Absolute Configuration of Oxabornyl Polyenes Prugosenes A1-A3 and Structural Revision of Prugosene A2.

Oxabornyl polyenes represent a unique group of polyketides characterized by a central polyene core flanked by a conserved oxabornyl moiety and a structurally diverse oxygen heterocyclic ring. They are widely distributed in fungi and possess a variety of biological activities. Due to the significant spatial separation between the two stereogenic ring systems, it is difficult to establish their overall relative configurations. Here, we isolated three oxabornyl polyenes, prugosenes A1-A3 (1-3), from Talaromyces sp. JNU18266-01. Although these compounds were first reported from Penicillium rugulosum, their overall relative and absolute configurations remained unassigned. By employing ozonolysis in combination with ECD calculations, we were able to establish their absolute configurations, and additionally obtained seven new chemical derivatives (4-10). Notably, through NMR data analysis and quantum chemical calculations, we achieved the structural revision of prugosene A2. Furthermore, prugosenes A1-A3 exhibited potent antiviral activity against the respiratory syncytial virus, with compound 1 displaying an IC50 value of 6.3 µM. Our study thus provides a valuable reference for absolute configuration assignment of oxabornyl polyene compounds.

Nine New Antibacterial Diterpenes and Steroids from the South China Sea Soft Coral Lobophytum catalai Tixier-Durivault.

Five new cembrane-type diterpenes, lobocalines A-E (1-5), and four new steroids, lobocaloids A-D (9-12), along with six known related compounds (6-8 and 13-15) were isolated from the Yalong Bay soft coral Lobophytum catalai Tixier-Durivault. The structures of the new compounds were elucidated by extensive spectroscopic analysis, NMR calculation with DP4+ analysis, time-dependent density functional theory-electronic circular dichroism (TDDFT-ECD) calculations, X-ray diffraction analyses and comparison with the reported spectroscopic data of known compounds. Further, with the aid of X-ray diffraction analysis, the structure of lobocrasol B (15) was firmly revised as 15a. In in vitro bioassays, compound 2 showed moderate antibacterial activities against fish pathogenic bacteria Streptococcus parauberis KSP28 and Phoyobacterium damselae FP2244 with minimum inhibitory concentration (MIC) values of 8.7 and 17.3 µg/mL, respectively. All the steroids exhibited antibacterial activities against the S. parauberis KSP28 with MIC values ranging from 12.3 to 53.6 µg/mL. Compounds 2, 7 and 14 have remarkable inhibitory effects on the hemolysin production of Staphylococcus aureus, while compounds 8-12 have medium inhibitory effects on the pyocyanin production in Pseudomonas aeruginosa.

Anti-HBV Activities of Cembranoids from the South China Sea Soft Coral Sinularia pedunculata and Their Structure Activity Relationship.

Hepatitis B Virus (HBV) infection is a global public health challenge that seriously endangers human health. Soft coral, as a major source of terpenoids, contains many structurally novel and highly bioactive compounds. Sixteen cembranoids (1-16), including a new one named sinupedunol B (16), were isolated from the South China Sea Soft coral Sinularia pedunculata. The structure of the sinupedunol B (16) was determined through a combination of spectroscopic analysis and X-ray single-crystal diffraction. In this study, cembranoids isolated from Sinularia pedunculata were found of anti-HBV activity for the first time. Among them, flexilarin D (6) showed significant anti-HBV activity with an IC50 value of 5.57 µM without cytotoxicity. We then analyzed the structure-activity relationship (SAR). Furthermore, it is demonstrated that flexilarin D (6) can accelerate the formation of capsid, inhibit HBeAg, HBV core particle DNA, HBV total RNA and pregenomic RNA in a dose dependent manner. We also confirmed the anti-HBV activity of 6 in HepG2-NTCP infection system. Finally, we demonstrated the anti-HBV mechanism of these compounds by inhibiting the ENI/Xp enhancer/promoter.

Efficacy of radiotherapy in combined treatment of hepatocellular carcinoma patients with portal vein tumor thrombus: a real-world study.

