四倍体及二倍体毛泡桐截干再生特性研究

为掌握人工诱导四倍体毛泡桐保持多倍体特性情况及毛泡桐截干再生特性,笔者以5a生四倍体及二倍体毛泡桐截干再生苗为材料,对截干再生苗的倍性、出芽数、生长速率、叶片特性、叶绿素含量及光合特性等进行研究.结果表明:四倍体毛泡桐截干再生苗能很好地保持其多倍体倍性,相对于二倍体来说,出芽数较少,生长较缓慢;气孔增大,气孔密度降低;...     

2-(2-Phenylethyl)chromone derivatives from Chinese agarwood induced by artificial holing

Three new 2-(2-phenylethyl)chromone derivatives (1–3), together with thirteen known ones (4–16), were isolated from the EtOAc extract of Chinese agarwood induced by artificial holing, originating from Aquilaria sinensis (Lour.) Gilg (Thymelaeaceae). The chemical structures of the new compounds were identified by spectroscopic techniques (UV, IR, MS, 1D and 2D NMR). Compounds 1, 6, 15 and 16 exhibited inhibitory effects on Staphylococcus aureus, and compounds 15 and 16 showed inhibitory effects on Ralstonia solanacearum. Compounds 1–3, 7, 9, 11, 12, 15 and 16 exhibited acetylcholinesterase inhibitory activity. A possible biogenetic pathway of compounds 1–16 was proposed to show the relationships between diepoxy-tetrahydro-2-(2-phenylethyl)chromones, epoxy-tetrahydro-2-(2-phenylethyl) chromones, tetrahydro-2-(2-phenylethyl)chromones, and 2-(2-phenylethyl)chromones of the flidersia type, the four main types of 2-(2-phenylethyl)chromones found in agarwood, on the basis of their appearances in different stage of agarwood formation.     

Effects of Gliricidia sepium (Jacq.) Steud and Leucaena leucocephala (Lam.) de Wit on growth and development of Imperata cylindrica (L.) Raeuschel.

Field studies carried out in a forest transition site on a tropical Alfisol in southwestern Nigeria, show that shading by gliricidia (Gliricidia sepium (Jacq.) Steud) and leucaena (Leucaena leucocephala (Lam.) de Wit) hedgerow species reduced density of speargrass (Imperata cylindrica (L.) Raeuschel) by 67% and 51%, respectively. Shoot biomass of speargrass decreased by 81% and 78% in gliricidia and leucaena hedgerows, respectively. Reduction in speargrass rhizome biomass in gliricidia plots was 96% while rhizome reduction in the leucaena plots was nearly 90%. Rhizome mortality was significantly higher in gliricidia plots than in leucaena and control plots. The bulk of rhizomes was found between 10 cm and 20 cm of soil depth but rhizome did not penetrate further than 30 cm depth in the Alfisol in which this study was carried out. Gliricidia was better than leucaena hedgerow species in suppressing speargrass.     

Screw-nail withdrawal and bonding strength of paulownia (Paulownia tomentosa Steud.) wood

The effects of screw type, moisture content, and grain direction on the screw and nail withdrawal strength and bonding strength were investigated for paulownia (Paulownia tomentosa Steud.) wood grown in Turkey. The withdrawal strength was carried out according to the ASTM-D 143 and ASTM-D 1761 and Turkish Standard 6094 in three directions (tangential, radial, and longitudinal) on 60 samples. The moisture content of half of the samples was 12 % and that of the other half 28 %.The experiment of bonding strength (BS EN 205) was applied to both sanded surfaces jointed by poly-vinly acetate and Desmodur-VTKA adhesives. Results of the tests indicate that, the withdrawal strength values at 12 % moisture content were higher than the 28 % for screws whereas the withdrawal strength for 28 % moisture content was higher than 12 % for nails. The maximum withdrawal strength value was found in the chipboard screw. In the case of directions, the withdrawal strength values of radial direction were found to be higher than the others for all parameters. The lowest withdrawal strength values were found in the longitudinal directions for both nails and screws. For adhesive types, the highest bonding strength of D-VTKA was found to be 5.64 N mm^?2 and it was higher than the bonding strength with PVAc (5.33 N mm^?2). However, there were no significant statistical differences between the two adhesive types. The results show that paulownia wood can be used for different purposes such as house construction, roof systems, and box cases as it possesses enough strength.     

