C12 Alkyl Chain Research Articles

Hybrid electrochemical and biological treatment of herbicidal ionic liquids comprising the MCPA anion

The present study was focused on the application of an electrochemical oxidation process combined with biodegradation for the removal of novel Herbicidal Ionic Liquids (HILs) –promising protection plant products which incorporate herbicidal anions and ammonium cations. The influence of carbon chain length (n = 8, 10, 12, 14, 16, 18) in the dialkyldimethylammonium cations on electrochemical oxidation kinetics, degradation efficiency and biodegradation by activated sludge was investigated. It was established that the applied cation influenced the heterogeneous rate constant and diffusion coefficient of electrochemical oxidation. The oxidation efficiency ranged from 17% in case of HILs with C8 alkyl chain to approx. 60% in case of HILs comprising C14 and C16 alkyl chains after 3 h of electrochemical treatment. Subsequent biodegradation studies revealed that electrochemical oxidation improved the mineralization efficiency of the studied HILs. The mineralization efficiency of electrochemically-treated HILs ranged from 28% in case of HILs comprising the C8 alkyl chain to 57% in case of HILs with C14 and C16 alkyl chains after 28 days. In case of untreated HILs, the corresponding mineralization efficiency ranged from 0 to 8%, respectively. This confirms the feasibility of a hybrid electrochemical-biological approach for treatment of herbicidal ionic liquids based on MCPA.

Confocal Raman Microscopy Investigation of Self-Assembly of Hybrid Phospholipid Bilayers within Individual Porous Silica Chromatographic Particles.

Hybrid-supported phospholipid bilayers are a model structure utilized for measurement of molecular interactions that typically occur at cell membranes. These membrane models are prepared by adsorption of a lipid monolayer onto a stable n-alkyl chain layer that is covalently bound to a support surface. Hybrid bilayers have been adapted to chromatographic retention measurements of lipophilicity through the assembly of a phospholipid monolayer onto n-alkane-modified silica surfaces in reversed-phase chromatographic particles. Recent Raman microscopy studies of these particles have shown that the acyl chains of the phospholipid interact with the C18-alkyl chains immobilized on the silica surface, where both lipid and C18 alkyl chains become ordered because of chain interdigitation. Confocal Raman microscopy has also been used to investigate the association of small molecules with hybrid-lipid bilayers in C18 chromatographic silica particles; the partitioning of model solutes compares favorably to that in lipid vesicle membranes with similar changes in acyl-chain structure (disordering) with solute partitioning. The present study seeks information about how these membrane-mimetic bilayers assemble onto the C18-derivatized silica surfaces of reversed-phase chromatographic silica particles. Confocal Raman microscopy is capable of interrogating the time-dependent internal composition and structure within individual silica particles. The Raman scattering data can be resolved into component Raman spectra and corresponding composition vectors that describe the time-dependent changes in intensity of the component spectra. This analysis provides insight into how the structures of both the lipid and C18 alkyl chains of hybrid lipid bilayers evolve during deposition and organization on the internal surfaces of reversed-phase chromatographic silica particles.

Amphiphilic tetracationic porphyrins are exceptionally active antimicrobial photosensitizers: In vitro and in vivo studies with the free-base and Pd-chelate.

