Kurilosides A1, A2, C1, D,E and F—Triterpene Glycosides from the Far Eastern Sea Cucumber Thyonidium (= Duasmodactyla) kurilensis (Levin): Structures with Unusual Non-Holostane Aglycones and Cytotoxicities

Six new monosulfated triterpene tetra-, penta- and hexaosides, namely, the kurilosides A₁ (1), A₂ (2), C₁ (3), D (4), E (5) and F (6), as well as the known earlier kuriloside A (7), having unusual non-holostane aglycones without lactone, have been isolated from the sea cucumber Thyonidium (= Duasmodactyla) kurilensis (Levin) (Cucumariidae, Dendrochirotida), collected in the Sea of Okhotsk near Onekotan Island from a depth of 100 m. Structures of the glycosides were established by 2D NMR spectroscopy and HR-ESI mass spectrometry. Kurilosides of the groups A and E contain carbohydrate moieties with a rare architecture (a pentasaccharide branched by C(4) Xyl1), differing from each other in the second monosaccharide residue (quinovose or glucose, correspondingly); kurilosides of the group C are characterized by a unique tetrasaccharide branched by a C(4) Xyl1 sugar chain; and kurilosides of the groups D and F are hexaosides differing from each other in the presence of an O-methyl group in the fourth (terminal) sugar unit. All these glycosides contain a sulfate group at C-6 of the glucose residue attached to C-4 Xyl1 and the non-holostane aglycones have a 9(11) double bond and lack γ-lactone. The cytotoxic activities of compounds 1–7 against mouse neuroblastoma Neuro 2a, normal epithelial JB-6 cells and erythrocytes were studied. Kuriloside A₁ (1) was the most active compound in the series, demonstrating strong cytotoxicity against the erythrocytes and JB-6 cells and a moderate effect against Neuro 2a cells.     

Two new chalcone glycosides from the stems of Entada phaseoloides

Two new chalcone glycosides 4′-O-(6″-O-galloyl-β-d-glucopyranosyl)-2′,4-dihydroxychalcone (1) and 4′-O-(6″-O-galloyl-β-d-glucopyranosyl)-2′-hydroxy-4-methoxychalcone (2) together with one known chalcone glycoside 4′-O-β-d-glucopyranosyl-2′-hydroxy-4-methoxychalcone (3) were isolated from the stems of Entada phaseoloides. The structures of the new compounds were elucidated on the basis of extensive spectroscopic analysis, including HSQC, HMBC, ¹H–¹H COSY, and chemical evidences. This is the first report of chalcone-type compounds isolated from the genus Entada.     

New monoterpene glycosides from Paeonia lactiflora

Three new monoterpene glycosides named 4-O-methyl-paeoniflorin (1), isopaeoniflorin (2), and isobenzoylpaeoniflorin (3), together with two known monoterpene glycosides, paeoniflorin (4) and benzoylpaeoniflorin (5), were isolated from the roots of Paeonia lactiflora. Their structures were established on the basis of spectral and chemical evidence.     

半边莲黄酮苷提取工艺优化

[目的]研究超声辅助提取半边莲黄酮苷的最佳工艺条件。[方法]以乙醇溶液为提取剂,采用正交试验法对半边莲黄酮苷提取过程中的乙醇浓度、提取时间、提取温度、料液比4个因素进行优选。[结果]最佳提取工艺条件为：乙醇浓度为50%,提取时间为35min,提取温度50℃,料液比为15∶0。在此条件下,黄酮苷的含量可达4.209 2 mg/g。[结论]该法提取率高、稳定性好,适合半边莲黄酮苷的测定。     

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.     

风箱果叶色变化及呈色机理研究

为研究风箱果叶片不同生长发育过程中叶色变化及呈色机理的问题,以风箱果、‘金叶’风箱果、‘紫叶’风箱果为材料,对其叶片从幼嫩到成熟转变过程5 个生长阶段的叶部特征和叶色变化进行比较研究,并采用徒手切片法观察叶片中色素空间分布。结果表明,随着3 种风箱果的生长,叶片面积均呈逐渐增大的趋势,‘紫叶’风箱果叶面积最大;3 种风箱果叶绿素a 含量、叶绿素b 含量、叶绿素/类胡萝卜素均呈现逐渐升高的趋势,风箱果不同生长阶段叶绿素a 含量、叶绿素b 含量均显著高于‘紫叶’风箱果和‘金叶’风箱果;3 种风箱果叶片色素均主要分布于栅栏组织内,在海绵组织和表皮细胞分布较少。上述结果明确了风箱果叶片在生长发育过程中的叶部特征和叶色表现,为其科学合理应用提供了理论依据。     

Glycosides from Marine Sponges (Porifera, Demospongiae): Structures, Taxonomical Distribution, Biological Activities and Biological Roles

Literature data about glycosides from sponges (Porifera, Demospongiae) are reviewed. Structural diversity, biological activities, taxonomic distribution and biological functions of these natural products are discussed.     

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.     

秦艽地上部位中环烯醚萜苷类功效成分提取分离工艺研究

[目的]优选出秦艽中环烯醚萜苷的最佳提取工艺,筛选出适合分离环烯醚萜苷的大孔吸附树脂。[方法]通过正交试验,以水为溶剂,以龙胆苦苷和獐牙菜苷含量为指标,考察温度、料液比及提取次数对秦艽中龙胆苦苷和獐牙菜苷提取率的影响,利用静态吸附法筛选出适合的大孔吸附树脂。[结果]秦艽中环烯萜苷的提取以水作溶剂,温度68℃,料液比1∶12,提取次数5次为最佳提取条件,D-101树脂为最佳提取树脂。[结论]最佳提取条件稳定,适合于秦艽中环烯醚萜苷的提取,D-101树脂适合分离秦艽中环烯醚萜苷类化合物。     

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。