Cis Content Research Articles

Distance-based global analysis of consistent cis-bonds in protein backbones

Biological polypeptides are known to contain cis-linkage in their main chain as a minor but important feature. Such anomalous connection of amino acids has different structural and functional effects on proteins. Experimental evidence of cis-bonds in proteins is mainly obtained using X-ray crystallography and other methods in the field of structural biology. To date, extensive analyses have been carried out on the experimentally found cis-bonds using the Protein Data Bank (PDB) entry-wise or residue-wise; however, their consistency in each protein has not been examined on a global scale. Data accumulation and advances in computational methodology enable the use of new approaches from a proteomic point of view. Here, we sought to carry out protein-wise analysis and describe a simple procedure for the detection and confirmation of cis-bonds from a set of experimental PDB chains for a protein to discriminate this type of bond from isomerizable and/or misassigned bonds. The resulting set of consistent cis bonds (found at identical positions in multiple chains) provides unprecedented insights into the trend of “high cis content” proteins and the upper limit of consistent cis bonds per polypeptide length. Recognizing such limit would not only be important for a practical check of upcoming structures, but also for the design of novel protein folds beyond the evolutionally-acquired repertoire.

Quantitative Chemical Composition, Anti-Oxidant Activity, and Inhibition of TNF Release by THP-1 Cells Induced by Extracts of Echinodorus macrophyllus and Echinodorus grandiflorus.

This study investigated the similarities between Echinodorus macrophyllus and Echinodorus grandiflorus, plant species that are traditionally used in Brazil to treat rheumatism and arthritis, whose anti-inflammatory effects are supported by scientific evidence. The contents of cis- and trans-aconitic acid, homoorientin, chicoric acid, swertisin, caffeoyl-feruloyl-tartaric acid, and di-feruloyl-tartaric acid were quantified by UPLC-DAD in various hydroethanolic extracts from the leaves, whereas their anti-oxidant activity and their effect on TNF release by LPS-stimulated THP-1 cells were assessed to evaluate potential anti-inflammatory effects. The 50% and 70% ethanol extracts showed higher concentrations of the analyzed markers in two commercial samples and a cultivated specimen of E. macrophyllus, as well as in a commercial lot of E. grandiflorus. However, distinguishing between the species based on marker concentrations was not feasible. The 50% and 70% ethanol extracts also exhibited higher biological activity, yet they did not allow differentiation between the species, indicating similar chemical composition and biological effects. Principal component analysis highlighted comparable chemical composition and biological activity among the commercial samples of E. macrophyllus, while successfully distinguishing the cultivated specimen from the commercial lots. In summary, no differences were observed between the two species in terms of the evaluated chemical markers and biological activities.

Cis-Selective Acyclic Diene Metathesis Polymerization of α,ω-Dienes.

The cis/trans stereochemistry of repeating alkenes in polymers provides a powerful handle to modulate the thermal and mechanical properties of these soft materials, but synthetic methods to precisely dictate this parameter remain scarce. We report herein a cis-selective acyclic diene metathesis (ADMET) polymerization of readily available α,ω-diene monomers with high functional group tolerance. Identification of a highly stereoselective cyclometalated Ru catalyst allowed the synthesis of a broad array of polymers with cis contents up to 99%. This platform was leveraged to study the impact of the cis geometry on the thermal and mechanical properties of polyalkenamers, including an ABA triblock copolymer synthesized via extension of a cis-rich telechelic polyoctenamer with d,l-lactide. These results suggest that cis-selective ADMET affords an efficient strategy to tune the properties of a variety of polymers.

Fatty acid and oxidative shelf-life profiles of meat from lambs fed finisher diets containing Acacia mearnsii leaf-meal

