Bacteriochlorophyll e : structure and stereochemistry of a new type of chlorophyll from Chlorobiaceae

A so far unknown chlorophyll has been isolated from several strains of brown-coloured chlorobacteria and has been designated bacteriochlorophyll e . Comparison of the physical and chemical properties of the new chlorophyll with those of bacteriochlorophylls c and d ( Chlorbium chlorophylls) allows one to deduce its structural formula. The stereochemistry of the hydroxyethyl side chain of bacteriochlorophylls c, d and e can be determined by a modified Horeau analysis of these pigments, and the results thus obtained are in agreement with those derived from oxidative degradation experiments. The latter method allows one furthermore to prove the structure of bacteriochlorophylls c and d proposed by Holt, and to establish the absolute configuration at carbon atoms 7 and 8. The presence of a δ-methylsubstituent in bacteriochlorophylls c and e is unambiguously demonstrated by nuclear magnetic resonance.

Author(s):  
Guili Ge ◽  
Lin Li ◽  
Dan Wang ◽  
Mingjian Chen ◽  
Zhaoyang Zeng ◽  
...  

Carbon dots (CDs) are a new type of carbon nanomaterial that have unique physical and chemical properties, good biocompatibility, low toxicity, easy surface functionalization, making them widely used in biological...


2013 ◽  
Vol 652-654 ◽  
pp. 765-769
Author(s):  
Qing Wang Liu ◽  
Yun Hai Zhu ◽  
Guang Zhi Han ◽  
Zhen Zhong Fan ◽  
Ji Gang Wang ◽  
...  

A cationic Gemini surfactant ethane-1, 2-bis (Cetyl dimethyl brominated ammonium), denoted 16-2-16 was synthesized from ethane and Hexadecyl dimethyl amine. The properties of the product were characterized, and the physical and chemical properties were determined. The results showed that the synthetic product was the target product, and its surface tension was 3.4×10-4N/m, and the CMC was 2.2×10-4mol/L at 25°C. At the same time, its synergistic effect with common surfactants was studied; the results showed that the synthetic product had good synergic effect.


2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Qing Liao ◽  
Tingting Song

In the development of modern society, many new materials and technologies have been integrated into the development of various industries. As a new type of two-dimensional carbon nanomaterials, graphene has great advantages in physical and chemical properties and is widely used in various fields of development. Among them, the electrochemical method is one of the important ways to prepare graphene materials, which has the characteristics of quickness and environmental protection, and can effectively produce a large amount of high-quality graphene and its composite materials. Based on this, the paper introduces the preparation method of graphene materials and studies the application of graphene materials in the field of electrochemistry.


2013 ◽  
Vol 791-793 ◽  
pp. 456-459
Author(s):  
Jian Jun Li ◽  
Yan Chun Liu

As a new type of green material with excellent physical and chemical properties and mechanical properties. Basalt fiber are widely used in the field of civil construction. This paper focused on the use of basalt fibers to improve the mechanism of asphalt concrete, demonstrated the prospects and market value of the basalt fiber that are widely used in asphalt concrete


1967 ◽  
Vol 53 (4) ◽  
pp. 359-371 ◽  
Author(s):  
Giovanni Ceriotti ◽  
Luigi Spandrio ◽  
Annibale Gazzaniga

A crystalline substance with marked antimitotic activity on several biological systems (mitoses of ascites S 180, of the megaloblasts of chick embryo, of the tips of wheat radicles) has been isolated from the bulbs of several varieties of Narcissus and named Narciclasine. After reference to the tests that led to its discovery and isolation and to the work of others in the same field, the method of isolation is described together with the physical and chemical properties of the substance (identification, chromatographic behavior, UV, IR and fluorescence). The structural formula, established on the basis of work reported elsewhere, is given.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Muhammad Javaid ◽  
Muhammad Khubab Siddique ◽  
Ebenezer Bonyah

Chemical structural formula can be represented by chemical graphs in which atoms are considered as vertices and bonds between them are considered as edges. A topological index is a real value that is numerically obtained from a chemical graph to predict its various physical and chemical properties. Thorn graphs are obtained by attaching pendant vertices to the different vertices of a graph under certain conditions. In this paper, a numerical relation between the Gutman connection (GC) index of a graph and its thorn graph is established. Moreover, the obtained result is also illustrated by computing the GC index for the particular families of the thorn graphs such as thorn paths, thorn rods, thorn stars, and thorn rings.


2018 ◽  
Vol 20 (1) ◽  
pp. 61-64 ◽  
Author(s):  
Tsutomu Arakawa

TOYOPEARL particles are cross-linked hydroxylated methacrylic polymers available in different pore and particle sizes. They are conjugated with different ligands to generate ion-exchange, hydrophobic interaction and affinity resins. They have excellent physical and chemical properties. A mixed-mode resin, TOYOPEARL MX-Trp-650M, is made of this particle with tryptophan conjugated via N-terminal amino group and hence has both hydrophobic/aromatic side chain and carboxyl group. In this review, I will summarize the properties of the TOYOPEARL particles and MX-Trp-650M resin and application of this resin for purification of proteins and in some detail the separation of disulfide (SS)- scrambled oligomers of insulin-like growth factor-1 (IGF-1). For this particular application, the intact IGF-1 was used to examine binding and elution conditions of TOYOSCREEN MX-Trp-650M column. Strong binding was obtained at pH 4.0, at which arginine, but not NaCl, resulted in elution. Both NaCl and arginine resulted in elution at pH 6.5. In addition, a pH gradient from 4.0 to 8.5 was effective. When applied to SS-scrambled IGF-1 oligomers, both pH and arginine gradient exhibited an efficient separation of the oligomers.


1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.


2017 ◽  
pp. 31-43
Author(s):  
Berta Ratilla ◽  
Loreme Cagande ◽  
Othello Capuno

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.


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