Identification of a nuclear localization motif in the serine/arginine protein kinase PSRPK of physarum polycephalum

Background  

Serine/arginine (SR) protein-specific kinases (SRPKs) are conserved in a wide range of organisms, from humans to yeast. Studies showed that SRPKs can regulate the nuclear import of SR proteins in cytoplasm, and regulate the sub-localization of SR proteins in the nucleus. But no nuclear localization signal (NLS) of SRPKs was found. We isolated an SRPK-like protein PSRPK (GenBank accession No. DQ140379) from Physarum polycephalum previously, and identified a NLS of PSRPK in this study.     

Crocipodin, a benzotropolone pigment from the mushroom Leccinum crocipodium (Boletales)

Crocipodin, an unusual benzotropolone pigment, has been isolated from the fruit bodies of the mushroom Leccinum crocipodium. Its structure was determined by spectroscopic methods, particularly 2D NMR spectroscopy. The structure was confirmed by total synthesis, starting from 4-bromocatechol and gallic acid.     

Necatorone,an alkaloidal pigment from the gilled toadstool lactarius necator (agaricales)

Necatorone, an alkaloid possessing an unusual 5,10-dihydroxydibenzo [de,h] [1,6] naphthyridin-6-one structure has been isolated from fruit-bodies of the toadstool $\text{Lactarius necator}$.     

Rufoolivacin B,a novel polyketide pigment from the fruiting bodies of the fungus Cortinarius rufo-olivaceus(basidiomycetes)

A novel polyketide pigment(1) with the 4',10-coupled linkage between 1-naphthalenol and 1,4-anthraquinone,named rufoolivacin B together with the known analog rufoolivacin(2),has been isolated from the fruiting bodies of the Chinese toadstool Cortinarius rufo-olivaceus(basidiomycetes).Their structures were characterized by means of analysis of spectroscopic methods,including 2D-NMR experiments and HR-ESI-MS.     

Laetiporic acid, a new polyene pigment from the wood-rotting basidiomycete Laetiporus sulphureus (Polyporales, Fungi)

A new pigment, laetiporic acid, has been isolated from fruit-bodies of the wood-rotting fungus Laetiporus sulphureus (sulfur shelf). Structure elucidation by application of extensive 2D NMR techniques permitted its identification as a polyene of non-isoprenoid origin. Laetiporic acid, which represents the main pigment in L. sulphureus basidiocarps, bears an unprecedented decaene skeleton as part of its chromophore and, interestingly, contains double bonds with a stable cis configuration.     

A guaianolide pigment from a deep sea gorgonian

Yellow pigment 3 is one of the minor constituents of a deep sea gorgonian, Placogorgia sp.     

Light irradiation induces fragmentation of the plasmodium, a novel photomorphogenesis in the true slime mold Physarum polycephalum: action spectra and evidence for involvement of the phytochrome

A new photomorphogenesis was found in the plasmodium of the true slime mold Physarum polycephalum: the plasmodium broke temporarily into equal-sized spherical pieces, each containing about eight nuclei, about 5 h after irradiation with light. Action spectroscopic study showed that UVA, blue and far-red lights were effective, while red light inhibited the far-red-induced fragmentation. Difference absorption spectra of both the living plasmodium and the plasmodial homogenate after alternate irradiation with far-red and red light gave two extremes at 750 and 680 nm, which agreed with those for the induction and inhibition of the fragmentation, respectively. A kinetic model similar to that of phytochrome action explained quantitatively the fluence rate-response curves of the fragmentation. Our results indicate that one of the photoreceptors for the plasmodial fragmentation is a phytochrome.     

Cribrarione A, a new antimicrobial naphthoquinone pigment from a myxomycete Cribraria purpurea

Cribrarione A (1), a new dihydrofuranonaphthoquinone pigment with antimicrobial activity against Bacillus subtilis has been isolated from a myxomycete Cribraria purpurea and its structure was elucidated by spectral data. The ¹H-¹³C long-range couplings through an intramolecular hydrogen bond were clearly observed in the HMBC spectrum of 1.     