芦苇植株再生体系优化

在前人工作基础上利用禾本科芦苇成熟种子为外植体建立了植株再生体系。芦苇成熟种子经2%洗涤灵溶液洗涤,70%乙醇处理30s,20%＂84＂消毒液处理25min后接种到MS＋4%蔗糖（pH 5.5）的种子萌发培养基中培养,种子萌发率为62%。萌发种子继代至MS＋1mg/L 6-BA＋0.1mg/L 2,4-D＋0.5mg/LNAA＋4%蔗糖（pH 5.5）培养基进行不定芽诱导,不定芽发生率为95%。无根丛生芽继代到不定根诱导培养基1/2MS＋0.5mg/L IBA＋0.5mg/L NAA＋4%蔗糖（pH 5.5）,不定根发生率为90%。     

泡桐(原变种)果实中抑菌性苯丙素苷成分的研究

研究了泡桐(原变种)果实的化学成分。采用Sephadex LH-20柱色谱及薄层色谱等方法进行分离,从其70%丙酮提取物水溶性部分分离得到4种苯丙素苷化合物,经波谱分析及理化性质分析,化合物分别鉴定为:毛蕊花苷(1)、异毛蕊花苷(2)、campneoside II(3)和isocampneoside II(4)。化合物1和2首次从该植物中得到。抑菌活性试验结果表明,泡桐(原变种)果实中分离得到的苯丙素苷化合物、丙酮提取物、乙酸乙酯溶及水溶性部分具有较高的抑菌活性,其中,对革兰氏阳性菌中表皮葡萄球菌的抑制能力最强。     

Three drimane sesquiterpene glucoside from the aerial parts of Dryopteris fragrans (L.) schot

Sesquiterpene glucoside was isolated from the aqueous extract of the aerial parts of Dryopteris fragrans (L.) schot. Three new sesquiterpene glucoside xianglinmaojuesides A–C (1–3), 3β,11-dihydroxy-drim-8 (12)-en-11-O-β-d-glucopyranoside (1), 3β,11-dihydroxy-drim-8(12)-en-3-O-β-d-glucopyranoside (2), and 11,14-dihydroxy-drim-8(12)-en-11-O-β-d-glucopyranoside (3) were finally obtained by reversed-phase HPLC and their structures were elucidated by HRESIMS and 1D, 2D NMR analyses.     

Sesquiterpene lactones from Centaurea musimomum. Antiplasmodial and cytotoxic activities

The chloroform extract of the aerial parts of Centaurea musimomum exhibited significant activity against Plasmodium falciparum. The phytochemical study of this extract gave seven native and four acetylated sesquiterpene lactones.     

New steroids and sesquiterpene from Turraea pubescens

Four new compounds, including three new steroids (1–3) and one new sesquiterpene (6), and two new natural products (4–5), as well as three known steroids (7–9) were isolated from the twigs of Turraea pubescens. Compounds 3–5 are C₂₂ steroids isolated from the Meliaceae family for the first time. Their structures were elucidated by extensive NMR and MS analyses. Compound 1 exhibited inhibitory activity against lipopolysaccharide (LPS) induced nitric oxide (NO) production in RAW264.7 cells with an IC₅₀ value of 11.5 μM.     

Isolation of xanthone and benzophenone derivatives from Cyclopia genistoides (L.) Vent. (honeybush) and their pro-apoptotic activity on synoviocytes from patients with rheumatoid arthritis

A fast and efficient method for the isolation of the C-glucosidated xanthones mangiferin and isomangiferin from the South-African plant Cyclopia genistoides was developed for the first time. The procedure involved extraction, liquid–liquid partitioning with ethyl acetate and subsequent precipitation of mangiferin and isomangiferin from methanol and acetonitrile–water fractions, respectively. Additionally, two benzophenone derivatives: 3-C-β-glucosides of maclurin and iriflophenone, were isolated from C. genistoides extracts using semi-preparative HPLC. Apart from the above, the isolation procedure also yielded hesperidin and small amounts of luteolin. The structures of the compounds were determined by 1D and 2D NMR experiments and/or LC-DAD-ESI–MS. The selected Cyclopia constituents were screened for pro-apoptotic activity on TNF-α-stimulated synovial cells isolated from rheumatoid arthritis patients. The strongest effect, measured as percent of apoptotic cells, was recorded for isomangiferin (75%), followed by iriflophenone 3-C-β-glucoside (71%), hesperidin (67%) and mangiferin (65%). The results are encouraging for further studies on the use of the above compounds in the treatment of rheumatoid arthritis.     