Five diets containing Acacia mearnsii leaf-meal (AMLM; 0, 50, 100, 150 and 200 g/kg DM) substituted for Triticum aestivum bran were fed to lambs for 42 days. The effect of diet and retail display period on meat fatty acid (FA) composition (day 1); colour, antioxidant activity, myoglobin and lipid oxidation (day 1, 3, 5, 7 and 9); protein oxidation (1, 3 and 7 d) and instrumental tenderness (day 1, 5 and 10) were evaluated. Dietary AMLM linearly decreased (P ≤ 0.05) individual (14:0, 16:0, 18:0) and total saturated FA and increased (P ≤ 0.05) trans(t)-monounsaturated FA (MUFA) mainly t10/t11–18:1, individual and total conjugated linoleic acids, n-3 and n-6 polyunsaturated FA (PUFA) contents. The contents of cis(c)-MUFA, mainly c9–18:1, exhibited a quadratic response reaching a minimum at 50 g/kg AMLM (P ≤ 0.05). Meat antioxidant on day 9 was higher (P ≤ 0.05) for diets containing ≥100 g/kg DM AMLM compared to the other diet × retail display period interactions. Relative to the other interactions, meat redness values were lowest on day 7 and 9 for AMLM diets containing ≥150 g/kg DM (P ≤ 0.05). Dietary addition of AMLM increased (P ≤ 0.05) meat lightness and oxymyoglobin, and reduced (P ≤ 0.05) TBARS and instrumental tenderness values. However, oxymyoglobin values declined (P ≤ 0.05) over the retail display period, while lightness, metmyoglobin, TBARS and carbonyls increased (P ≤ 0.05). Results indicate that AMLM up to 200 g/kg DM in lamb finisher diets, improves meat fatty acid composition, tenderness, and lipid shelf-life.

Bioinspired Sustainable Polymer with Stereochemistry-Controllable Thermomechanical Properties

The regulation of polymer properties based on stereochemistry is essential but rarely studied. Inspired by the isomerization of unsaturated phospholipids in cell membranes, we report a novel method of preparing stereocontrolled polymer using sustainable Eucommia ulmoides gum (EUG) as a raw material. Under the catalysis of thiyl radical, EUG with 100% trans-1,4-polyisoprene structure isomerized to cis-configuration partly in a controllable way, thus achieving the rational modulate of thermomechanical properties. The isomerization mechanism was verified by density functional theoretical calculation. The isomerized EUG (IEUG) with low cis content (≤8.7%) can serve as plastics or shape memory materials, while high cis content (≥10.7%) IEUG transferred into elastomer materials. Especially for IEUG-10.7%, its vulcanizates without filler reinforcement shows high tensile strength (15.5 MPa) and elasticity (97%) comparable to natural rubber due to its strain-induced crystallization ability, which has the potential to be the second natural rubber. This paper provides a new strategy for stereocontrol of polymer properties, and the prepared materials have broad application prospects in the intelligent sensing and rubber industry.

Facile Fabrication of Hierarchically Porous Boronic Acid Group-Functionalized Monoliths With Optical Activity for Recognizing Glucose With Different Conformation.

At present, various materials based on helical polymers are nanoparticle or microsphere, which is not ease of use in practical application. Accordingly, facile preparation hierarchically porous monolith based on helical polymer needs to be developed. Herein, hierarchically porous boronic acid group-functionalized monoliths that exhibited optical activity were fabricated with a facile method based on crosslinking and polymerization-induced phase separation (CPIPS). Chiral substituted acetylene and achiral substituted acetylene with a boronic acid group were used as monomers. By regulating the composition of the pre-polymerization solution, the permeability and macropore size of the porous structure could be controlled. The hierarchically porous structure and large surface area were confirmed by scanning electron microscopy and nitrogen gas adsorption/desorption isotherms. In particular, the boronic acid functional group that can interact with a cis-diol group was successfully introduced on the skeleton surface of the monoliths. Further, the main chain of the copolymer that constituted the monoliths exhibited a high cis content and tacticity, and the monoliths showed good optical activity. Thus, the present study established a facile method to synthesize hierarchically porous boronic acid group-functionalized monoliths with optical activity via CPIPS, and the monoliths showed potential in recognition, separation, and adsorption of compound with chirality and cis-diol groups.

Molecular Dynamics of Azobenzene Polymer with Photoreversible Glass Transition

The azobenzene polymer with photoswitchable glass transition temperatures and reversible solid-to-liquid transitions has attracted much attention in recent years. The different glass transition temperatures of the azopolymer in the trans-state and the cis-state introduce evident dynamical heterogeneity during cis–trans interconversion. The correlation between molecular dynamics and rheology in azopolymers remains elusive. In this work, we studied the molecular dynamics of an unentangled amorphous azopolymer without a liquid crystal phase. We found that the Lodge–Mcleish self-concentration (SC) model can quantitatively describe the composition dependence of the glass transition temperature, revealing the local environment of the cis (or trans) segments. The terminal relaxation behavior can be well predicted by the Rouse model with the homogeneous bead friction coefficient and the heterogeneous bead–spring (HBS) model with varying friction coefficients for cis or trans subchains. The difference between two models lies in the relaxation time at small length scales and its distribution. The HBS model predicts broadening the relaxation time spectrum, whose width varies with temperature and the cis content. This prediction is consistent with the broadening of the glass transition temperature in azopolymers. Then, the models were used to study the kinetics of thermal cis-to-trans isomerization of the azopolymer in the melt, proving to be a first-order kinetic process and further justified by the ultraviolet absorption spectrum.

