Silica Column Research Articles

System Maps for the Retention of Neutral Compounds on an Electrostatic-Shielded Reversed-Phase Column

The system constants of the solvation parameter model are used to prepare system maps for the retention of small neutral compounds on an octadecylsiloxane-bonded positive shield porous silica stationary phase (Luna Omega PS C18) for aqueous mobile phases containing 10–70% (v/v) methanol or acetonitrile. Electrostatic interactions (cation exchange) for weak bases were observed using acetonitrile–water but not methanol–water mobile phases at a similar level to a sterically shielded octadecylsiloxane-bonded silica column (Kinetex XB-C18). The system constants of the solvation parameter model and retention factor correlation plots for varied compounds indicated that the Luna Omega PS C18 stationary phase was (near) selectivity equivalent to the diisobutyloctadecylsiloxane-bonded superficially porous silica column Kinetex XB-C18. No specific interactions related to the embedded charged/chargeable functional group were observed compared with other high-purity type-B silica octadecylsiloxane-bonded stationary phases for typical reversed-phase separation conditions with unbuffered mobile phases.

Polycyclic Aromatic Hydrocarbon Accumulation and Biomarker Responses in Cockles from Moroccan Mediterranean Coasts

This study aims to evaluate levels and effects of Polycyclic Aromatic Hydrocarbons (PAHs) in cockles (Acanthocardia tuberculatae) collected from two differently influenced areas in the Mediterranean Western Moroccan coasts. PAHs accumulation was studied in soft tissues using Soxhlet extraction and separation on silica column methods. The measure of those organic compounds was realized by Gas chromatography coupled to Mass spectrometer technics (GC/MS). The impact evaluation was carried out by the study of biochemical responses in gills and digestive gland using two enzymes activities: Glutathione S-Transferase (GST) and Acetylcholinesterase (AchE). The PAHs displayed significant rates of accumulation ranging from 10.12µg/g Dried Weight (DW) to 11.65µg/g (DW) respectively in Oued Laou and Martil sites. Pyrolytic and petrogenic origins were observed in both sites. Pyrolytic origin of PAHs was strongly detected in Oued Laou site while petrogenic origin was mostly detected in Martil site. Biochemical study revealed significant enzymatic response of GST and AchE in gills and digestive gland. The study showed significant biochemical response more important in Martil site than Oued Laou site traduced by GST induction and AchE inhibition. Those results seemed to be related to accumulation rates of PAHs, which was also suggested by the statistical analysis PCA.

A handheld lateral flow strip for rapid DNA extraction from staphylococcus aureus cell spiked in various samples

Deoxyribonucleic acid (DNA) extraction procedure is commonly based on well-developed and commercialized silica-based techniques. However, there are limits to utilize in resource-limited environments due to being time-consuming, labor-intensive, and expensive. Although simple DNA extraction systems have been recently reported, there are still remaining challenges for conventional treatment to complex samples such as blood, food, and soil. Here, we demonstrated a handheld lateral flow strip for rapid DNA extraction from complex samples. We designed the lateral flow system based on investigation of basic property for DNA binding and proper arrangements of various materials. Engineering structure of the lateral flow strip made by the arrangement of convenient pad materials is playing a key role for DNA extraction device without expensive fabrication technique. Different binding affinity to DNA molecules of pad materials is inducing DNA transportation and concentration on the elution hole by lateral flow separation. Result of rapid DNA extraction by the handheld strip was shown similar efficiency to a commercialized silica column. In the concentration between 10 CFU to 106 CFU, and the volume of 5 μl to 100 μl, DNA extraction from Staphylococcus aureus cells in buffer was successfully performed by the handheld strip. We successfully showed that the rapid and effective DNA extraction in various type of complex samples (such as saliva, whole blood, urine, milk, meat, soil, and pond water) can be performed using the handheld strip within 3 min. Moreover, this fabricated strip could be an excellent platform for DNA storage and transportation, thus being potentially suitable for expanding the area of DNA analysis in resource-limited environments.

