Reactive pyrolysis-GC: A simple, one-step, quantitative method for the analysis of fatty acids in natural products

2011 ◽  
Vol 23 (11) ◽  
pp. 254-256
Author(s):  
Robert R. Freeman ◽  
Tetsuro Yuzawa ◽  
Chu Watanabe
Keyword(s):  
Fatty Acids ◽  
Natural Products ◽  
Quantitative Method ◽  
One Step

Direct Cyclization of Alkenyl Thioester via Transition Metal‐hydrogen Atom Transfer/radical‐polar Crossover Mechanism

2019 ◽  
Author(s):  
Shiori Date ◽  
Kensei Hamasaki ◽  
Karen Sunagawa ◽  
Hiroki Koyama ◽  
Chikayoshi Sebe ◽  
...  
Keyword(s):  
Natural Products ◽  
Hydrogen Atom ◽  
Transition Metal ◽  
Hydrogen Atom Transfer ◽  
Synthetic Method ◽  
Atom Transfer ◽  
Reaction Conditions ◽  
Hydride Hydrogen ◽  
Sulfur Heterocycles ◽  
One Step

<div>We report here a catalytic, Markovnikov selective, and scalable synthetic method for the synthesis of saturated sulfur heterocycles, which are found in the structures of pharmaceuticals and natural products, in one step from an alkenyl thioester. Unlike a potentially labile alkenyl thiol, an alkenyl thioester is stable and easy to prepare. The powerful Co catalysis via a cobalt hydride hydrogen atom transfer and radical-polar crossover mechanism enabled simultaneous cyclization and deprotection. The substrate scope was expanded by the extensive optimization of the reaction conditions and tuning of the thioester unit.</div>

One-step Separation and Purification of Four Phenolic Acids from Stenoloma chusanum (L.) Ching by Medium-pressure Liquid Chromatography and High-speed Counter-current Chromatography

2019 ◽  
Vol 9 (2) ◽  
pp. 138-143
Author(s):  
Tianyun Li ◽  
Xiling Dai ◽  
Yichen Li ◽  
Guozheng Huang ◽  
Jianguo Cao
Keyword(s):  
Natural Products ◽  
Liquid Chromatography ◽  
Phenolic Acids ◽  
High Speed ◽  
High Efficiency ◽  
Total Phenolic ◽  
Medium Pressure ◽  
Medium Pressure Liquid Chromatography ◽  
One Step ◽  
Counter Current

Background:Stenoloma chusanum (L.) Ching is a Chinese traditional medicinal fern with high total flavonoid and total phenolic content. Traditionally, phenolic compounds were separated by using column chromatography, which is relatively inefficient. </P><P> Objective: This study aims to use an efficient method to separate natural products from S. chusanum by Medium-Pressure Liquid Chromatography (MPLC) and High-Speed Counter-Current Chromatography (HSCCC).Methods:In the present research, firstly, a sample (2.5 g) from the dichloromethane extract of S. chusanum was separated by MPLC. Next, fraction P5 was purified by HSCCC with a two-phase solvent system composed of hexane-ethyl acetate-methanol-water (HEMWat) at a volume ratio of 2:4:1:4 (v/v/v/v). </P><P> Result: Four phenolic acids were obtained and their structures were identified by means of NMR and ESI-mass analysis. They were identified as: 1) protocatechuic acid (34 mg, purity 90.1%), 2) syringic acid (66 mg, purity 99.0%), 3) p-hydroxybenzoic acid (5 mg, purity 91.2%) and 4) vanillic acid (6 mg, purity 99.3%).Conclusion:The combination of MPLC and HSCCC is a high-efficiency separation method for natural products. This is the first report with regard to the separation of four phenolic acids in one step by MPLC and HSCCC from S. chusanum (L.) Ching.

