包结物晶析法选择分离辛夷挥发油中1，8-枝叶素

We used 1,1,6,6-tetraphenylhexa-2,4-diyne-1,6-diol(A) as the host molecule to selectively recognize the component 1,8-cineole(B) in the volatile oil of Flos Magnoliae(Xin Yi). The inclusion com-pound (A B) was formed as crystalline, and the structure was confirmed by means of IR, ^1H NMR, and single crystal X-ray diffraction, with the 1:2 molar ratios of the host to the guest. The component 1,8-cineole(B) was selectively isolated from the inclusion compound(A B) by Kugelrohr vaccum technology, and then further characterized by IR, ^1H NMR and ^13C NMR. The whole components in the volatile oil of Flos Magnoliae (Xin Yi) and the isolation effect of 1,8-cineole isolated from inclusion crystals were analyzed by GC and GC-MS, respectively. The result indicate that the good isolation effect is given by the inclusion method, with purity and yield of the component 1,8-cineole(B) separated from the volatile oil of Flos Magnoliae are 100% and 85%, respectively.     

包结物晶析法分离小茴香挥发油中茴香醚

包结化合物法;包结物晶析法分离小茴香挥发油中茴香醚     

中药材辛夷挥发油GC-MS指纹图谱的建立

通过对12个产地辛夷挥发油进行气相色谱-质谱联用分析,建立不同产地、不同采收期辛夷药材质量控制方法.通过计算机谱库检索,其主要成分为1,8-桉叶素、芳樟醇、α-松油醇、石竹烯、α-依兰油烯、西柏三烯、异合金欢醇,不同批次药材成分含量有一定的差别,不同产地及不同采收期样品问有较大差异.通过色谱峰的相对保留值α和量化的面积归一化值ci两个参数实现了从图谱形式到数字形式的转换,其重叠率除5、6号较低外(小于75%),其余都较高,在75%～90%之问,从指纹图谱中提取13强峰、特征指纹等信息,方法重复性RSD小于1.05%,样品在48 h内稳定.     

主客体包结法选择分离青花椒挥发油中的化学成分

以1,1,6,6-四苯基-2,4-己二炔-1,6-二醇为主体分子, 可简单、迅速地从青椒挥发油中选择分离出化学成分烯丙基茴香醚, 基于挥发油的用量, 收率为3.78%. IR, ¹H NMR, ¹³C NMR光谱和单晶衍射证实了包结化合物结构, 用气相色谱法评价了选择分离效果, 分离的烯丙基茴香醚气相色谱纯度为94.5%. 同时, 主体分子形成的隧道框架对茴香醛具有识别作用, 形成2∶1(主/客)物质的量比的特殊结构包结物晶体, 它是主客体分子物质的量比为1∶2包结物的超分子异构体.     

β-环糊精与肉桂醇包结物的制备及包结性能的研究

本文期望对β-环糊精(β-CD)/肉桂醇包结物在食品、化妆品、医药等领域中的实际应用以及肉桂醇的水相有机反应提供理论基础。采用水溶液法制备肉桂醇与β-CD的包结物。在β-CD∶肉桂醇(摩尔比)=1∶1的基础上,以肉桂醇的包结率为考察指标,优选出的包结工艺为:包结温度为333 K,包结时间为1h,肉桂醇的包结率达到88.7%。通过DSC、1H NMR和UV-vis对包结物结构进行表征,表明β-CD与肉桂醇形成了摩尔比为1∶1的包结物,298K时的包结常数为206 M-1,ΔG为-13.2 kJ·mol-1,表明此包结过程是一个自发的过程。进一步用PM3/ONIOM分层法对β-CD/肉桂醇包结物的最稳定结构进行了分子模拟,认为包结物的最稳定结构为肉桂醇的羟基位于β-CD的小口端。     

新型1,8-萘酰亚胺类化合物与DNA相互作用的研究

用荧光光谱、紫外光谱、粘度法对两种新型1,8-萘酰亚胺类化合物N-羟乙基-3-硝基-4-溴-1,8-萘酰亚胺(B)和N-羟乙基-4-羟乙基-3-硝基-1,8-萘酰亚胺(N)与DNA的相互作用进行了研究,考察和比较了它们与DNA的作用模式和强度,求出了两种化合物的嵌入常数。结果表明,化合物N和B主要以插入方式与DNA作用,且化合物N与DNA的作用强于化合物B。     

1,8-二甲氧基乙基萘的合成

以1,8-二萘酸酐为原料,经氢化铝锂还原得1,8-二羟甲基萘(2);2经浓盐酸酸化生成1,8-二氯甲基萘(3);3经氢化铝锂还原为1,8-二甲基萘(4);用强碱丁基锂和叔丁醇钾将4转化成二钾盐后与甲氧基氯甲烷反应合成了1,8-二甲氧基乙基萘,其结构经1H NMR和13C NMR和HR-MS表征.     

人参茎叶挥发油中含氧化合物的分离与结构鉴定

组成鉴定;人参茎叶挥发油中含氧化合物的分离与结构鉴定     

超临界CO_2萃取-分子蒸馏对白术挥发油的提取分离和GC-MS分析

用超临界CO2萃取技术提取白术挥发油，然后用分子蒸馏对所得的萃取物进行精分离，得到蒸出物；超临界萃取物收率为2．42％(w)，分子蒸馏蒸出物收率26．3％(w)；对超临界萃取物和分子蒸馏蒸出物分别进行GC—MS分析，结果超临界萃取物检测出33个化合物，分子蒸馏蒸出物检测出27个化合物，主要成分均为2，7-二甲氧基-3，6-二甲基萘、γ-芹子烯、大根香叶烯等，但相对含量有区别。     

3-羟基4-氯-1,8-萘酐的分子设计及免溶剂微波法合成

1,8-萘酐衍生物具有优良的光电性能(固相荧光量子产率高和光热稳定性好)[1-2],它们不仅是一类性能优异的红光和绿光材料[3-5],而且还可以用作电子传输材料.     