Chemical composition and antimicrobial activity of the essential oil from Ferula glauca L. (F. communis L. subsp. glauca) growing in Marche (central Italy)

The essential oil obtained from different parts of Ferula glauca L. (formerly considered as a subspecies of F. communis) growing in Marche (central Italy), was analyzed for the first time by GC-FID and GC-MS. The major volatiles were (E)-caryophyllene and caryophyllene oxide in leaves, alpha-pinene, myrcene and germacrene D in flowers, alpha- and beta-pinene in fruits, (E)-beta-farnesene, myristicin and elemicin in roots, respectively. The differences in composition detected with respect to F. communis, made the volatile fraction a reliable marker to distinguish between them, and confirm the botanical data at the base of their discrimination. Furthermore, the oil was assayed for its antimicrobial activity by the broth microdilution method. B. subtilis was found to be the most sensitive microorganism, with the lowest MIC values.     

Sesquiterpene lactones from Sonchus arvensis L. and their antibacterial activity against Streptococcus mutans ATCC 25175

Two new sesquiterpene lactones, 1β-sulfate-5α, 6βH-eudesma-3-en-12, 6α-olide (1) and 1β-(p-hydroxyphenyl acetyl)-15-O-β-d-glucopyranosyl-5α, 6βH-eudesma-3-en-12, 6α-olide (2) were isolated from Sonchus arvensis L. (Asteraceae), together with eight known compounds. Their structures were elucidated through spectroscopic and chemical methods. They were evaluated for antibacterial activity. Among them, compounds 1 and 7 exhibited antibacterial activity against oral pathogen Streptococcus mutans ATCC 25175 with MIC values of 15.6 and 62.5 µg/ml, respectively.     

New sources and antifungal activity of sesquiterpene lactones.

In the search for new sources of sesquiterpene lactones, six Centaurea species have been analyzed. The activity against the fungus Cunninghamella echinulata of (+)-cnicin (1) and (+)-salonitenolide (2), isolated from the Centaurea plants, as well as that of (+)-costunolide (3), (-)-dehydrocostuslactone (4), (-)-lychnopholide (5) and (-)-eremantholide C (6), has been evaluated. Compounds 3 and 4 showed noticeable EC50 values, whilst more polar lactones were inactive. These results suggest that a relatively low polarity is one of the molecular requirements for the antifungal activity of sesquiterpene lactones.     

Limonoids and phytol derivatives from Cedrela sinensis.

Two new compounds, cedrellin (1) and 2,6,10,15-phytatetraene-14-ol (2), together with five known compounds, 7 alpha-obacunyl acetate, 6-acetoxyobacunol acetate, 7 alpha-acetoxydihydronomilin, 2,6,10-phytatriene-1,14,15-triol and phytol were isolated from leaves of Cedrela sinensis. Their structures were elucidated on the basis of combined one- and two-dimensional spectral techniques.     

千层塔中石杉碱甲提取分离工艺研究

利用单因素法和正交试验设计,确定了从千层塔中提取石杉碱甲的最佳工艺条件为:乙醇体积分数80%,料液比1:25(g:mL),提取时间3 h,提取温度60℃;最佳分离条件为:D101树脂吸附,80%乙醇室温下洗脱,总收率0.3%,纯度可达10%.     

无梗五加果多糖与黄酮类化合物的研究

采用薄层色谱法对树脂纯化后的无梗五加果总黄酮进行了研究,表明以聚酰胺为固定相、微乳液为展开剂进行薄层层析鉴定效果最好,共分得9个组分.各种层析条件下的Rf值分析表明,无梗五加果中含药用成分金丝桃苷,未发现芦丁和槲皮素.采用HPLC法对经脱色、脱蛋白、DEAE52纤维素柱层析得到的主要多糖组分ASP-Ⅰ、ASP-Ⅱ进行单糖组成和纯度、相对分子质量(Mr)测定,表明无梗五加果多糖单糖组成为甘露糖、氨基葡萄糖、鼠李糖、葡萄糖醛酸、半乳糖醛酸、葡萄糖、半乳糖、木糖及岩藻糖,主要由Mr为21 800、147 000、45 400和18 100的4种均一多糖组成;其中,均一多糖ASP-Ⅰ由半乳糖和鼠李糖组成,物质的量之比为1∶0.7,Mr为18 100.对水提醇沉后得到的无梗五加果多糖进行生物活性研究表明,其具有抗疲劳和耐缺氧的能力.     

Presence of longitudinal cracks in planks from storm-felled pine (Pinus sylvestris L.) and spruce (Picea abies (L.) Karst.)

