scholarly journals Aroma Profile of Star Anise and the Structure-odor Relationship of Anethole

2014 ◽  
Vol 9 (2) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Toshio Hasegawa ◽  
Haruna Seimiya ◽  
Takashi Fujihara ◽  
Noriko Fujiwara ◽  
Hideo Yamada
Keyword(s):  
Hydrogen Atom ◽  
Methoxy Group ◽  
Structural Characteristics ◽  
Structural Features ◽  
Aroma Profile ◽  
Methyl Group ◽  
Star Anise ◽  
Main Component ◽  
Relationship Of ◽  
Methyl Benzene

Star anise is an important fragrance material that has a characteristic anise-like odor. Although the main component of star anise is ( E)-anethole, which accounts for over 90% of the constituents, the odor of ( E)-anethole is different from that of the material itself. Here, we examined the aroma profile of star anise. GC-MS analysis of star anise extracts showed that it contains many compounds with structures similar to ( E)-anethole. Our results indicate that ( E)-anethole is the key compound in the odor of star anise, but structurally similar compounds play an important role in creating its odor. We examined the structure-odor relationship of ( E)-anethole, focusing on the methoxy and 1-propenyl substituents. Altering the 1-propenyl group changed the odors of all the anethole derivatives. Replacing the methoxy group with a hydrogen atom created compounds with similar fatty odors. This shows that the methoxy group is important for the characteristic odor of anethole. We synthesized anethole derivatives where the methoxy group was replaced with a methyl group. In both methoxy- and methyl-substituted anethole derivatives, altering the 1-propenyl group changed the odors of the derivatives. Therefore, the methoxy and methyl benzene moieties are important structural features for the odor of star anise. The structural characteristics of anethole are closely related to its odor expression.

Study on Wood Carbon Sequestration Based on Micro-Characteristics of Wood

2010 ◽  
Vol 113-116 ◽  
pp. 1693-1696
Author(s):  
Ming Hui Guo ◽  
Xin Guan ◽  
Li Zhu ◽  
Jian Li
Keyword(s):  
Carbon Sequestration ◽  
Forest Ecosystems ◽  
Structural Characteristics ◽  
Structural Features ◽  
Carbon Stocks ◽  
Xylem Parenchyma ◽  
Micro Level ◽  
Relationship Of ◽  
The Relationship

Trees are complicated and important organisms in forest ecosystem. They are both carbon stocks and carbon source. In order to give full play to the role of wood carbon sequestration, this paper discussed the relationship of wood structural features and wood carbon sequestration at micro-level. It shows that wood carbon sequestration can be synthetically reflected by vessel, tracheid/xylon, wood rays, intercellular canal, xylem parenchyma and so on. The rate of cell wall and wood carbon sequestration is the relationship of direct proportional function. Micro-structural characteristics of wood can reflect wood carbon sequestration of forest ecosystems, as well as have a practical guide to enhance carbon storage of wood.

scholarly journals Evaluation of a Series of 9,10-Anthraquinones as Antiplasmodial Agents

2019 ◽  
Vol 16 (3) ◽  
pp. 353-363 ◽  
Author(s):  
Che Puteh Osman ◽  
Nor Hadiani Ismail ◽  
Aty Widyawaruyanti ◽  
Syahrul Imran ◽  
Lidya Tumewu ◽  
...  
Keyword(s):  
Mode Of Action ◽  
Hydrophobic Interactions ◽  
Structural Characteristics ◽  
Structural Features ◽  
Antiplasmodial Activity ◽  
Hydroxyl Groups ◽  
Phytochemical Study ◽  
Methyl Group ◽  
Ic50 Value

