Limonoids from the bark of Toona ciliata var pubescens and their anti-tumor activities

Two previously undescribed B-ring seco-limonoids named toonacilinatin I (1) and toonacilinatin J (2), together with ten known analogues (3–12), were isolated from the ethyl acetate extract of the bark of Toona ciliata var pubescens. All structures were elucidated by extensive spectroscopic analysis involving IR, MS, and NMR. Among them, compounds 1–10, and 12 were discovered from this plant for the first time. All the compounds except 7 and 8 were evaluated for their anti-tumor activity by MTT method of MDA-MB-231 and A-673 cell lines, the bioassay results showed that compounds 1, 2, 5, 9 and 11 exerted superior inhibitory activity with IC₅₀ values as 0.11–1.60 μM. Notably, those active compounds exhibited little effect on normal hepatocellular HL-7702 cells.     

Two new sesquiterpenoids and one new p-coumaroyl-triterpenoid derivative from Myrcia guianensis

Two new sesquiterpenoids (1 and 2) and one new p-coumaroyl-triterpenoid derivative (3), along with five known sesquiterpenoids (4–8), seven triterpenoids (9–15), and two steroids (16 and 17) were isolated from Myrcia guianensis. Compound 1 [6-methyl-5-(2-hydroxy-3-chloro-5-methyl phenyl)-heptan-2-one] contains a chlorine atom attached to C-10, which seems to be the first report of a chlorine-containing sesquiterpenoid in the Myrtaceae family. The biogenesis of the two new sesquiterpenoids (1 and 2) are proposed herein, whereas the isolation of these sesquiterpenoids and triterpenoids from M. guianensis may present chemophenetic relevance to consolidate the genus Myrcia within the Myrtaceae family.     

HS-SPME-GC-MS法分析3种块菌子囊果主要挥发性成分

本研究采用顶空-固相微萃取结合气相色谱-质谱联用技术(HS-SPME-GC-MS)比较分析了假喜马拉雅块菌Tuber pseudohimalayense、中华夏块菌T. sinoaestivum和印度块菌T. indicum子囊果主要挥发性有机化合物(volatile organic compounds,VOCs)组成与含量。结果表明,在3种块菌子囊果中共鉴定到173种VOCs,其中假喜马拉雅块菌、中华夏块菌和印度块菌子囊果中分别检测到79、63和71种挥发性成分,3种块菌子囊果中共有成分11种,其中1-辛烯-3-醇是含量最高的共有化合物(39.52%、38.98%和8.46%)。利用挥发性成分对3种块菌种类进行判别分析,结果表明2-丁酮、庚醛、苯乙烯、1-辛烯-3-醇和环十四烷能100.0%地将3种块菌样品按照种类正确分类。本研究初步确定了3种块菌子囊果VOCs组成和含量的差异,并探究了用VOCs相对含量区分3种块菌种类的可行性,为我国块菌质量评价,尤其是加工的块菌商品的鉴别提供了重要的理论依据。     

香豆素类化合物功能及生物合成研究进展*

香豆素类化合物是自然界中一类重要的化合物,具有抗肿瘤、抗凝血、抗菌、杀虫等多种生物活性,应用领域广泛。目前大多数香豆素类化合物从植物中提取,受环境因素影响较大,得率低、成本高,不利于大规模生产,从而限制了其应用和推广。利用合成生物学的思路合成香豆素类化合物具有无污染、原料易得、成本低、过程可控等优势。对香豆素类化合物生物合成途径的研究,尤其是靶标天然产物生物合成表达元件、宿主和发酵条件的优化,以及合成途径中关键酶的挖掘,已经成为研究热点。综述香豆素类化合物及其衍生物的结构、功能和生物合成研究进展,为其生物合成路径中的基因挖掘及异源表达提供参考。     

长航海勤人员骨密度状况调查及影响因素分析*

目的:研究长航海勤人员骨密度情况及影响因素,为开展针对性干预提供理论依据。方法:采用双能X线法检测2018-05至2018-09来我院疗养的199名长航海勤人员,其中水面舰艇艇员77人、潜艇艇员122人(核潜艇69人)的骨密度(BMD)值,并分析年龄、体质指数、长期饮用(≥6个月)碳酸/含糖饮料对骨密度的影响。结果:长航海勤人员骨密度(BMD) 值平均为 0.5544±0.0599,骨质疏松3例(1.5%),骨量减少58例(29.2%);30 ～39岁年龄段的BMD明显高于<30岁年龄段(P＜0.05);潜艇官兵的BMD值显著高于水面舰艇组(P＜0.01);长期饮用碳酸/含糖饮料者的BMD值高于不饮用者(P＜0.05)。结论:长航作业环境及不良生活方式可导致长远航海勤人员骨密度降低;做好针对性干预,对维护海勤官兵骨骼健康具有重要意义。     

基于高速逆流色谱的大极性海参多肽分离方法研究

本文通过对HEMWat溶剂体系中28种常用溶剂系统单相以及整体极性进行系统分析,探讨了无法用常规J型逆流色谱实现对大极性化合物实现有效分离的原因。根据分析结果建立了一种以分离物质理化性质为基础选择潜在改性剂,样品在溶剂系统上相中的溶解程度为判断指标进行筛选逆流色谱溶剂系统改性剂,进而得到适宜的溶剂系统对大极性海参多肽样品进行系统分段方法。经过两步分离,共得到8个随极性分布的海参多肽片段,为海参多肽最佳活性物质的追踪和筛选提供了技术支持。