scholarly journals Studies on the antimicrobial potential and structural characterization of fatty acids extracted from Sydney rock oyster Saccostrea glomerata

2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Subbiahanadar Chelladurai Karthikeyan ◽  
Subramanian Velmurugan ◽  
Mariathason Birdilla Selva Donio ◽  
Mariavincent Michaelbabu ◽  
Thavasimuthu Citarasu
Keyword(s):  
Fatty Acids ◽  
Structural Characterization ◽  
Antimicrobial Potential ◽  
Rock Oyster ◽  
Saccostrea Glomerata

Structural Characterization of Natural Polyisoprenes: Solve the Mystery of Natural Rubber Based on Structural Study

2001 ◽  
Vol 74 (3) ◽  
pp. 355-375 ◽  
Author(s):  
Yasuyuki Tanaka
Keyword(s):  
Fatty Acids ◽  
Natural Rubber ◽  
Structural Characterization ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Terminal Group ◽  
Radical Scavenger ◽  
Branch Points

Abstract Structural characterization of naturally occurring polyisoprenes was carried out to solve the mystery of natural rubber (NR), such as the biosynthesis mechanism of rubber formation, the origin of outstanding properties of NR and the role of rubber in rubber trees. The NMR analysis, based on terpenes and polyprenols as models, disclosed the structure of both terminal groups of rubber chain. Structural evidence indicated that the biosynthesis of rubbers from Lactarius mushroom and leaves of high plants starts from trans, trans-farnesyl diphosphate or trans, trans, trans-geranylgeranyl diphosphate and terminates by dephosphorylation to form a hydroxyl terminal group. The biosynthesis of NR was presumed to start from unidentified initiating species containing two trans-isoprene units and peptide group and to terminate forming a phospholipid terminal group. The initiating group of NR associated with proteins formed branch points, which can be decomposed by enzymatic deproteinization. The branch points formed by phospholipid group were decomposed by transesterification with sodium methoxide. Rapid crystallization of NR was explained by the presence of mixed fatty acids synergistically with linked fatty acids, which were included in phospholipid. Saturated fatty acids linked to rubber chain induced crystallization, while mixed unsaturated fatty acids acted as plasticizer and accelerated the crystallization rate. This was confirmed by the preparation of model cis-polyisoprene grafted with stearic acid. The green strength of NR decreased to the same level as synthetic cis-polyisoprene after transesterification, indicating the effect of branching formed by the phospholipid terminal group and fatty acids in NR. The role of NR in Hevea trees was analyzed using NR from Hevea trees never tapped before. The formation of hard gel and oxidative degradation during the storage of NR in Hevea trees suggested that NR acted as a radical scavenger to remove hydroperoxide.

Biosynthesis and structural characterization of medium-chain-length poly(3-hydroxyalkanoates) produced by Pseudomonas aeruginosa from fatty acids

2001 ◽  
Vol 29 (2) ◽  
pp. 107-114 ◽  
Author(s):  
Alberto Ballistreri ◽  
Mario Giuffrida ◽  
Salvatore P.P. Guglielmino ◽  
Santina Carnazza ◽  
Annamaria Ferreri ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Pseudomonas Aeruginosa ◽  
Chain Length ◽  
Structural Characterization ◽  
Medium Chain ◽  
Medium Chain Length

Biosynthesis and structural characterization of polyhydroxyalkanoates produced by Pseudomonas aeruginosa ATCC 27853 from long odd-chain fatty acids

2018 ◽  
Vol 108 ◽  
pp. 608-614 ◽  
Author(s):  
Giuseppe Impallomeni ◽  
Alberto Ballistreri ◽  
Giovanni M. Carnemolla ◽  
Maria G. Rizzo ◽  
Marco S. Nicolò ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Pseudomonas Aeruginosa ◽  
Structural Characterization ◽  
Odd Chain Fatty Acids ◽  
Chain Fatty Acids

Composition of Color Substances of Hevea Brasiliensis Natural Rubber

2007 ◽  
Vol 80 (2) ◽  
pp. 212-230 ◽  
Author(s):  
Jitladda Sakdapipanich ◽  
Kittipong Insom ◽  
Nataphon Phupewkeaw
Keyword(s):  
Fatty Acids ◽  
High Resolution ◽  
Natural Rubber ◽  
Structural Characterization ◽  
Unsaturated Fatty Acids ◽  
Rubber Latex ◽  
Naturally Occurring ◽  
Bottom Fraction ◽  
Light Color

Abstract It is accepted that NR gives naturally occurring color, which restrict many applications such as light-color products. Therefore, characterization of color substances presenting in NR is very useful to develop the certain methodology to eliminate them completely or partly from NR in the future. In this work, an attempt was made to purify and characterize the color substances extracted from various fractions of Hevea rubber latex by certain methods, using high-resolution structural characterization techniques. It was found that the content of color substances extracted from fresh latex (FL), rubber cream, bottom fraction (BF), Frey Wyssling (FW) particles and STR 20 were different. Based on the high-resolution spectroscopic analyzes, it was found that the color substances extracted from NR were composed of carotenoids, tocotrienol esters, fatty alcohol esters, tocotrienols, unsaturated fatty acids, fatty alcohols, diglyceride and monoglyceride. The results will be useful for rubber-technologist to identify the origin to make obnoxious color in natural rubber, especially in some applications which are restricted by such the color.

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