Puromycin is an aminoglycoside antibiotic that inhibits protein synthesis
**Background**
Protein synthesis is a fundamental biological process essential for cell growth, proliferation, and the maintenance of cellular homeostasis. The translation of mRNA into polypeptide chains by ribosomes is a tightly regulated mechanism, and any disruption in this process can lead to significant cellular stress or cell death. Understanding the dynamics of translation is critical for researching various pathologies, including viral infections and malignancy. In the context of oncology, studying the rate of protein synthesis helps in identifying vulnerabilities in rapidly dividing cells. Therefore, we will introduce an aminoglycoside antibiotic used to study translation and induce cytotoxicity – Puromycin.
**Definition**
Puromycin is an aminoglycoside antibiotic that acts as a protein synthesis inhibitor. According to the Puromycin description, it is provided as a dihydrochloride salt and functions as an analog of the 3′ end of aminoacyl-tRNA.
**Mechanism of Action**
Puromycin inhibits protein synthesis through two primary modes of action. First, it acts as an acceptor substrate that attacks peptidyl-tRNA in the P site of the ribosome to form a nascent peptide. Second, it competes with aminoacyl-tRNA for binding to the A site. This leads to the premature termination of translation and the release of incomplete peptide chains, resulting in the accumulation of small peptides. Because of this unique Puromycin biological activity, the incorporation of the drug into newly synthesized proteins can be used to directly reflect the rate of mRNA translation. Furthermore, puromycin immunodetection serves as a non-radioactive alternative to amino acid labeling, allowing for the evaluation of translation activity in single cells via immunofluorescence microscopy or in heterogeneous populations using fluorescence-activated cell sorting.
**In Vitro Studies**
The cytotoxic effects of puromycin have been extensively documented across various human cell lines. In vitro studies demonstrate that puromycin exhibits potent growth inhibition and cytotoxicity. In HEK293 cells, the IC50 values vary depending on the assay and duration, ranging from 0.35 nM (alamar blue assay) to 0.81 μM (resazurin assay after 72 h). Specifically, puromycin showed an IC50 of 0.36 μM in HEK293 cells after 72 h using PrestoBlue staining. In human A549 cells, the IC50 was reported at 0.6 μM, while in BEAS-2B cells with low TrxR expression, the IC50 was 0.74 μM after 48 h of incubation. Additionally, puromycin exhibited an EC50 of 6.1 μM in HCT-8 cells and a CC50 of 0.42 μM in HEK-293T cells after 72 h. In HL-60 cells, antiproliferative activity was observed with an EC50 of 0.055 μM after 72 h. In conclusion, puromycin is a powerful inhibitor of protein synthesis that serves as a critical tool for studying translation and cellular cytotoxicity.
Keywords
Puromycin, 53-79-2, CL13900, CL 13900, CL-13900, Bacterial, Antibiotic, Parasite, Inhibitor, inhibitor, inhibit
References
[1] Nathans D, et al. Puromycin inhibition of protein synthesis: incorporation of puromycin intopeptide chains. Proc Natl Acad Sci U S A. 1964 Apr;51:585-92.
[2] Miyamoto-Sato E, et al. Specific bonding of puromycin to full-length protein at the C-terminus. Nucleic Acids Res. 2000 Mar 1;28(5):1176-82.
[3] Schmidt EK, et al. SUnSET, a nonradioactive method to monitor protein synthesis. Nat Methods. 2009 Apr;6(4):275-7.
The accurate and sensitive detection of fatty acids (FAs) in biological samples is essential for advancing lipidomics and metabolic research. Traditional methods, such as gas chromatography coupled with electron-capture detection of pentafluorobenzyl esters, offer high sensitivity but require specialized equipment and complex sample preparation. In contrast, liquid chromatography–electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) has become a dominant platform due to its compatibility with diverse matrices and direct infusion capabilities. However, native FAs exhibit suboptimal ionization efficiency and limited fragmentation in negative ion mode, restricting their analytical utility.
To address these limitations, we developed a charge reversal derivatization strategy using N-(4-aminomethylphenyl)pyridinium (AMPP), which transforms the carboxylic acid group into a permanently charged amide derivative. This modification enables analysis in positive ion mode, where ionization efficiency is significantly enhanced. The resulting AMPP amides demonstrate exceptional sensitivity—over 60,000-fold greater than underivatized FAs analyzed in negative ion mode. This dramatic improvement is attributed to the stable positive charge that facilitates efficient ESI and robust fragmentation patterns during CID.
The method was optimized for use with reverse-phase LC columns, employing a gradient elution system with water and acetonitrile containing formic acid. A total of 37 FA molecular species, including saturated, monounsaturated, and polyunsaturated forms, were successfully resolved within a 15-minute run. Each analyte exhibited distinct retention times and unique MS/MS transitions, enabling confident identification. Key product ions, such as m/z 239 derived from cleavage between C3 and C4, were observed across all FA classes, providing a universal detection channel. Additionally, higher-mass fragment ions specific to individual species—such as m/z 295 for oleic acid and m/z 323 for vaccenic acid—enhanced analytical specificity by distinguishing structural isomers that co-elute.