Background: A phytochemical study on medicinal plants used for the treatment of fever and malaria in Africa yielded metabolites with potential antiplasmodial activity, many of which are Anthraquinones (AQ). AQs have similar sub-structure as naphthoquinones and xanthones, which were previously reported as novel antiplasmodial agents. </P><P> Objective: The present study aimed to investigate the structural requirements of 9,10- anthraquinones with hydroxy, methoxy and methyl substituents to exert strong antiplasmodial activity and to investigate their possible mode of action. </P><P> Methods: Thirty-one AQs were synthesized through Friedel-Crafts reaction and assayed for antiplasmodial activity in vitro against Plasmodium falciparum (3D7). The selected compounds were tested for toxicity and probed for their mode of action against β-hematin dimerization through HRP2 and lipid catalyses. The most active compounds were subjected to a docking study using AutoDock 4.2. </P><P> Results: The active AQs have similar common structural characteristics. However, it is difficult to establish a structure-activity relationship as certain compounds are active despite the absence of the structural features exhibited by other active AQs. They have either ortho- or meta-arranged substituents and one free hydroxyl and/or carbonyl groups. When C-6 is substituted with a methyl group, the activity of AQs generally increased. 1,3-DihydroxyAQ (15) showed good antiplasmodial activity with an IC50 value of 1.08 &#181;M, and when C-6 was substituted with a methyl group, 1,3- dihydroxy-6-methylAQ (24) showed stronger antiplasmodial activity with an IC50 value of 0.02 &#181;M, with better selectivity index. Compounds 15 and 24 showed strong HRP2 activity and mild toxicity against hepatocyte cells. Molecular docking studies showed that the hydroxyl groups at the ortho (23) and meta (24) positions are able to form hydrogen bonds with heme, of 3.49 Å and 3.02 Å, respectively. </P><P> Conclusion: The activity of 1,3-dihydroxy-6-methylAQ (24) could be due to their inhibition against the free heme dimerization by inhibiting the HRP2 protein. It was further observed that the anthraquinone moiety of compound 24 bind in parallel to the heme ring through hydrophobic interactions, thus preventing crystallization of heme into hemozoin.

scholarly journals Equiprobable Symbolization Pattern Entropy for Time Series Complexity Measurement

2021 ◽  
Author(s):  
Fuyi Wang ◽  
Leo Yu Zhang
Keyword(s):  
Time Series ◽  
Structural Characteristics ◽  
Sliding Window ◽  
Original Data ◽  
Structural Features ◽  
Complex Signals ◽  
Complexity Measurement ◽  
Conversion Frequency ◽  
Consistent Increase ◽  
Relationship Of

Abstract In order to more effectively mine the structural features in time series, while simplifying the complexity of time series analysis, equiprobable symbolization pattern entropy (EPSPE) based on time series symbolization combined with sliding window technology is proposed in this paper. Firstly, time series are implemented symbolic procession according to the equal probability distribution of the original data, which greatly simplifies the difficulty of analyzing the signal on the premise of small loss of precision to the original signal. Then, sliding window technique is used to obtain a finite number of different symbolic patterns, and the pattern pairs are determined by calculating the conversion between the symbolic patterns. Next, the conversion frequency between symbolized patterns is counted to calculate the probability of the pattern pairs, thus estimating the complexity measurement of complex signals. The results of test using the Logistic system with different parameters show that compared with multiscale sample entropy(MSE), EPSPE can more concisely and intuitively reflect the structural characteristics of time series. Finally, EPSPE is used to investigate the natural wind field signals collected at an outdoor space in which nine high precision two-dimensional (2D) ultrasonic anemometers are deployed in line with 1m interval. The values of EPSPE show consistent increase or decrease trend with the spatial regular arrangement of the nine anemometers. While the results of MSE are irregular, and cannot accurately predict the spatial deployment relationship of nine 2D ultrasonic anemometers.

scholarly journals Aroma Profile of Galangal Composed of Cinnamic Acid Derivatives and Their Structure-Odor Relationships

2016 ◽  
Vol 11 (10) ◽  
pp. 1934578X1601101 ◽  
Author(s):  
Toshio Hasegawa ◽  
Momohiro Hashimoto ◽  
Takashi Fujihara ◽  
Hideo Yamada
Keyword(s):  
Cinnamic Acid ◽  
Methoxy Group ◽  
Steam Distillation ◽  
Linear Chain ◽  
Hexane Extract ◽  
Hexane Extraction ◽  
Cinnamic Acid Derivatives ◽  
Aroma Profile ◽  
Main Component ◽  
Fruity Odor