Egg yolk phosphatidylcholine: Extraction, purification and its potential neuroprotective effect on PC12 cells

Abstract Phosphatidylcholine (PC), a main phospholipid component in egg yolk, provides nourishment and protection for the body. In this study, an attempt has been made to explore the neuroprotective effect of PC that extracted and purified from egg yolk and its corresponding molecular species profile. Egg-yolk PC was obtained by solvent extraction and silica column chromatography, and the purity reached 98%. The neuroprotective effect of egg-yolk PC was investigated via scopolamine-induced PC12 cell model. The results indicated that the pre-treatment of egg-yolk PC could inhibit scopolamine-induced neurotoxicity and oxidative stress in PC12 cells via down-regulation of acetylcholinesterase (AChE) activity, monoamine oxidase (MAO) activity, and the malonaldehyde (MDA) level. This neuroprotective effect might be attributed to plentiful unsaturated fatty acids in egg-yolk PC that was identified to possess 9 kinds of molecular species including 16:0/16:0-PC, 16:0/16:1Δ9-PC, 16:0/18:0-PC, 16:0/18:1Δ9-PC, 16:0/18:2Δ9,12-PC, 18:0/18:1Δ9-PC, 18:0/18:2Δ9,12-PC, 18:1/18:2Δ9,12-PC and 18:0/20:4Δ5,8,11,14-PC by MALDI TOF-MS combined with GC-MS.

Linear and nonlinear optical properties of chlorophyll-a extracted from Andrographis paniculata leaves

This paper reports the linear and third-order nonlinear optical (NLO) properties of chlorophyll-a, a natural pigment extracted from the medicinal plant Andrographis paniculata. Silica column chromatography technique was used to extract the chlorophyll-a from the plant leaves. The functional groups present in the extracted sample were recognized by Fourier transform infrared (FT-IR) spectra. The sample was also characterized by UV–Vis, fluorescent spectra and Z–scan techniques. Z–scan study reveals that the extracted natural pigment chlorophyll-a evinces a large negative nonlinear refractive index n2 and nonlinear absorption coefficient β respectively owing to self-defocusing and saturable absorption behaviors. Third-order NLO susceptibility χ(3) of chlorophyll-a was measured to be of the order of 10–6 esu. The sample fulfilled the conditions for figure of merit and we believe that the natural pigments extracted from the Andrographis paniculata leaves may be suitable for all-optical switching applications.

Correlation of Tacrolimus Levels and Metabolizer Status Based on CYP3A5 Polymorphism in Indian Lung Transplant Recipients

Purpose Tacrolimus (Tac) variable pharmacokinetics influences its efficacy and toxicity. CYP3A5 gene polymorphism leads to marked differences in metabolism of Tac. Aim is to assess the impact of CYP3A5 polymorphism on Tac. dose. Methods Retrospective analysis of 3 months post-op, weekly Tac. levels, on lung transplant recipients between 01/2018 to 09/2018. Tac levels monitored every 3 days, aiming therapeutic range of 8 to 12 ng/mL. Monitoring continued twice weekly for 4 weeks, then weekly till 12 weeks. Genomic DNA was extracted from 0.1 ml of blood by silica column based protocol. A few ng of the DNA sample was subjected to AS-rtPCR-MPA in duplicates, thus yielding a total of 2 replicates. CYP3A5 polymorphisms was detected from each of the 2 replicates, thus dividing the patients into poor, intermediate or extensive metabolizer phenotypes Results 18 patients were divided into 3 groups - poor, intermediate, and rapid metabolizers, n = 5, 10, 3 respectively. As shown in Graph 1, most variation in weekly mean Tac dose was noted in rapid metabolizers. C/D ratio (Concentration Dose ratio) was calculated using the formula: C/D ratio = blood Tacrolimus trough level / daily Tac. dose, and plotted over time, displaying significant variation in the rapid metabolizers. Conclusion Results suggest CYP3A5 genetic polymorphism significantly influences Tac. pharmacokinetics. This can help plan Tac. dose, obtain therapeutic levels, & minimize toxicity. Larger studies are required to establish the clinical correlation across age, sex and ethnic variations. Tacrolimus (Tac) variable pharmacokinetics influences its efficacy and toxicity. CYP3A5 gene polymorphism leads to marked differences in metabolism of Tac. Aim is to assess the impact of CYP3A5 polymorphism on Tac. dose. Retrospective analysis of 3 months post-op, weekly Tac. levels, on lung transplant recipients between 01/2018 to 09/2018. Tac levels monitored every 3 days, aiming therapeutic range of 8 to 12 ng/mL. Monitoring continued twice weekly for 4 weeks, then weekly till 12 weeks. Genomic DNA was extracted from 0.1 ml of blood by silica column based protocol. A few ng of the DNA sample was subjected to AS-rtPCR-MPA in duplicates, thus yielding a total of 2 replicates. CYP3A5 polymorphisms was detected from each of the 2 replicates, thus dividing the patients into poor, intermediate or extensive metabolizer phenotypes 18 patients were divided into 3 groups - poor, intermediate, and rapid metabolizers, n = 5, 10, 3 respectively. As shown in Graph 1, most variation in weekly mean Tac dose was noted in rapid metabolizers. C/D ratio (Concentration Dose ratio) was calculated using the formula: C/D ratio = blood Tacrolimus trough level / daily Tac. dose, and plotted over time, displaying significant variation in the rapid metabolizers. Results suggest CYP3A5 genetic polymorphism significantly influences Tac. pharmacokinetics. This can help plan Tac. dose, obtain therapeutic levels, & minimize toxicity. Larger studies are required to establish the clinical correlation across age, sex and ethnic variations.

