People’s Hospital of Linfen in Shanxi Province between August 2016 and November 2017 were enrolled. Serum and peripheral blood mononuclear cells were isolated from patients before antibiotic treatment and from 30 healthy subjects. The frequency of Tregs (CD4+ CD25+ FoxP3+ T cells) and expression of CTLA-4, GITR, and PD-1 on Treg cells were detected by flow cytometry. Levels of Treg-related cytokines, including IL-35, TGF-β1, and IL-10, were measured by customised multiplex cytokine assays using the Luminex platform. Results The frequency of Tregs was higher in chronic patients than in healthy controls (P = 0.026) and acute patients (P = 0.042); The frequency of CTLA-4+ Tregs in chronic patients was significantly higher than that in healthy controls (P = 0.011). The frequencies of GITR+ and PD-1+ Tregs were significantly higher in acute and chronic patients than in healthy controls (P 0.05). Serum TGF-β1 levels were higher in chronic patients (P = 0.029) and serum IL-10 levels were higher in acute patients (P = 0.033) than in healthy controls. We detected weak correlations between serum TGF-β1 levels and the frequencies of Tregs (R = 0.309, P = 0.031) and CTLA-4+ Tregs (R = 0.302, P = 0.035). Conclusions Treg cell immunity is involved in the chronicity of Brucella infection and indicates the implication of Tregs in the prognosis of brucellosis. CTLA-4 and TGF-β1 may contribute to Tregs-mediated immunosuppression in the chronic infection stage of a Brucella infection.

A polarization-reconfigurable cylindrical dielectric resonator antenna (DRA) based on a tunable feed network is presented in this paper. HEM11δ modes excited by two-port side-fed probes are adapted to design the proposed DRA. Polarization reconfigurable characteristic can be obtained by a tunable feed network that consists of Wilkinson equal power divider, parasitic elements used for phase shifters, and p-i-n diodes between them. By controlling the four pairs of p-i-n diode switches to active corresponding elements as effective phase shifters, two sources with equal amplitude and 0° or ±90° phase differences are obtained to generate linear-polarized (LP) or circular-polarized (CP) states, respectively. A fully functional prototype of the proposed antenna with the dimension of 0.55\λ × 0.55λ × 0.14λ has been designed, fabricated, and tested. The results indicate that the proposed DRA can achieve the bandwidths of more than 30% for both impedance bandwidth and 3-dB axial ratio bandwidth at CP states, and two LP states with the impedances of 6.3% and 9.5%. Stable directional patterns and realized gains are obtained for all the states. These performances make the proposed DRA suitable for polarization diversity scenarios in communication systems.

A compact, frequency-reconfigurable dielectric resonator antenna (DRA) with wideband and continuously tunable narrowband states is presented. It is intended for the application scenario in the cognitive radio system. The wideband state is the sensing state and operationally covers 3.82-8.94 GHz. The narrowband states are intended to cover communications within the 5.14-5.98 GHz range, which completely covers the WLAN frequency bands. Three p-i-n diodes are employed to switch between wide and some narrowband operational states by selecting the corresponding path. A varactor diode is used to shift the operational frequencies continuously among the narrowband states. The proposed DRA consists of a rectangular dielectric resonator excited by microstrip feedline with a reconfigurable filter; it has a compact dimension: 0.31λL × 0.41λL × 0.06λL, where the wavelength λL corresponds to the lower bound of its operating frequencies. The measured reflection coefficients, far-field radiation patterns, and realized gains for both operation states are in good consistent with their simulated values.

Immunochromatographic assay (ICA) is an efficient analytical technique and rapid, convenient, easy-to-use, low-cost, and on-site detection method that has been widely used to evaluate food safety. However, an important issue to be addressed for this method is its matrix effect. In this work, time-resolved fluorescent nanobead ICA (TRFN-ICA) and colloidal gold ICA (CG-ICA) were developed to detect clenbuterol in swine urine. Under optimized working conditions, the limits of detection of TRFN-ICA and CG-ICA were 16 and 68 pg/mL, respectively. The matrix effect on TRFN-ICA and CG-ICA was assessed in 20 swine urine samples. Results indicated that the sensitivity of TRFN-ICA was better than that of CG-ICA, and the detection time of the former was shorter than that of the latter. The matrix effect on TRFN-ICA was more serious than that on CG-ICA.