Cinnamic acid derivatives are important odorants due to their characteristic scent. Some fragrance materials, such as cinnamon bark, matsutake mushrooms, and Kaempferia galanga L. rhizome (galangal), contain several cinnamic acid derivatives as important odor constituents. The main odor constituent of galangal is ( E)-ethyl 4-methoxycinnamate, but the odor of this compound is different from that of galangal. We investigated the aroma profile of galangal using our previously described method that considers the intermolecular interactions of the odorant compounds with their receptors. Odorant compounds in galangal were extracted by hexane extraction, steam distillation, and headspace sampling. The odor of the hexane extract was different from that of the steam distillate and similar to that of galangal; therefore, we searched for the key compounds contributing to the aroma profile of galangal by separating the constituents of the hexane extract. A fraction with a galangal-like odor was obtained by bulb-to-bulb distillation of the hexane extract. The main component of this fraction was not ( E)-ethyl 4-methoxycinnamate, but rather ethyl cinnamate. These results indicate that ethyl cinnamate is more important in the aroma profile of galangal than ( E)-ethyl 4-methoxycinnamate. GC-MS analysis revealed that this fraction contained aromatic compounds, cyclic terpenes, and linear chain compounds in addition to ethyl cinnamate. We synthesized cinnamic acid derivatives and examined the importance of the odor expression of these cinnamic acid derivatives. Cinnamic acid derivatives lacking a p-methoxy group had a strong fruity odor. Replacement of the hydrogen atom at the para position with a methoxy group altered and weakened the odor. We found that a p-methoxy group in cinnamic acid derivatives plays an important role in the aroma profile of galangal.

scholarly journals ISOLATION, PURIFICATION AND STRUCTURAL CHARACTERISTICS OF GLYCOSAMINOGLYCANS FROM SEA CUCUMBER STICHOPUS HORRENS

2021 ◽  
Vol 58 (6A) ◽  
pp. 199
Author(s):  
Pham Duc Thinh
Keyword(s):  
Sea Cucumber ◽  
Structural Characteristics ◽  
Anion Exchange Chromatography ◽  
Enzymatic Digestion ◽  
Structural Features ◽  
Exchange Chromatography ◽  
Molar Ratios ◽  
Structural Types ◽  
Relationship Of ◽  
Stichopus Horrens

Sea cucumber glycosaminoglycans have been well known as potential anticoagulant and antithrombin agents. In this investigation, glycosaminoglycans were isolated from sea cucumber Stichopus horrens by papain enzymatic digestion. Crude glycosaminoglycans were fractionated and purified by using anion-exchange chromatography on the DEAE-Macro Prep column to give two fractions of fucosylated chondroitin sulfate (FCS1) and fucan sulfate (FS2). Structural characteristics of F1 and F2 fractions were elucidated using chemical and IR, NMR spectroscopic methods. The results showed that the monosaccharide compositions of FCS1 consist of N-Acetyl-Galactosamine (GlcNAc), D-Glucuronic acid (GlcA) and Fucose (Fuc) residues with different molar ratios, while FS2 content only fucose residues. Sulfate contents of FCS1 and FS2 were 47.4% and 48.1%, respectively. FCS1 and FS2 fractions were different in the pattern of sulfation of  N-Acetyl-Galactosamine and fucose residues. IR and NMR spectra of two frations showed that sulfate groups were primarily occupied at C4 of pyranose residues in FS2 and C6, C2 and/or C3 of pyranose residues in FCS1 fraction. Our results contributed to knowledge on structural types of glycosaminoglycan from sea cucumbers in Vietnam. The establishment of structural features plays an important role in further studies of the structure-bioactivity relationship of sea cucumber glycosaminoglycan.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

scholarly journals Structure-Acid Lability Relationship of N-alkylated α,α-dialkylglycine Obtained via a Ugi Multicomponent Reaction

