Lipase-Catalyzed Synthesis of Sn-2 Palmitate: A Review

Human milk fat(HMF)is an important source of nutrients and energy for infants.Triacylglycerols(TAGs)account for about 98%of HMF and have a unique molecular structure.HMF is highly enriched in palmitic acid(PA)at the sn-2 position of the glycerol backbone(more than 70%)and in unsaturated fatty acids at the sn-1,3 position.The specific TAG structure in HMF plays a valuable function in infant growth.Sn-2 palmitate(mainly 1,3-dioleoyl-2-palmitoyl-glycerol)is one of the structured TAGs that is commonly supplemented into infant formula in order to enable it to present a similar structure to HMF.In this review,the development of the lipase-catalyzed synthesis of sn-2 palmitate over the last 25 years are summarized,with a focus on reaction schemes in a laboratory setting.Particular attention is also paid to the commercialized sn-1,3 regioselective lipases that are used in structured TAGs synthesis,to general methods of TAG analysis,and to successfully developed sn-2 palmitate products on the market.Prospects for the lipase-catalyzed synthesis of sn-2 palmitate are discussed.

Dihydroartemisinin ameliorates palmitate-induced apoptosis in cardiomyocytes via regulation on miR-133b/Sirt1 axis

Excessive fat ectopically deposited in the non-adipose tissues is considered as one of the leading causes of myopathy.The aim of this study was to investigate the role of Dihydroartemisinin(DHA)in palmitate(PAL)-incubated H9c2 cells(lipotoxicity-induced cell injury model).Cell viability of PAL-treated cells was determined by MTT assay,and apoptotic regulators were examined by qRT-PCR and western blot analysis,in the absence or in the presence of DHA,respectively.Expression levels of miR-133b and Sirt1 were also evaluated by qRT-PCR and western blotting examination.PAL decreased the viability of H9c2 cells and enhanced the expression of apoptotic genes.DHA reversed the effect of PAL on cell viability and lowed the level of Caspase3 and Bax.It also lowered the expression of miR-133b,while enhanced the expression of Bcl-2.Sirt1 was revealed as target of miR-133b through transcriptional regulation and the process was affected by DHA.DHA partially protected against the PAL-induced lipotoxicity by influencing the expression of miR-133b that hindered the activity of Sirt1.DHA may be used as a potential treatment in clinical management for lipotoxicity induced heart complications.

Paliperidone palmitate-induced facial angioedema:A case report

BACKGROUND Paliperidone palmitate is a once-monthly injectable,atypical antipsychotic.To our knowledge,there has been only one report of paliperidone palmitate-induced angioedema presenting with acute laryngeal edema with subsequent respiratory arrest.Here,we present a case report of paliperidone palmitate-induced angioedema with a relatively mild clinical presentation compared with the previously reported case,and the patient's condition was not complicated by lifethreatening anaphylaxis.CASE SUMMARY A 79-year-old female,who had a major neurocognitive disorder due to Alzheimer's disease with behavioral disturbances.Paliperidone palmitate was offlabel used to control her aggression,irritability,and psychosis.After induction doses(150 mg and 100 mg intramuscularly,given 1 wk apart),she developed intermittent swelling of the face,eyelids,and lips on day 17 after the initial dose,and the edema was explicitly seen on day 20.The diagnosis was paliperidone palmitate-induced angioedema.The monthly injection dose was discontinued on day 33 after the initial dose.The angioedema was subsequently alleviated,and it had completely resolved by day 40 after the initial dose.CONCLUSION Paliperidone palmitate-induced angioedema is a rare condition and can present with a mild,intermittent facial edema,which may be overlooked in clinical practice.

