Cytotoxic and Apoptosis-Inducing Activity of Triterpene Glycosides from Holothuria scabra and Cucumaria frondosa against HepG2 Cells

The cytotoxic effects of thirteen triterpene glycosides from Holothuria scabra Jaeger and Cucumaria frondosa Gunnerus (Holothuroidea) against four human cell lines were detected and their cytotoxicity-structure relationships were established. The apoptosis-inducing activity of a more potent glycoside echinoside A (1) in HepG2 cells was further investigated by determining its effect on the morphology, mitochondrial transmembrane potential (Δψ_m) and mRNA expression levels of the apoptosis-related genes. The results showed that the number of glycosyl residues in sugar chains and the side chain of aglycone could affect their cytotoxicity towards tumor cells and selective cytotoxicity. 1 significantly inhibited cell viability and induced apoptosis in HepG2 cells. 1 also markedly decreased the Δψ_m and Bcl-2/Bax mRNA express ratio, and up-regulated the mRNA expression levels of Caspase-3, Caspase-8 and Caspase-9 in HepG2 cells. Therefore, 1 induced apoptosis in HepG2 cells through both intrinsic and extrinsic pathway. These findings could potentially promote the usage of these glycosides as leading compounds for developing new antitumor drugs.     

Productivity of two stevia varieties under reduced irrigation and fertilization inputs

A 3-year field study was conducted in central Greece to determine the productivity of two stevia [(Stevia rebaudiana (Bertoni) Bertoni] varieties (‘Morita’ and ‘Candy-stevia’) under normal and reduced irrigation (100% and 75% of the evapotranspiration) and fertilization [1:0.8:1.1 or 1:0.4:0.8 N:P:K ratio in the first year and only N fertilization (100% or 74% of the recommended rate) in the second and third years] inputs. Averaged across years, stevia cv. Morita achieved greater dry leaf yield (3.48 t ha^?1) than the cv. Candy-stevia (2.85 t ha^?1). Irrigation and fertilization inputs did not significantly affect stevia cv. Morita dry leaf and steviol glycosides (stevioside plus rebaudioside-A) yields; however, decreasing irrigation and fertilization caused slight reduction of cv. Candy-stevia yields. In cv. Morita leaves, the concentrations of stevioside and rebaudioside-A ranged from 5.97% to 7.78% and 3.73% to 4.79%, respectively, while the corresponding concentrations in cv. Candy-stevia leaves were 8.21–9.36% and 3.89–6.33%. Conclusively, both stevia varieties could achieve satisfactory dry leaf biomass and steviol glycosides yield, even when grown under reduced irrigation (at 75% of evapotranspiration) and reduced N fertilization (74% of the recommended rate). Thus, stevia could represent an alternative crop to tobacco in the Mediterranean conditions.     

紫外分光光度法快速测定龙泉破壁灵芝孢子粉三萜含量

选取5种龙泉破壁灵芝孢子粉为研究对象,使用紫外分光光度法,建立了一种快速、简单、高灵敏度,专门针对灵芝孢子粉中三萜测定的方法。结果表明,该方法测得龙泉破壁灵芝孢子粉三萜含量为2.94%~3.43%。熊果酸浓度在20~140μg范围内呈良好的线性关系,精密度(RSD)为0.88%,回收率为88.6%~92.5%,完全能够满足于破壁灵芝孢子粉中三萜成分的分析研究。     

超临界流体萃取红芝三萜化合物

采用超临界流体设备,以ＣＯ２为萃取剂,从野生红芝子实体中萃取灵芝三萜化合物。分析了ＣＯ２密度、温度、时间及改性剂（甲醇）对红芝三萜化合物萃取的影响。     

小佛肚竹生氰糖苷合成关键酶CYP79家族同源基因的克隆和鉴定

生氰糖苷是由氰醇衍生物的羟基和D-葡萄糖缩合形成的糖苷,已在2 000多种植物中发现,分属于蕨类植物、裸子植物和被子植物的130个家族.生氰糖苷的主要生物学功能在于阻止食草动物和病原体对植物的侵害.通过反转录-聚合酶链式反应(RT-PCR)和cDNA末端快速扩增(RACE)技术从小佛肚竹Bambusa ventricosa幼笋中克隆到CYP79家族同源基因的cDNA全长,命名为BvCYP79.BvCYP79共有1 913个碱基对,翻译起始点为193碱基处,终止子位于1 752 bp,包含1个1 559 bp的完整编码区,开放阅读框共编码519个氨基酸.具有PERF和SFSTGRRGCIA保守结构域,属于典型的单子叶植物CYP79家族基因.生氰糖苷途径可能也存在于竹类植物,因而在食用笋的安全性评估上具有一定指导意义.     