BACKGROUND AND AIMS: Hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT) has an extremely poor prognosis. A previous study proved that low-dose radiotherapy (RT) could prolong the prognosis of HCC patients with PVTT. This study aims to explore the sensitivity of PVTT to RT treatment. METHODS: Patients were selected based on imaging diagnosis of HCC accompanied by PVTT and received combined treatment of radiotherapy, antiangiogenic drugs and immune checkpoint inhibitors, followed by hepatectomy or liver transplantation from January 2019 to August 2022. The efficacy was evaluated by Response Evaluation Criteria in Solid Tumors (RECIST) guidelines and pathological assessment. The sensitivity of tumor cells to the treatment was compared between the primary tumor (PT)and PVTT by analyzing their residual tumor and pathologic complete remission (PCR) incidence. RESULTS: Data from 14 patients were collected in the study. After combined treatment, the size of PVTT decreased more significantly than that of the primary tumor in the imaging study (p < 0.05). The residual cancer was significantly more restrictive than that of primary tumor in paired patients based on pathological measurement (p = 0.008). The PCR incidence of the primary tumor (21.42%) was significantly lower (p = 0.008) than that of PVTT in the pathologic study (78.57%). CONCLUSION: PVTT is more sensitive to radiotherapy treatment than the primary tumor in patients with HCC. This combination therapy might be an effective option as a downstaging therapy for patients with HCC with PVTT.

The Rigid Unit Mode model: review of ideas and applications.

We review a set of ideas concerning the flexibility of network materials, broadly defined as structures in which atoms form small polyhedral units that are connected at corners. One clear example is represented by the family of silica polymorphs, with structures composed of corner-lined SiO4tetrahedra. TheRigid Unit Mode(RUM) is defined as any normal mode in which the structural polyhedra can translate and/or rotate without distortion, and since forces associated with changing the size and shape of the polyhedra are much stronger than those associated with rotations of two polyhedra around a shared vertex, the RUMs might be expected to have low frequencies compared to all other phonon modes. In this paper we discuss the flexibility of network structures, and how RUMs can arise in such structures, both in principle and in a number of specific examples of real systems. We also discuss applications of the RUM model, particularly for our understanding of phenomena such as displacive phase transitions and negative thermal expansion in network materials. .

Structurally Diverse Diterpenoids from the Sanya Bay Nudibranch Hexabranchus sanguineus and Its Sponge-Prey Chelonaplysilla sp.

Investigation of the South China Sea nudibranch Hexabranchus sanguineus from Sanya Bay afforded, in addition to three known compounds, nine new diterpenoids of the 5,19-cycloclerodane- (sanyanolides A-D), clerodane- (sanyanolide E) and subersin- (sanyanolides F-I) type. Remarkably, six diterpenoids aforementioned from H. sanguineus were also isolated from the sponge Chelonaplysilla sp. from the same water region, suggesting a trophic relationship between H. sanguineus and Chelonaplysilla sp. The structure and absolute configuration of new compounds were established by a combination of spectroscopic data, X-ray diffraction analysis and/or time-dependent density functional theory/electronic circular dichroism calculations. A plausible biogenetic relationship between these diterpenoids, along with the chemo-ecological implications of their co-occurrence in the two organisms investigated, was proposed and discussed. In in vitro bioassays, echinoclerodane A exhibited a potent inhibitory effect (IC50 =2.81 µM) on LPS-induced inflammatory response in RAW 264.7 macrophage cells. In addition, echinoclerodane A and oculatolide showed considerable antibacterial activities with MIC values ranging from 1.0 to 8.0 µg/mL.

Nanolobatone A, An Unprecedented Diterpenoid and Related New Casbanoids from the Hainan Soft Coral Sinularia nanolobata.

Nanolobatone A, featuring an unprecedented tricyclo[10.3.0.01,2 ]pentadecane carbon skeleton, along with four new polyoxygenated and four unusual endoperoxide-bridged casbane-type diterpenoids were isolated from the Hainan soft coral Sinularia nanolobata. The structures of the new compounds were established by extensive spectroscopic analysis, X-ray diffraction analysis, and time-dependent density functional theory/electronic circular dichroism calculations. A plausible biosynthetic pathway of new isolates was proposed. Bioassays revealed that nanolobatone A showed weak antibacterial activity against the Gram-positive bacteria Streptococcus pyogenes.

Integrative analysis of purine metabolites and gut microbiota in patients with neuromyelitis optica spectrum disorders after mycophenolate mofetil treatment.