Abstract

After the severe storm Gudrun in southern Sweden in 2005, a quantitative study was done in order to investigate the presence of lengthwise crack on planks taken from storm-felled trees in southern Sweden, compared to planks from standing trees not subjected to this storm (central Sweden). The main yield from each log was examined. In total, 1087 pine (Pinus sylvestris) planks and 3626 spruce (Picea abies) planks from the storm-struck area were investigated and compared to 1953 spruce and 2000 pine planks from trees outside the storm-struck area. The examination of cracks was done visually on dried planks. For pine, 51.7% of the planks from storm-felled trees had a total length longer than 0.5 m, compared to 7.3% for the reference material. As for spruce, 11.0% of the planks from storm-felled trees had a total crack length of more than 0.5 m, compared to the reference material where 2.2% had cracks longer than 0.5 m. The results show that the storm-felled trees had more longitudinal cracks than the reference material and that pine was more likely to develop storm-related cracks than spruce.     

Sesquiterpene lactones from Mikania micrantha and Mikania cordifolia and their cytotoxic and anti-inflammatory evaluation

The guaianolide 8-epi-mikanokryptin (1) and the melampolide 11Hβ-11,13-dihydromicrantholide (2) along with known sesquiterpene lactones (3–13) and other constituents were isolated from the aerial parts of different populations of Mikania micrantha and Mikania cordifolia collected in several states of Mexico. The relative and absolute configurations of 1 were determined by X-ray diffraction and CD analysis, respectively. Considering the ¹H and ¹³C NMR chemical shift similarities and the H–H coupling constant values, a [¹D¹⁴, ¹⁵D₅] conformation was established for micrantholides (2, 8–13). We tested nearly all the sesquiterpene lactones for antiproliferative activity in human cancer cell lines, and they exhibited moderate activity. Additionally, in a mouse ear model of edema induced by TPA, the anti-inflammatory activities were marginal.     

橄榄多酚的提取研究

利用溶剂浸提法、超声波辅助提取法和微波辅助提取法对橄榄中的多酚物质进行提取研究,并比较了3种方法的提取效果。结果表明:以1g橄榄果肉粉为原料,60%~70%丙酮水溶液是提取橄榄多酚的最适溶剂,最佳提取时间1h,温度20~30℃,固液比1∶20(g∶mL);超声波提取的最适功率为80W,最佳提取时间25min;微波提取的最适功率为280W,提取时间5s。3种提取方法的多酚提取得率分别为17.1%、19.3%和20.3%,与溶剂浸提法相比,超声波法和微波法提取时间短、效率高,提取效果明显优于前者,并且三者提取物的UV和HPLC检测图谱完全一致。     

Alley cropping with Leucaena leucocephala (Lam.) De Wit and Acioa barteri (Hook.f.) Engl.

The effect of alley cropping with seven combinations of Acioa and Leucaena hedgerows and a control (no hedgerow) treatment on sequentially cropped maize and cowpea was studied in 1985 and 1986. The trial was carried out on an Alfisol in the humid zone of southwestern Nigeria. Hedgerows were established in 1983, using 4 m inter-hedgerow spacing and pruned to 25 cm height during cropping. Highest dry matter, wood, and nutrient yields of prunings of Acioa and Leucaena hedgerows were obtained with sole cropping. Growing Leucaena and Acioa in the same hedgerow suppressed dry matter production and nutrient yield of Acioa more than of Leucaena owing to the latter's faster growth. Total pruning dry matter yield was reduced as the proportion of Acioa increased in the combination. Leucaena prunings had higher nutrient yield than Acioa. Under 22-month old uncut hedgerows, weed biomass declined in the presence of Leucaena, either alone or in combination with Acioa. Weed weight under sole Leucaena hedgerows was about a third of that in the control plot. There was no significant effect of alley cropping on weed biomass, although alley cropping with Acioa and Leucaena hedgerows resulted in the dominance of broadleaf weeds while the control had a mixture of broadleaves and grasses. Alley cropping with various combinations of Acioa and Leucaena hedgerows increased maize and cowpea yields compared to control. Nitrogen application in both years increased maize grain yield. Mean yield increase due to N application in both years was highest in the control (47.2%) followed by the sole Acioa hedgerow (25.2%) and less in hedgerows with Leucaena. The results of observations over two years do not show any advantage for the tested Leucaena and Acioa combinations on maize and cowpea crops as compared to the sole hedgerows. B.T. Kang (IITA), c/o Miss Maureen Larkin