Correction: Naphthylisoindolinone alkaloids: the first ring-contracted naphthylisoquinolines, from the tropical liana , with cytotoxic activity.

[This corrects the article DOI: 10.1039/D2RA05758A.].

Naphthylisoindolinone alkaloids: the first ring-contracted naphthylisoquinolines, from the tropical liana , with cytotoxic activity.

The West African liana is a rich source of structurally most diverse naphthylisoquinoline alkaloids. From its roots, a series of four novel representatives, named ancistrobrevolines A-D (14-17) have now been isolated, displaying an unprecedented heterocyclic ring system, where the usual isoquinoline entity is replaced by a ring-contracted isoindolinone part. Their constitutions were elucidated by 1D and 2D NMR and HR-ESI-MS.

Enabling new mindsets and transformative skills for negotiating and activating climate action: Lessons from UNFCCC conferences of the parties.

Technological and policy solutions for transitioning to a fossil-free society exist, many countries could afford the transition, and rational arguments for rapid climate action abound. Yet effective action is still lacking. Dominant policy approaches have failed to generate action at anywhere near the rate, scale or depth needed to avoid potentially catastrophic futures.

Release of Melamine and Formaldehyde from Melamine-Formaldehyde Plastic Kitchenware.

The release of melamine and formaldehyde from kitchenware made of melamine resins is still a matter of great concern. To investigate the migration and release behavior of the monomers from melamine-based food contact materials into food simulants and food stuffs, cooking spoons were tested under so-called hot plate conditions at 100 °C. Release conditions using the real hot plate conditions with 3% acetic acid were compared with conditions in a conventional migration oven and with a release to deionized water.

Ancistrosecolines A-F, Unprecedented -Naphthylisoquinoline Alkaloids from the Roots of , with Apoptosis-Inducing Potential against HeLa Cancer Cells.

Ancistrosecolines A-F (-) are the first -type naphthylisoquinoline alkaloids discovered in Nature. In all these novel compounds, the tetrahydroisoquinoline ring is cleaved, with loss of C-1. They were isolated from the root bark of (Ancistrocladaceae), along with 1--8--demethylancistrobrevine H (), which is the first naturally occurring naphthylisoquinoline lacking the otherwise generally present methyl group at C-1.

Discovery of the Streptoketides by Direct Cloning and Rapid Heterologous Expression of a Cryptic PKS II Gene Cluster from sp. Tü 6314.

Genome sequencing and bioinformatic analysis have identified numerous cryptic gene clusters that have the potential to produce novel natural products. Within this work, we identified a cryptic type II PKS gene cluster () from sp. Tü 6314.

Ealamines A-H, a Series of Naphthylisoquinolines with the Rare 7,8'-Coupling Site, from the Congolese Liana , Targeting Pancreatic Cancer Cells.

From the twigs and leaves of the Central African liana (Ancistrocladaceae), a series of ten 7,8'-coupled naphthylisoquinoline alkaloids were isolated, comprising eight new compounds, named ealamines A-H (, , -), and two known ones, 6--demethylancistrobrevine A () and yaoundamine A (), which had previously been found in related African species. Only one of the new compounds within this series, ealamine H (), is a typical Ancistrocladaceae-type alkaloid, with 3-configuration at C-3 and an oxygen function at C-6, whereas seven of the new alkaloids are the first 7,8'-linked "hybrid-type" naphthylisoquinoline alkaloids, i.e.

Characterization and Nonenzymatic Transformation of Three Types of Alkaloids from MGR072 and Discovery of Inhibitors of Indoleamine 2,3-Dioxygenase.

The known benzonaphthyridine alkaloid, albogrisin A (), and six new compounds, including two pyrazinone stereoisomers, albogrisin B ()/B' (), together with four 4-pyrroloquinolinones, two diastereoisomers, albogrisin C ()/C' (), and their methyl esters, albogrisin D ()/D' (), were isolated from mangrove-derived MGR072. and are converted into in acidic aqueous solution but into / and / in 0.05% trifluoroacetic acid acetonitrile.