BACKGROUND: Neuromyelitis optica spectrum disorder (NMOSD) is a recurring inflammatory demyelinating disease that is commonly observed in Asian countries like China. Prior investigations have shown that mycophenolate mofetil (MMF) with better biocompatibility compared to azathioprine (AZA), and can prevent relapses of NMOSD, but the efficacy was controversially reported in different NMOSD cases. We aimed to explore the factors that weaken efficacy of MMF in NMOSD. METHODS: A total of 34 NMOSD patients treated with MMF were prospectively enrolled and grouped according to the therapeutic efficacy as effective group (EG, n = 23) versus less-effective group (LEG, n = 11). The purine metabolites were profiled in serum samples and gut microbiota was analyzed using 16S rRNA sequencing with stool samples from the same patients. RESULTS: Purine salvage pathway (PSP) metabolites (inosine, hypoxanthine, xanthine, guanine and uric acid) in the serum of NMOSD patients were elevated in the LEG compared to EG (p < 0.05). Additionally, the richness and microbial diversity of gut microbiota was found to be similar between EG and LEG patients. However, LEG patients had increased presence of Clostridium and Synergistes but decreased abundance of the Coprococcus genus. CONCLUSIONS: The PSP metabolites and composition of the gut microbiota were changed between patients with or without optimal clinical response after MMF treatment. This may help us to understand the pharmacodynamics of MMF in NMOSD.

Antimicrobial resistance in E. Coli of animal origin and discovery of a novel ICE mobile element in Northeast China.

BACKGROUND: Multidrug resistance in Enterobacteriaceae including resistance to quinolones is rising worldwide. The development of resistance may lead to the emergence of new transmission mechanisms. In this study, the collection of different E. coli was performed from animals and subjected to subsequent procedures including pulsed-field gel electrophoresis, micro-broth dilution method, polymerase chain reaction. Whole genome sequencing of E. coli C3 was performed to detect the affinity, antimicrobial resistance and major carriers of the isolates. RESULTS: A total of 66 E. coli were isolated and their antibiotic resistance genes, frequency of horizontal transfer and genetic environment of E. coli C3 were determined. The results showed there were both different and same types in PFGE typing, indicating clonal transmission of E. coli among different animals. The detection of antimicrobial resistance and major antibiotic resistance genes and the plasmid transfer results showed that strains from different sources had high levels of resistance to commonly used clinical antibiotics and could be spread horizontally. Whole-genome sequencing discovered a novel ICE mobile element. CONCLUSION: In summary, the antimicrobial resistance of E. coli in northeast China is a serious issue and there is a risk of antimicrobial resistance transmission. Meanwhile, a novel ICE mobile element appeared in the process of antimicrobial resistance formation.

Lobosteroids A-F: Six New Highly Oxidized Steroids from the Chinese Soft Coral Lobophytum sp.

To explore the steroidal constituents of the soft coral Lobophytum sp. at the coast of Xuwen County, Guangdong Province, China, a chemical investigation of the above-mentioned soft coral was carried out. After repeated column chromatography over silica gel, Sephadex LH-20, and reversed-phase HPLC, six new steroids, namely lobosteroids A-F (1-6), along with four known compounds 7-10, were obtained. Their structures were determined by extensive spectroscopic analysis and comparison with the spectral data reported in the literature. Among them, the absolute configuration of 1 was determined by X-ray diffraction analysis using Cu Kα radiation. These steroids were characterized by either the presence of an α,ß-α',ß'-unsaturated carbonyl, or an α,ß-unsaturated carbonyl moiety in ring A, or the existence of a 5α,8α-epidioxy system in ring B, as well as diverse oxidation of side chains. The antibacterial bioassays showed that all isolated steroids exhibited significant inhibitory activities against the fish pathogenic bacteria Streptococcus parauberis FP KSP28, Phoyobacterium damselae FP2244, and Streptococcus parauberis SPOF3K, with IC90 values ranging from 0.1 to 11.0 µM. Meanwhile, compounds 2 and 6-10 displayed potent inhibitory effects against the vancomycin-resistant Enterococcus faecium bacterium G7 with IC90 values ranging from 4.4 to 18.3 µM. Therefore, ten highly oxidized steroids with strong antibacterial activities were isolated from the Chinese soft coral Lobophytum sp., which could be developed as new chemotypes of antibacterial drug leads.

Extending the Record of Terpenes from Soft Coral Sarcophyton mililatensis.