Antimicrobial photodynamic inactivation (aPDI) employs the combination of nontoxic photosensitizing dyes and visible light to kill pathogenic microorganisms regardless of drug-resistance, and can be used to treat localized infections. A meso-substituted tetra-methylpyridinium porphyrin with one methyl group replaced by a C12 alkyl chain (FS111) and its Pd-derivative (FS111-Pd) were synthesized and tested as broad-spectrum antimicrobial photosensitizers when excited by blue light (5 or 10 J/cm2 ). Both compounds showed unprecedented activity, with the superior FS111-Pd giving 3 logs of killing at 1 nM, and eradication at 10 nM for Gram-positive methicillin-resistant Staphylococcus aureus. For the Gram-negative Escherichia coli, both compounds produced eradication at 100 nM, while against the fungal yeast Candida albicans, both compounds produced eradication at 500 nM. Both compounds could be categorized as generators of singlet oxygen (ΦΔ = 0.62 for FS111 and 0.71 for FS111-Pd). An in vivo study was carried out using a mouse model of localized infection in a partial thickness skin abrasion caused by bioluminescent Gram-negative uropathogenic E. coli. Both compounds were effective in reducing bioluminescent signal in a dose-dependent manner when excited by blue light (405 nm), but aPDI with FS111-Pd was somewhat superior both during light and in preventing recurrence during the 6 days following PDT.

Controlled Growth of Porphyrin Wires at a Solid‐Liquid Interface

AbstractBis(zinc porphyrin) scaffolds bearing C8 or C18 alkyl chains and imidazole end groups self‐assembled in a head‐to‐tail fashion into multi‐porphyrin assemblies on both HOPG and mica. Due to weaker molecule surface‐interactions, longer arrays formed on mica than on HOPG. In both cases, it was essential first to generate monomers that were drop casted on the surface, then to allow time for the bis(zinc porphyrins) to assemble. Although thicker fibrous assemblies were observed with the C8 alkyl substituents than with the longer chains, noncovalent assemblies up to 1 μm long were observed for each molecule. These investigations provide a reproducible, noncovalent method to grow porphyrin arrays that may be of interest in molecular electronics for charge transport.

Surfactant-mediated enzymatic superactivity in water/ionic liquid mixtures, evaluated on a model hydrolytic reaction catalyzed by α-chymotrypsin

In this work, the influence of the C12-, C14-, and C16-alkyl chain derivatives of 1-alkyl-3-methyl-imidazole tetrafluoroborate over the hydrolisis of p-nitrophenyl trimethylacetate catalyzed by α-chymotrypsin was studied in water and water - ionic liquids mixtures. The ionic liquid used is 1-butyl-3-methyl-imidazole tetrafluoroborate (BMIMBF4).1-alkyl-3-methylimidazole tetrafluoroborate derived surfactants can increase the catalytic efficiency of α-chymotrypsin on the hydrolysis of p-nitrophenyl trimethylacetate. This effect is negatively affected by the decrease on the surfactant's critical micelle concentration (CMC) and the partition of the substrate between the micelles and the external media observed above the critical miscellar concentration (CMC). In water/BMIMBF4 mixtures, the presence of the ionic liquid (IL), render the C14 and C16 surfactants insoluble, and overrides the effect elicited by the C12 alkyl chain surfactant on the activity of α-chymotrypsin. The loss of the surfactants influence on the enzymatic activity due to the presence of BMIMBF4 seems to be a complex process, controlled by a decreased affinity between α-chymotrypsin and the surfactant molecules and, to a larger extent, the appearance of an “acquired resistance” of the enzyme to the influence of the surfactants, related to a more compact and resilient conformation of the protein in the presence of BMIMBF4. The influence of BMIMBF4 is not only limited to the surfactant/enzyme interaction, but also it does modifies the partition of the substrate between the aqueous media and the micellar environment.

Impact of molecular structure, headgroup and alkyl chain geometry, on the adsorption of the anionic ester sulfonate surfactants at the air-solution interface, in the presence and absence of electrolyte