HPLC Quantification of Dexamethasone Palmitate in Bronchoalveolar Lavage Fluid of Rat after Lung Delivery with Large Porous Particles

A high-performance liquid chromatography (HPLC) method has been developed and validated for the determination of dexamethasone palmitate (DXP) in bronchoalveolar fluid lavage samples (BALF). DXP in rat BALFs containing the internal standard (IS), testosterone decanoate (TD), was extracted using a mixture of chloroform and methanol (9:1, v/v). Extracts were then centrifuged, dried and dissolved in acetonitrile. A chromatographic separation based on an isocratic elution was done using acetonitrile and water (85:15, v/v) as a mobile phase at a flow rate of 1.2 mL/min. The graph of the developed method was linear within the tested calibration range of 0.5 - 40 μg/mL. The overall extraction recovery of DXP from BALF samples was 84.3% ± 1.6%. The accuracy (relative error) and precision (coefficient of variation) values were within the pre-defined limits of ≤15% at all concentrations. This methodology has been applied to determine levels of DXP in BALF samples collected from rats treated with DXP large porous particles. The measured concentrations were successfully evaluated using a non-compartment pharmacokinetic model. Since the developed method requires only a microvolume (100 μL) of BALF sample for analysis, it is therefore particularly suitable for the evaluation of drug biodistribution in lung.

Microencapsulation by Spray Drying of Vitamin A Palmitate from Oil to Powder and Its Application in Topical Delivery System

Vitamin A palmitate (VAP) contains retinol and palmitic acid which is easily absorbed by body and widely used in skin care products. But, it is a hydrophobic and oxidation sensitive molecule which undergoes rapid degradation especially in an aqueous environment. The purpose of this study was to prepare microcapsules of VAP using combination maltodextrin and modified starches. Emulsion of VAP was prepared using cremophore RH 40 with Tween 80 in a homogenizer and formed emulsion was spray-dried. The spray process was optimized using a central composite design for two variables to obtain microcapsules with desirable characteristics. Microcapsules containing 30% of VAP were produced using different concentration of wall materials. The prepared microcapsules were evaluated for their physical, morphological, in-vitro drug release and SEM study. The results showed that obtained microcapsules are nearly spherical in shape with a particle size ranged from 1 to 12 μm. The drug content and encapsulation efficiency (53% - 63%) of different batches were found within acceptable range. These stabilized drug loaded microcapsules were incorporated into silicone cream based formulation for convenient topical application and evaluated for its physicochemical parameters. The drug release study showed 80.18% to 83.43% of drug release from VAP microcapsules while topical formulations prepared by VAP microcapsules showed 67.09% to 71.45% drug release at the end of 24 hrs. The formulations were kept for 3 months stability study as per ICH guidelines and found to be stable.

Effects of methyl palmitate and lutein on LPS-induced acute lung injury in rats

AIM: To investigate the effects of methyl palmitate and lutein on lipopolysaccharide(LPS)-induced acute lung injury(ALI) in rats and explore the possible mechanisms. METHODS: Male Sprague-Dawley rats were divided into 4 groups:(1) control;(2) LPS;(3) Methyl palmitate; and(4) Lutein groups. Methyl palmitate(300 mg/kg, ip) was administered 3 times per week on alternating days while lutein(100 mg/kg, oral) was given once daily. After 1 wk of vehicle/methyl palmitate/lutein treatment, ALI was induced by a single dose of LPS(7.5 mg/kg, iv). After 24 h of LPS injection, animals were sacrificed then biochemical parameters and histopathology were assessed. RESULTS: Treatment with methyl palmitate attenuated ALI, as it significantly decreased the lung wet/dry weight(W/D) ratio, the accumulation of the inflammatory cells in the bronchoalveolar lavage fluid(BALF) andhistopathological damage. However, methyl palmitate failed to decrease lactate dehydrogenase(LDH) activity in BALF. On the other hand, lutein treatment produced significant anti-inflammatory effects as revealed by significant decrease in accumulation of inflammatory cells in lung, LDH level in BALF and histopathological damage. Methyl palmitate and lutein significantly increased superoxide dismutase(SOD) and reduced glutathione(GSH) activities with significant decrease in the lung malondialdehyde(MDA) content. Importantly, methyl palmitate and lutein decreased the level of the inflammatory cytokine tumor necrosis factor-α(TNF-α) in the lung. Lutein also reduced LPS-mediated overproduction of pulmonary nitrite/nitrate(NO-2/NO-3), which was not affected by methyl palmitate pretreatment. CONCLUSION: These results demonstrate the potent protective effects of both methyl palmitate and lutein against LPS-induced ALI in rats. These effects can be attributed to potent antioxidant activities of these agents, which suppress inflammatory cell infiltration and regulated cytokine effects.

