长春花叶片愈伤组织诱导及培养过程中生物碱合成类型的变化和调节及有关酶的分析

在４种不同培养基上诱导长春花叶片愈伤组织发生的过程中,叶片中含量较高的文多灵（ｖｉｎｄｏｌｉｎｅ）和长春质碱（ｃａｔｈａｒａｎｔｈｉｎｅ）迅速降解至极低水平,而在叶片中含量较低的阿玛碱（ａｊ－ｍａｌｉｃｉｎｅ）和蛇根碱（ｓｅｒｐｅｎｔｉｎｅ）的合成却逐渐增加,同时酸性和碱性过氧化物酶（ｐｅｒｏｘｉｄａｓｅ）活性呈上升趋势,尤其碱性过氧化物酶与蛇根碱和阿玛碱的相关性较密切。光照和黑暗中的变化趋势基本一致,但光照可提高过氧化物酶的活性,对培养物的长春质碱、文多灵和蛇根碱的合成有利。不同的培养基对生物碱的合成影响较大,２,４－Ｄ显著抑制生物碱的合成,持续光照使愈伤组织的生长受到抑制,使阿玛碱向其蛇根碱转化。     

长春花密码子使用偏好性分析

以长春花为研究对象,分析其密码子使用偏好性,以期为相关基因的异源表达、基因的预测、物种的进化研究提供指导。该研究以长春花的30 437条蛋白质编码序列为数据来源,对长春花密码子组成和密码子偏性的各项参数进行了计算和统计分析。计算了长春花萜类吲哚生物碱(terpenoid indole alkaloids,TIAs)生物合成途径中25个关键酶基因含有大肠杆菌或酿酒酵母稀有密码子的比例。结果显示,长春花基因的平均GC量为42.47%,密码子第3位碱基平均GC量为35.89%。长春花中共有28个密码子的同义密码子相对使用度(relative synonymous codon usage,RSCU)大于1,其中26个以A或T结尾。25个关键酶基因含有大肠杆菌稀有密码子的比例明显高于酿酒酵母稀有密码子的比例。长春花主要偏爱使用以A和T结尾的密码子;相比于酿酒酵母,其密码子使用特点与大肠杆菌的差异更大,推测酿酒酵母可能是长春花基因更合适的异源表达宿主。     

长春花叶片中吲哚生物碱增产的研究

目的探讨乙烯利、乙酰水杨酸、色氨酸3种试剂对长春花植株中药用成分积累的影响。方法用不同质量浓度的3种试剂溶液分别处理温室盆栽长春花植株,2d后,测定叶片中的总吲哚生物碱含量,并采用RP-HPLC法测定长春碱和长春质碱的含量。结果3种试剂处理后吲哚总碱、长春碱、长春质碱的积累均有明显的提高,并确定了最适的处理质量浓度。结论3种试剂对长春花植物中吲哚生物碱的产生有明显的促进作用。     

EMS诱变的长春花细胞系突变研究

目的 通过化学诱变的手段筛选生长快且吲哚碱含量高的长春花突变细胞系。方法 用不同浓度的甲基磺酸乙酯(EMS)处理长春花愈伤组织，挑选成活愈伤组织块继代扩大培养，比较其与对照愈伤组织生长速率、吲哚总碱积累等方面的差异。结果 用EMS处理的长春花愈伤组织与对照相比，不仅生长快，并且吲哚总碱含量高。结论 EMS处理的愈伤组织发生了变异，变异种是所期望的比较理想的细胞系。     

干旱胁迫及施加氮素对长春花生物碱的调控

目的:为了阐明不同的干旱条件及氮素水平对长春花叶片中4种生物碱(文多灵、长春质碱、长春碱、长春新碱)含量的影响,为提高长春花生物碱含量提供理论指导。方法:实验设置了CK(对照组即自然生长)、CN(对照+施氮素)、LK(轻度干旱)、LN(轻度干旱+施氮素)、HK(重度干旱)、HN(重度干旱+施氮素)6个处理组,探讨各处理组条件下长春花叶片全氮含量、碱性POD活性、TDC活性、4种生物碱含量的变化特性。结果:轻度干旱条件下POD,TDC的酶活性在处理的整个时期均提高,且胁迫的早期(0～21 d),有利于文多灵、长春质碱、长春碱、长春新碱的积累,后期(28～35 d)反而起抑制作用4种生物碱含量降低。施加外源氮素能有效提高各组长春花叶片中全氮含量、POD和TDC酶活性、文多灵和长春质碱的含量,干旱+施加氮素(LN,HN)处理下有利于长春碱和长春新碱的积累。结论:干旱胁迫及施加氮素对长春花叶片中POD,TDC的活性及4种生物碱的含量均能产生影响,轻度干旱条件下施加氮素(LN)对文多灵、长春质碱、长春碱、长春新碱含量的提高最为显著,是通过全氮含量及酶活性提高来调控的。     

