Wyniki wyszukiwania - BazTech

1

Geochemical characterization and palaeoenvironmental implications of lipids in Neogene lignites and lignitic shales in NW Poland

Czechowski Franciszek, Polowczyk Marzena, Simoneit Bernt R. T., Grelowski Cezary, Hojniak Marek

Annales Societatis Geologorum Poloniae

|

2023

|

Vol. 93, No. 4

447--466

EN

The lipophilic biomarker distributions in lipids of Neogene lignites and lignitic shales in western Pomerania and the midlands of Poland are presented. Twenty-six lignite samples and seven lignitic shales were obtained from twenty-four boreholes. Their extracts were separated, using thin-layer chromatography, and the saturate and aromatic fractions were analyzed by gas chromatography-mass spectrometry. The molecular compositions of n-alkanes, isoprenoids, n-alkylcyclohexanes, n-alkylbenzenes, tri- and tetracyclic diterpenoids, pentacyclic triterpenoids, as well as polycyclic aromatic hydrocarbons (PAHs) with up to five rings, were determined. The samples displayed n-alkane distributions in the range of C14–C35 and high odd-over-even carbon number predominances (CPI(25–33) from 2.9 to 7.9). Diterpanes consisted primarily of phyllocladane, abietane, isopimarane, labdane, and kaurane structures, although their abundances varied among the samples. Hopanes exhibited the biological and geochemical characteristics of low-maturity organic matter. Minor oleanane triterpenoids from angiosperms were also found. A few samples displayed evidence of biodegradation on the basis of the advanced isomerization of αβ-hopanes and the presence of short-chained n-alkanes, n-alkylcyclohexanes, and n-alkylbenzenes. A more mature stage of the above biomarkers also may have resulted in part from the oxidation of organic matter. The lignite source materials were derived from conifer and angiosperm flora as well as microbial remnants. The contribution from marine phytoplankton was excluded on the basis of the lack of C27 steroids. PAHs were predominantly perylene or phenanthrene, with minor other analogues. Thus, the data support progressive lacustrine/lagoonal sedimentation in the palaeoenvironmental mires.

2

UPLC/Q-TOF-MS Analysis for Identification of Hydrophilic Phenolics and Lipophilic Diterpenoids from Radix Salviae Miltiorrhizae

Yang S. T., Wu X., Rui W., Guo J., Feng Y. F.

Acta Chromatographica

|

2015

|

Vol. 27, no. 4

711--728

EN

A rapid method has been used for simultaneous identification of both hydrophilic and lipophilic compounds from Radix Salviae Miltiorrhizae (RSM, the root of Salvia miltiorrhiza BGE.) by ultra-performance liquid chromatography/quadrupole time-offlight mass spectrometry (UPLC/Q-TOF-MS). A total of 58 compounds extracted by methanol were detected and tentatively identified within 20 min, including hydrophilic phenolics, lipophilic diterpenoids, a verbascose, and several organic acids. These compounds were separated on an Acquity UPLC BEH C18 column and identified based on tandem mass spectrometry (MS/MS) fragmentation patterns under the positive and negative ion modes, respectively. Among them, micranthin B and 9-oxo-10E,12Zoctadecadienoic acid were reported in RSM for the first time. Their fragmentation patterns in electrospray ionization (ESI)—MS/MS spectra were first investigated by matching their accurate molecular masses. This contribution presented one of the first reports on the analysis of hydrophilic phenolics and lipophilic diterpenoids from Radix Salviae Miltiorrhizae using UPLC/Q-TOF-MS. The results demonstrated that UPLC/Q-TOF-MS method could be applied to rapidly and expediently describe and provide comprehensive chemical information for simultaneous analysis of two different polar components in RSM.

3

Limbatolide F and G: Two New trans-Clerodane Diterpenoids from Otostegia limbata

Farooq U., Khan A., Ahmad V., Kousar F., Iqbal S.

Polish Journal of Chemistry

|

2005

|

Vol. 79 / nr 11

1757-1762

EN

Two new trans-clerodane diterpenoids pro vi sion ally named as limbatolide F (1) and limbatolide G (2) were isolated from the chloroform extract of Otostegia limbata. Both compounds 1 and 2 have a unique feature of C-4/C-6 five membered a,b-un saturated lactone. The structures of these new compounds as well as their relative configurations were determined by 1D and 2D NMR techniques including COSY, HMQC, HMBC, NOESY and NOE experiments.

4

Związki naturalne z układem gem-dimetylocykloheksanu

Grabarczyk M.

Wiadomości Chemiczne

|

2004

|

[Z] 58, 7-8

613--635

EN

Many natural terpenoids include in their structure a gem-dimethylcyclohexane ring. Such compounds are often isolated from plants or animals, where they fulfil different functions. Compounds a with gem-dimethylcycloxehane ring have been found in many marine algaes molluscs. These compounds show different biological properties, for example antibiotic [10, 66, 67, 79], cytotoxic [15, 16], fungicidal [17], inhibiting HIV [11]. Similar properties are also found in compounds isolated from plants growing in different places on Earth, plants which for many years have been known and used in tradicional medicine as antidote against different diseases [24-27, 36-46, 72-74]. These discoveries are very important for people searching for new and effective medicines against old and new diseases. For example some compounds with a gem-dimethylcyclohexane ring show an inhibitory effect on not yet curable cancers [50-57, 81]. The compounds with a gem-dimethylcyclohexane ring which occur in plants or animals have an affect not only on humans, but also on other plants or animals. Such affect can be observed in both marine and terrestial organisms [59-61, 71]. In our times very safe and effective crop protection is a very important problem. Because of this people try to find natural compounds which can produce desirable biological effects. Compounds with a gem-dimethylcycloxehane ring found in some plants can act as natural herbicides [22, 23]. Some of these compounds can also work as deterrents against insect pests. These deterrents affect the insects' sense of taste and prevent them from eating, which finally makes them die despite the abundance of food [28-33].