This paper presents an experimental and analytical investigation on the performance of partial penetration welds used to adjoin steel plates in irregular shaped multicell concrete filled steel tubes. The experimental program of this study is designed based on an actual implementation of such members as mega columns in a super high rise building in China. A total of six specimens are designed with different plate arrangements for the purpose of testing the performance of the partial penetration welds at different locations of the specimen. The designed specimens are tested under different load procedures and directions; this is achieved by placing them in vertical and slantwise manners between two loading plates which impose monotonic and cyclic actions. The failure conditions of each of the tested specimens are presented and discussed in detail and are based on the conclusions drawn from the experimental observations; the partial penetration weld at the corner of the tested specimens is found to be the most vulnerable. To facilitate large scale analysis, a finite element model constructed by the finite element analysis program ABAQUS is verified against experimental results. The evaluation of the stress at the partial penetration welded corner is carried out following an empirical procedure, which is adopted due to the complexity of the problem domain. The adopted procedure consists of two steps: the first one is to initially evaluate the stress based on an existing method in the literature, and the second one is to fit the results of the initial evaluation with the finite element model results based on parametric and regression analysis. After performing regression analysis, a formula to predict the weld stress is concluded, and the results of the proposed equation are found to be satisfactory when compared with the finite element model results.

Background/Aims: To investigate the clinical significance of myeloid zinc finger 1 (MZF1) expression in various gastric mucosal lesions including chronic superficial gastritis (CSG), chronic atrophic gastritis (CAG), intestinal metaplasia (IM), dysplasia (DYS) and gastric cancer (GC) in comparison with normal tissues and gastric cell lines. Methods: MZF1 protein expression was detected using immunohistochemical staining in 37 CSG, 88 CAG, 77 IM, 51 DYS, 165 GC and 8 normal tissue samples. Quantitative real-time PCR (qRT-PCR) and western blotting were used to detect the level of MZF1 in gastric cell lines, 15 normal tissues and 34 GC samples, as well as 2 groups of paired primary GC and adjacent normal samples. Results: Reduced MZF1 expression was detected in most GC cells and tissues. Among the gastric tissues consisting of various stages of lesions (normal, CSG, CAG, IM, DYS and GC), MZF1 protein expression was downregulated in precancerous lesions and GC. The data from clinical analyses showed that decreased MZF1 expression was correlated with tumour invasion (p = 0.044), lymph node metastasis (p = 0.048) and poor prognosis of GC patients (p = 0.003). Moreover, MZF1 was identified as an independent prognostic biomarker for GC patients in multivariate Cox regression analysis (p = 0.009). Conclusion: Downregulation of MZF1 was associated with gastric tumourigenesis, which may be a novel early predictive and prognostic biomarker in GC patients.

Abstract Replenishment of NAD+ has been shown to protect against brain disorders such as amyotrophic lateral sclerosis and ischemic stroke. However, whether this intervention has therapeutic effects in intracerebral hemorrhage (ICH) is unknown. In this study, we sought to determine the potential therapeutic value of replenishment of NAD+ in ICH. In a collagenase-induced ICH (cICH) mouse model, nicotinamide mononucleotide (NMN), a key intermediate of nicotinamide adenine dinucleotide (NAD+) biosynthesis, was administrated at 30 minutes post cICH from tail vein to replenish NAD+. NMN treatment did not decrease hematoma volume and hemoglobin content. However, NMN treatment significantly reduced brain edema, brain cell death, oxidative stress, neuroinflammation, intercellular adhesion molecule-1 expression, microglia activation and neutrophil infiltration in brain hemorrhagic area. Mechanistically, NMN enhanced the expression of two cytoprotective proteins: heme oxygenase 1 (HO-1) and nuclear factor-like 2 (Nrf2). Moreover, NMN increased the nuclear translocation of Nrf2 for its activation. Finally, a prolonged NMN treatment for 7 days markedly promoted the recovery of body weight and neurological function. These results demonstrate that NMN treats brain injury in ICH by suppressing neuroinflammation/oxidative stress. The activation of Nrf2/HO-1 signaling pathway may contribute to the neuroprotection of NMN in ICH.

