More Values of L-Quebrachitol from Skim Natural Rubber Latex

2015 ◽  
Vol 659 ◽  
pp. 458-462 ◽  
Author(s):  
Teerawan Wannuch ◽  
Adun Nimpaiboon ◽  
Jitladda Sakdapipanich

Natural rubber (NR) latex collected from Hevea brasiliensis rubber tree exists as a colloidal suspension with 30% dry rubber content (DRC). For convenient use and transportation, the latex is concentrated by centrifugation process. Through this process, the 60% DRC concentrated NR latex and 5% DRC skim latex as a by-product were produced. After using acid coagulation of skim latex, the skim rubber is obtained to use as a low-grade application due to high amount of non-rubber components as impurities. The water portion remaining after the coagulation of skim rubber consists of various water-soluble materials such as sugars, lipids, proteins and minerals, which can cause the water pollution if serum is directly discharged into the environment without proper treatment. However, 1.5% of L-quebrachitol was found in skim latex. It can be used in many applications such as a starting material for the synthesis of bioactive materials and inositol pharmacy. Thus, this work is an attempt to investigate the most effective extraction method of L-quebrachitol from skim latex. It was found that the appropriate solvent for extraction L-quebrachitol at high temperature and for recrystallization at low temperature is ethanol. The yield of L-quebrachitol about 2-3% by weight of solid serum was obtained. Moreover, a sweetness and antibacterial activity were also studied for its further applications. It was found that the sweetness of L-quebrachitol was twice than that of sucrose. No antibacterial activity of L-quebrachitol against Staphylococcus aureus and Streptococcus mutans was found.

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1039 ◽  
Author(s):  
Nanxi Zhang ◽  
Hui Cao

To enhance the antibacterial activity of natural rubber latex foam (NRLF), chitin was added during the foaming process in amounts of 1–5 phr (per hundred rubber) to prepare an environmentally friendly antibacterial NRLF composite. In this research, NRLF was synthesized by the Dunlop method. The swelling, density, hardness, tensile strength, elongation at break, compressive strength and antibacterial activity of the NRLFs were characterized. FTIR and microscopy were used to evaluate the chemical composition and microstructure of the NRLFs. The mechanical properties and antibacterial activity of the NRLF composites were tested and compared with those of pure NRLF. The antibacterial activity was observed by the inhibition zone against E. coli. NRLF composite samples were embedded in a medium before solidification. The experimental results of the inhibition zone indicated that with increasing chitin content, the antibacterial activity of the NRLF composites increased. When the chitin content reached 5 phr, the NRLF composite formed a large and clear inhibition zone in the culture dish. Moreover, the NRLF–5 phr chitin composite improved the antibacterial activity to 281.3% of that of pure NRLF against E. coli.


2013 ◽  
Vol 747 ◽  
pp. 103-106 ◽  
Author(s):  
Prapaporn Boonme ◽  
Hasleena Boontawee ◽  
Wirach Taweepreda ◽  
Wiwat Pichayakorn

The mucous liquid of Hevea brasiliensis or Para rubber tree, called natural rubber latex (NRL), composes of cis-1,4-polyisoprene which can form a patch under suitable formulation. In this study, blank and 5% lidocaine-loaded NRL patches were formulated and then characterized for physicochemical properties as well as evaluated in vitro drug release and stability. The patches were observed for their appearances. Surface morphology of the patches was investigated using a SEM. XRD was employed to study the crystallinity of the drug, the patch, and the drug-loaded patch. The extractions of lidocaine-loaded patches were analyzed for drug contents by HPLC. In vitro drug release study was performed using modified Franz diffusion cells. The patches at initial preparation and after kept at 4, 25, and 45 °C for 3 months were investigated for the stability determination. The results suggested that NRL could be used as a main component in pharmaceutical transdermal patches with acceptable physicochemical properties. Lidocaine-loaded NRL patches provided desirable drug release but high storage temperatures could age the patches resulting in darken color and lower release amount.


BioResources ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 3168-3181 ◽  
Author(s):  
José Antonio Fiorote ◽  
Alair Pereira Freire ◽  
Dasciana de Sousa Rodrigues ◽  
Maria Alice Martins ◽  
Larissa Andreani ◽  
...  

Rubber tree and oil palm are industrial crops cultivated in the same climate and environment. These plants are used to prepare nanocomposites of natural rubber and cellulose from empty fruit bunches, an abundant residue in the palm oil industry. For this study, the cellulose particles were extracted from the bunches and subjected to enzymatic hydrolysis or microfibrillation to produce nanostructured particles. The nanoparticles were blended with natural rubber latex in an aqueous medium, and the mixture was dried. The properties of the nanocomposites were compared to those of pure natural rubber and unprocessed cellulose composites. The mechanical properties of the natural rubber can be modified by the cellulose content and morphology. As a consequence, it is possible to modulate the material properties by changing only the filler morphology. The use of microfibrillated cellulose had stronger reinforcement effects. The thermal properties of natural rubber were not affected by the addition of cellulose.


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