Shape Memory Behavior of Biocompatible Polyurethane Stereoelastomers Synthesized via Thiol–Yne Michael Addition

Biodegradable shape memory elastomers have the potential for use in soft tissue engineering, drug delivery, and device fabrication applications. Unfortunately, few materials are able to meet the targeted degradation and mechanical properties needed for long-term implantable devices. In order to overcome these limitations, we have designed and synthesized a series of unsaturated polyurethanes that are elastic, degradable, and nontoxic to cells in vitro. The polymerization included a nucleophilic thiol-yne Michael addition between a urethane-based dipropiolate and a dithiol to yield an α,β-unsaturated carbonyl moiety along the polymer backbone. The alkene stereochemistry of the materials was tuned between 32 and 82% cis content using a combination of an organic base and solvent polarity, which collectively direct the nucleophilic addition. The bulk properties such as tensile strength, modulus, and glass transition temperature can also be tuned broadly, and the hydrogen bonding imparted by the urethane moiety allows for these materials to elicit cyclic shape memory behavior. We also demonstrated that the in vitro degradation properties are highly dependent on the alkene stereochemistry.

Preparation and characterization of vulcanized natural rubber with high stereoregularity

Vulcanized natural rubber with outstanding mechanical properties due to the rapid strain-induced crystallization was prepared by controlling stereoregularity, based on structural analysis of the vulcanized rubbers. The vulcanized rubbers were prepared at 110, 130, 150 and 170 °C for t90 from natural rubber compounded with sulfur, ZnO, stearic acid and N-tert-butyl-2-benzothiazole sulfenamide (TBBS). The vulcanized natural rubbers were characterized by swelling method, rubber-state NMR spectroscopy, tensile test and XRD measurement. Stereoregularity, i.e., contents of cis- and trans-1,4-isoprene units, and strain-induced crystallization depended on vulcanization temperature. The vulcanized natural rubber prepared at 130 °C possessed the highest cis-1,4-isoprene unit content and the lowest trans-1,4-isoprene unit content among the vulcanized rubbers, which resulted in the rapid strain-induced crystallization. The content of carbon linking to sulfur was also low for the vulcanized natural rubber prepared at 130 °C. It was found that the vulcanized natural rubber prepared at 130 °C was superior in tensile properties due to high stereoregularity after vulcanization.

Living ring‐opening metathesis polymerization of norbornenes bay‐functionalized perylene diimides

AbstractRing‐opening metathesis polymerization (ROMP)‐derived poly(oxanorbornene imide)s bearing bay‐linked mono‐alkoxy‐M1 and 1,7‐di‐alkoxy M2 functionalized perylene diimides (PDIs) were synthesized using Grubb's third (G3) and Hoveyda‐Grubbs second generation (HG2) ruthenium‐alkylidene metathesis initiators. The mono‐alkoxy‐derived PDI‐based non‐ladderphane polymer polyM1 displayed 67% to 77% of the trans olefin content in the polymer chain depending on the initiator used for the polymerization. When using the symmetrical 1,7‐di‐alkoxy‐derived PDI‐based polymer polyM2 having the ladderphane type‐structure, this displayed a significant amount of cis and trans olefin contents in the polymer chains, irrespective of the type of initiators used for the polymerization. ROMP of both monomers M1 and M2 proceeded in a well‐controlled manner with a linear dependence of molecular weight on the monomer/initiator ratio using G3 as initiator. Optical properties of the ladderphane‐based polyM2 and non‐ladderphane‐based polyM1 were characterized in both solution and the film state. X‐ray diffraction (XRD) analysis for all the polymers showed significant π‐stacking in the thin film state with ordered molecular packing and closer values of d‐spacing for both polyM1 and polyM2. Film morphology examined by AFM elucidated homogenous smooth polymer surface for both polymers in general, but with some irregularities observed for polyM1. In addition, CV analysis revealed both polymers could be good candidates as electron‐accepting materials, with excellent film‐forming ability, and thermal stability.