不同因子对长春花愈伤组织中药用成分积累的影响

 目的 研究继代次数、继代龄(继代组织块的年龄)、生长素、金属离子等因子的改变对长春花愈伤组织生长及吲哚生物碱类药用成分积累的影响。方法 测定不同因子的影响下,长春花愈伤组织的鲜重,并对吲哚总碱进行提取、含量测定和比较。结果 随继代次数的增加,长春花愈伤组织中吲哚总碱含量有所下降;20 d继代龄最利于组织生长;2,4-二氯苯氧乙酸的存在对吲哚总碱的积累有一定的抑制作用,但却有利于愈伤组织生长,两种生长素组合比单一的生长素更利于组织生长,也较利于吲哚总碱积累;钙离子浓度为220 mg·L^-1,锌离子浓度为8.6哗·L^-1时,对提高吲哚总碱产量最有效。结论 继代次数、继代龄、生长素、金属离子对长春花愈伤组织生长及吲哚生物碱类药用成分的积累有较大影响。     

高速逆流色谱法分离纯化长春花中长春新碱

目的采用高速逆流色谱(HSCCC)分离纯化长春花中长春新碱,建立相关工艺条件,为工业生产提供参考数据。方法采用高速逆流色谱仪,氯仿-甲醇-0.3mol.L-1 HCl(4∶3∶2)溶剂体系,上相为固定相,下相为流动相,流动相流速为2.0mL.min-1,紫外检测波长为280nm,主机转速为800r.min-1,恒温循环温度为28℃。结果 HPLC检测HSCCC纯化后长春新碱质量分数为79.7%。结论高速逆流色谱纯化长春花中长春新碱容量大、分离纯度和效率高,避免了有机溶剂的大量使用,适用于工业生产高纯度产品。     

长春花组织培养研究进展

长春花含有100多种吲哚类生物碱,具有抗肿瘤、降血压等多种生物活性,有较高的药用价值,但是含量偏低。长春花组织培养可从提高繁殖系数、调控次生代谢产物的累积等来提高长春花生物碱类成分含量。本文就外植体和培养基的选择、药用成分累积的影响因素、悬浮细胞培养应用、影响毛状根因素和基因工程技术应用等方面,综述了长春花组织培养的主要研究进展,为进一步开发利用长春花药物资源提供参考。     

Severe Bone Marrow Depression Induced by an Anticancer Herb Cantharanthus Roseus

We report a 67‐yr‐old woman with hepatitis C–related liver cirrhosis and hepatoma who had developed severe bone marrow suppression after taking Cantharanthus roseus as an alternative anticancer treatment. The patient developed severe pancytopenia with initial presentations of vomiting, diarrhea, oral ulcer, and fever about 1 week after taking 5‐days' course of Cantharanthus roseus. Bone marrow biopsy showed autolysis, which indicated massive necrosis of the hematopoietic cells. There was no malignant cell infiltration. The patient also had severe gastrointestinal disturbances, bacteremia, urinary tract infection, and impaired renal and liver function. Supportive care with broad‐spectrum antibiotics, granulocyte colony‐stimulating factor, repeated blood transfusions, and albumin supplement was given. She recovered and was discharged after 48 days hospitalization. Coadministration of Cantharanthus roseus and cisapride was noted, and these two drugs are both substrates of cytochrome P450 3A4 enzymes (CYP 3A4). Because the vinca alkaloids are extensively metabolized by the liver cytochrome P450 enzymes, poor hepatic function and drug‐herb interaction might predispose the patient to develop the bone marrow toxicity. This case report demonstrated possible effect of oral dose of vinca alkaloids and also hinted that all the substrates and inhibitors of CYP 3A4 have propensity to interfere with metabolism of vinca alkaloids.     

Correlation between wing bone microstructure and different flight styles: The case of the griffon vulture (gyps fulvus) and greater flamingo (phoenicopterus roseus)

Flying is the main means of locomotion for most avian species, and it requires a series of adaptations of the skeleton and of feather distribution on the wing. Flight type is directly associated with the mechanical constraints during flight, which condition both the morphology and microscopic structure of the bones. Three primary flight styles are adopted by avian species: flapping, gliding, and soaring, with different loads among the main wing bones. The purpose of this study was to evaluate the cross-sectional microstructure of the most important skeletal wing bones, humerus, radius, ulna, and carpometacarpus, in griffon vultures (Gyps fulvus) and greater flamingos (Phoenicopterus roseus). These two species show a flapping and soaring flight style, respectively. Densitometry, morphology, and laminarity index were assessed from the main bones of the wing of 10 griffon vultures and 10 flamingos. Regarding bone mineral content, griffon vultures generally displayed a higher mineral density than flamingos. Regarding the morphology of the crucial wing bones involved in flight, while a very slightly longer humerus was observed in the radius and ulna of flamingos, the ulna in griffons was clearly longer than other bones. The laminarity index was significantly higher in griffons. The results of the present study highlight how the mechanics of different types of flight may affect the biomechanical properties of the wing bones most engaged during flight.