Effective Molecular Identification of Ectomycorrhizal Fungi: Revisiting DNA Isolation Methods

A better understanding of ectomycorrhizal symbiosis leads to numerous advancements in forest management and environmental protection. The morphological identification of the ectomycorrhizae often proves to be misleading. For this reason, in order to study the ectomycorrhizal fungi communities, a number of molecular methods that require the isolation of nucleic acids are being used. However, ectomycorrhizal root tips, low mass heterogenic material rich in inhibitors, are a recalcitrant substrate in DNA isolation. It is common for published studies to include some number of unidentified root tips in their results, in spite of diverse isolation protocols being available to researchers. This study aims to analyze the relationship between the collected fungal material and later isolation results, and to propose a DNA isolation protocol specifically optimized for ectomycorrhizal root tips. It was found that the taxonomic position can be used to predict the potential isolation efficiency, with Ascomycota being generally more difficult from which to isolate DNA. After a number of cell lysis and lysate purification methods were evaluated, the joined approach of mechanical and chemical lysis, followed by silica column purification, was found to provide the best results, even with recalcitrant material.

Cytotoxic Furan- and Pyrrole-Containing Scalarane Sesterterpenoids Isolated from the Sponge Scalarispongia sp.

Three furan-containing scalarane sesterterpenoids (1–3) and a novel pyrrole-containing analog (4) were isolated from the sponge Scalarispongia species. Compound 3, reported in the literature as a synthetic derivative of furoscalarol 2, was for the first time isolated from a natural source. During the separation performed using a silica column in the presence of methanol, 16-methoxy derivatives (5, 6) were obtained from the unintended reaction of 2. The isolated natural products 3 and 4 and the artifact 5 showed moderate to high cytotoxicity against six human cancer cell lines, whereas compound 6, the C-16 epimer of 5, showed no cytotoxicity at a concentration of 60 μΜ.

Determination of the polyphenolic fraction of Pistacia vera L. kernel extracts by comprehensive two-dimensional liquid chromatography coupled to mass spectrometry detection.

Pistachio (Pistacia vera L.) belongs to the Anacardiaceae family and it is a small tree species. It is native of the Middle East and Central Asia, but currently, it is cultivated also in California and in some Mediterranean countries, such as Greece and Italy. The most important pistachio producers are Iran, the USA, and Turkey. Besides being a delicious nut, pistachio, due to its wholesome nutritional properties, could be considered as a functional food. According to the results of several studies, pistachios have been proven to have various groups of valuable phytochemicals such as anthocyanins, flavan-3-ols, proanthocyanidins, flavonols, isoflavones, flavanones, stilbenes, and phenolic acids, possessing excellent biological activities. The most common analytical technique employed for their analysis is represented by liquid chromatography coupled to photodiode array and mass spectrometry detection. However, conventional LC can present some limits especially in terms of resolving power. In this contribution, as a powerful alternative, comprehensive two-dimensional liquid chromatography (LC×LC) was applied to the determination of the polyphenolic fraction of pistachio kernels from different geographical origins. A 150-mm micro-bore cyano column (2.7μm dp) and 50-mm superficially porous C18 silica column (2.7μm dp) in the first (1D) and second (2D) dimensions were employed, respectively. For boosting orthogonality, a shift 2D gradient was investigated leading to an increase in the overall peak capacity. The newly developed LC×LC method showed satisfactory linearity, sensitivity, precision and accuracy, which was then applied to sample quantitative analysis. A total of 51 different polyphenolic compounds were determined in the four samples investigated and 18 out of them are hereby reported for the first time.