A novel pattern-reconfigurable cylindrical dielectric resonator antenna is presented. By the incorporation of four p-i-n diode switches and four parasitic elements, the mode of dielectric resonator excited by the probe changed. The antenna's radiation patterns can be shaped to concentrate energy in four specific directions, while minimizing the gain in other unwanted directions without affecting the impedance bandwidth of the antenna for its complete symmetry in structure. The antenna switches its radiation patterns among four reconfigurable modes with orthogonal directions at azimuth plane covering a bandwidth of several 870 MHz and exhibiting a high maximum gain of 9.74 dBi. A fully functional prototype has been designed, fabricated, and tested. The measured results of the reflection coefficient, radiation patterns, and realized gain verify the effectiveness of the proposed pattern switching concept for cylindrical dielectric resonator antenna. These capabilities make the antenna suitable for smart wireless devices in next generation communication systems as it can enhance the radio frequency front-end flexibility and performance by adding pattern diversity, especially for muti-input-muti-output systems in multipath environments.

Three new phenolic compounds 1–3 and twenty known ones 4–23 were isolated from the flowers of Bombax malabaricum. Their chemical structures were elucidated by spectroscopic analyses (IR, ESI-MS, HR-ESI-MS, 1D- and 2D-NMR) and chemical reactions. The antioxidant capacities of the isolated compounds were tested using FRAP and DPPH radical-scavenging assays, and compounds 4, 6, 8, 12, as well as the new compound 2, exhibited stronger antioxidant activities than ascorbic acid. Furthermore, all of compounds were tested for their antiviral activities against RSV by the CPE reduction assay and plaque reduction assay. Compounds 4, 10, 12 possess in vitro antiviral activities, and compound 10 exhibits potent anti-RSV effects, comparable to the positive control ribavirin.

Marine sponges are well known as rich sources of biologically natural products. Growing evidence indicates that sponges harbor a wealth of microorganisms in their bodies, which are likely to be the true producers of bioactive secondary metabolites. In order to promote the study of natural product chemistry and explore the relationship between microorganisms and their sponge hosts, in this review, we give a comprehensive overview of the structures, sources, and activities of the 774 new marine natural products from sponge-derived microorganisms described over the last two decades from 1998 to 2017.

Sesquiterpenoids constitute a marvelously varied group of natural products that feature a vast array of molecular architectures. Among them, the unusual bicyclo [6.3.0] undecane sesquiterpenoids are one of the most representative. To date, only approximately 42 naturally occurring compounds with this unique scaffold, which can be classified into seven different groups, have been reported. As the first-found member of each type, dactylol, asteriscanolide, dumortenol, toxicodenane C, and capillosanane S are characteristic of the four methyl groups on the five-eight-membered ring system. Only 11-hydroxyjasionone and sinuketal decorate the core with an isopropyl group. These natural products exhibit a wide range of bioactivities, including antifouling, anti-inflammatory, immune suppression, cytotoxic, antimutagenic, antiplasmodial, and antiviral activities. It was noted that some total syntheses of precapnellane-sesquiterpenoids (dactylol, poitediol, precapnelladiene), asteriscanolide, and 11-hydroxyjasionone have been achieved, because their cyclooctanoid core represents an important target for the development of synthetic strategies to prepare eight-membered ring-containing compounds. This review focuses on these natural sesquiterpenoids and their biological activities and synthesis, and aims to provide a foundation for further research of these interesting compounds.

Three new furanocembranoids—briaviodiol F (1) and briaviotriols A (2) and B (3)—along with a known analogue, briaviodiol A (4), were obtained from a cultured-type octocoral Briareum violaceum. The structures of cembranoids 1–3 were elucidated by using spectroscopic methods. In vitro study demonstrated that compounds 2 and 4 exerted inhibition effects on inducible nitric oxide synthase (iNOS) release from RAW 264.7, a macrophage cell line that originated from a mouse monocyte macrophage, stimulated with lipopolysaccharides.

Chemical investigation on the soft coral Sarcophyton sp. collected from the South China Sea yielded three new polyhydroxylated steroids, compounds (1–3), together with seven known ones (4–10). Their structures were established by extensive spectroscopic methods and comparison of their data with those of the related known compounds. All the isolates possessed the 3β,5α,6β-trihydroxylated steroidal nucleus. The cytotoxicities against selected HL-60, HeLa and K562 tumor cell lines and anti-H1N1 (Influenza A virus (IAV)) activities for the isolates were evaluated. Compounds 2, 3 and 5–8 exhibited potent activities against K562 cell lines with IC50 values ranging from 6.4 to 10.3 μM. Compounds 1, 6–8 potently inhibited the growth of HL-60 tumor cell lines, and 6 also showed cytotoxicity towards HeLa cell lines. In addition, preliminary structure-activity relationships for the isolates are discussed. The OAc group at C-11 is proposed to be an important pharmacophore for their cytotoxicities in the 3β,5α,6β-triol steroids. Compounds 4 and 9 exhibited significant anti-H1N1 IAV activity with IC50 values of 19.6 and 36.7 μg/mL, respectively.