The transition from monolayer to multilayer adsorption at the air-water interface in the presence of multivalent counterions has been demonstrated for a limited range of anionic surfactants which exhibit increased tolerance to precipitation in the presence of multivalent counterions. Understanding the role of molecular structure in determining the transition to surface ordering is an important aspect of the phenomenon. The focus of the paper is on the alkyl ester sulfonate, AES, surfactants; a promising group of anionic surfactants, with the potential for improved performance and biocompatibility. Neutron reflectivity measurements were made in aqueous solution and in the presence of NaCl, CaCl2, MgCl2 and AlCl3, for a range of alkyl ester sulfonate surfactants, in which the headgroup and alkyl chain geometries were manipulated.In the regions of monolayer adsorption changing the AES headgroup and alkyl chain geometries results in an increased saturation adsorption and in a more gradual decrease in the adsorption at low concentrations, consistent with a greater adsorption efficiency. Changing the AES headgroup and alkyl chain geometries also results in changes in the transition from monolayer adsorption to more ordered surface structures with the addition of AlCl3 and mixed multivalent electrolytes. A more limited surface layering is observed for the ethyl ester sulfonate, EES, with a C14 alkyl chain. Replacing the C14 alkyl chain with a C18 isostearic chain results in only monolayer adsorption.The results demonstrate the role and importance of the surfactant molecular structure in determining the nature of the surface adsorption in the presence of different electrolytes, and in the tendency to form extended surface multilayer structures.

Studies of thermal properties of di(methacryloyloxymethyl)naphthalene\u2013divinylbenzene (DMN\u2013DVB) copolymer and its alkyl-bonded derivatives

This paper presents the thermal properties of highly crosslinked di(methacryloyloxymethyl)naphthalene–divinylbenzene (DMN–DVB) copolymeric microspheres containing polar groups in the structure and their alkyl-bonded derivatives. C8 and C18 alkyl chains were introduced into the aromatic rings of the DMN–DVB porous copolymer by means of the Friedel–Crafts reaction. As a source of C8 and C18 alkyl chains, octyl and octadecyl chlorides were used. It was necessary to check whether the introduction of alkyl chains into the structure of polymeric packing had an impact on its thermal properties. The studies were carried out by thermogravimetry coupled online with FTIR spectroscopy and differential scanning calorimetry in inert atmosphere (helium). It was stated that the modified materials showed 20 and 50% mass losses at higher temperatures than the non-modified one while 1% mass loss was observed at lower temperatures. Moreover, an analysis of volatile decomposition products was performed.

Synthesis, characterization and in vitro antiproliferative evaluation of ionic liquids based on alkyl-substituted thiabendazolium

A series of 3-methyl-1-alkyl-2-(thiazol-4-yl)benzimidazol-3-ium ionic liquids were prepared synthetically in three steps with high overall isolated yields and their physicochemical and chemical structure were determined using different analysis techniques. The biological application of the synthesized ionic liquids has been evaluated in vitro against a panel of four human cancer cell lines: HT29, MDA-MB 231, K652 and SKBR3 using a MTT colorimetric assay. It can be concluded that among all of them compound 4fy containing C18 alkyl chain and BF4− as counter-ion was found to significantly inhibit the growth of studied cell lines in dose-dependent manner with IC50 values from 0.94 to 3.59 μM after 72 h of treatment. According to structure-activity relationships study, the chain length of alkyl substitution on the cation with different anions could play important role towards cytotoxicity of these ionic liquids. Therefore, these results show very promising future for the application of the ionic liquids based on thiabendazole as possible anticancer agents in cancer treatment.

Effect of Molecular Composition of Head Group and Temperature on Micellar Properties of Ionic Surfactants with C12 Alkyl Chain