Microwave-assisted protocol for squalene isolation and conversion from oil-deodoriser distillates

Abstract Aiming to design a green and efficient protocol for squalane production from low-cost biomasses, a practical and scalable procedure for squalene extraction and hydrogenation to squalane is presented herein. The oil-deodoriser distillates that are produced by the vegetal-oil production chain are a renewable and cheap source of squalene. We were able to isolate an enriched fraction containing 89.0% of pure squalene (yield 55.4%) from a matrix containing about 2% squalene. Efficient microwave- assisted esterification under heterogeneous catalysis enabled the separation of fatty-acid methyl esters (FAME) via vacuum distillation. The residue was purified by flash-chromatography on a C-18 silica column using MeOH/H2O/2-propanol as the mobile phase. Finally, squalene was hydrogenated to the more stable squalane in a pressure-resistant microwave reactor. The reaction was performed over a Pd/C catalyst in EtOH, and even in solvent-free conditions, and was optimised using commercial squalene (5 bar of H2 at 100°C for 1 h).

Design, synthesis and evaluation of a series of alkylsiloxane-bonded stationary phases for expanded supercritical fluid chromatography separations

Supercritical fluid chromatography (SFC) today represents an alternative technique in analytical chemistry due to its obvious benefits in kinetic performance and its complementarity to liquid chromatography. In this paper, a series of alkylsiloxane-bonded stationary phases were synthesized and evaluated to expand their SFC applications. Five kinds of non-endcapped C8 stationary phases (C8-1 to C8-5) with increasing bonding density were synthesized, and the carbon content was 3.91%, 6.07%, 7.97%, 8.65% and 9.10% respectively. Retention mechanism of the C8 phases in SFC in SFC was investigated by the use of a linear solvation energy relationship (LSER) model. Results underlined a close relationship between the bonding density of alkyl chain and the dispersion and polar interactions of the stationary phase. Complementary evaluation was studied based on the calculation of vector angle (θ), and the widest θ of 123° was found between silica and C8 with the highest bonding density. Selective diversity also existed between the two C8 phases with the highest and lowest bonding densities. In addition, the effect of modifier on the SFC mechanism was investigated. Modifiers (methanol, ethanol, isopropanol and acetonitrile) had insignificant influence on the dispersion interaction but they mainly affected the hydrogen bonding interaction by changing the LSER parameters a and b. Finally, C8 and silica columns were applied for separation of eight amide alkaloids of Piper kadsura. Silica provided better retention but limited selectivity while C8 can distinguish alkaloids different in alkyl chain, double bond and cis-trans structure. This research further contributed to demonstrate the potential of alkylsiloxane-bonded stationary phase in improving selectivity of SFC.

Development and validation of LC-MS/MS methods for the quantification of the novel anticancer agent guadecitabine and its active metabolite β‑decitabine in human plasma, whole blood and urine

Guadecitabine (SGI-110), a dinucleotide of β‑decitabine and deoxyguanosine, is currently being evaluated in phase II/III clinical trials for the treatment of hematological malignancies and solid tumors. This article describes the development and validation of bioanalytical assays to quantify guadecitabine and its active metabolite β‑decitabine in human plasma, whole blood and urine using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Since β‑decitabine is rapidly metabolized further by cytidine deaminase, plasma and whole blood samples were kept on ice-water after collection and stabilized with tetrahydrouridine (THU) directly upon sample collection. Sample preparation consisted of protein precipitation for plasma and whole blood and dilution for urine samples and was further optimized for each matrix and analyte separately. Final extracts were injected onto a C6-phenyl column for guadecitabine analysis, or a Nova-Pak Silica column for β‑decitabine analysis. Gradient elution was applied for both analytes using the same eluents for each assay and detection was performed on triple quadrupole mass spectrometers operating in the positive ion mode (Sciex QTRAP 5500 and QTRAP 6500). The assay for guadecitabine was linear over a range of 1.0–200 ng/mL (plasma, whole blood) and 10–2000 ng/mL (urine). For β‑decitabine the assay was linear over a range of 0.5–100 ng/mL (plasma, whole blood) and 5–1000 ng/mL (urine). The presented methods were successfully validated according to the latest FDA and EMA guidelines for bioanalytical method validation and applied in a guadecitabine clinical mass balance trial in patients with advanced cancer.

