Bazzanane sesquiterpenoids from the New Zealand liverwort Frullania falciloba

Two new bazzanane-type sesquiterpenoids have been isolated from the New Zealand liverwort Frullania falciloba. Their structures were confirmed by NMR and CD spectroscopy and chemical reactivity.     

Diterpenoids and aromatic compounds from the three New Zealand liverworts Jamesoniella kirkii, Balantiopsis rosea, and Radula species

Three new aromatics were isolated from the New Zealand liverwort Balantiopsis rosea. A new bibenzyl was isolated from an unidentified Radula species, together with known bibenzyls. Jamesoniella kirkii yielded three known ent-isopimarane and two ent-kaurane diterpenoids. Their structures were confirmed by NMR techniques, chemical reaction, and X-ray crystallographic analysis.     

Rh‐Catalyzed Direct Carboxylation of Alkenyl C−H Bonds of Alkenylpyrazoles

The Rh‐catalyzed direct carboxylation of alkenyl C?H bonds was achieved by using pyrazole as a removable directing group. In the presence of 5 mol% RhCl₃ ? 3H₂O, 6 mol% P(Mes)₃, and 2 equiv. of AlMe₂(OMe), the alkenyl C?H bond of various alkenylpyrazoles was directly carboxylated in good yields under CO₂ atmosphere. Furthermore, several useful transformations of the pyrazole moiety of the product were achieved to afford synthetically useful carboxylic acid derivatives in good yields.     

Synthesis of a highly transparent poly(o‐hydroxyamide) in the i‐line region and its application to photosensitive polymers

A novel poly(σ‐hydroxyamide) (PHA) based photosensitive polymer that exhibits high transparency at 365 nm wavelength (i‐line) has been developed. Time‐dependent density functional theory (TD‐DFT) calculations using the B3LYP hybrid functional were performed to predict the transparencies of various hydroxyamides in the i‐line region. Based on the calculations, 4,4′‐sulfonylbis(σ‐aminophenol) (SAP) was prepared and polymerized with 4,4′‐oxybis(benzoyl chloride) (OBBC), and the resulting PHA, which is abbreviated as PHA‐S, showed a high transparency comparable to that of PHA derived from 4,4′‐(hexafluoroisopropylidene)bis(σ‐aminophenol). Positive‐type photosensitive PHA was then formulated based on PHA‐S with a crosslinker 1,3,5‐tris[(2‐vinyloxy)ethoxy]benzene (TVEB) and a photoacid generator (5‐propylsulfonyloxyimino‐5H‐thiophen‐2‐ylidene)‐2‐(methylphenyl)acetonitrile (PTMA) (17:3:1 in weight ratio), and demonstrated photosensitivity and contrast of 14 mJ/cm² and 2.7, respectively, when the resist film was prebaked at 120 °C for 5 min, irradiated by i‐line, post exposure baked at 120 °C for 5 min, developed with an 2.38 wt% TMAH solution for 5 s. A clear positive image featuring 10‐μm line‐and‐space was also printed in a film which was exposed to 50 mJ/cm² of i‐line by contact‐printing. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2527–2535, 2005     

Cytotoxic bibenzyls, and germacrane- and pinguisane-type sesquiterpenoids from Indonesian, Tahitian and Japanese liverworts

Cytotoxic bibenzyls, and germacrane- and pinguisane-type sesquiterpenoids have been isolated from unidentified Indonesian and Tahitian Frullania sp. and Japanese Porella perrottetiana by using a combination of chromatographic methods. The structure activity relationship (SAR) study showed that the presence of a phthalide group in bibenzyls, an alpha-methylene-gamma-lactone in germacrane-type sesquiterpenoids, and beta-hydroxycarbonyl in pinguisane-type sesquiterpenoids play an important role in providing cytotoxic activity against both human promyelocytic leukemia (HL-60) and human pharyngeal squamous carcinoma (KB) cell lines. The structure of each isolated compound was elucidated by using spectroscopic methods and the cytotoxicity was determined by using the WST-8 colorimetric assay.     

Chemosystematics of Porella (Marchantiophyta, Porellaceae)

The taxonomy of the liverwort genus Porella based on plant morphology has been regarded as difficult. Recent DNA-based studies have brought new insights into the systematics of these liverworts and have uncovered some novel relationships that allowed the resolution of controversial treatments based on morphology. One of the outstanding features of these plants, in addition to their form, is their chemical composition, which is characterized by great diversity of secondary metabolites. In this paper the sesqui- and diterpenoids occurring in Porella species are described and their chemosystematic relevance is explored. On the basis of chemical data, the Porella species have been divided into six chemotypes: the drimane- (I), sacculatane- (II), pinguisane-sacculatane- (III), guaiane-germacrane- (IV), pinguisane- (V) and africane- (VI) types. Species belonging to type I are characterized by their hot taste, whereas the other chemotypes are comprised of non-pungent species. Consideration of recent DNA data shows striking correlations between molecular groups and their terpenoid chemistry. The chemical data suggest that the P. vernicosa complex (chemotype I) deserves recognition as a separate section of Porella and that terpenoids are important chemosystematic markers in the family Porellaceae.     

Preparation of long-afterglow colloidal solution of Sr2MgSi2O7: Eu, Dy by laser ablation in liquid

We have successfully prepared a novel nanoparticle solution of Sr₂MgSi₂O₇: Eu²⁺, Dy³⁺ with afterglow properties by means of laser ablation in liquid. This process also produced by-products of different kinds, depending on the liquid used. The amount of by-product and the size of the nanoparticles were controlled by the energy density of laser ablation. The amount of by-product was reduced by a decrease in the energy density, which also decreased the particle size of the nanoparticles. The PL spectrum of the nanoparticles was the same as that of the target materials used for laser ablation. The afterglow properties deteriorated with a decrease in particle size. We concluded that an increase in specific surface area caused by a decrease in particle size resulted in the decrease of luminescent intensity.     

An FEM identification procedure for a wing section within a class of finite Laurent series

This paper concerns a determination procedure for conformal mapping of a wing through a finite element computation of potential function associated with the flow of 2-dimensional perfect fluid around the given wing section. Through our numerical procedure a family of mappings is obtained in the forms of finite Laurent series for an initial wing section input. Each member of the family describes a wing section located in a neighboring domain of the input one. Some of them could be expected as modified versions of the original wing section input, although they could not recover completely it.Inputting the shape of wing section has ambiguity in practical cases of wing sections such as the NACA23012 wing section. We would like to postulate that our identification procedure should be employed in the determination process of numerical profiles of the wing section considered, since identified ones are significantly easier in numerical processing than the original input shape.     

Volatile components of selected liverworts, and cytotoxic, radical scavenging and antimicrobial activities of their crude extracts

Crude extracts of the Tahitian liverworts Mastigophora diclados and Frullania sp., the Indonesian Frullania sp., Dumortiera hirsuta and Marchantia sp., and the Japanese Porella perrottetiana were investigated chemically by using gas chromatography-mass spectrometry (GC-MS). All extracts contained various volatile sesqui- and diterpenoids and a few aromatic compounds. The Tahitian M. diclados and Frullania sp., and the Indonesian Frullania sp. exhibited cytotoxic activity against HL-60 and KB cell lines. The extracts of the Tahitian M. diclados and the Indonesian Marchantia sp. showed radical scavenging activity, whereas the crude extracts of the Tahitian M. diclados and Frullania sp., and the Indonesian Frullania and Marchantia sp. showed antimicrobial activity against Staphylococcus aureus and Bacillus subtilis.