scholarly journals Polyurethane-based bioadhesive synthesized from polyols derived from castor oil (Ricinus communis) and low concentration of chitosan

2017 ◽  
Vol 32 (19) ◽  
pp. 3699-3711 ◽  
Author(s):  
Yomaira L. Uscátegui ◽  
Said J. Arévalo-Alquichire ◽  
José A. Gómez-Tejedor ◽  
Ana Vallés-Lluch ◽  
Luis E. Díaz ◽  
...  
Keyword(s):  
Castor Oil ◽  
Ricinus Communis ◽  
Low Concentration ◽  
Image Position

Abstract

scholarly journals Kinetic and regulatory properties of cytosolic pyruvate kinase from germinating castor oil seeds

1991 ◽  
Vol 279 (2) ◽  
pp. 495-501 ◽  
Author(s):  
F E Podestá ◽  
W C Plaxton
Keyword(s):  
Pyruvate Kinase ◽  
Castor Oil ◽  
Mixed Type ◽  
Competitive Inhibition ◽  
Ricinus Communis ◽  
Cytosolic Ph ◽  
Oil Seeds ◽  
Saturation Kinetics ◽  
Regulatory Properties

The kinetic and regulatory properties of cytosolic pyruvate kinase (PKc) isolated from endosperm of germinating castor oil seeds (Ricinus communis L.) have been studied. Optimal efficiency in substrate utilization (in terms of Vmax/Km for phosphoenolpyruvate or ADP) occurred between pH 6.7 and 7.4. Enzyme activity was absolutely dependent on the presence of a bivalent and a univalent metal cation, with Mg2+ and K+ fulfilling this requirement. Mg2+ binding showed positive and negative co-operativity at pH 6.5 (h = 1.6) and pH 7.2 (h = 0.69) respectively. Hyperbolic saturation kinetics were observed with phosphoenolpyruvate (PEP) and K+, whereas ADP acted as a mixed-type inhibitor over 1 mM. Glycerol (10%, v/v) increased the S0.5(ADP) 2.3-fold and altered the pattern of nucleotide binding from hyperbolic (h = 1.0) to sigmoidal (h = 1.79) without modifying PEP saturation kinetics. No activators were identified. ATP, AMP, isocitrate, 2-oxoglutarate, malate, 2-phosphoglycerate, 2,3-bisphosphoglycerate, 3-phosphoglycerate, glycerol 3-phosphate and phosphoglycolate were the most effective inhibitors. These metabolites yielded additive inhibition when tested in pairs. ATP and 3-phosphoglycerate were mixed-type inhibitors with respect to PEP, whereas competitive inhibition was observed for other inhibitors. Inhibition by malate, 2-oxoglutarate, phosphorylated triose sugars or phosphoglycolate was far more pronounced at pH 7.2 than at pH 6.5. Although 32P-labelling studies revealed that extensive phosphorylation in vivo of soluble endosperm proteins occurred between days 3 and 5 of seed germination, no alteration in the 32P-labelling pattern of 5-day-germinated endosperm was observed after 30 min of anaerobiosis. Moreover, no evidence was obtained that PKc was a phosphoprotein in aerobic or anoxic endosperms. It is proposed that endosperm PKc activity of germinating castor seeds is enhanced after anaerobiosis through concerted decreases in ATP levels, cytosolic pH and concentrations of several key inhibitors.

Castor Oil ( Ricinus communis )

2022 ◽  
pp. 51-78
Author(s):  
Is Fatimah ◽  
Suresh Sagadevan ◽  
Baranya Murugan ◽  
Oki Muraza
Keyword(s):  
Castor Oil ◽  
Ricinus Communis

Phosphorylation of glyoxysomal malate synthase from castor oil seeds Ricinus communis L.