Determination of cis/trans fatty acid contents in edible oils by 1H NMR spectroscopy in association with multivariate calibration

In this work, cis and trans fatty acid (FA) contents in edible oils was determined using 1H nuclear magnetic resonance (1H NMR) spectroscopy. The comparison of 1H NMR spectra of edible oil and cis-trans isomerized oil showed that they were different in three regions: (1) 2.880 - 2.650 ppm caused by bis-allylic protons; (2) 2.140 - 1.900 ppm due to allylic protons; and (3) 1.030 - 0.930 ppm due to methyl protons of linolenic acyl groups. The 1H NMR signals in these regions were combined with partial least squares method to predict contents of cis/trans fatty acids in edible oils. The results showed that the predicted values were consistent with the gas chromatography-measured values and had a good linear relationship with a correlation coefficient (R2) of above 0.98. This work demonstrates that 1H NMR spectroscopy was successfully used to determine the composition of both cis and trans fatty acids in edible oils.

Reinvestigation of thermal isomerization of cis-stereoregulated poly(phenylacetylene) by spectroscopic study and DFT calculation

Cis-stereoregulated poly(phenylacetylene) [poly(PA)] was synthesized by polymerization of PA using Rh catalysts, and the thermal isomerization behavior was analyzed by DSC, 1H NMR, IR and Raman spectroscopies. Cis-poly(PA) exhibited DSC exothermic peaks around 170 °C corresponding to isomerization of main chain from cis to trans. The cis content decreased to 12% after heating at 170 °C, and became almost zero after heating at 180 °C, which was determined by 1H NMR spectroscopy. Vibration frequencies of 8-mer models of cis- and trans-poly(PA) were calculated by DFT method to simulate IR and Raman spectra. DFT calculations indicated that an IR absorption peak at 737 cm−1 of poly(PA) originates from out-of-plane bending vibrations of C–H and C–Ph bonded to cis-main chain, and a peak at 692 cm−1 originates from out-of-plane deformation vibrations of C–H in phenyl moieties substituted with trans-main chain. These two IR absorption peaks were used to determine the geometrical structures of poly(PA) main chain. The present study confirmed that DFT calculations provide useful evidences for characterizing geometrical structures of poly(PA).

Optimization of 1,3-butadiene monomer coordination polymerization using response surface methodology (RSM)

Laboratory runs can be minimized via experimental design which yields the optimum and best data regarding the independent parameters. In this research work, response surface methodology (RSM) based on a threelevel central composite design (CCD) was utilized to optimize and evaluate the interactive effects of processing conditions for polymerization of 1,3-butadiene (Bd) diene monomer using Ziegler-Natta catalyst. The polybutadiene rubber (PBR) having different cis content and molecular weight was obtained. The catalyst components included neodymium versatate (NdV3) as catalyst, triethyl aluminum (TEAL) as cocatalyst or activator, and ethylaluminum sesquichloride (EASC) as chloride donor. For the modeling, three independent variables, namely monomer concentration (8-28 wt%), reaction time (1.5-2.5 h), and reaction temperature (45-75oC) at three levels were selected to optimize the dependent variables or responses including monomer conversion, viscosity-average molecular weight and the cis isomer content of the obtained polymer. The interaction between three crucial parameters was studied and modeled. Quadratic models were obtained to relate process conditions to dependent variables. It was observed that the optimal conditions predicted by RSM were consistent with the experimental data. Statistical analysis demonstrated that concentration of the monomer and the time of reaction significantly affected cis content. Moreover, processing conditions to achieve the desired response variables were predicted and experimentally approved. The optimal reaction conditions derived from RSM are monomer concentration = 19 wt%, polymerization time = 2 hours, and polymerization temperature = 50oC. Polymerization was carried out at optimum conditions. The appropriate level of dependent variables including 94.2% monomer conversion, 151812 g/mol viscosity-average molecular weight and 98.8% cis content was acquired.

An Ion‐Pairing Approach to Stereoselective Metal‐Free Ring‐Opening Metathesis Polymerization

AbstractStereochemistry can have a profound impact on polymer and materials properties. Unfortunately, straightforward methods for realizing high levels of stereocontrolled polymerizations are often challenging to achieve. In a departure from traditional metal‐mediated ring‐opening metathesis polymerization (ROMP), we discovered a remarkably simple method for controlling alkene stereochemistry in photoredox mediated metal‐free ROMP. Ion‐pairing, initiator sterics, and solvation effects each had profound impact on the stereochemistry of polynorbornene (PNB). Simple modifications to the reaction conditions produced PNB with trans alkene content of 25 to >98 %. High cis content was obtained from relatively larger counterions, toluene as solvent, low temperatures (−78 °C), and initiators with low Charton values. Conversely, smaller counterions, dichloromethane as solvent, and enol ethers with higher Charton values enabled production of PNB with high trans content. Data from a combined experimental and computational investigation are consistent with the stereocontrolling step of the radical cationic mechanism proceeding under thermodynamic control.

