A furostanol saponin and phytoecdysteroid from roots of <Emphasis Type="Italic">Helleborus orientalis</Emphasis>

A furostanol saponin mixture and a known phytoecdysteroid were isolated from the roots of Helleborus orientalis Lam. Their structures were established as 26-[(β-D-glucopyranosyl)oxy]-22α-hidroxyfurosta-5,25(27)-dien-1β,3β,11α-triol (1a), 26-[(β-D-glucopyranosyl)oxy]-22α-methoxyfurosta-5,25(27)-dien-1β,3β,11α-triol (1b), and 20-hydroxy-β-ecdyson-3-O-β-D-glycoside (2). Acid hydrolysis of 1a,b gave (1β,3β,11α,22α)-22,26-dimethoxyfurosta-5,25(27)-dien-1,3,11-triol (aglycone 1) and of 2 gave 20-hydroxy-β-ecdyson (aglycone 2). Their structures were elucidated by spectral analysis. Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 75–77, January–February, 2007.     

Theoretical and numerical analysis of coherent Smith-Purcell radiation

Coherent enhancement of Smith-Purcell radiation has attracted people's attention not only in adopting a better source but also in beam diagnostics aspect. In this paper, we study the intrinsic mechanism of coherent Smith-Purcell radiation on the basis of the van den Berg model. The emitted power of Smith-Purcell radiation is determined by the bunch profile in transverse and longitudinal directions. For short bunch whose longitudinal pulse length is comparable with the radiation wavelength, it can be concluded approximately that the power is proportional to the square number of electrons per bunch.     

Formation mechanism of InxGa1−xAs bridge layers on patterned GaAs substrates

The formation mechanism of In_xGa_1−xAs (x=0.06) bridge layers on patterned GaAs (1 1 1)B substrates using liquid-phase epitaxy has been investigated. For this (i) the effect of density gradient in the solution on the formation of bridge layer and (ii) growth of bridge layer on 1 1 0 line-seed-substrates were studied. The convection induced by destabilizing density gradient in the solution led to an increase of lateral growth rate of the InGaAs bridge layers on a substrate mounted on the upper portion of the solution. However, it did not have any significant effect on the formation of the bridge layers. The formation of bridge layer on 1 1 0 line-seed-substrate took place only for the {1 1 1}B growth fronts, which indicated that “Berg effect” is responsible for the formation of bridge layers.     

Two new protostane-type triterpenoids from Alisma orientalis

Two new protostane-type triterpenoids, 17-epi alisolide (1) and 24-epi alismanol D (2), were isolated from Alisma orientalis together with one known compound. Their structural elucidations were conducted by NMR, UV and HRESIMS spectroscopic analyses, and comparison with the literature data. All the isolated compounds were evaluated for inhibitory effects on HCE-2. Compound 2 displayed moderate inhibitory activity against HCE-2 with IC₅₀ value of 23.1 μM.     

A new triterpenoid from Alisma orientalis

A new triterpenoid,named 11,25-aahydro-alisol E was isolated from the rhizomes of Alisma orientalis together with nine known compounds.Their structures were elucidated by spectroscopic methods.Some compounds showed weak anti-tumor activities in cytotoxic experiments.     

Mutation scanning-based analysis of Theileria orientalis populations in cattle following an outbreak

Bovine theileriosis is a tick-borne disease caused by one or more hemoprotozoan parasites of the genus Theileria. In the past, Theileria infection in cattle in Australia was largely asymptomatic and recognized to be associated with Theileria buffeli. However, outbreaks of theileriosis have occurred in beef and dairy cattle in subtropical climatic regions (New South Wales) of Australia. There is also one published report of a recent theileriosis outbreak in a beef farm near Seymour in the southeastern state of Victoria. In order to gain an improved insight into the genetic composition of Theileria populations following this outbreak, we undertook herein an integrated PCR-coupled mutation scanning-sequencing-phylogenetic analysis of sequence variation in part of the major piroplasm surface protein (MPSP) gene within and among samples from cattle involved in the outbreak. Theileria DNA was detected in 89.4% of 94 cattle in the Seymour farm; the genetic analysis showed that the ikeda and chitose genotypes representing the Theileria orientalis complex were detected in 75 and 4.8% of 84 infected cattle, respectively, and that mixed populations of these two genotypes were found in 20.2% of infected cattle. Given unpublished reports of a significant increase in the number of outbreaks in Victoria, future investigations should focus sharply on elucidating the epidemiology of Theileria to subvert the economic impact on the cattle industry in this state. Although used here to explore genetic variation within the T. orientalis complex in Australia, a mutation scanning-based approach has broad applicability to other species of Theileria in other countries.     

超临界萃取蝼蛄脂肪酸成分及其气相色谱-质谱分析

采用超临界CO2萃取蝼蛄总脂肪酸，对影响萃取效果的各个因素应用正交设计试验，优化了各萃取参数。各个因素的影响顺序为：压力〉温度〉时间〉流量。萃取的优化条件为压力35MPa，温度50℃，时间1h，流量45kg／h。运用该萃取条件改善了萃取物的物理性状，脂肪酸的纯度提高，总脂肪酸的含量可达83.29％；而采用常规的有机溶剂提取法，脂肪酸的纯度仅为60％左右。甲酯化采用气相色谱-质谱分析技术对其中的16个成分进行了鉴定，并测定了相对含量，其中主要有油酸甲酯（30．40％）、十六烷酸甲酯（14．19％）、9，12-十八碳二烯酸甲酯（11．99％）、油酸乙酯（11．75％）、9-十六碳烯酸甲酯（7．77％）、十六烷酸乙酯（5．97％）、9，12-十八碳二烯酸乙酯（4．53％）及9-十六碳烯酸乙酯（2．87％）等。     

New cytotoxic flavonoids from aerial parts of Platycladus orientalis L.

Abstract

Investigation of Platycladus orientalis yielded five flavonoids, including aglycone flavone 1 (apigenin), flavone glycoside 2 (apigenin 7-O-β-D-glucopyranoside), new gernaylated flavone glycoside 3 (apigenin 8-gernayl-4′-O-α-gluco pyranoside) and two new pernylated flavonoid glycosides 4 & 5 (apigenin 8-pernyl-4′-glucopyranosyl-7-O-α-glucopyranoside and apigenin 5-pernyl-7-glucopyranosyl-4′-O-β-D-glucopyranoside). Their structures were elucidated on the basis of spectroscopic evidence. The cytotoxicity of compounds 1–5 were tested against Lung adenocarcinoma (A549), human hepatocellular liver carcinoma (HepG2), human breast carcinoma (MCF-7) cell lines and mouse fibroblast cell line NIH/3T3 as normal cells. This assay gave spot on structure activity relationship which, showed that cytotoxicity of compounds (1) and (2) against three cell lines was weak as IC₅₀?>?15. Compounds (4) and (5) had moderate cytotoxic and no toxic effect on normal cell. Compound (3) showed high cytotoxic activity against tested three cell lines with no toxic effect of normal cells.