银杏组培繁殖及黄酮糖苷的产生

以银杏(Ginkgobiloba)腋芽为外植体进行组织培养,筛选出了适宜银杏芽萌发、增殖和生根的培养基配方和培养条件,其根、芽诱导率都在89%以上,增殖倍数达8.1.在固体培养基上诱导银杏芽产生愈伤组织,将黄绿色、蓬松状、生长快的愈伤组织转入液体培养基中建立悬浮细胞培养系,在液体继代培养基中添加5ml·1-1蜂蜜可明显促进细胞分裂、生长及黄酮糖苷的累积,提高细胞产量.经过10次液体继代培养,悬浮细胞中黄酮糖苷含量接近成熟叶片含量水平,相对含量为叶片的92.4%.     

山茱萸总苷提取工艺研究

[目的]研究山茱萸中山茱萸总苷的最佳提取工艺。[方法]以四川产山茱萸鲜果为材料提取山茱萸总苷,采用单因素和正交试验优选提取工艺,并进行验证试验。[结果]50%乙醇是山茱萸总苷的最佳提取溶剂。当料液比为1∶4时,提取液中总苷的含量最大。随着提取时间的延长,山茱萸总苷的含量逐渐增加,2～6h增幅最大,时间再延长,总苷含量没有明显增加。随着提取次数的增加,总苷含量呈上升趋势,但提取3次后,所得固形物很少。提取次数对山茱萸总苷含量的影响最显著,然后是料液比、提取时间。[结论]山茱萸中山茱萸总苷的最佳提取工艺是50%乙醇提取,料液比1∶3,提取6h,提取3次,总苷含量达10.016mg/ml,RSD为2.52%。该研究为山茱萸总苷的进一步研究奠定了基础。     

Postharvest changes in pigment concentrations in ‘Fuji’ apples with ‘Fuji’ stain

’Fuji’ apples (Malus domestica Borkh cv. ‘Fuji’) sometimes develop a discolouration in the peel during cold storage, typically in the periphery of sunburned peel. We refer to this particular postharvest disorder as ‘Fuji’ stain as we have not observed it in any cultivar other than ‘Fuji’ and the discolouration looks like a stain on the peel. Because peel discolouration occurs, peel pigments are thought to be involved. Hence the concentrations of anthocyanins, epicatechin, quercetin glycosides, chlorogenic acid, chlorophylls, and carotenoids in peel disks taken from areas exhibiting ‘Fuji’ stain were compared to concentrations observed in peel disks not exhibiting ‘Fuji’ stain. In 2005, peel from sunburned apples exhibiting ‘Fuji’ stain was compared to peel from three areas of sunburned apples not exhibiting stain [i.e. sunburned peel, the area around the sunburned peel (halo), and the area around the halo (OH)]. Additionally, stained peel was compared to the sun-exposed side of non-stained non-sunburned apples (NSNB). The second year, 2006, we compared stained peel to NSNB peel and the area outside the stained area (OS) on those fruit with stain. The concentrations of idaein, epicatechin, and quercetin glycosides were consistently low in the stained peel both years. This is in contrast to our earlier studies in which sunburned ‘Fuji’ apples had high concentrations of quercetin glycosides and epicatechin and low concentrations of idaein, and non-sunburned apples had low concentrations of quercetin glycosides and epicatechin and high concentrations of idaein. The consistent and unique characteristic of stained peel reported here indicates an association of these compounds with the incidence of stain. In 2005, chlorogenic acid concentrations in the stain peel were lower than other peel types, but in 2006 they were higher. Differences in chlorophyll and carotenoid concentrations were observed among many of the peel types. However, there is not a clear association between stain development and changes in chlorophyll and carotenoid concentrations due to significant differences not being observed in both years. While our research provides insight into pigment changes associated with ‘Fuji’ stain formation, more work is needed to help clarify the inconsistencies observed between the 2 years.     

甜菊全生育期含甙量变化调查

试验结果表明,两个高RA型甜菊品种的含甙总量（TSG）和RA含量占TSG含量比重总趋势是均随着田间植株生长而递增,ST含量占TSG含量比重总趋势则是随田间植株生长而递减。守田3号TSG含量在80d时达最高,RA含量占TSG含量比重在130d时（现蕾期）达最高,ST含量占TSG含量比重在100d时降至最低。谱星1号TSG含量也在80d时达最高,RA含量占TSG含量比重、ST含量占TSG含量比重在100d时升至最高和降至最低。试验结果对于选择最佳收获期意义重大。     

几种大量元素对银杏愈伤组织细胞生长及黄酮醇糖苷含量的影响

以MS＋NAA1mg/L KT2mg/L为基本培养基,研究了不同浓度的5种大量元素对银杏愈伤组织的细胞生长及其黄酮醇糖苷含量的基本培养基,研究了不同浓度的5种大量元素与细胞生长率呈负相关;KNO3浓度对细胞生长率影响不大,但对黄酮醇糖苷含量影响明显;随着MgSO4浓度的增加,细胞生长率和黄酮醇糖苷的含量呈现同步变化;随CaCl2浓度的变化,细胞生长率和黄酮醇糖苷含量呈负相关。