Three New Polyoxygenated Steroids from Two Species of the South China Sea Gorgonian Muricella flexuosa and Menella verrucosa Brundin

Three new polyoxygenated steroids, muricesteroid ( 1 ), and menellsteroids A ( 2 ) and B ( 3 ), were isolated from two species of the South China Sea gorgonian Muricella flexuosa and Menella verrucosa Brundin , respectively. The structures of these new compounds were elucidated on the basis of extensive spectroscopic analysis, chemical methods and comparison with known related compounds.     

Surface area of papermaking woodpulps used by the British paper industry

The surface area was determined for various papermaking woodpulps: bleached eucalyptus globulus sulphate pulp; bleached eucalyptus grandis sulphate pulp; bleached betula verrucosa sulphate pulp; bleached pine/spruce sulphate pulp; bleached pine/spruce sulphate pulp fines. The method of negative adsorption was used which gives an effective wet surface area. By looking at negative adsorption data more closely, some inference can be made about the morphology of the substrate.Glossary of symbols B (e²/2kT)^1/2 - ¯C concentration of fibre per unit volume of pulp - 1 - ¯¯c - h angle between pore and the axis of the bed in a permeable material - K permeability coefficient - k Boltzmann constant - k ₀ shape factor for pores in a permeable material - n _i concentration of co-ion in the bulk solution - n _i experimentally observed increase in concentration of co-ion in the bulk solution - S surface area - S _t wS - S ₀ surface area per unit volume of permeable material - V _t total volume of solution - V excluded volume - V _s excluded volume accessible to water but not to ions - V _obs experimentally observed excluded volume - w weight of dry fibre - ¯ effective volume of fibres in a permeable pad - surface potential at outer Helmholtz plane     

三亚鹿回头海域疣状杯形珊瑚反射率光谱分析

珊瑚礁地物光谱特征是珊瑚礁遥感研究的理论基础,可以作为遥感定性和定量研究珊瑚礁的依据。采用我国南海三亚湾鹿回头海域的优势物种疣状杯形珊瑚(Pocillopora verrucosa)为研究对象,用光纤光谱仪测量其反射率光谱。利用珊瑚反射率光谱和导数分析的方法研究了健康和白化两种状态下疣状杯形珊瑚的反射率光谱的差异。研究分析的结果显示:健康疣状杯形珊瑚的反射率光谱,在波长580,604.7和647 nm处出现了特征波峰,在波长669 nm处出现一个显著的波谷;白化疣状杯形珊瑚的反射率光谱明显高于健康疣状杯形珊瑚的反射率光谱,但是其波形相对较为平缓,在波长663 nm处存在一个相对较弱的波谷。反射率光谱导数分析发现健康与白化疣状杯形珊瑚存在多个可区分波段,其中主要可区分波段包括:一阶导数,404~425,456~466,513~532,563~568和661~667 nm等;二阶导数,408~420,542~556,563~573,615~634和687~695 nm等;四阶导数,402~418,466~472,478~481,617~622和684~689 nm等。     

Further Highly Oxygenated Guaiane Lactones from the South China Sea Gorgonian Menella sp.

Four new highly oxygenated guaiane lactones, 1‐epimenverin B ( 1 ), menverin F ( 2 ), 1‐deoxymenverin F ( 3 ), and menverin G ( 4 ), together with the two known related analogues menverins B ( 5 ) and C ( 6 ), were isolated from the South China Sea gorgonian Menella sp. Their structures and relative configuration were elucidated by analysis of spectroscopic data and by comparison with those of known related compounds.     

Menverins H–L,New Highly Oxygenated Guaiane Lactones from the Gorgonian Coral Menella kanisa

By further chemical investigation of South China Sea gorgonian Menella kanisa, five new highly oxygenated guaiane lactones, menverins H–L ( 1 – 5 , resp.), were obtained. Their structures were established by employing spectroscopic methods, computer modeling, and comparison of their data with those of related metabolites.     

A new sesquiterpene from the gorgonian coral Menella sp.

A new sesquiterpene named menecubebane B (1) and a known analogue (2) were isolated from the gorgonian coral Menella sp. Their structures were elucidated by the extensive analyses of spectroscopic data and by the comparison with related literature. Cytotoxic effect against both Eca9706 and HeLa cell lines was evaluated, revealing 1 exhibited moderate cytotoxicity against the two cell lines involved with IC₅₀ values being 20.8 and 30.6 μM, respectively.     

Capillary electrophoresis in allergen preparation research and in production control

A CE method has been developed for the analysis of wasp venoms and pollen extracts of Phleum pratense and Betula verrucosa. Various electrolyte systems can be used but the best separation and reproducibility are attained in 0.15 mol/l phosphoric acid, pH 1.8. UV photometric detection at 190 nm is sufficiently sensitive for determination of the polypeptides and glycoproteins contained in these materials (the detection limit for phospholipase A₂ is 0.4 ng). The allergens from wasp venoms and pollen extracts yield characteristic electropherograms which can be used for control of the allergen production. Modification of capillary wall with poly(ethylhydroxy methacrylate) causes a decrease in the migration times and the separation efficiency is retained.