An Ion‐Pairing Approach to Stereoselective Metal‐Free Ring‐Opening Metathesis Polymerization

Stereochemistry can have a profound impact on polymer and materials properties. Unfortunately, straightforward methods for realizing high levels of stereocontrolled polymerizations are often challenging to achieve. In a departure from traditional metal-mediated ring-opening metathesis polymerization (ROMP), we discovered a remarkably simple method for controlling alkene stereochemistry in photoredox mediated metal-free ROMP. Ion-pairing, initiator sterics, and solvation effects each had profound impact on the stereochemistry of polynorbornene (PNB). Simple modifications to the reaction conditions produced PNB with trans alkene content of 25 to >98 %. High cis content was obtained from relatively larger counterions, toluene as solvent, low temperatures (-78 °C), and initiators with low Charton values. Conversely, smaller counterions, dichloromethane as solvent, and enol ethers with higher Charton values enabled production of PNB with high trans content. Data from a combined experimental and computational investigation are consistent with the stereocontrolling step of the radical cationic mechanism proceeding under thermodynamic control.

Elastomeric polyamide biomaterials with stereochemically tuneable mechanical properties and shape memory

Biocompatible polymers are widely used in tissue engineering and biomedical device applications. However, few biomaterials are suitable for use as long-term implants and these examples usually possess limited property scope, can be difficult to process, and are non-responsive to external stimuli. Here, we report a class of easily processable polyamides with stereocontrolled mechanical properties and high-fidelity shape memory behaviour. We synthesise these materials using the efficient nucleophilic thiol-yne reaction between a dipropiolamide and dithiol to yield an α,β − unsaturated carbonyl moiety along the polymer backbone. By rationally exploiting reaction conditions, the alkene stereochemistry is modulated between 35–82% cis content and the stereochemistry dictates the bulk material properties such as tensile strength, modulus, and glass transition. Further access to materials possessing a broader range of thermal and mechanical properties is accomplished by polymerising a variety of commercially available dithiols with the dipropiolamide monomer.

Genome-Wide Identification, Classification, and Expression Profiling Reveals R2R3-MYB Transcription Factors Related to Monoterpenoid Biosynthesis in Osmanthus fragrans

Osmanthus fragrans is widely grown for the purpose of urban greening and the pleasant aroma emitted from its flowers. The floral scent is determined by several monoterpenoid volatiles, such as linalool and its oxides, which are a few of the most common volatiles and the main components of the essential oils in most sweet osmanthus cultivars. In addition, the relative contents of cis- and trans-linalool oxide (furan) may affect the aromas and quality of the essential oils. MYB proteins represent the largest family of transcription factors in plants and participate in regulating secondary metabolites. Several cis-elements, especially AC-rich regions, are known to be bound by 2R-MYBs and could be found in the promoter of the enzyme genes in the terpenoid metabolic pathway. However, there has to date been no investigation into the 2R-MYB family genes involved in regulating terpenoid biosynthesis in O. fragrans. Here, 243 non-redundant 2R-MYB proteins were grouped into 33 clusters based on the phylogeny and exon-intron distribution. These genes were unevenly distributed on 23 chromosomes. Ka/Ks analysis showed that the major mode of 2R-MYB gene evolution was purifying selection. Expression analysis indicated that 2R-MYB genes in O. fragrans exhibited varied expression patterns. A total of 35 OfMYBs representing the highest per kilobase per million mapped reads in the flower were selected for quantitative real-time PCR analysis. The correlation analysis between the expression level and the contents of fragrant compounds at different flowering stages suggested that OfMYB19/20 exhibited remarkably positive correlation with the accumulation of cis-linalool oxides. OfMYB51/65/88/121/137/144 showed significantly negative correlations with one or more linalool oxides. Characterization of these proteins revealed that OfMYB19 and OfMYB137 were localized in the nuclei, but did not show transcriptional activation in the yeast system, which suggested that they may be bound to other transcription factors to exert regulatory functions. These findings provide useful information for further functional investigation of the 2R-MYBs and offer a foundation for clarifying the 2R-MYB transcription factors involved in the molecular mechanism of the regulation of monoterpenoid biosynthesis in Osmanthus fragrans.