顶空气相色谱-质谱联用结合同位素峰形校正检索技术鉴别芝麻油风味成分

采用顶空气相色谱-质谱联用(GC-MS)仪结合同位素峰形校正检索技术鉴别了市售芝麻油风味成分中的71种化合物,占总检出化合物的90.2%。检出化合物可分为吡嗪、吡咯、吡啶、噻唑、噻吩、吲哚、唑、呋喃、醛类和酚类等,其中醛、酚、吡嗪和呋喃类化合物的含量较高,分别占风味成分含量的37.4%,20.1%,10.0%和6.7%。同位素峰形校正检索技术在低分辨率质谱上可对化合物的相对分子质量实现精确测量,从而为低分辨率四极杆质谱确定化合物的元素组成和解析化合物结构提供了重要依据,同时也为芝麻油的成分分析提供了新的技术手段。     

New Natural Oxygenated Sesquiterpenes and Chemical Composition of Leaf Essential Oil from Ivoirian Isolona dewevrei (De Wild. & T. Durand) Engl. & Diels

This study aimed to investigate the chemical composition of the leaf essential oil from Ivoirian Isolona dewevrei. A combination of chromatographic and spectroscopic techniques (GC(RI), GC-MS and ¹³C-NMR) was used to analyze two oil samples (S1 and S2). Detailed analysis by repetitive column chromatography (CC) of essential oil sample S2 was performed, leading to the isolation of four compounds. Their structures were elucidated by QTOF-MS, 1D and 2D-NMR as (10βH)-1β,8β-oxido-cadin-4-ene (38), 4-methylene-(7αH)-germacra-1(10),5-dien-8β-ol (cis-germacrene D-8-ol) (52), 4-methylene-(7αH)-germacra-1(10),5-dien-8α-ol (trans-germacrene D-8-ol) (53) and cadina-1(10),4-dien-8β-ol (56). Compounds 38, 52 and 53 are new, whereas NMR data of 56 are reported for the first time. Lastly, 57 constituents accounting for 95.5% (S1) and 97.1% (S2) of the whole compositions were identified. Samples S1 and S2 were dominated by germacrene D (23.6 and 20.5%, respectively), followed by germacrene D-8-one (8.9 and 8.7%), (10βH)-1β,8β-oxido-cadin-4-ene (7.3 and 8.7), 4-methylene-(7αH)-germacra-1(10),5-dien-8β-ol (7.8 and 7.4%) and cadina-1(10),4-dien-8β-ol (7.6 and 7.2%). Leaves from I. dewevrei produced sesquiterpene-rich essential oil with an original chemical composition, involving various compounds reported for the first time among the main components. Integrated analysis by GC(RI), GC-MS and ¹³C-NMR appeared fruitful for the knowledge of such a complex essential oil.     

Assessing the MALDI-TOF MS sample preparation procedure to analyze the influence of thermo-oxidative ageing and thermo-mechanical degradation on poly (Lactide)

Multiple processing by means of successive injection cycles was used to simulate the thermo-mechanical degradation effects on the oligomeric distribution of PLA under mechanical recycling. Likewise, an accelerated thermal ageing over PLA glass transition was performed in order to simulate its service life. MALDI-TOF MS was used for the analysis and the sample preparation procedure was assessed by means of a statistical Design of Experiments (DoE). The quality effects in use for the analysis were signal-to-noise ratio and Resolution. Different matrixes, analyte/matrix proportions and the use of NaTFA as cationization agent were considered. A deep inspection of the statistical results provided a better understanding of the influence of the different factors, individually or in combination, to the signal. The application of DoE for the improvement of the MALDI measurement of PLA stated that the best combination of factors (levels) was the following: matrix (s-DHB), proportion analyte/matrix (1/5 V/V), and no use of cationization agent. Degradation primarily affected the initially predominant cyclic [LA_C]_n and linear H[LA_L]_nOH species, where LA stands for a PLA repeating unit. Intramolecular and intermolecular transesterifications as well as hydrolytic and homolytic reactions took place during the formation and disappearance of oligomeric species. In both degradation mechanisms induced by thermal ageing and thermo-mechanical degradation, the formation of H[LA_L]_nOCH₃ by intermolecular transesterifications was highlighted.     

Biological activities from andiroba (Carapa guianensis Aublet.) and its biotechnological applications: A systematic review

Carapa guianensis is a tree from Meliaceae family traditionally known as andiroba that has a wide range of biological properties, including therapeutic effects, antioxidant activities, insecticidal and repellent effects that can be used in biotechnological approaches to medicine, agriculture, and cosmetic products. Therefore, we aim to explore the biological activities exhibited by this species and their respective biotechnological applications of interest. For this, a systematic review was carried out following the PRISMA guidelines dated from 1993 to 2022 through the Scopus, Web of Science and Agricultural Research Database (Base de Dados da Pesquisa Agropecuária - BDPA), screened for biological activity/bioactive compounds. A total of 129 studies were included in the PRISMA flow analysis. Biological properties and major bioactive compounds, as well as biotechnological approaches could be identified. The biological activity from C. guianensis could be observed in different vegetative parts through diverse methods of extractions. These activities are mainly due to the unsaturated fatty acids and bioactive compounds, such as the limonoids and a small fraction of phenolic compounds. Gedunin-type limonoids, like gedunin and its derivatives, represent the class of compounds that show the highest bioactivities in different applications.