An efficient FE-implementation of implicit gradient-enhanced damage models to simulate ductile failure-Supplementary Material

The dataset contains input-files and user defined routines for ABAQUS to reproduce the results shown within the following paper: Seupel, A., Hütter, G., Kuna, M., An efficient FE-implementation of implicit gradient-enhanced damage models to simulate ductile failure, Engineering Fracture Mechanics (2018), doi: https://doi.org/10.1016/j.engfracmech.2018.01.02

Data for: An efficient FE-implementation of implicit gradient-enhanced damage models to simulate failure

The dataset contains a material routine (UMAT.f) and a user-defined hardening routine (UHARD.f) to be used in conjunction with FE-program ABAQUS. These subroutines enable to take into account gradient-enhanced damage. A special ductile damage model is implemented. Different examples (input-files) are given to conduct convergence studies (shear band specimen, plate-with-hole, double-notched tensile test). More information about usage is given in the short-documentation (Doc.pdf)

An efficient FE-implementation of implicit gradient-enhanced damage models to simulate ductile failure-Supplementary Material

The dataset contains input-files and user defined routines for ABAQUS to reproduce the results shown within the following paper: Seupel, A., Hütter, G., Kuna, M., An efficient FE-implementation of implicit gradient-enhanced damage models to simulate ductile failure, Engineering Fracture Mechanics (2018), doi: https://doi.org/10.1016/j.engfracmech.2018.01.02

5′-O-Methyldioncophylline D, a 7,8′-coupled naphthylisoquinoline alkaloid from callus cultures of Triphyophyllum peltatum, and its biosynthesis from a late-stage tetrahydroisoquinoline precursor

The natural tetrahydroisoquinoline phylline (4) was synthesized in a specifically [1,1′-13C2]-labeled form, and fed to callus cultures of Triphyophyllum peltatum. Its incorporation into naphthylisoquinoline alkaloids, among them habropetaline A (8) (as evidenced by1H,13C NMR, and 2D INADEQUATE experiments), proved 4 to be the authentic coupling substrate for the enzyme-mediated phenol-oxidative coupling with a naphthalene portion. During the feeding experiments, a new alkaloid was discovered, 5′-O-methyldioncophylline D (5). It is the first 7,8′-linked (d-type) naphthylisoquinoline isolated from a Dioncophyllaceae plant. The new alkaloid consists of two closely eluting, slowly interconverting atropo-diastereomers, (P)-5 and (M)-5. Their full absolute stereostructures were assigned, i.e., by spectroscopic and online HPLC-CD investigations

Axially chiral dimeric naphthalene and naphthoquinone metabolites, from root cultures of the West African liana Triphyophyllum peltatum

Root cultures of the West African liana Triphyophyllum peltatum were initiated from stem explants of in vitro cultivated shoots. From these organ cultures, three new binaphthalenes, one binaphthoquinone, and two (bi)naphthalene glucosides were isolated, with substitution patterns related to those of the naphthylisoquinoline alkaloids, which are the "normal" main metabolites of T. peltatum. The structures of the diglucoside dioncoquinoside A (1) and of the axially chiral biaryls triphyoquinols A1 (3), A2 (4), and B (5), triphyoquinoside A (6), and triphyoquinone A (7) were elucidated by spectroscopic analysis (HRESIMS, 1D and 2D NMR) and by application of electronic circular dichroism (ECD) spectroscopy in combination with the exciton chirality method and quantum-chemical ECD calculations. The root cultures likewise produced the known alkaloids dioncophylline A (8), 5'-O-demethyldioncophylline A (9), dioncopeltine A (10), habropetaline A (11), and 5'-O-methyldioncophylline D (12a/b), the naphthalene glucoside plumbaside A (2), and the naphthoquinones plumbagin (13), droserone (14), and 8-hydroxydroserone (15)

Axially chiral dimeric naphthalene and naphthoquinone metabolites, from root cultures of the West African liana Triphyophyllum peltatum

Root cultures of the West African liana Triphyophyllum peltatum were initiated from stem explants of in vitro cultivated shoots. From these organ cultures, three new binaphthalenes, one binaphthoquinone, and two (bi)naphthalene glucosides were isolated, with substitution patterns related to those of the naphthylisoquinoline alkaloids, which are the "normal" main metabolites of T. peltatum. The structures of the diglucoside dioncoquinoside A (1) and of the axially chiral biaryls triphyoquinols A1 (3), A2 (4), and B (5), triphyoquinoside A (6), and triphyoquinone A (7) were elucidated by spectroscopic analysis (HRESIMS, 1D and 2D NMR) and by application of electronic circular dichroism (ECD) spectroscopy in combination with the exciton chirality method and quantum-chemical ECD calculations. The root cultures likewise produced the known alkaloids dioncophylline A (8), 5'-O-demethyldioncophylline A (9), dioncopeltine A (10), habropetaline A (11), and 5'-O-methyldioncophylline D (12a/b), the naphthalene glucoside plumbaside A (2), and the naphthoquinones plumbagin (13), droserone (14), and 8-hydroxydroserone (15)