The retention behavior of diblock copolymers in gradient chromatography; Similarities of diblock copolymers and homopolymers

The retention of binary diblock copolymers in solvent gradient interaction chromatography (SGIC) was investigated theoretically and compared with experimental results. The isocratic and gradient elution behavior of binary block copolymers can be described by the equations of an equivalent homopolymer having a suitable critical eluent composition and size to pore size ratio.For diblock copolymers the adsorption-desorption transition occurs at a limiting interaction energy, which is characterized by a limiting interaction parameter cA,lim, like the critical interaction parameter of homopolymers. Both, the limiting interaction parameter and the critical interaction parameter are independent of pore size. However, while for homopolymers the critical energy is also independent of molecular size, the limiting interaction parameter of block copolymers depends on the size and composition of the macromolecule. Therefore, even for block copolymers of a fixed composition a molar mass independent elution cannot be realized at isocratic conditions.Since binary block copolymers in solvent gradients elute very close to the stronger adsorbing homopolymer, separation of the block copolymer from the stronger adsorbing homopolymer becomes difficult. A slightly better separation is expected to occur in larger pores.The close elution of block copolymers and homopolymers in gradient elution was confirmed for poly(methy methacrylate)-block-poly(styrene)s in chloroform-THF gradients on a bare silica column.

Ground-State Heterogeneity along with Fluorescent Byproducts Causes Excitation-Dependent Fluorescence and Time-Dependent Spectral Migration in Citric Acid-Derived Carbon Dots.

The integrity of fluorescent carbon dot (FCD) emission deserves its highest appreciation when sample purification is performed with extreme care. Several controversial phenomena of FCD fluorescence including excitation-dependent emission, spectral migration with time, and thereby violation of the Kasha-Vavilov rule, which sparked intense debate during recent reports, disappeared when we rigorously purified the as-synthesized FCD sample. Purification was performed by first visual silica column chromatography (observing the emissions under UV illumination) and subsequently prolonged membrane dialysis. Most of the surprising phenomena of FCD fluorescence reported earlier apparently arose from ground-state spectral heterogeneity of FCD sample containing a large amount of fluorescent impurities (mostly polymeric or oligomeric in nature). Observation of our ensemble spectroscopic measurements, albeit nicely matched with recent reports based on single-particle experiments, differed largely from that of other ensemble measurements. Our results reconciled a number of long-standing controversies on FCD emission mostly by emphasizing the urgency of sample purification with more scientific rigor.

Comparison and optimization for DNA extraction of archived fish specimens

The DNA extracted from museum alcohol-fixed specimens can be a valuable source of information for solving taxonomic, phylogenetic, ecological and conservational questions. However, this type of DNA, also called ancient DNA, is routinely obtained in small portions and highly fragmented. We have tested two different extraction kits in museum type-specimens of the fish family Characidae. Aiming to increase the DNA yield, we made modifications on a Qiagen manufacturer protocol, in the elution step. Also, to overcome the issue of DNA fragmentation, we applied our efforts in Sanger sequencing, to find a highly variable and, in result, informative COI fragment. Based on our results, there is no correlation between amount of the DNA extracted and the age of the sample. The Sanger sequencing generated sequences which are useful in solving taxonomic puzzles. Here are presented the customization and guidelines that allowed us to recover DNA from the archived fish specimens.•DNA extraction from archived fish specimens is more effective when using silica columns.•Change of the elution times from minutes in room temperature to 24 h in freezer greatly improved the DNA yielded.•Short but highly variable sequences replace the need to sequence the entire gene to identify a species.

Determination of Amino Acids in Plasma Samples of Preeclampsia Patients by Liquid Chromatography Coupled to High-Resolution Mass Spectrometry

This work presents the application of a simple and sensitive method developed for the simultaneous analysis of the levels of twenty two underivatizated free L-amino acids in plasma samples of preeclampsia patients by high performance liquid chromatography coupled to high-resolution mass spectrometer (LC-HRMS) using hydrophilic interaction liquid chromatography (HILIC) silica column. The linearity was evaluated in the range of 0.009 to 8.018 µmol L-1 showing coefficients of determination (R2) in the range of 0.999 to 0.911 (p < 0.05). The intra- and inter-day precisions were above of 9.84 and 15.31, respectively. The limits of detection (LOD) and quantification (LOQ) were in the range of 0.003 to 0.683 µmol L-1 and 0.009 to 2.276 µmol L-1, respectively. The results of the investigation of free L-amino acids showed that the levels of GABA, Arg, Ser, Leu, Ile, Met, Val, Ala, Gly, Bet, His and Lys in plasma of patients with preeclampsia were significantly different from healthy patients.

DNA Extraction from Keratin and Chitin.

DNA extracted from keratinous and chitinous materials can be a useful source of genetic information. To effectively liberate the DNA from these materials, buffers containing relatively high levels of DTT, proteinase K, and detergent are recommended, followed by purification using either silica column or organic methods.