FEBS Letters ◽  
1988 ◽  
Vol 234 (2) ◽  
pp. 275-279 ◽  
Author(s):  
Yan-Ping Yang ◽  
Douglas D. Randall ◽  
Richard N. Trelease
Keyword(s):  
Castor Oil ◽  
Ricinus Communis ◽  
Malate Synthase ◽  
Oil Seeds ◽  
Ricinus Communis L

scholarly journals Addition of increasing doses of ricinoleic acid from castor oil (Ricinus communis L.) in diets of Nellore steers in feedlots

2012 ◽  
Vol 21 (4) ◽  
pp. 566-576 ◽  
Author(s):  
J. Gandra ◽  
P. Nunes Gil ◽  
N. Cônsolo ◽  
E. Gandra ◽  
A. Gobesso
Keyword(s):  
Ricinoleic Acid ◽  
Castor Oil ◽  
Ricinus Communis

scholarly journals Produksi Metil 12-Hidroksistearat via Proses Hidrogenasi Ester Minyak Jarak

2020 ◽  
Vol 18 (1) ◽  
pp. 7
Author(s):  
Indra G. Pasaribu ◽  
Arry K. Rizky ◽  
Mario C. Gultom ◽  
Retno G. Dewi ◽  
Tirto P. Prakoso ◽  
...  
Keyword(s):  
Methyl Ester ◽  
Ricinoleic Acid ◽  
Iodine Value ◽  
Castor Oil ◽  
Ricinus Communis ◽  
Acid Methyl Ester ◽  
Hydrogenation Process ◽  
Operating Pressure ◽  
Acid Methyl ◽  
Ricinus Communis L

bstrak. Minyak jarak kaliki (Ricinus communis L.) merupakan salah satu bahan baku terbarukan yang banyak diaplikasikan di berbagai industri kimia. Salah satu dari turunan minyak jarak kaliki yaitu metil 12-hidroksistearat merupakan metil ester yang memiliki manfaat dalam berbagai jenis industri, khususnya industri pelumas. Makalah ini membahas produksi metil 12-hidroksistearat via hidrogenasi ester minyak jarak dalam reaktor mini-pilot. Makalah ini membahas kondisi optimum proses hidrogenasi dari metil ester risinoleat dengan melakukan variasi terhadap tekanan dan temperatur operasi. Tekanan dan temperatur operasi proses hidrogenasi divariasikan pada rentang 2-4 bar dan 150-210℃. Diperoleh produk hidrogenasi metil ester risinoleat dengan konsentrasi massa metil 12-hidroksistearat mencapai 61,28% dan angka iodin 23,84. Peningkatan temperatur dan tekanan operasi meningkatkan konversi metil 12-hidroksistearat dan menurunkan angka iodin. Pada rentang variasi kondisi, kondisi operasi optimum untuk proses ini adalah temperatur 210℃ dan tekanan 4 bar. Penambahan waktu reaksi hidrogenasi selama 3 jam menghasilkan penurunan angka iodin hingga mencapai 9,82 dan bentuk fisik seperti mentega. Kata kunci: angka iodin, hidrogenasi, metil 12-hidroksistearat, metil ester risinoleat, minyak jarak kaliki. Abstract. Production of Methyl 12-Hydroxystearate through the Hydrogenation Process of Castor Oil Esters. Castor oil (Ricinus communis L.) is one of renewable raw materials widely applied in various chemical industries. One of the castor oil derivatives is methyl 12-hydroxistearate, a methyl ester fatty acid which has been applied in various industries especially lubricants industry. This paper discusses the methyl ester production of methyl 12-hydroxystearate from castor oil via hydrogenation of ester of castor oil in a mini-pilot reactor. The purpose of this study is to determine the optimum operating condition of the hydrogenation process of the ricinoleic acid methyl ester by varying operating pressure and temperature. The operating pressure and temperature of the hydrogenation process were varied in the range of 2-4 bar and 150-210℃. The experimental results show that the hydrogenation process of ricinoleic acid methyl ester produces methyl-12-hydroxistearate with concentration up to 61.28%-wt and Iodine Value of 23.84. Higher operating temperature and pressure increase the conversion of methyl 12- hydroxistearate and reduce the iodine value. Further, the optimum operation condition for this process is at 210℃ and 4 bar. Increasing reaction time for about 3 hours results in a significant reduction of iodine value up to 9.82. Keywords: castor oil, hydrogenation, iodine number, methyl 12-hidroxystearate, methyl ester ricinoleic. Graphical Abstract

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