Development and Application of a Validated HPLC Method for the Determination of Clindamycin Palmitate Hydrochloride in Marketed Drug Products: An Optimization of the Current USP Methodology for Assay

A simple efficient isocratic reversed-phase HPLC method was developed and validated for the determination of clindamycin palmitate hydrochloride (CPH) and its commercially available oral solution products. Separation was achieved on a Phenomenex Zorbax (Luna) cyano column (150 × 4.6 mm, 5 μm) with a Phenomenex cyano guard cartridge (4 × 3.0 mm) on Agilent 1050 series HPLC system. CPH and its resolution standard lincomycin were eluted isocratically at a flow rate of 1 mL/min with a simplified mobile phase (potassium phosphate buffer (5 mM, pH 3.0)—acetonitrile—tetrahydrofuran (20:75:5, v/v/v)) and detected at 210 nm. The column was maintained at 25?C. The method was validated according to USP category I requirements. Robustness and forced degradation studies were also conducted. CPH marketed drug products were obtained from a drug distributor and assayed for potency using the validated method. Validation acceptance criteria were met in all cases. The analytical range for CPH was 15 - 500 μg/mL and the linearity was r2 > 0.999 over three days. The method was determined to be specific and robust. Both accuracy (92.0% - 103.8%) and precision (0.67% - 1.52%) were established across the analytical range for low, intermediate and high QC concentrations. Method applicability was demonstrated by analyzing two marketed products of CPH, in which results showed potency >98%. The method was determined to be an enhancement over the current USP methodology for assay as a result of increased efficiency, reduced organic solvents and the elimination of matrix modifiers. This method was successfully applied for the quality assessment of: 1) currently marketed drug products and 2) will in future assess the product quality of novel dosage forms of CPH for pediatric use.

Long-Term Impact of Acute Retinoic Acid Supplementation at the Young Age on Testicular Architecture of Wistar Albino Rats

Introduction: Inappropriate and excess vitamin supplementation, particularly for vitamin A, is increasingly recognized as a public health problem in developed countries. On the other hand, blind supplementation of vitamin A, for children in developing countries is a subject of controversy in the literature. The crucial role of vitamin A in the process of spermatogenesis in adult rodents is well established, but only a few publications are consecrated to the long-term effect of vitamin A intake at a young age on testicular development and differentiation. Objectives: Our study aimed to evaluate the long-term effects of acute supplementation at an early age, in the post-natal period, on spermatogenesis and testicular trophicity at adult age. Material and Methods: Young Wistar Albinos rats of 22 days received an acute high dose of supplementation of vitamin A (retinyl palmitate). The control group, group 1, received only extra virgin olive oil, Group 2 a dose of 7000 IU/kg of retinyl palmitate, group 3, 14,000 IU/kg, and Group 4 a dose of 28,000 IU/kg. At 10 weeks of age, the testes’ testosterone levels were measured by ELISA. For histological assessment, sections were stained with Hematoxylin eosin, and the Johnsen score was used to evaluate spermatogenesis in the seminiferous tubules. Results: The average testicular weights of rats were significantly lower in group 4 (p < 0.05), and so was the testosterone level in the testis compared to the control group (p .01). Most of the seminiferous tubules were concerned by an arrest of spermatogenesis and the Johnsen score was decreased with a mean score of 5.96 ± 1.60 (p .001) in that Group. In Group 3, Johnsen’s score was significantly better than the one obtained with the control. Conclusion: We observed a negative effect in the long term with a high acute dose of supplementation of retinyl palmitate at a young age, on testicular development and differentiation. Despite a return to normal diet after that supplementation, during childhood, impaired spermatogenesis was identified at the adult age with an arrest of spermatogenesis. The reversibility of that lack of differentiation by a return to a normal diet is questionable and would need more investigation.

