sp. nov. (Bacillariophyta) from the Yongle River in Hunan Province, China.

A new species, Bing Liu & Rioual, , found in the Yongle River, a tributary of the Xiang River (Hunan Province, southern China) is described on the basis of morphological observations made under light and scanning electron microscopes. is distinguished from other taxa by a unique combination of characters that includes its lanceolate valve outline with rostrate apices, sternum gradually becoming wider from valve apices to center, and a greater valve width than the other members of the genus. inhabits the epilithic community in the headwaters of a freshwater river.

Semisynthesis and antitumor activity of endertiin B and related triterpenoids from .

, a fungus used in traditional Chinese medicine, is known for its medicinal value attributed to its active components called triterpenoids (GTs). However, the limited isolation rate of these GTs has hindered their potential as promising drug candidates. Therefore, it is imperative to achieve large-scale preparation of GTs.

A new picrotoxane-type sesquiterpene from Dendrobium findlayanum.

A new picrotoxane-type sesquiterpene, findlayanin (1), was isolated from Dendrobium findlayanum with crystallinin (2). The structure of compound 1 was established to be (1R,2S,3R,4S,5R,6S,9R)-2,3,11,12-tetrahydroxypicrotoxan-12(15)-lactone by spectroscopic methods.

Six new induced sesquiterpenes from the cultures of ascomycete Daldinia concentrica.

Six new sesquiterpenes having the botryane carbon skeleton (1-6), together with known compounds (7-10) were induced and isolated from the ascomycete Daldinia concentrica (strain S 0318). Structures elucidation was accomplished by NMR spectroscopic and X-ray crystallographic studies.

Induced daldinin A, B, C with a new skeleton from cultures of the ascomycete Daldinia concentrica.

Daldinin A, B, C with a new skeleton, together with four known compounds, were induced and isolated from cultures of the ascomycete Daldinia concentrica. Their structures were elucidated by spectroscopic analysis, and that of daldinin A was confirmed by single-crystal X-ray diffraction.

[Effects of PBD on the luminescence properties of PVK: Ir(ppy)3].

The effects of PBD on the luminescence properties of PVK : Ir(ppy)3 codoped with PBD with lower concentration were investigated. Two kinds of devices with the structures of ITO/PVK : Ir(ppy)3/PBD/Al and ITO/PVK : Ir(ppy)3 : PBD/ Al were fabricated. PVK emission appears in the electroluminescence (EL) spectra of ITO/PVK : Ir(ppy)3/PBD/Al.

New phenyl-ethanediols from the culture broth of Boletus edulis.

A new phenyl-ethanediol, (1S)-(4-acetylphenyl)-1, 2-ethanediol (1), and a new natural product, (1S)-(3-ethenylphenyl)-1, 2-ethanediol (2), were isolated from the culture broth of the basidiomycete Boletus edulis together with three related known compounds, 1-(4-ethylphenyl)-1, 2-ethanediol (3), 1-(3-ethylphenyl)-1, 2-ethanediol (4) and 1-(3-formylphenyl)-ethanone (5). Their structures were elucidated by spectroscopic methods including extensive 2D-NMR techniques.

Antioxidant activities of three dihydrochalcone glucosides from leaves of Lithocarpus pachyphyllus.

In vitro antioxidant activities of three sweet dihydrochalcone glucosides from the leaves of Lithocarpus pachyphyllus (Kurz) Rehd. (Fagaceae), trilobatin 2"-acetate (1), phloridzin (2) and trilobatin (3), were investigated. The IC50 (50% inhibitory concentration) values for compounds 1-3 of lipid peroxidation in rat liver homogenate were 261, 28, 88 microM, respectively.

Natural aromatic steroids as potential molecular fossils from the fruiting bodies of the ascomycete Daldinia concentrica.

The identification of aromatic steroid hydrocarbons bearing a methyl group at positions 1, 2, 3, 4, or 6 in sediments and petroleum has been puzzling since possible steroidal precursors have not yet been reported in living organisms. Two new aromatic steroids, (17beta,20R,22E,24R)-19-norergosta-1,3,5,7,9,14,22-heptaene (1) and (17beta,20R,22E,24R)-1-methyl-19-norergosta-1,3,5,7,9,14,22-heptaene (2), were isolated from the ascomycete Daldinia concentrica, of which compound 2 bears an unusual methyl group at position 1. We propose that the origin of these compounds is derived from the transformation undergone by their precursor due to microbial action.

A new sweet dihydrochalcone-glucoside from leaves of Lithocarpus pachyphyllus (Kurz) Rehd. (Fagaceae).

A new sweet dihydrochalcone-glucoside, trilobatin 2"-acetate (1), was isolated from the leaves of Lithocarpus pachyphyllus, together with phlorizin and trilobatin. The structures were established by spectroscopic methods, including one- and two-dimensional NMR (COSY, HMQC and HMBC).