The paper analyses influences of the temperature and hydrophilic groups on micellar properties of ionic surfactants with 12-carbonic hydrophobic chains. The aim is to assess the impact of hydrophilic groups and temperature on thermodynamic parameters and micellization. This knowledge is indispensable for the formulation of new dosage forms. The method uses conductometric measurements. The following hydrophilic groups are analyzed: trimethylammonium bromide, trimethylammonium chloride, ethyldimethylammonium bromide, didodecyldimethylammonium bromide, pyridinium chloride, benzyldimethyl-ammonium chloride, methylephedrinium bromide, cis and trans-[(2-benzyloxy)-cyclohexyl-methyl]-N, N-dimethylammonium bromide, sodium sulphate and lithium sulphate. Except for a few cases, there is a good agreement between values of critical micellar concentrations (CMC) and critical vesicle concentration (CVC) obtained here and those which were obtained by other authors and/or by other physicochemical methods. Values of the CMC are compared with respect to the molar masses of hydrophilic groups. It was found that CMC values increased non-linearly with increasing system temperature. The degrees of counterion binding and thermodynamic parameters, like the standard molar Gibbs energy, enthalpy and entropy of micellization are determined and discussed in detail. The results obtained will be incorporated into in silico processes of modeling and design of optimal dosage forms, a current interdisciplinary research focus of the team.

Enhanced Capacities of Mixed Fatty Acid-Modified Sawdust Aggregators for Remediation of Crude Oil Spill.

Mixed fatty acid-modified aggregators have been developed as potential crude oil sorbents. Cheap pine wood flour was first modified with oleic acid (OA) and further modified with a second fatty acid by a leaving group chemistry, where a surface hydroxyl group is first replaced by p-toluenesulfonyl group and a fatty acid forms a covalent bond on sawdust surface through esterification at the elevated temperature (55 °C). Two OA-modified base materials, pine/OA-106 and pine/OA-124, with different OA-coverages were first prepared and the second fatty acids with C3, C6, C8, C10, C12, C14, or C16 alkyl chains were applied to cover the remaining surface hydroxyl groups. The crude oil sorption capacities of the mixed fatty acid-modified aggregators were studied and compared with those of the base materials. The results showed that mixed fatty acid-modified aggregators increased up to 45.6% more crude oil sorption than those of OA-modified base materials. A correlation between surface property and sorption capacity was studied by moisture sorption, Fourier transform infrared spectroscopy, X-ray diffraction, 13C cross polarization and magic angle spinning nuclear magnetic resonance, thermal gravimetric analysis, and scanning electron microscopy. To our knowledge, no report has been published for mixed fatty acid-modified herders or aggregators in the environmental remediation.

Reaction-free and MMP-independent fluorescent probes for long-term mitochondria visualization and tracking.

Visualizing and tracking mitochondrial dynamic changes is crucially important in the fields of physiology, pathology and pharmacology. Traditional electrostatic-attraction based mitochondrial probes fail to visualize and track the changes due to their leakage from mitochondria when mitochondrial membrane potential (MMP) decreases. Reaction-based MitoTracker probes can realize visualization and tracking of mitochondria changes independent of MMP changes. However, such probes impair mitochondrial proteins and exhibit high cytotoxicity. Therefore, it still remains challenging to explore reaction-free and highly biocompatible probes for visualizing and tracking mitochondrial dynamics independent of MMP fluctuations. Herein we synthesized two reaction-free fluorescent mitochondrial probes ECPI-12 and IVPI-12 bearing a long C12-alkyl chain. These cationic probes can firmly immobilize in the mitochondrial inner membrane by strong hydrophobic interaction between the C12-alkyl chain and lipid bilayer, resulting in high specificity and long-term mitochondrial staining regardless of MMP changes. They also exhibit large two-photon absorption cross-sections and show deep penetration in live tissues in two-photon microscopy. Furthermore, they display excellent biocompatibility and realize in situ and real-time mitophagy tracking in live cells. These excellent properties could make ECPI-12 and IVPI-12 the first selective tools for long-term visualization and tracking of mitochondrial dynamics.

Development and characterization of lanthanide-HPDO3A-C16-based micelles as CEST-MRI contrast agents.