Five new oxygenated sesquiterpenes, molestins A⁻D (1, 3⁻5) and epi-gibberodione (2), three new cyclopentenone derivatives, ent-sinulolides C, D, and F ((+)-9⁻(+)-11), one new butenolide derivative, ent-sinulolide H ((+)-13), and one new cembranolide, molestin E (14), together with 14 known related metabolites (6⁻8, (⁻)-9⁻(⁻)-11, (±)-12, (⁻)-13, 15⁻19) were isolated from the Paracel Islands soft coral Sinularia cf. molesta. The structures and absolute configurations were elucidated based on comprehensive spectroscopic analyses, quantum chemical calculations, and comparison with the literature data. Compound 5 is the first example of a norsesquiterpene with a de-isopropyl guaiane skeleton isolated from the genus Sinularia. Molestin E (14) exhibited cytotoxicities against HeLa and HCT-116 cell lines with IC50 values of 5.26 and 8.37 μM, respectively. Compounds 4, 5, and 8 showed significant inhibitory activities against protein tyrosine phosphatase 1B (PTP1B) with IC50 values of 218, 344, and 1.24 μM, respectively.

Three new sesquiterpenoids (sinuketal (1), sinulins A and B (2 and 3)) and two new cembranoids (sinulins C and D (4 and 5)), as well as eight known sesquiterpenoids (6–13) and eight known cembranoids (14–21), were isolated from the Xisha soft coral Sinularia sp. Their structures were elucidated by extensive spectroscopic analysis. Compound 1 possesses an unprecedented isopropyl-branched bicyclo [6.3.0] undecane carbon skeleton with unique endoperoxide moiety, and a plausible biosynthetic pathway of it was postulated. According to the reported biological properties of endoperoxide, the antimalarial, cytotoxic, antiviral, and target inhibitory activities of 1 were tested. Compound 1 showed mild in vitro antimalarial activity against Plasmodium falciparum 3D7, weak cytotoxic activities toward Jurkat, MDA-MB-231, and U2OS cell lines, inhibitory effects against influenza A viruses H1N1 and PR8, as well as mild target inhibitory activity against acetylcholinesterase. The other compounds were evaluated for cytotoxicities against HeLa, HCT-116, and A549 tumor cell lines and target inhibitory activities against protein tyrosine phosphatase 1B (PTP1B). Compound 20 exhibited cytotoxicities against HeLa and HCT-116, and compounds 5, 11, and 15 showed mild target inhibitory activities against PTP1B.

The title compound [systematic name: 3β-hydroxylup-20(29)-en-28-oic acid methanol monosolvate], C30H48O3·CH3OH, is a solvent pseudopolymorph of a naturally occurring plant-derived lupane-type pentacyclic triterpenoid, which was isolated from the traditional Chinese medicinal plant Syzygium jambos (L.) Alston. The dihedral angle between the planes of the carboxylic acid group and the olefinic group is 12.17 (18)°. The A/B, B/C, C/D and D/E ring junctions are all trans-fused. In the crystal, O—H...O hydrogen bonds involving the hydroxy and carboxylic acid groups and the methanol solvent molecule give rise to a two-dimensional network structure lying parallel to (001).

A chemical investigation was conducted on the aerial parts of the mangrove plant Sonneratia paracaseolaris, yielding five new triterpenoid paracaseolins A–E (1–4, and 11) together with twelve known analogues (5–10, 12–17). Their structures were established by extensive spectroscopic methods and comparisons their spectroscopic data with those of the known related compounds. The cytotoxicities against P388, HeLa, A549, and K562 tumor cell lines and anti-H1N1 (Influenza A virus) activities for the isolates were evaluated. Compound 4 showed potent cytotoxicity against the A549 cell line with an IC50 value of 1.89 µM, and compound 1 exhibited significant anti-H1N1 virus activity with an IC50 value of 28.4 µg/mL. A preliminary structure activity relationship was discussed.