Synthesis of Polycycles and Oxacycles by Tandem Metathesis of endo–norbornene Derivatives

Synthesis ◽  
2021 ◽  
Author(s):  
Sambasivarao Kotha ◽  
Sunil Pulletikurti ◽  
Ambareen Fatma ◽  
gopal dhangar ◽  
gonna somu Naidu
Keyword(s):  
Natural Products ◽  
Metal Complex ◽  
Carbonyl Group ◽  
Single Step ◽  
Time Dependent ◽  
Computational Studies ◽  
Nmr Studies ◽  
Tricyclic Compounds ◽  
One Step ◽  
Norbornene Derivatives

Here, we have demonstrated that the presence of a carbonyl group at C7 position is preventing the olefin metathesis of endo-norbornene derivatives due to the complexation of the metal alkylidene. Time-dependent NMR studies showed the presence of new proton signals in the metal alkylidene region, which indicate the formation of metal complex with the carbonyl group of the substrate. These observations were further proved by ESI-MS analysis. Whereas, computational studies provided that the catalyst was interacting with the C7 carbonyl group and aligned perpendicular to that of norbornene olefin. Later, these endo-keto norbornene derivatives were reduced to hydroxyl derivatives diastereoselectively. Ring-rearrangement metathesis (RRM) of these hydroxyl derivatives, produced the [6/5/6], and [5/6/5] carbo-tricyclic cores of the natural products in one step. Whereas the RRM of O-allyl derivatives, delivered the oxa-tricyclic compounds in a single step with excellent yields.

A one step quantitative method for ria optimization

1985 ◽  
Vol 18 (3) ◽  
pp. 202
Author(s):  
F. Rousseau ◽  
J.-C. Forest ◽  
A. Lemay
Keyword(s):  
Quantitative Method ◽  
One Step

Sequential one-step extraction and analysis of triacylglycerols and fatty acids in plant tissues

2003 ◽  
Vol 317 (2) ◽  
pp. 247-254 ◽  
Author(s):  
Noemı́ Ruiz-López ◽  
Enrique Martı́nez-Force ◽  
Rafael Garcés
Keyword(s):  
Fatty Acids ◽  
Plant Tissues ◽  
One Step

Eremophilane-type sesquiterpenes from fungi and their medicinal potential

2017 ◽  
Vol 399 (1) ◽  
pp. 13-28 ◽  
Author(s):  
Kamila Tomoko Yuyama ◽  
Diana Fortkamp ◽  
Wolf-Rainer Abraham
Keyword(s):  
Fatty Acids ◽  
Natural Products ◽  
Carbon Skeleton ◽  
New Drugs ◽  
Special Focus ◽  
Bioactive Natural Products ◽  
Pharmacokinetic Assessment ◽  
Immunomodulatory Properties ◽  
Chemical Tools ◽  
Subsequent Improvement

AbstractEremophilanes are sesquiterpenes with a rearranged carbon skeleton formed both by plants and fungi, however, almost no plant eremophilanes are found in fungi. These eremophilanes possess mainly phytotoxic, antimicrobial, anticancer and immunomodulatory properties and in this review fungal eremophilanes with bioactivities of potential medicinal applications are reviewed and discussed. A special focus is set on natural products bearing highly functionalized fatty acids at C-1 or C-3 position of the eremophilane backbone. Many of these fatty acids seem to contribute to the bioactivity of the metabolites enhancing the activity of the sesquiterpene moieties. Several approaches for optimization of these natural products for clinical needs and testing of the resulting derivatives are presented and discussed. The combination of identification of bioactive natural products with their subsequent improvement using a variety of genetical or chemical tools and the pharmacokinetic assessment of the products is presented here as a promising approach to new drugs.

One-step hydroprocessing of fatty acids into renewable aromatic hydrocarbons over Ni/HZSM-5: insights into the major reaction pathways

2017 ◽  
Vol 19 (4) ◽  
pp. 2961-2973 ◽  
Author(s):  
Shiyou Xing ◽  
Pengmei Lv ◽  
Jiayan Wang ◽  
Junying Fu ◽  
Pei Fan ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Aromatic Hydrocarbons ◽  
Reaction Pathways ◽  
Major Reaction ◽  
One Step ◽  
Catalytic Mechanisms

We describe the production of renewable aromatic hydrocarbons by a new facile one-step hydroprocessing of fatty acids with an in-depth exploration of the major reaction pathways and catalytic mechanisms.

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