The synthesis and characterization of a novel HPDO3A-based ligand having a C16 alkyl chain and its Eu3+, Gd3+ and Yb3+ complexes are reported. These amphiphilic paramagnetic complexes can form micelles with very good stability both in phosphate buffer and in human serum. A high number of Ln-complexes (ca. 200 molecules) are present in the micelle, providing this system with good sensitivity (μM in terms of micelle concentration) for MRI detection. Moreover, it has been found that the cell toxicity of the micelles may be reduced by adding DSPE-PEG2000 in the formulation. Both relaxometric and CEST properties of the micelles were investigated in detail. The micelles loaded with Eu- and Yb-HPDO3A complexes, similar to what was reported for the water-soluble analogs, act as pH-sensors and appear to be suitable for CEST multicolor experiments.

Morphological transformation of self-assemblies by tuning hydrophobic segment of small amphiphiles

HypothesisWith increasing surge in the development of supramolecular self-assemblies, it is crucial to predict the influence of amphiphilic segment in dictating the morphology of self-aggregates. This article reports the design and synthesis of low molecular weight amphiphiles with varying hydrophobicity both in the spacer unit and at the terminal moiety. ExperimentsHydrophobicity at the spacer moiety was modulated by altering alkyl chain length and by inclusion of aromatic ring and the same was changed at hydrophobic terminal using pyrene, naphthalene, n-hexadecane having 2-aminopyridine as polar head. Microscopy and spectroscopy were used to investigate the morphologies of self-aggregated amphiphiles. FindingsVariation of hydrophobicity of the spacer moiety either by changing the alkyl chain length (C0, C2, C6, C11 and phenyl ring) having pyrene as terminal hydrophobic unit led to the formation of only spherical vesicles in respective solvent system. Morphological transformation of self-aggregates from vesicle to fused-vesicle to gel was observed in DMSO-water upon alteration in the hydrophobic end of amphiphile from pyrene to naphthyl to C16 alkyl chain having C6 alkyl chain as spacer. Hence, the hydrophobicity at the terminal of the amphiphile has the predominant role in tuning the morphology of self-aggregates through modulation in the hydrophobic-lipophilic balance (HLB) of amphiphiles.

The first mesomorphic benzimidazolium-based silver(I)-N-heterocyclic dicarbene complexes: Synthesis, characterization and phase properties

The first mesomorphic benzimidazolium based mononuclear silver (I) N-heterocyclic dicarbene complexes, Ag(I)-NHC were prepared via in situ deprotonation of 1-octadecyl-3-alkyl/arylbenzimidazolium salts with silver oxide (Ag2O). Both series of Ag (I)-NHC complexes contained a C18 alkyl chain on one N atom and differed in term of the substituent (alkyl and substituted benzyl moiety) on the other N atom in the benzimidazolium ring. All the synthesized compounds were characterized by elemental analysis, Fourier-transform infrared, 1H and 13C NMR spectroscopy. Cation geometry, anion and alkyl chain length were found to be essential parameters for mesophase formation in the salts and Ag(I)-NHC complexes in this study. All dialkylated salts except the one with the shortest chain, n = 10 were smectogenic. On the other hand, a large width-to-length ratio of the cationic core in the benzyl analogues had a negative effect on the formation and stability of mesophase. No mesophases were observed for these compounds. Wider mesophase range was seen with decrease in anion size and elongation of alkyl chains. A metastable SmA phase was observed in two Ag(I)-NHC complexes. The minimum chain length required for compounds with different anions to exhibit liquid crystal (LC) properties was addressed. Mesophase was observed for bromide salts with C12 onwards while C14 is the minimum chain length required for the hexaflurophosphate containing Ag(I)-NHC complexes to display LC properties. All Ag(I)-NHC complexes except the one bearing a cyano group could be considered ionic liquids with melting/clearing temperatures below 100 °C.

