Synthesis and Comparative Physical-chemical Characterisation of Neutral and Cationic Amphiphiles Using RP-HPLC

2013 ◽  
Vol 9 (4) ◽  
pp. 653-658
Author(s):  
Jennifer Squire ◽  
Luke Henderson ◽  
Xavier Conlan
2014 ◽  
Vol 26 (1) ◽  
pp. 219
Author(s):  
R. H. Alvarez ◽  
B. E. Almeida ◽  
M. T. C. P. Ribela ◽  
F. L. N. Natal ◽  
A. J. F. Melo ◽  
...  

Superovulation in ruminants can be induced with a single injection of equine chorionic gonadotropin (eCG). However, ovarian response is sometimes lower than expected because of, among other factors, the source of eCG used. This study aimed at establishing the physical-chemical profile of commercial eCG, in order to find differences which can be related to their biological activity. Four different commercial eCG products for veterinary use (A, B, C, D) and one eCG chemical reagent from Sigma (St. Louis, MO, USA), here used as reference preparation, were analysed by reversed-phase high-performance liquid chromatography (RP-HPLC) using a C4-Grace Vydac 214 TP 54-column (25 cm × 4.6 mm I.D.), with UV detection at 220 nm. All eCG preparations presented at least three peaks with retention times (tR) of ~27(I), 34(II), and 36(III) minutes, with a peak at tR = 27 min common to A, C, D, and Sigma eCG, whereas preparation B did not present this peak. A bioassay test was carried with all of these preparations. Immature 21- to 25-day-old Wistar female rats received the equivalent to 10 IU of eCG of each one of these preparations. Autopsy was performed 48 h later and ovaries were removed and weighed. The average ovarian weight for preparations A, C, D, and Sigma were ~0.0795 ± 0.0107 g, whereas preparation B was 0.035 ± 0.007 g (P < 0.01). Preparation B was not different from saline (0.034 ± 0.002 g). In order to establish which one of these three peaks presented the highest biological activity, a mass equivalent to 10 IU of eCG from peaks I, II, and III of Sigma and of product A were studied. The average ovarian weight of animals injected with material from peak II and III (~0.0285 ± 0.003 g) were similar to that of the control whereas peak I produced ovarian weights of 0.059 ± 0.007 g and 0.075 ± 0.010 g for Sigma and product A, respectively (P < 0.01). These results suggest that the lack of ovarian response to eCG treatments can be related to differences in the physical-chemical profile of commercial eCG products and that RP-HPLC is a fast and reliable tool for detecting these differences. Supported by FAPESP (Grant 11/13096-0).


Author(s):  
Henry S. Slayter

Electron microscopic methods have been applied increasingly during the past fifteen years, to problems in structural molecular biology. Used in conjunction with physical chemical methods and/or Fourier methods of analysis, they constitute powerful tools for determining sizes, shapes and modes of aggregation of biopolymers with molecular weights greater than 50, 000. However, the application of the e.m. to the determination of very fine structure approaching the limit of instrumental resolving power in biological systems has not been productive, due to various difficulties such as the destructive effects of dehydration, damage to the specimen by the electron beam, and lack of adequate and specific contrast. One of the most satisfactory methods for contrasting individual macromolecules involves the deposition of heavy metal vapor upon the specimen. We have investigated this process, and present here what we believe to be the more important considerations for optimizing it. Results of the application of these methods to several biological systems including muscle proteins, fibrinogen, ribosomes and chromatin will be discussed.


2019 ◽  
Vol 3 (5) ◽  
pp. 435-443 ◽  
Author(s):  
Addy Pross

Despite the considerable advances in molecular biology over the past several decades, the nature of the physical–chemical process by which inanimate matter become transformed into simplest life remains elusive. In this review, we describe recent advances in a relatively new area of chemistry, systems chemistry, which attempts to uncover the physical–chemical principles underlying that remarkable transformation. A significant development has been the discovery that within the space of chemical potentiality there exists a largely unexplored kinetic domain which could be termed dynamic kinetic chemistry. Our analysis suggests that all biological systems and associated sub-systems belong to this distinct domain, thereby facilitating the placement of biological systems within a coherent physical/chemical framework. That discovery offers new insights into the origin of life process, as well as opening the door toward the preparation of active materials able to self-heal, adapt to environmental changes, even communicate, mimicking what transpires routinely in the biological world. The road to simplest proto-life appears to be opening up.


2018 ◽  
Vol 2 (2) ◽  
Author(s):  
SULASMI ANGGO

The Analysis of physical chemical from dara shells (Anadara granosa) origin from Kayutanyo, kab. Banggai, has been conducted.Dara shell meat is sleaned and dried and after that powered with blender. Determine % rendement, water bonding capacity and index water solubility with Anderson method, coarse fat content with gravimetric method and carbohydrate method with “bye difference” decrease method.The result of analysis showed rendement value is 24,35%, water bonding capacity is 1,6248 gram/ml, index water solubility is 0,202 gram/ml, water content is 79,0045%, total dust content is 1,072%, coarse protein content is 2,25%, coarse fat content is 8,47%, carbohydrate content is 9,2035%. Keyword : Dara shells, (Anadara granosa), analysis physical chemical


Author(s):  
Prof. Asoc. Dr. Shurki MAXHUNI ◽  
Prof.Asiss.Dr.Nerimane BAJRAKTARI

The dairy industry seems to have convinced the food industry that whey is a miracle product. The list of supposed benefits it gives to food is as long as your arm. Some of the benefits may be real. Whey is the liquid remaining after milk has been curdled and strained. It is a by-product of the manufacture of cheese or casein and has several commercial uses. To produce cheese, rennet or an edible acid is added to heated milk. This makes the milk coagulate or curdle, separating the milk solids (curds) from the liquid whey. Sweet whey is the byproduct of rennet-coagulated cheese and acid whey (also called sour whey) is the byproduct of acid-coagulated cheese. Sweet whey has a pH greater than or equal to 5.6, acid whey has a pH less than or equal to 5.1. Whey is also a great way to add sweetness to a product without having to list sugar as an ingredient as whey contains up to 75% lactose. And it sounds healthy. This study is done to research the examinations for the production of mozzarella cheese from Cow’s milk, after research and analyses of a physical-chemical peculiar feature of whey from coagulum. We have followed the processes from the drying of whey from the coagulum analyzer's physical-chemical peculiar feature. We carried out three experiments. For every experiment, we took three patterns and analyzed the physical-chemical. The calculation was appraised statistically. This paper deals with the research of% of whey fat during the process of milk production from standardized to non-standardized milk. Where% of whey fat should be an economic indicator for standardizing milk for dairy production.


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