Effects of the novel polyphenol conjugate DPP-23 on head and neck squamous cell carcinoma cells in vitro

Despite partial advances in therapy for patients suffering from head and neck squamous cell carcinomas (HNSCC), prognosis still remains poor with minimal improvement in survival for over the last several decades. Some agents found are known to cause cancer cell death in vitro by promoting cellular reactive oxygen species (ROS) accumulation. This is particularly of interest as some cancer cells are more sensitive to ROS than normal cells. It could be shown that the novel polyphenol conjugate (E)-3-(3',5'-Dimethoxyphenyl)-1-(2'-methoxyphenyl)prop-2-en-1-one (DPP-23) offers antitumor effects by the selective generation of ROS without an indication of toxicity in normal tissues in vitro and in vivo. In order to further evaluate the role of DPP-23 as a potential agent in head and neck oncology, the present study investigated its cytotoxic effects on well-established HNSCC cell lines such as HLaC 78 and FaDu, as well as primary human bone marrow stem cells (hBMSCs) and human peripheral blood lymphocytes in vitro. As DPP-23 is not commercially available, it was synthesized via a 'cold' procedure of the Claisen-Schmidt condensation. Following cell treatment with DPP-23 for 24 h, viability and apoptosis were measured via a MTT assay and the Annexin V-propidium iodide test. The results suggest a dose-dependent cytotoxicity in the tested HNSCC tumor cell lines, as well as in hBMSC and lymphocytes. In contrast to previous findings, these preliminary results indicate that the cytotoxic effects of DPP-23 in benign cells may be notably greater than previously suspected. This may indicate a limitation for in the feasibility, or at least of the systemic application, of DPP-23 for patients with HNSCC

Effects of the novel polyphenol conjugate DPP-23 on head and neck squamous cell carcinoma cells in vitro

Despite partial advances in therapy for patients suffering from head and neck squamous cell carcinomas (HNSCC), prognosis still remains poor with minimal improvement in survival for over the last several decades. Some agents found are known to cause cancer cell death in vitro by promoting cellular reactive oxygen species (ROS) accumulation. This is particularly of interest as some cancer cells are more sensitive to ROS than normal cells. It could be shown that the novel polyphenol conjugate (E)-3-(3',5'-Dimethoxyphenyl)-1-(2'-methoxyphenyl)prop-2-en-1-one (DPP-23) offers antitumor effects by the selective generation of ROS without an indication of toxicity in normal tissues in vitro and in vivo. In order to further evaluate the role of DPP-23 as a potential agent in head and neck oncology, the present study investigated its cytotoxic effects on well-established HNSCC cell lines such as HLaC 78 and FaDu, as well as primary human bone marrow stem cells (hBMSCs) and human peripheral blood lymphocytes in vitro. As DPP-23 is not commercially available, it was synthesized via a 'cold' procedure of the Claisen-Schmidt condensation. Following cell treatment with DPP-23 for 24 h, viability and apoptosis were measured via a MTT assay and the Annexin V-propidium iodide test. The results suggest a dose-dependent cytotoxicity in the tested HNSCC tumor cell lines, as well as in hBMSC and lymphocytes. In contrast to previous findings, these preliminary results indicate that the cytotoxic effects of DPP-23 in benign cells may be notably greater than previously suspected. This may indicate a limitation for in the feasibility, or at least of the systemic application, of DPP-23 for patients with HNSCC

Epoxides related to dioncoquinone B: Synthesis, activity against multiple myeloma cells, and search for the target protein

Epoxide 2b is an analog of the synthetic intermediate 2a en route to the polyketide-derived antitumoral naphthoquinone dioncoquinone B (1), isolated from cell cultures of the tropical liana Triphyophyllum peltatum (Dioncophyllaceae). Compound 2b was found to induce strong apoptosis in multiple myeloma cells at a concentration (EC50 = 3.5 μM), distinctly lower than that of 1 and any related analog, without exerting significant toxicity against normal blood cells. Preliminary studies showed that 2b follows different SAR rules as compared to the naphthoquinones. Among the series of synthesized epoxides, 2b was the most active one and was thus, after biotinylation, subjected to mass spectrometry-based affinity capture experiments aiming at the identification of target proteins. The MS data revealed 2b to address proteins that are associated with stress regulation processes which are critical for multiple myeloma cell survival