Chinese marine materia medica (CMMM) is a vital part of traditional Chinese medicine (TCM). Compared with terrestrial TCM, CMMM, derived from specific marine habitats, possesses peculiar chemical components with unique structures reflecting as potent pharmacological activities, distinct drug properties and functions. Nowadays, CMMM appears to be especially effective in treating such difficult diseases as cancers, diabetes, cardio-cerebrovascular diseases, immunodeficiency diseases and senile dementia, and therefore has become an important medicinal resource for the research and development of new drugs. In recent years, such development has attracted wide attention in the field of medicine. In this study, the CMMM resources in China were systematically investigated and evaluated. It was found that the historic experiences of Chinese people using CMMM have continuously accumulated over a period of more than 3600 years, and that the achievements of the research on modern CMMM are especially outstanding. By June 2015, 725 kinds of CMMMs from Chinese coastal sea areas have been identified and recorded, covering 1552 organisms and minerals. More than 3100 traditional prescriptions containing CMMMs have been imparted and inherited. However, the number of CMMMs is less than the 8188 terrestrial TCMs, from more than 12,100 medicinal terrestrial plants, animals and minerals. In the future, the research and development of CMMM should focus on the channel entries (TCM drug properties), compatibility, effective ingredients, acting mechanisms, drug metabolism and quality standard. This study reveals the high potential of CMMM development.

Estimations of rainfall-induced soil erosion are mostly derived from the weight of sediment measured in natural runoff. The transport distance of eroded soil is important for evaluating landscape evolution but is difficult to estimate, mainly because it cannot be linked directly to the eroded sediment weight. The volume of eroded soil is easier to calculate visually using popular imaging tools, which can aid in estimating the transport distance of eroded soil through geometry relationships. In this study, we present a straightforward geometry model to predict the maximum sediment transport distance incurred by rainfall events of various intensity and duration. In order to verify our geometry prediction model, a series of experiments are reported in the form of a sediment volume. The results show that cumulative rainfall has a linear relationship with the total volume of eroded soil. The geometry model can accurately estimate the maximum transport distance of eroded soil by cumulative rainfall, with a low root-mean-square error (4.7–4.8) and a strong linear correlation (0.74–0.86).

Marine sponges continue to serve as a rich source of alkaloids possessing interesting biological activities and often exhibiting unique structural frameworks. In the current study, chemical investigation on the marine sponge Pericharax heteroraphis collected from the South China Sea yielded one new imidazole alkaloid named naamidine J (1) along with four known ones (2–5). Their structures were established by extensive spectroscopic methods and comparison of their data with those of the related known compounds. All the isolates possessed a central 2-aminoimidazole ring, substituted by one or two functionalized benzyl groups in some combination of the C4 and C5 positions. The cytotoxicities against selected HL-60, HeLa, A549 and K562 tumor cell lines and anti-H1N1 (Influenza a virus (IAV)) activity for the isolates were evaluated. Compounds 1 and 2 exhibited cytotoxicities against the K562 cell line with IC50 values of 11.3 and 9.4 μM, respectively. Compound 5 exhibited weak anti-H1N1 (influenza a virus, IAV) activity with an inhibition ratio of 33%.

The title compound, C16H12O2, is a coumarin which was isolated from stones of the Chinese traditional medicine Clausena lansium. The pyrone ring is almost planar, with a mean deviation of 0.0135 (4) Å. The benzene ring (A) of the benzopyrone unit forms dihedral angles of 1.82 (5) and 72.86 (2)° with the pyrone ring and the substituent benzene ring, respectively. The crystal structure is stabilized by weak π–π stacking interactions, with a minimum centroid–centroid distance between benzene rings of 3.6761 (7) Å.

In the crystal structure of the title compound, [Ag(NO3)(C15H8N2O2)2], tryptanthrin (indolo[2,1-b]quinazoline-6,12-dione) and silver nitrate form a 2:1 complex. The silver ion is surrounded by two tryptanthrin ligands, each coordinating through the N atoms, with Ag—N bond lengths of 2.247 (3) and 2.264 (3) Å, and an anionic nitrate ligand coordinating through two O atoms, with Ag—O bond lengths of 2.499 (3) and 2.591 (3) Å. The N—Ag—N plane and the O—Ag—O plane are roughly perpendicular, making a dihedral angle of 81.6 (2)°. In the crystal, C—H...O interactions between aromatic H atoms and keto and nitrate O atoms as well as π–π interactions [centroid-centroid distance = 3.706 (4) Å] give rise to a three-dimensional network.