In the present study, a new polyoxygenated cembranoid named sarcomililatol H (1) as well as six known terpenes 2-7 with different skeletons were isolated from South China Sea soft coral Sarcophyton mililatensis. Based on the comprehensive analyses of 1D and 2D NMR spectroscopic data, the structure of the new compound 1 was established. This new cembranoid was characterized by the presence of the rarely encountered tetrahydropyran ring with the ether linkage across C-2 and C-12. By applying the time-dependent density functional theory electronic circular dichroism (TDDFT ECD) approach, the absolute configuration of sarcomililatol H (1) was determined. All of the isolates were subjected to the anti-inflammatory and anti-tumor bioassays. However, none of them was active in these evaluations. Additionally, the preliminary virtual screening of inhibitory against SARS-CoV-2 by molecular docking showed that diterpene 1 could be regarded as a SARS-CoV-2 main protease (Mpro ) inhibitor (binding energy: -7.63 kcal/mol). The discovery of these terpenes has expanded the chemical diversity and complexity of terpenes from the species S. mililatensis.

Anti-Inflammatory Steroids from the South China Sea Soft Coral Lobophytum sarcophytoides.

Three new steroids, along with two known related analogs, were isolated from the Xisha Island soft coral Lobophytum sarcophytoides. The structures and absolute configurations of the new compounds were elucidated by extensive spectroscopic data analyses, time dependent density functional theory electronic circular dichroism calculation, and comparison with the spectral data previously reported in the literature. In in vitro bioassay, four compounds showed interesting suppressive effects on lipopolysaccharide (LPS) induced inflammation in BV-2 microglial cells at 10 µM level.

Oxygenated Cembrane Diterpenes from the South China Sea Soft Coral Sinularia tumulosa.

The chemical investigation of the rarely studied soft coral Sinularia tumulosa resulted in the discovery of five oxygenated cembrane diterpenes 1-5, including two new compounds situmulins A (1) and B (2). The structures of 1 and 2 were established through the extensive analyses of 1D and 2D NMR spectral data together with the comparisons with the known compounds. Furthermore, the absolute configuration of 1 was determined by the time-dependent density functional theory (TDDFT) ECD approach, while the relative configuration of 2 was assigned via the quantum mechanical-NMR (QM-NMR) calculations. It might be worth to point out it is the first time to disclose the presence of cembrane diterpenes in the title species. In the bioassays, compound 2 not only showed strong antibacterial activities against fish pathogenic bacteria Streptococcus parauberis FP KSP28 and Phoyobacterium damselae FP2244 with both minimum inhibitory concentration for 90 % (MIC90 ) values of 25 µM, but also demonstrated substantial inhibitory efficacy against vancomycin-resistant Enterococcus faecium bacteria G1, G4, G7, G8 and G13 from several individuals, with MIC90 values of 25, 50, 100, 50 and 25 µM, respectively.

Two New Cembranoids from the Chinese Soft Coral Sarcophyton boettgeri.

Two new cembranoids, namely sarcoboettgerols D and E, together with four known related ones, have been isolated from the soft coral Sarcophyton boettgeri collected from Weizhou Island in the South China Sea. Their structures including absolute configurations were elucidated by extensive spectroscopic analysis, quantum mechanical nuclear magnetic resonance methods, time-dependent density functional theory-electronic circular dichroism calculations, as well as comparison with the reported data in the literature. A plausible biogenetic relationship of four cembranoids was proposed. In bioassays, sarcomililatin B exhibited cytotoxic activity against H1299 cell (IC50 =35.0 µM), whereas sarcomililatin B and sarcomililatin A displayed moderate antibacterial activities (MIC 17.4-34.8 µg/mL).

Antitumor Cembrane Diterpenoids from the South China Sea Soft Coral Lobophytum sp.

Two new highly functionalized cembrane diterpenoids named ximaolobophytolides A (1) and B (2) as minor components, together with seven related known compounds (3-9), have been isolated and identified from the Ximao soft coral Lobophytum sp. They were characterized by the presence of an α-methylene-γ-lactone moiety. Based on the comprehensive analyses of 1D and 2D NMR spectroscopic data, the absolute configurations of these two new compounds were elucidated by the combination of quantum mechanical (QM)-NMR and time-dependent density functional theory/electronic circular dichroism (TDDFT-ECD) calculation approaches. In the anti-tumor bioassays, compounds 3-9 showed moderate to significant inhibitory effects (IC50 values ranging from 29.66 to 0.39 µM) against the proliferations of five tumor cells HEL, A549, H1975, MDA-MB-231, and H1299. It might be worthy to point out that compounds 4, 7, and 8 exhibited better anti-tumor activities than that of the positive control Doxorubicin.