Quantification of Hepatitis B Virus Covalently Closed Circular DNA in Infected Cell Culture Models by Quantitative PCR.

Persistence of the human hepatitis B virus (HBV) requires the maintenance of covalently closed circular (ccc)DNA, the episomal genome reservoir in nuclei of infected hepatocytes. cccDNA elimination is a major aim in future curative therapies currently under development. In cell culture based in vitro studies, both hybridization- and amplification-based assays are currently used for cccDNA quantification. Southern blot, the current gold standard, is time-consuming and not practical for a large number of samples. PCR-based methods show limited specificity when excessive HBV replicative intermediates are present. We have recently developed a real-time quantitative PCR protocol, in which total cellular DNA plus all forms of viral DNA are extracted by silica column. Subsequent incubation with T5 exonuclease efficiently removes cellular DNA and all non-cccDNA forms of viral DNA while cccDNA remains intact and can reliably be quantified by PCR. This method has been used for measuring kinetics of cccDNA accumulation in several in vitro infection models and the effect of antivirals on cccDNA. It allowed detection of cccDNA in non-human cells (primary macaque and swine hepatocytes, etc.) reconstituted with the HBV receptor, human sodium taurocholate cotransporting polypeptide (NTCP). Here we present a detailed protocol of this method, including a work flowchart, schematic diagram and illustrations on how to calculate "cccDNA copies per (infected) cell".

Secondary metabolite Constituents, Antimicrobial Activity and Gas chromatography-Mass spectroscopy Profile of Bombax buonopozense P. Beauv.(Bombacaceae) Stem bark Extract

This study evaluated the phytochemical constituents, antimicrobial activity and structural characteristics using GC-MS of bioactive constituents from the stem bark extract of Bombax buonopozense. Secondary metabolite constituents was assayed using standard procedures. The antimicrobial activity was carried out using agar diffusion method to determine the susceptibility of these microorganisms: (Staphylococcus aureus (ATCC 29213), Streptococcus faecials, Bacillus subtilis (ATCC 8263), Escherichia coli (ATCC 25922), Salmonella tiphi, Pseudomonas aeruginosa (ATCC 27853), Candida albican (ATCC 90029), Aspergillusniger and Phytophera megakarya. EtOAc fraction was chromatographed on silica column to afford oil isolate and its chemical structures were proven with the employment of GC-MS. Phytochemical screening revealed the presence of saponins, flavonoids, reducing sugars, steroids, terpenoids, anthraquinone, phenols and alkaloids. The antimicrobial sensitivity test showed higher activity on Candida albican, Bacillus subtilis, Pseudomonas aeruginosa and Staphylococcus aureus, moderate to little activity on the rest organisms. The GC-MS of the stem bark oil extract revealed the main constituents as: 1, 2 Benzenedicarboxylic acid 4.10%, Diisobutyl phthalate 1.18%, Dibutyl phthalate 0.72%, Lupenone 0.62%, Lupeol 4.93%, Lupenyl acetate 86.28%, Testosterone decanoate 0.87% and 3-O-Acetyl-6-methylcycloartenol 0.67%. The findings indicate stem bark extract has bioactive compounds which may be effective in the treatment of infection diseases.

Seeds of Centranthus ruber and Valeriana officinalis Contain Conjugated Linolenic Acids with Reported Antitumor Effects.

Conjugated linolenic acids (CLNs) are naturally occurring fatty acids that are believed to have anticancer properties. In this study, we examined various plant seeds from herbs to discover seed oils containing CLNs. The ultraviolet spectra of total lipids from these seeds were measured. An absorption maximum around 270 nm was observed in seed oils belonging to the Valerianaceae family (Centranthus ruber and Valeriana officinalis). When the fatty acid compositions of these seed oils were measured, CLNs were detected. By silica column chromatography, neutral lipids (NLs), glycolipids, and phospholipids were eluted from seed oils of C. ruber and V. officinalis. Then, fatty acid compositions of these fractions were measured. This revealed that most of the CLNs in these seed oils existed in the NL fraction. When the NL fractions of these seed oils were reacted with lipase, CLNs showed good sensitivity to lipase hydrolysis. This suggested that the CLNs in the seed oils of C. ruber and V. officinalis existed predominantly at the sn-1,3 position of triacylglycerol and less at the sn-2 position. These results suggested that the CLNs from the seed oils of C. ruber and V. officinalis could easily be taken up by cancer cells as free fatty acids and had good potential as antitumor substances.