Polyketides from Marine-Derived : Challenges and Opportunities for Determining Absolute Configuration.

Fungal natural products have inspired and enabled countless modern therapeutics. During a survey of the secondary metabolites of endophytic fungi, we found that produces new polyketides with interesting structural features named porosuphenols A-D (, , , and ). The structural elucidation of these metabolites was performed with 1D and 2D NMR techniques, Mosher ester analysis, -based conformational analysis, and isotope exchange studies.

An Unusually Broad Series of Seven Cyclombandakamines, Bridged Dimeric Naphthylisoquinoline Alkaloids from the Congolese Liana Ancistrocladus ealaensis.

A series of seven unusual dimeric naphthylisoquinoline alkaloids was isolated from the leaves of the tropical liana Ancistrocladus ealaensis J. Léonard, named cyclombandakamine A (1), 1-epi-cyclombandakamine A (2), and cyclombandakamines A (3-7). These alkaloids have a chemically thrilling structural array consisting of a twisted dihydrofuran-cyclohexenone-isochromene system.

A novel mba-based Real time PCR approach for genotyping of Ureaplasma parvum validated in a cohort of Mongolian mothers and offspring.

The role of Ureaplasma parvum in abnormal outcomes of human pregnancy has been discussed controversially in the past. Of the 14 known ureaplasma serovars, the Ureaplasma parvum serovars 1, 3, 6 and 14, have been found to derive from smaller genomes. Serovars 3 and 6 have been described more often to cause complications in pregnancy.

Antiprotozoal Spirombandakamines A and A, Fused Naphthylisoquinoline Dimers from a Congolese Ancistrocladus Plant.

From the leaves of a yet undescribed Congolese Ancistrocladus species, two novel naphthylisoquinoline dimers, spirombandakamines A (1) and A (2), were isolated, together with a new, but "classical" dimer, mbandakamine B (3). The cage-like stereostructures of 1 and 2 were established by combining spectroscopic, chemical, and chiroptical methods with quantum-chemical ECD calculations. Their unique molecular frameworks may originate from "open-chain" dimers, such as 3, by an oxidation-induced cascade of reactions.

Jozilebomines A and B, Naphthylisoquinoline Dimers from the Congolese Liana Ancistrocladus ileboensis, with Antiausterity Activities against the PANC-1 Human Pancreatic Cancer Cell Line.

Two new naphthylisoquinoline dimers, jozilebomines A (1a) and B (1b), were isolated from the roots of the Congolese plant Ancistrocladus ileboensis, along with the known dimer jozimine A (2). These compounds are Dioncophyllaceae-type metabolites, i.e.

Metallocorroles as inherently chiral chromophores: resolution and electronic circular dichroism spectroscopy of a tungsten biscorrole.

An inherently chiral metallocorrole has been resolved for the first time by means of HPLC on a chiral stationary phase. For the compound in question, a homoleptic tungsten biscorrole, the absolute configurations of the enantiomers were assigned using online HPLC-ECD measurements in conjunction with time-dependent CAM-B3LYP calculations, which provided accurate simulations of the ECD spectra.

Cyclombandakamines A and A, Oxygen-Bridged Naphthylisoquinoline Dimers from a Congolese Ancistrocladus Liana.

Cyclombandakamines A (1) and A (2), both with an unprecedented pyrane-cyclohexenone-dihydrofuran sequence and six stereocenters and two chiral axes, are the first oxygen-bridged dimeric naphthylisoquinoline alkaloids. They were isolated from the leaves of an as yet unidentified Congolese Ancistrocladus species. Their stereostructures were established by spectroscopic, chemical, and chiroptical methods in combination with DFT and TDDFT calculations.

Vibrational Optical Activity of BODIPY Dimers: The Role of Magnetic-Electric Coupling in Vibrational Excitons.