Guayule natural rubber composites: impact of fillers on their cure characteristics, dynamic and mechanical behavior

Guayule natural rubber (GNR) is an alternative resource of Hevea natural rubber (HNR) with 99.9% cis content in its 1,4-polyisoprene chemical backbone. In this study, compounds were formulated independently with four different reinforcing fillers such as carbon black (HAF), precipitated silica (VN3), fume silica (FUM) and nanofly ash (NFA) for the advancement of GNR based products. The cure characteristic, dynamic-mechanical performance and mechanical properties of GNR composite were studied with the reinforcing effect of different fillers on GNR. The cure characteristic results demonstrated that HAF and FUM silica filled compounds had more processing safety than VN3 and NFA filled compounds. Viscoelastic parameters of the vulcanizates were studied by dynamic mechanical analysis to estimate the glass transition characteristics and dynamic behavior. The higher storage modulus of FUM silica vulcanizate was an indication of superior filler reinforcing nature and improved rolling resistance than other filled systems. Additionally, HRTEM analysis also proved the better filler dispersion ability of FUM silica in GNR matrix. The mechanical properties were studied with a variation of each filler loading of 8, 16, and 32 phr in GNR vulcanizates. The tensile strength of each filled system increased with an increase of filler content from 8 to 32 phr. In comparison, FUM silica GNR vulcanizates exhibited better mechanical properties, therefore, it was considered as a better structure-performance composite than those of HAF, VN3 and NFA filled composites.

Variability among the coconut varieties with respect to nutritional qualities and total mineral content in inflorescence sap

A field experiment was conducted at Nileswaram farm, Regional Agricultural Research Station, Pilicode, Kerala Agricultural University during 2014-2016 to compare the varieties on nutritional qualities and total mineral content of coconut inflorescence sap. The varieties tried were Malayan Yellow Dwarf, Kerasree, West Coast Tall and Keraganga. Fully emerged unopened bunches were selected for tapping and samples were collected. Samples were immediately stored in refrigerator and used for analysis of nutritional qualities and total mineral content. From the results it was revealed that the phosphorous and potassium content of sap were significantly influenced by the varieties. The variety MYD registered the highest phosphorous content while WCT records the highest potassium content in sap. The variety MYD was superior with respect to calcium content of sap while sap from the tall variety WCT had superior sulphur content. The micronutrient content of sap was not influenced by the varieties except for copper wherein MYD was superior to other varieties. The variety WCT was superior in terms of total mineral content of sap which was followed by the variety MYD. There was no varietal difference with respect to protein nitrogen content of CIS. Non protein nitrogen couldnot be detected in the sap from any of the varieties.

Polymerization of 1,3-butadiene using neodymium versatate: optimization of NdV3/TEAL/EASC molar ratios via response surface methodology (RSM)

Response surface methodology (RSM) with central composite design was used to optimize and analyze the molar ratio of catalyst components for polymerization of 1,3-butadiene (Bd) using Ziegler–Natta catalyst. In this research work, the catalyst component includes neodymium versatate (NdV3) as catalyst, triethylaluminum as cocatalyst or activator and ethylaluminum sesquichloride as chloride donor. The symbols [Nd], [Al], [Cl] and [Bd] were used for catalyst, cocatalyst, donor and monomer concentration, respectively. The interaction between three important and critical variables was studied and modeled. For this purpose, independent variables are [Bd]/[Nd], [Al]/[Nd] and [Cl]/[Nd] molar ratios at three levels to optimize the dependent or response ones which are monomer conversion, molecular weight and cis content of resulting polymer. Quadratic models were achieved and developed to correlate the catalyst components’ molar ratio with dependent variables. The optimum conditions predicted via RSM were in good agreement with experimental data obtained from the experimental runs. The statistical analysis of the results showed that [Cl]/[Nd] molar ratio had a significant effect on monomer conversion and cis content. Furthermore, the catalyst components’ molar ratio to reach the desirable response parameters is forecasted and experimentally verified. The optimum catalyst components’ molar ratio derived via RSM is as follows: [Bd]/[Nd] = 5363.0, [Al]/[Nd] = 27.2 and [Cl]/[Nd] = 2.2.