The Discovery and Anti-Colorectal Cancer Activities of Cembranolides from the South China Sea Soft Coral Sinularia pendunculata.

A new cembranolide, namely, sinupendunculide A (1), along with eight known related compounds (2-9), was isolated from the South China Sea Soft coral Sinularia pendunculata. The structure of sinupendunculide A (1) was established by extensive spectroscopic analysis and X-ray diffraction experiments. In a bioassay, anti-colorectal cancer (CRC) activity was performed, and the results showed that several compounds exhibited cytotoxicity against RKO cells, and a preliminary structure-activity relationship was analysed. Meanwhile, the most effective compound 7 was proven to increase reactive oxygen species levels, which promoted cell apoptosis and inhibited cell proliferation.

Hyrtiosins F and G, two new scalarane sesterterpenes from the South China sea sponge Hyrtios erecta.

Two new scalarane sesterterpenes, hyrtiosins F and G (1 and 2), along with two known related compounds, hyrtiosin D and sesterstatin 6 (3 and 4), were isolated from the Hainan marine sponge Hyrtios erecta. The structures of new compounds 1 and 2 were determined by detailed analysis of 1D and 2D NMR spectra and by comparison of the spectroscopic data with those reported in the literatures.

Two new compounds from the Hainan Soft Corals Sinularia tumulosa and Sinularia depressa with their anti-inflammatory or cytotoxic activities.

The detailed chemical investigations of the South China Sea soft corals Sinularia tumulosa and Sinularia depressa, yielded two new compounds, namely tumulosterol A (1) and 11'-hydroxy-α-tocopherylquinone (3), along with four related known ones (2, 5-7). Their structures were determined by extensive spectroscopic analysis and comparison with the spectral data previously reported in the literature. In bioassays, compound 1 displayed significant cytotoxic effects against H1975 and MDA-MB-231 cells with IC50 values of 6.0 and 6.3 µM, respectively. In addition, compound 3 exhibited interesting inhibitory effect on lipopolysaccharide (LPS)-induced inflammatory responses in RAW264.7 cells with IC50 value of 9.5 µM.

Cembrane Diterpenes Possessing Nonaromatic Oxacycles from the Hainan Soft Coral Sarcophyton mililatensis.

Documents on the chemical composition of the soft coral Sarcophyton mililatensis are sparse. The present investigation of the Hainan soft coral S. mililatensis resulted in the discovery of six new cembrane diterpenes, sarcoxacyclols A-F (1-6) and four known analogs (7-10). Their structures were elucidated by extensive spectroscopic analysis along with a comparison with the data in current literature. The nonaromatic oxacycles in their structures were the rarely found tetrahydrofuran ether across C-1 and C-12 and tetrahydropyran ether across C-1 and C-11, respectively. Moreover, the absolute configuration of compound 4 was established unambiguously by X-ray diffraction analysis using Ga Kα radiation (λ = 1.34139 Å). Based on the biogenetical consideration, the absolute configurations of other five new compounds were tentatively assumed. Assessment of the bioactivity for these secondary metabolites revealed that compound 1 exhibited significant tumor necrosis factor (TNF)-α inhibitory activity (IC50 = 9.5 µmol/L), similar to the positive control dexamethasone (IC50 = 8.7 µmol/L), but no obvious cytotoxicity towards RAW264.7 cells (CC50 > 50 µmol/L). The preliminary molecular docking suggested the crucial roles of the hydroxyl and acetoxyl groups in the computational prediction of the binding mode between the diterpene and the protein.

Four New Diterpenoids from the South China Sea Soft Coral Sinularia nanolobata and DFT-Based Structure Elucidation.

Three new cembranoids (1-3) and a new casbanoid (4), along with three known analogues (5-7), have been isolated from the soft coral Sinularia nanolobata collected off Ximao Island. The structures, including the absolute configurations of new compounds, were established using extensive spectroscopic data analysis, time-dependent density functional theory/electronic circular dichroism (TDDFT-ECD) calculations, and the comparison with spectroscopic data of known compounds. In the in vitro bioassay, compounds 1 and 5 exhibited moderate cytotoxic activities against human erythroleukemia (HEL) cell lines, with IC50 values of 37.1 and 42.4 µM, respectively.