The vibrational exciton (VE) interpretation of intense bisignated couplets in vibrational circular dichroism (VCD) spectra of a pair of atropisomeric BODIPY (boron dipyrrin) dimers is discussed. The role of intrinsic magnetic moments is crucial to reproduce the different behaviors of quasi-isomeric BODIPY dimers with different aryl junction.

Circularly Polarized Luminescence from Axially Chiral BODIPY DYEmers: An Experimental and Computational Study.

With our new home-built circularly polarized luminescence (CPL) instrument, we measured fluorescence and CPL spectra of the enantiomeric pairs of two quasi-isomeric BODIPY DYEmers 1 and 2, endowed with axial chirality. The electronic circular dichroism (ECD) and CPL spectra of these atropisomeric dimers are dominated by the exciton coupling between the main π-π* transitions (550-560 nm) of the two BODIPY rings. Compound 1 has strong ECD and CPL spectra (g =4×10 ) well reproduced by TD-DFT and SCS-CC2 (spin-component scaled second-order approximate coupled-cluster) calculations using DFT-optimized ground- and excited-state structures.

Trangmolins A-F with an Unprecedented Structural Plasticity of the Rings A and B: New Insight into Limonoid Biosynthesis.

The absolute stereostructures of trangmolins A-F (1-6), limonoids with three new and one known topologies of the rings A and B, were unambiguously determined by NMR spectroscopic investigations, single-crystal XRD analysis, and quantum-chemical electronic circular dichroism calculations. Compounds 1-3 contain a hexahydro-1H-inden-4-one motif, compound 4 comprises a hexahydro-2,6-methanobenzofuran-7-one cage, and compound 5 consists of a hexahydro-2H-2,8-epoxychromene scaffold. The C1-C30 linkage in 1-3 and the C3-C30 connection in 4 form two unprecedented types of ring A/B-fused carbobicyclic cores: viii and ix.

Good Computational Practice in the Assignment of Absolute Configurations by TDDFT Calculations of ECD Spectra.

Quantum-mechanical calculations of chiroptical properties have rapidly become the most popular method for assigning absolute configurations (AC) of organic compounds, including natural products. Black-box time-dependent Density Functional Theory (TDDFT) calculations of electronic circular dichroism (ECD) spectra are nowadays readily accessible to nonexperts. However, an uncritical attitude may easily deliver a wrong answer.

Axial, Helical, and Planar Chirality in Directly Linked Basket-Handle Porphyrin Arrays.

The single-electron oxidative dimerization of basket-handle porphyrins (BHPs) with different coordinated metal ions [Cu(II), Ni(II), Pd(II), Zn(II)] yielded directly meso-meso linked dimers in excellent yields. The synthetic protocol is suited for coupling substrates with different meso-substituents (H, Br, aryl, alkyl) opposite to the coupling site. Experimental findings concerning reactivities and selectivities were in good agreement with theoretical investigations using ALIE calculations.

Singlet oxygen oxidation products of biliverdin IXα dimethyl ester.

Biliverdin IXα is a naturally occurring linear tetrapyrrolic product of the enzymatic oxidative ring cleavage of heme. Evidence is mounting that biliverdin possesses antioxidant properties in mammals but its mode of action is unclear. We present the single crystal X-ray structure analysis of two regioisomeric biladien-1,19-diones-ab that are derived from biliverdin IXα dimethyl ester by addition of two vicinal trans-methoxy groups to the 4,5- or 15,16-double bonds, respectively.

Monomeric Chiral and Achiral Basket-Handle Porphyrins: Synthesis, Structural Features, and Arrested Tautomerism.

Chiral and achiral basket-handle porphyrins (BHPs) with different p-xylene straps and peripheral solubilizing groups were synthesized using a previously established synthetic approach. Subsequent modification, functionalization, and metalation of the tetrapyrrolic macrocycle yielded more than 80 BHPs. The chiral representatives were resolved into their enantiomers, whose absolute configurations were determined by comparison of their ECD spectra with other experimental or quantum chemically calculated spectra.