Double-lipase Catalyzed Synthesis of Kojic Dipalmitate in Organic Solvents

Kojic dipalmitate（KDP） was synthesized by the way of esterification ofpalmitic and kojic acids in organic solvent, with double-lipase as the biocatalyst. Four commercially available lipases（Amano PS, Novozym 435, Lipozyme TL IM and Lipozyme RM IM） were used to group six double-lipase combinations. These combinations were studied and Amano PS-Novozym 435 was found to have the best efficiency and was selected for optimizing the reaction conditions. The optimal reaction conditions were as follows. The mass ratio ofAmano PS to Novozyme 435 was 1：1.5, with stirring speed of 500 r/min, substrates molar ratio of 1：2, 50 ℃, 5%（mass fraction） catalyst dosage of kojic acid quantity and using acetone as co-solvent. Under these conditions, the diesterification of C5 and C7 hydroxyl groups of kojic acid molecule could be well catalyzed by double-lipase and realize a high KDP yield of 85%.

Carbon-coated Ni-Co alloy catalysts:preparation and performance for in-situ aqueous phase hydrodeoxygenation of methyl palmitate to hydrocarbons using methanol as the hydrogen donor

Carbon-coated Ni,Co and Ni-Co alloy catalysts were prepared by the carbonization of the metal doped resorcinol-formaldehyde resins synthesized by the one-pot extended Stöber method.It was found that the introduction of Co remarkably reduced the carbon microsphere size.The metallic Ni,Co,and Ni-Co alloy particles(mainly 10-12 nm)were uniformly distributed in carbon microspheres.A charge transfer from Ni to Co appeared in the Ni-Co alloy.Compared with those of metallic Ni and Co,the d-band center of the Ni-Co alloy shifted away from and toward the Fermi level,respectively.In the in-situ aqueous phase hydrodeoxygenation of methyl palmitate with methanol as the hydrogen donor at 330℃,the decarbonylation/decarboxylation pathway dominated on all catalysts.The Ni-Co@C catalysts gave higher activity than the Ni@C and Co@C catalysts,and the yields of n-pentadecane and n-C6-n-C16 reached 71.6%and 92.6%,respectively.The excellent performance of Ni-Co@C is attributed to the electronic interactions between Ni and Co and the small carbon microspheres.Due to the confinement effect of carbon,the metal particles showed high resistance to sintering under harsh hydrothermal conditions.Catalyst deactivation is due to the carbonaceous deposition,and the regeneration with CO_(2) recovered the catalyst reactivity.

Inhibition of protein kinase B by Palmitate in the insulin signaling of HepG2 cells and the preventive effect of Arachidonic acid on insulin resistance

Elevated plasma levels of free fatty acids(FFAs)may contribute to insulin resistance(IR)that is characteristic of type 2 diabetes mellitus.In this study,we investigated the effects of two fatty acids,palmitate(PA)and arachidonic acid(AA)on glycogenesis under insulin signaling in HepG2cells,a transformed hepatic carcinoma cell line.In the presence of 200μmol of palmitate,insulin(10−7 mol/L)stimulation of glycogenesis was inhibited,as evidenced by increased glucose in the medium and decreased intracellular glycogen.Wortmannin(WM),a specific inhibitor of PI3K,dramatically decreased the amount of intracellular glycogen in cells without PA incubation.However,glycogen in PA treated cells was not significantly changed by WM,indicating that PA may also act on PI3K.Interestingly,AA restored the effects of WM inhibition on glycogenesis in PA cells.Western blot analysis demonstrated that PA in the absence of WM increased phosphorylated glycogen synthase(inactive form of GS)and decreased phosphorylated protein kinase B(active form of PKB),causing a reduction of intracellular glycogen.AA,however,reversed the effects of PA on GS and PKB.Furthermore,inhibition of protein kinase C(PKC)by a specific inhibitor chelerythrine chloride(CC)abolished the inhibitory effect of PA on glycogen synthesis by decreasing phosphorylated GS and increasing phosphorylated PKB.However,the effect of CC in the presence of PA disappeared when AA was also present.Our results suggest that there is a disruption of the insulin signaling pathway between PKB and GS when the cells were exposed to PA,contributing to IR.PA may also interrupt the PKC signaling pathway.In contrast,AA could rescue glycogenesis impaired by PA.