In the crystal structure of the title compound, C14H12ClNO2S, the molecules display a trans conformation with respect to the C=N double bond. The dihedral angle between the methylsulfonyl benzene and chlorobenzene rings is 59.59 (8)°. The crystal packing is stabilized by weak C—H...O interactions and by π–π stacking interactions between inversion-related methylsulfonyl benzene rings [centroid–centroid distance = 3.8579 (11) Å].

In the crystal structure of the title compound {systematic name: (1′S,2R,2′R,3′S,6′R)-3′-ethyl-4-methyl-5H-5′-oxa-10′-azaspiro[furan-2,4′-tricyclo[8.3.0.02,6]tridecane]-5,11′-dione hemihydrate}, C17H23NO4·0.5H2O, the asymmetric unit contains two molecules of tuberostemoamide with similar conformations and one water molecule. The tuberostemoamide molecule is composed of one seven-membered ring (A) and three five-membered rings (B, C and D). Ring A exists in a chair conformation, both rings B and C exist in envelope conformations, and ring D is almost planar with a mean deviation of 0.0143 (4) Å in one molecule and 0.0095 (3) Å in the other.. The dihedral angles between the planes of rings C and D are 75.1 (3)° in one molecule and 74.5 (3)° for the other. The solvent water molecule links the tuberostemoamide molecules through O—H...O(ketone) hydrogen bonds. Weak C—H...O interactions are also present, involving both the water molecule and a heterocyclic ether O-atom acceptor.

In the title compound (systematic name 1-hydroxy-1,2-dihydroobacunoic acid 3,4-lactone monohydrate), C26H32O8·H2O, the dihedral angles between the planes of the ester groups and the furan plane are 43.06 (12) and 56.06 (7)°, while that between the furan plane and the keto group is 58.50 (9)°. The A/B, B/C and C/D ring junctions are all trans-fused. Intermolecular O—H...O hydrogen bonds between the hydroxy and carbonyl groups and the water molecule give rise to a three-dimensional structure.

The title compound, C19H18O7 [systematic name 5-hydroxy-3,6,7-trimethoxy-2-(4-methoxyphenyl)-4H-1-benzopyran-4-one], is a flavonoid which was isolated from the traditional Chinese medicine Laggera alata. The benzene ring of the benzopyranone unit forms dihedral angles of 1.72 (3) and 37.39 (5)° with the pyran ring and the substituent benzene ring, respectively. The molecular conformation is stabilized by an intramolecular phenol O—H...Oketone hydrogen bond.

In the crystal structure of the title compound [systematic name: 2-hydroxy-2-(4-hydroxybenzyl)butanedioic acid methanol monosolvate], C11H12O6·CH3OH, the dihedral angles between the planes of the carboxyl groups and the benzene ring are 51.23 (9) and 87.97 (9)°. Intermolecular O—H...O hydrogen-bonding interactions involving the hydroxy and carboxylic acid groups and the methanol solvent molecule give a three-dimensional structure.

The title compound, C18H20O4, was synthesized by a Wittig–Horner reaction of diethyl 3,4-dimethoxybenzylphosphate and 3,5-dimethoxybenzaldehyde. In the crystal, the dihedral angle between the two aromatic rings is 2.47 (12)°. All the methoxy groups are almost coplanar with the aromatic ring to which they are attached [C—C—O—C torsion angles = −2.8 (3), −5.2 (4), −176.3 (2) and −178.0 (2)°].

In the title compound, C8H5F4NO2, synthesized by esterification of 2,3,4,5-tetrafluoroanthranilic acid with methanol, an intramolecular amine N—H...Ocarbonyl hydrogen bond is present, while intermolecular N—H...O hydrogen bonds produce chains in the crystal, which extend along the b-axis direction.

The asymmetric unit of the title compound, [Sn4(C7H6Cl)8(C8H7O2)2O2(OH)2], comprises one-half of the centrosymmetric tin(IV) complex. μ3-Oxide and μ2-hydroxide bridges link the four five-coordinate SnIV atoms to generate three fused four-membered Sn—O—Sn—O rings in a ladder-like structure. The two endocyclic Sn atoms each bind to two μ3-oxide anions and a μ2-hydroxide ligand, together with two 2-chlorobenzyl groups. The exocyclic Sn atoms each carry a monodentate phenylacetate ligand, two 2-chlorobenzyl groups, and μ3-oxide and μ2-hydroxide ligands. Both types of Sn atoms adopt a distorted trigonal–bipyramidal coordination geometry. The molecular conformation is stabilized by intramolecular O—H...O interactions involving the μ2-hydroxide ligands and the C=O group of the phenylacetate ligand.