Membrane permeabilization and perturbation induced by alkyl- biguanidium salts

ABSTRACTAlkylbiguanidium salts show membrane perturbing properties toward simple phospholipid bilayer (liposomes) and complex phospholipid membranes (bacterial membranes). Compared to metformin and phenformin, alkylbiguanidium salts induce a more significant permeabilization of the phospholipid membranes, leading to highly selective H+/OH− ion transport and subsequent depolarization of the membrane. Although alkylbiguanidium salts with shorter C6 and C8 chains are too hydrophilic to be inserted into the membrane and perturb it, those with C10, C12, C14, and C16 alkyl chains show high membrane permeabilization and depolarization activity. In addition, the C10, C12, and C14 compounds possess interesting antimicrobial activity, and, at concentrations close to their minimal inhibitory concentrations, they show low hemolytic activity and toxicity.

Indenoquinaldine-Based Unsymmetrical Squaraine Dyes for Near-Infrared Absorption: Investigating the Steric and Electronic Effects in Dye-Sensitized Solar Cells.

A series of near-infrared (NIR)-responsive unsymmetrical squaraine dyes (ISQ1-3) incorporating a fused indenoquinaldine-based donor have been designed and synthesized. C12 alkyl chains were incorporated at the sp3 -hybridized carbon center of the indene unit of the indenoquinaldine in an out-of-plane orientation to control dye aggregation on the surface of titanium dioxide, and indole (ISQ1), benzo[e]indole (ISQ2), and quinoline (ISQ3) moieties were included as the donor component bearing the anchoring carboxy group to extend the absorption in the NIR region and to systematically study the effect of the electronic modification on the performance of dye-sensitized solar cells (DSSC). All the dyes exhibit intense absorption (ϵ≥105 m-1 cm-1 ) in the NIR region, and the dye-adsorbed TiO2 films exhibit broad panchromatic absorption. The incident photon-to-current efficiency (IPCE) spectrum of the ISQ3-based DSSC device displays a panchromatic IPCE response up to 880 nm. Additionally, the ISQ3-sensitized device provides the best efficiency of 4.15 % with a short circuit current density (JSC ) of 10.02 mA cm-2 , open-circuit voltage (VOC ) of 0.58 V, and fill factor (ff) of 72 % in the presence of 10 equivalents of 3α,7α-dihydroxy-5β-cholanic acid (CDCA). Electrochemical impedance spectroscopy analysis showed attenuated charge recombination in the ISQ3-sensitized DSSC, which contributes to its higher value of VOC compared with the other dyes.

Synthesis of cationic alkylated chitosans and an investigation of their rheological properties and interaction with anionic surfactant

Two methods were used to alkylate high MW chitosan with glycidyltrimethylammonium chloride (GTAC) in order to produce chitosan derivatives that are water-soluble throughout the pH range. In addition, a novel chitosan derivative was created by alkylating one of the products with the GTAC analogue Quab 342 containing C12 alkyl chains. The phase behaviour and rheological characteristics of the chitosan derivatives were studied in the presence of anionic surfactant. The derivatives were found to form soluble complexes at low and high SDS concentrations and that the Quab 342 derivative was able to form gels.

Design, Synthesis, and Evaluation of Homochiral Peptides Containing Arginine and Histidine as Molecular Transporters.