Studies on bio-antioxidants——Ⅱ.An ESR study on the antioxidant efficiency of ascorbyl palmitate in micelles

The kinetics for the reaction of ascorbyl palmitate and 4-hydroxy-TEMPO,4-methoxy- TEMPO or 4-hexanoyloxy-TEMPO in CTAB and SDS micelles was studied by ESR spectroscopy. It was found that the behavior of ascorbyl palmitate is remarkably different from ascorbic acid in their antioxidant activity in micelles.The predominant factors governing the activity in micelles involve the lipophilicity of the antioxidant and the oxidant,the charge type of the substrates and the concentra- tion of the surfactant.As high as 2×10~4 fold rate variation was observed by changing the lipophilicity of the antioxidant and the microenvironment of the reaction medium.

Predictor of discontinuation with paliperidone palmitate in patients with schizophrenia

Objective To explore the influence of demographic characteristics,psychiatric symptoms and medication on the adherence of long-acting injectable paliperidone palmitate(PP)treatment in schizophrenia patients.Methods In this one year,naturalistic longitudinal study,156 consecutive patients with schizophrenia were initi-

Similarity of Binding Potentials Between Plant DUF538 and Animal Lipocalin: Cholesterol Binding Ability of DUF538

Objective DUF538(domain of unknown function 538) domain containing proteins are known as putative hypothetical proteins in plants. Until yet, there is no much information regarding their structure and function. Methods In the present research work, the homologous structures and binding potentials were identified between plant/mammalian lipocalins and plant DUF538 protein by using bioinformatics and experimental tools including molecular dynamics simulation, molecular docking and recombinant technology-based techniques. Results Molecular docking analysis of their interactions with lipidic ligands including cholesterol and palmitic acid revealed the similar and comparable binding potentials between DUF538 and lipocalin proteins. Both the test proteins were found to have more affinity to cholesterol molecule in compare to palmitic acid. By using recombinant technology-based experiments, the heterologously expressed and purified fused product of DUF538 protein exhibited about 61% cholesterol binding ability. Conclusion As a conclusion, plants DUF538 protein family was predicted to be the structural and may be the functional homologues of plants/animals lipocalin superfamily.

Scavenger receptor A-mediated nanoparticles target M1 macrophages for acute liver injury

Acute liver injury(ALI)has an elevated fatality rate due to untimely and ineffective treatment.Although,schisandrin B(SchB)has been extensively used to treat diverse liver diseases,its therapeutic efficacy on ALI was limited due to its high hydrophobicity.Palmitic acid-modified serum albumin(PSA)is not only an effective carrier for hydrophobic drugs,but also has a superb targeting effect via scavenger receptor-A(SR-A)on the M1 macrophages,which are potential therapeutic targets for ALI.Compared with the common macrophage-targeted delivery systems,PSA enables site-specific drug delivery to reduce off-target toxicity.Herein,we prepared SchB-PSA nanoparticles and further assessed their therapeutic effect on ALI.In vitro,compared with human serum albumin encapsulated SchB nanoparticles(SchB-HSA NPs),the SchB-PSA NPs exhibited more potent cytotoxicity on lipopolysaccharide(LPS)stimulated Raw264.7(LAR)cells,and LAR cells took up PSA NPs 8.79 times more than HSA NPs.As expected,the PSA NPs also accumulated more in the liver.Moreover,SchB-PSA NPs dramatically reduced the activation of NF-κB signaling,and significantly relieved inflammatory response and hepatic necrosis.Notably,the high dose of SchB-PSA NPs improved the survival rate in 72 h of ALI mice to 75%.Hence,SchB-PSA NPs are promising to treat ALI.

旋覆花杀菌活性成分的分离与鉴定

以小麦赤霉病菌(FusariumgraminearumSchw)和小麦白粉病菌(ErysiphegraminisDC)为活性跟踪菌种,从旋覆花(InulabritanicaL.)花中分离得到3种杀菌活性化合物。经波谱分析并与标准图谱比较,鉴定化合物 为倍半萜类化合物1-O-Acetylbritannilactone,化合物 和 分别为三萜类化合物Taraxasterylpalmitate和Taraxasterolacetate。

High fat diet dysregulates microRNA-17-5p and triggers retinal inflammation:Role of endoplasmic-reticulum-stress