Novel acyl alpha-pyronoids, dictyopyrone A, B, and C, from Dictyostelium cellular slime molds

For the elucidation of the diversity of secondary metabolites of Dictyostelium cellular slime molds, we investigate the constituent of three species of slime molds. From the methanol extract of their fruit bodies, we obtained three novel compounds, dictyopyrone A (1) and B (2) from D. discoideum and D. rhizoposium and dictyopyrone C (3) from D. longosporum. They possess a unique alpha-pyrone moiety with a side chain at the C-3 position. Their relative structures were elucidated by spectral means, and the absolute configuration was confirmed by asymmetric synthesis of 1. Since these compounds were obtained from different species of Dictyostelium slime molds, they may be a type of compound common to this genus.     

NMR structure characterization of a new vinylpyranoanthocyanin-catechin pigment (a portisin)

A new polyphenolic compound, the structure of which corresponds to a pyranomalvidin-3-glucoside linked to a (+)-catechin unit through a vinyl linkage, has been characterized by UV-vis, MS and NMR spectroscopy. This compound was obtained in an aqueous alcoholic solution from the reaction between a malvidin-3-glucoside-pyruvic acid derivative and (+)-catechin in the presence of acetaldehyde.     

Hinnuliquinone,a bis-indolyl-2,5-dihydroxybenzoquinone pigment from nodulisphorium hinnuleum

A pigment, hinnuliquinone, isolated from the fungus $\text{Nodulisporium}$$\text{hinnuleum}$, has been shown to be 2,5-bis-[2-(1,1,-dimethyl-2-propenyl)1H-indol-3-yl-]-3,6-dihydroxy-2,5-cyclohexadiene-1,4-dione and to be biosynthesized from tryptophan and mevalonic acid.     

Polycephalin B and C: Unusual Tetramic Acids from Plasmodia of the Slime Mold Physarum polycephalum (Myxomycetes)

Illumination results in increased formation of metabolites 1 and 2 in the plasmodia of the slime mold Physarum polycephalum. This was determined from HPLC studies undertaken in the search for the photoactive substances involved in the “blue-light phenomenon”. The isolation and structure elucidation of 1 and 2 is described.     

Inophyllin A, a new pyranoxanthone from Calophyllum inophyllum (Guttiferae)

In the authors' continuing search for new natural products, their recent studies on the roots of Calophyllum inophyllum (Guttiferae) have yielded a new prenylated pyranoxanthone, Inophyllin A together with the common triterpenes friedelin and stigmasterol. Structural elucidations of these compounds were achieved through (1)H, (13)C, DEPT, COSY, HSQC and HMBC experiments. The molecular mass was determined using MS techniques. The authors report here the isolation of and structural elucidation for Inophyllin A as well as its toxicity test result. The discovery of this new natural product from the unexploited Malaysian forest will certainly contribute to the search for potential natural larvicides.     

Cypripediquinone A, a new phenanthraquinone from Cypripedium macranthum (Orchidaceae)

Cyprlpedium macranthum SW. is widely distributed in northeast and southwest of China.As a Chinese folk herb medicine, Its rhizome and the whole plant are used to treat edema,bacillary dysentery, headache and epilepsy. No phytochemical investigation of thisspecies has so far been repofted. During the course of our study on the constituents ofthis plant in order to obtain a more comprehensive understanding of its effectiveconstituents, a new 9, 10- phenanthraquinone l, was isolated from the C…     

Phyllofenone A, a New Scalarane Sesterterpene from the Sponge Phyllospongia Foliascens(Pallas)

The present paper covers the structure of a new sesterterpene, phyllofenone A(1) , isolated from the South China Sea sponge Phyllospongia foliascens. Phyllofenone A is a member of the scalarane class of sesterterpenes with a (C-20, C-24)-bishomo-(C-25)-nortetra-cyclic skeleton. The structure charcterization was based on one- and two-dimensional NMR and mass spectroscopy with the assistance of molecular modeling. Phyllofenone A shows weak antifungal activity against Candida pseudotropicalis.     

Investigations towards the synthesis of xylindein,a blue-green pigment from the fungus Chlorociboria aeruginosa

An approach towards the synthesis of the fungal pigment xylindein 1 is described. Synthesis of the pyranonaphthoquinone corresponding to one half of the xylindein framework is achieved over 11 steps from 1,2-epoxypentane, utilizing multiple Diels–Alder cycloaddition processes. Methods for self-coupling of dihydroxynaphthoquinones to give extended quinones are explored.