Spatio-temporal distribution pattern of the red band-fish Cepola rubescens Linnaeus at different stages of its life cycle in the northwestern Mediterranean

The larvae of Cepola rubescens Linnaeus, 1766 were collected from May to October with a surface temperature of 17.5°C at the beginning of the spawning. They were widely distributed over the continental shelf and the greatest concentrations were found at stations with depth around 100 m. During all months, most of the larvae were of small size, between 2.0 and 3.0 mm s.l . The juveniles and adults were caught in a wide range of depths, from less than 25 m to about 200 m, and the highest abundance was also found at depths of about 100 m, but no large individuals were found at depths less than 50 m. The catches of the trawling fleet showed a marked seasonality, with maximum values at the end of spring and minimum at the end of autumn and the beginning of winter. This seasonality seems to be related to reproduction since the highest catches were obtained during the spawning period.     

Stratification by cyanobacteria in lakes: a dynamic buoyancy model indicates size limitations met by Planktothrix rubescens filaments

The ability of the Planktothrix rubescens to stratify in Lake Zürich is related to the size and shape of the cyanobacterial filaments. Detailed measurements made in the lake are used in a dynamic computer model of buoyancy regulation to investigate the vertical movements of filaments tracking the depth at which the irradiance would support neutral buoyancy. The movement of the filament lags behind the constantly changing target depth owing to (a) the time taken for the filament to respond to the irradiance by changing its density and (b) the time it takes to move by sinking down or floating up through the water column. The model simulates the stratification depth over a 5-month period of the summer from the continuous measurements of irradiance and weekly measurements of light attenuation and temperature, without any further adjustment over the period. Models using filaments of the size observed in Lake Zürich explain several details of the observed depth changes: smaller planktonic cyanobacteria (e.g. Limnothrix sp.) are unable to migrate fast enough and larger ones (e.g. Anabaena spp.) will overshoot and become entrained in the epilimnion. The model can be used to simulate recruitment of Planktothrix filaments from different depths after vernal stratification. Recruitment of filaments from depths down to 45 m will contribute to the metalimnetic population increase in early July.     

Ent-Kaurene Diterpenoids from Rabdosia eriocalyx

Two new named maoecrystal F(1) and G(2) and seven known ent-kaurene diterpenoids were isolated from the leaves of Rabdosia eriocalyx (Dunn) Hara collected at Xundian County, Yunnan Province, and their structures were determined by spectroscopic analysis. Maoecrystal F and G are elucidated as ent-7α, 15α-dihydrooxyl- lβ,6α-diacetoxyl-7β, 20-epoxy-16-kaurene (1) and ent-7α,15α-dihydroxyl-6α-ace-toxyl-7β, 20-epoxy-16-kaurene(2), respectively.     

冬凌草水溶性化学成分研究

新鲜冬凌草用70％丙酮水溶液组织破碎提取,然后经Diaion HP-20、Toyopearl HW-40、MCI Gd、silica gel等柱层析方法分离得到5个单体化合物,经波谱分析鉴定为α-D-呋喃果糖(1),阿魏酸(2),丹参素甲正丁酯(3),3,4-二羟基苯乳酸(4),延命素-1β-D-吡喃葡萄糖苷(5)。除延命素-1β-D-吡喃葡萄糖苷外,其它4个化合物均为首次从冬凌草及其同属植物中分离得到。     

大萼香茶菜庚素的化学结构

从大萼香茶菜（Ｒａｂｄｏｓｉａ ｍ ａｃｒｏｃａｌｙｘ （Ｄｕｎｎ） Ｈａｒａ）叶的乙醇提取物中又分离到３ 个二萜成分（结晶Ⅰ、Ⅱ、Ⅲ）,通过ＩＲ、ＭＳ、１Ｈ－１Ｈ ＣＯＳＹ、１３Ｃ－１Ｈ ＣＯＳＹ和ＮＯＥ等光谱分析及衍生物的制备,确定结晶Ⅰ的结构为ｅｎｔ－７β－２０－ｅｐｏｘｙ－６α, ７α,１４α,１５α,１６α－ｐｅｎｔａｈｙｄｒｏｋａｕｒａｎｅ－１７－ａｃ－ｅｔａｔｅ,为新的二萜化合物,命名为大萼香茶菜庚素;结晶Ⅱ和Ⅲ为已知化合物ｒａｂｄｏｐｈｙｌｌｉｎ Ｈ和ｐｏｎｉｃｉｄｉｎ。     

线纹香茶菜酸的化学结构

从线纹香茶菜Ｒａｂｄｏｓｉａ ｖａｒ．ｌｏｐｈａｎｔｈｏｉｄｅｓ Ｈａｒａ中分得五种成分,其中之一线纹香茶菜酚为Ａｂｉｅｔａｎｅ ａｃｉｄ型的新二萜酸。根据波谱解析、衍生物制备及Ｘ线单晶衍射,测定了它的化学结构。其余四种成分,分别鉴定为２ａ－羟基乌索酸、齐墩果酸、β－谷甾醇及β－谷甾醇－Ｄ－葡萄糖甙。     

冬凌草组织培养及其愈伤组织诱导研究

实验采用L9（34）正交试验方法优化冬凌草组织培养快繁培养基,筛选冬凌草增殖、生根和愈伤组织诱导的最佳培养基配方。结果表明：不定芽诱导的最适培养基为MS＋0.2 mg/L IBA＋0.1 mg/L6-BA＋0.2 mg/L NAA;生根培养基为1/2 MS＋1 mg/L IBA＋1 g/L活性炭;以冬凌草茎段为外植体诱导愈伤最佳培养基为MS＋1.5 mg/L6-BA＋2 mg/L2,4-D。     

冬凌草中一新的二萜成分--冬凌草辛素

从河南省鹤壁地区产冬凌〖Ｉｓｏｄｏｎ ｒｕｂｅｓｃｅｎｓ（Ｈｅｍｓｌ．）Ｈａｒａ〗叶中分得一个新地二萜化合物,命名为冬凌草辛素（Ｒｕｂｅｓｃｅｎｓｉｎ Ｈ）〈经ＮＭＲ谱等确定其结构为６β,７β,１４β,１５Ｒ－四羟基－１１β－甲酰氧基－７α,２０－环氧－对映－贝壳杉－１６－烯。     

细锥香茶菜的化学成分研究

从云南丽江产细锥香茶菜(Rabdosia coetsa)叶中分离得到11个单体成分,根据光谱方法分别鉴定为:gesneroidin c 1、胡萝卜甙(daucosterol 2)、熊果酸(ursolic acid 3)、乌发醇(uvaol 4)、齐墩果酸(oleanolic acid 5)、2α,3β-二羟基齐墩果酸(2α,3β-dihydroxy-oleano-lic acid 6)、白桦脂酸(Betulinic acid 7)、植物醇(phytol 8)、肉豆蔻酸植物醇酯(phytyl myris-tate 9)、9Z,12Z-二烯肉豆蔻酸乙酯(ethyl 9Z,12Z-dien-palmitate 10),12Z,15Z-二烯花生酸甘油酯(glyceryl 12Z,15Z-dien-arachidate 11)。