AIM To elucidate how high diet-induced endoplasmic reticulum-stress upregulates thioredoxin interacting protein expression in Müller cells leading to retinal inflammation. METHODS Male C57Bl/J mice were fed either normal diet or 60% high fat diet for 4-8 wk. During the 4 wk study, mice received phenyl-butyric acid(PBA); endoplasmic reticulum-stress inhibitor; for 2 wk. Insulin resistance was assessed by oral glucose tolerance. Effects of palmitate-bovine serum albumin(BSA)(400 μmol/L) were examined in retinal Müller glial cell line and primary Müller cells isolated from wild type and thioredoxin interacting protein knock-out mice. Expression of thioredoxin interacting protein, endoplasmic reticulum-stress markers, mi R-17-5p m RNA, as well as nucleotide-binding oligomerization domain-like receptor protein(NLRP3) and IL1β protein was determined.RESULTS High fat diet for 8 wk induced obesity and insulin resistance evident by increases in body weight and impaired glucose tolerance. By performing quantitative real-time polymerase chain reaction, we found that high fat diet triggered the expression of retinal endoplasmic reticulum-stress markers(P < 0.05). These effects were associated with increased thioredoxin interacting protein and decreased mi R-17-5p expression, whichwere restored by inhibiting endoplasmic reticulumstress with PBA(P < 0.05). In vitro, palmitate-BSA triggered endoplasmic reticulum-stress markers, which was accompanied with reduced mi R-17-5p and induced thioredoxin interacting protein m RNA in retinal Müller glial cell line(P < 0.05). Palmitate upregulated NLRP3 and IL1β expression in primary Müller cells isolated from wild type. However, using primary Müller cells isolated from thioredoxin interacting protein knock-out mice abolished palmitate-mediated increase in NLRP3 and IL1β.CONCLUSION Our work suggests that targeting endoplasmic reticulumstress or thioredoxin interacting protein are potential therapeutic strategies for early intervention of obesityinduced retinal inflammation.

Defect of insulin signal in peripheral tissues: important role of ceramide

In healthy people,balance between glucose production and its utilization is precisely controlled.When circulating glucose reaches a critical threshold level,pancreaticβcells secrete insulin that has two major actions:to lower circulating glucose levels by facilitating its uptake mainly into skeletal muscle while inhibiting its production by the liver.Interestingly,dietary triglycerides are the main source of fatty acids to fulfill energy needs of oxidative tissues.Normally,the unconsumed fraction of excess of fatty acids is stored in lipid droplets that are localized in adipocytes to provide energy during fasting periods.Thus,adipose tissue acts as a trap for fatty acid excess liberated from plasma triglycerides.When the buffering action of adipose tissue to store fatty acids is impaired,fatty acids that build up in othertissues are metabolized as sphingolipid derivatives such as ceramides.Several studies suggest that ceramides are among the most active lipid second messengers to inhibit the insulin signaling pathway and this review describes the major role played by ceramide accumulation in the development of insulin resistance of peripherals tissues through the targeting of specific proteins of the insulin signaling pathway.

Retardation of 4-Hydroxy-2-Transnonenal (HNE), a Toxic Aldehyde Formation by Antioxidants in Heat-Treated Corn Oil at Frying Temperature

The antioxidative properties of four antioxidants such as rosemary extracts (RE), tert-butylhydroquinone (TBHQ), ascorbyl palmitate (AP), citric acid (CA) and their mixtures were investigated on the formation of 4-hydroxy-2-transnonenal (HNE) in commercial corn oil heated at 185°C for up to 6 hours. Among the antioxidants 100 ppm RE and a mixture of 200 ppm tertiary butylated hydroquinone (TBHQ) + 100 ppm ascorbyl palmitate (AP) + 50 ppm citric acid (CA) exhibited excellent antioxidative activity, as determined by the thiobarbituric acid reaction (TBARS) assay, measuring the formations of the secondary lipid oxidation products and by high-performance liquid chromatography (HPLC), measuring the formation of the toxic α, β-unsaturated hydroxyaldehyde HNE after heat treatment of corn oil at 185°C up to 6 hours. TBHQ, AP and CA alone did not show much protective properties. The synergistic effects of TBHQ + AP + CA mixture shown to reduce the formation of HNE after 6 hours heat-treated corn oil by 27%. RE 100 ppm was also found to be a very effective antioxidant, reducing the formation of HNE after 6 hours heat-treated corn oil in the same condition by 29%.