Molecules ◽  
2021 ◽  
Vol 26 (1) ◽  
pp. 197
Author(s):  
Iván Ramos-Tomillero ◽  
Marisa K. Sánchez ◽  
Hortensia Rodríguez ◽  
Fernando Albericio
Keyword(s):  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Structural Features ◽  
Amide Bond ◽  
Acidic Media ◽  
Phase Synthesis ◽  
Acyl Chains ◽  
Cyclic Compounds ◽  
Relationship Of ◽  
Fine Tune

Using the classical Ugi four-component reaction to fuse an amine, ketone, carboxylic acid, and isocyanide, here we prepared a short library of N-alkylated α,α-dialkylglycine derivatives. Due to the polyfunctionality of the dipeptidic scaffold, this highly steric hindered system shows an interesting acidolytic cleavage of the C-terminal amide. In this regard, we studied the structure-acid lability relationship of the C-terminal amide bond (cyclohexylamide) of N-alkylated α,α-dialkylglycine amides 1a–n in acidic media and, afterward, it was established that the most important structural features related to its cleavage. Then, it was demonstrated that electron-donating effects in the aromatic amines, flexible acyl chains (Gly) at the N-terminal and the introduction of cyclic compounds into dipeptide scaffolds, increased the rate of acidolysis. All these effects are related to the ease with which the oxazolonium ion intermediate forms and they promote the proximity of the central carbonyl group to the C-terminal amide, resulting in C-terminal amide cleavage. Consequently, these findings could be applied for the design of new protecting groups, handles for solid-phase synthesis, and linkers for conjugation, due to its easily modulable and the fact that it allows to fine tune its acid-lability.

The Research and Simulation Analysis of a New Type of Translational Transmission Device

2014 ◽  
Vol 556-562 ◽  
pp. 1408-1412
Author(s):  
Zhi Qiang Zhang
Keyword(s):  
Modeling And Simulation ◽  
Theoretical Foundation ◽  
Simulation Analysis ◽  
Structural Modeling ◽  
Structural Features ◽  
Practical Application ◽  
Optimization Analysis ◽  
New Type ◽  
Mechanism Parameter ◽  
Relationship Of

In this paper, the following work is done: a new type of translational transmission device is designed; explained in detail are the operating principle, structural features, relationship of mechanism parameter and non interference conditions of the movement; the optimization analysis of transmission device is implemented on the basis of non interference conditions of the bucket movement; structural modeling and simulation analysis are carried out by utilization of Pro/e & Recurdyn; and based on virtual prototype technology, the new type of translational transmission device is verified by experiments, the data of which prove the translational transmission device reasonable and practicable. In conclusion, this paper has laid the theoretical foundation of the practical application of the translational transmission device.

scholarly journals Non-negative sparse Laplacian regularized latent multi-view subspace clustering

2021 ◽  
Vol 15 ◽  
pp. 174830262110249
Author(s):  
Cong-Zhe You ◽  
Zhen-Qiu Shu ◽  
Hong-Hui Fan
Keyword(s):  
Subspace Clustering ◽  
Structural Features ◽  
Space Representation ◽  
Graph Regularization ◽  
Structure Information ◽  
Cluster Data ◽  
Latent Space ◽  
Low Dimensional ◽  
Relationship Of ◽  
The Relationship

Recently, in the area of artificial intelligence and machine learning, subspace clustering of multi-view data is a research hotspot. The goal is to divide data samples from different sources into different groups. We proposed a new subspace clustering method for multi-view data which termed as Non-negative Sparse Laplacian regularized Latent Multi-view Subspace Clustering (NSL2MSC) in this paper. The method proposed in this paper learns the latent space representation of multi view data samples, and performs the data reconstruction on the latent space. The algorithm can cluster data in the latent representation space and use the relationship of different views. However, the traditional representation-based method does not consider the non-linear geometry inside the data, and may lose the local and similar information between the data in the learning process. By using the graph regularization method, we can not only capture the global low dimensional structural features of data, but also fully capture the nonlinear geometric structure information of data. The experimental results show that the proposed method is effective and its performance is better than most of the existing alternatives.

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