Linear (HR)n and cyclic [HR]n peptides (n = 4,5) containing alternate arginine and histidine residues were synthesized. The peptides showed 0–15% cytotoxicity at 5–100 µM in human ovarian adenocarcinoma (SK-OV-3) cells while they exhibited 0–12% toxicity in human leukemia cancer cell line (CCRF-CEM). Among all peptides, cyclic [HR]4 peptide was able to improve the delivery of a cell impermeable fluorescence-labeled phosphopeptide by two-fold. Fatty acids of different alkyl chain length were attached at the N-terminal of the linear peptide (HR)4 to improve the molecular transporter property. Addition of fatty acyl chains was expected to help with the permeation of the peptides through the cell membrane. Thus, we synthesized seven fatty acyl derivatives of the linear (HR)4 peptide. The peptides were synthesized using Fmoc/tBu solid phase peptide chemistry, purified by reverse-phase high-performance liquid chromatography (RP-HPLC) and characterized by matrix-assisted laser desorption/ionization (MALDI) spectrometry. The fatty acyl peptides containing C8, C12, C14, and C18 alkyl chain did not show cytotoxicity on SK-OV-3 or CCRF-CEM cell lines up to 50 µM concentration; however, at higher concentration (100 µM), they showed mild cytotoxicity. For example, C16-(HR)4 was also found to reduce the proliferation of SK-OV-3 cells by 11% at 50 µM and C20-(HR)4 showed mild toxicity at 10 µM, reducing the proliferation of SK-OV-3 cells by 21%. Increase in the length of alkyl chain showed cytotoxicity to the cell lines. C20-(HR)4 peptide showed better efficiency in translocation of F′-GpYEEI to SK-OV-3 than the phosphopeptide alone. Further investigation of C20-(HR)4 peptide efficacy showed that the peptide could deliver doxorubicin and epirubicin into SK-OV-3 and also improved the drug antiproliferative ability. These studies provided insights into understanding the structural requirements for optimal cellular delivery of the fatty acyl-(HR)4 peptide conjugates.

Atomic Force Microscopy and Angular-Dependent X-ray Photoelectron Spectroscopy Studies of Anchored Quaternary Ammonium Salt Biocides on Quartz Surfaces.

A siloxane surface-anchored quaternary ammonium salt (AQAS: BIOSAFE HM4100 in this study) has been chemisorbed onto a quartz substrate. The aim of this study is to elucidate, using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), the structure of the chemisorbed AQAS layers. The AQAS biocide includes a C18 alkyl chain previously invoked in lysis potency. The AQAS coverage appears in zones on the surface, which include a first layer (2.6 ± 0.1 nm) and multilayering that were explored using AFM. The XPS data exhibited two N 1s signals at about 402 and 399 eV, with only the former exhibiting angular dependence. This signal at 402 eV was assigned to the first anchored layer with perpendicular orientation determined by the AQAS anchoring to the surface. In preliminary AFM studies of bacteria on these AQAS surfaces, perturbations on the Staphylococcus aureus cells and the degradation of Escherichia coli cells suggest lysis potency.

Impact of Headgroup Asymmetry and Protonation State on the Aggregation Behavior of a New Type of Glycerol Diether Bolalipid.

In the present work, we describe the synthesis and the temperature-dependent aggregation behavior of a new class of asymmetrical glycerol diether bolalipids. These bolalipids are composed of a membrane-spanning alkyl chain with 32 carbon atoms (C32) in the sn-3 position, a methyl-branched C16 alkyl chain in the sn-2 position, and a zwitterionic phosphocholine headgroup in the sn-1 position of a glycerol moiety. The long C32 alkyl chain is terminated either by a second phosphocholine (PC-Gly(2C16Me)C32-PC) or by a phosphodimethylethanolamine headgroup (PC-Gly(2C16Me)C32-Me2PE). The temperature- and pH-dependent aggregation behavior of both lipids was studied using differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, small-angle X-ray scattering (SAXS), and small-angle neutron scattering (SANS) experiments. The morphology of the formed aggregates in an aqueous suspension was visualized by transmission electron microscopy (TEM). We show that PC-Gly(2C16Me)C32-PC and PC-Gly(2C16Me)C32-Me2PE at pH 5 self-assemble into large lamellar aggregates and large lipid vesicles. Within these structures, the bolalipid molecules are probably assembled in a monolayer with fully interdigitated chains. The lipid molecules seem to be tilted with respect to the layer normal to ensure a dense packing of the alkyl chains. A temperature increase leads to a transition from a lamellar gel phase to the liquid-crystalline phase at about 28-30 °C for both bolalipids. The lamellar aggregates of PC-Gly(2C16Me)C32-Me2PE started to transform into nanofibers when the pH value of the suspension was increased to above 11. At pH 12, these nanofibers were the dominant aggregates.