Validation studies using commercial mouse serum revealed consistent detection across multiple runs. Intra-assay precision (n = 5) averaged below 4% coefficient of variation (CV), while inter-assay precision (n = 6 independent extractions) remained under 6% CV. Quantification limits were determined at 50–100 femtograms on-column, demonstrating suitability for trace-level analysis. Calibration curves showed excellent linearity over four orders of magnitude, confirming reliable quantitation across dynamic ranges.
Sample preparation involved a simple two-phase extraction with isooctane, effectively isolating free FAs from serum proteins and lipoproteins.Efavirenz Protocol All glassware and reagents were rigorously cleaned via oven baking and solvent distillation to minimize background contamination, particularly for low-chain-length FAs (C12–C18).UiO 66 Formula Derivatization was performed under mild conditions (60°C, 30 min) using EDCI/HOAt activation, ensuring complete conversion without degradation.PMID:34435735 Excess reagents were removed via pre-column diversion, preventing source fouling and maintaining instrument stability.
The use of deuterated internal standards (e.g., d8-AA, d17-oleic acid) enabled accurate absolute quantification by correcting for matrix effects and ionization variability. Alternative approaches using non-deuterated heavy atom-labeled standards were also explored, though less precise. Notably, no significant isotope effects were observed in product ion formation, validating the reliability of isotopic dilution.
This method provides a comprehensive, high-throughput solution for profiling diverse FA species in complex biological fluids. Its compatibility with standard LC-ESI-MS/MS instrumentation makes it widely accessible. By combining charge reversal derivatization with selective fragmentation, it achieves unprecedented sensitivity and specificity—making it ideal for clinical diagnostics, metabolic phenotyping, and systems biology applications. The ability to detect minor FA species previously undetectable underscores its transformative potential in lipidomic research.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
**Background**
Ischemic brain injury, such as that caused by stroke, often leads to extensive neuronal death and permanent neurological deficits. A primary driver of this damage is the overactivation of N-methyl-D-aspartate (NMDA) receptors, which triggers an excessive influx of calcium ions and the subsequent production of reactive oxygen species (ROS). This cascade of excitotoxicity and oxidative stress results in the degeneration of both neurons and glia. Therefore, developing agents that can selectively inhibit NMDA receptors while simultaneously scavenging free radicals is a critical strategy for neuroprotection. In this context, we will introduce a potent NR2B-selective antagonist and free radical scavenger – Nelonemdaz.
**Definition**
Nelonemdaz (Salfaprodil free base) is an NR2B-selective and uncompetitive antagonist of the NMDA receptor that also functions as a free radical scavenger.
**In Vitro and In Vivo Studies**
According to the Nelonemdaz description, this compound exhibits dual-action neuroprotection against both NMDA-induced and free radical-induced cell death. In terms of Nelonemdaz in vitro activity, concentrations of 10-300 μM provide apparent neuroprotection against 300 μM NMDA, with significant effects observed at doses as low as 30 μM. Furthermore, Nelonemdaz (10-500 μM) inhibits the electrophysiologic response of cultured cortical neurons to 300 μM NMDA in a concentration-dependent manner. Its antioxidant properties are equally potent; Nelonemdaz (0.1-1 μM) markedly reduces Fe2+-induced neurotoxicity and blocks the degeneration of neurons and glia in cortical cultures. Specifically, it effectively scavenges superoxide radicals (IC50 = 63.07±1.44 μM), nitric oxide (IC50 = 155.8±4.88 μM), and hydroxyl radicals (IC50 = 58.45±1.74 μM). Additionally, it inhibits malondialdehyde (MDA) formation with an IC50 of 2.72±0.26 μM and reduces iron-ascorbate-induced lipid peroxidation (IC50 = 24.56±0.07 μM).
Regarding Nelonemdaz in vivo efficacy, studies using male Sprague-Dawley rats in middle cerebral artery occlusion (MCAO) models demonstrated significant benefits. Administration of Nelonemdaz (0.5-20 mg/kg; i.v.) 5 minutes after reperfusion reduced cerebral infarct volume dose-dependently, with a maximal reduction of 66% at doses of 2.5 to 5 mg/kg. At a dose of 5 mg/kg, no neuronal damage was observed in the most vulnerable cortical areas. In intraluminal thread occlusion models, i.v. administration of 5 mg/kg 30 minutes after reperfusion substantially reduced infarct volume in the cortex and striatum, as well as white matter damage in the striatum and external capsule, without altering physiologic variables such as arterial pH or PCO2. In conclusion, Nelonemdaz is a potent NR2B-selective NMDA antagonist and antioxidant that provides comprehensive neuroprotection against ischemic brain injury.
Keywords
Nelonemdaz, 640290-67-1, Salfaprodil, Neu2000, Neu 2000, Neu-2000, iGluR, Ionotropic glutamate receptors, NMDA, neuroprotection, antioxidant, free, radical, scavenger
References
[1] Gwag BJ, et al. Marked prevention of ischemic brain injury by Neu2000, an NMDA antagonist and antioxidant derived from aspirin and sulfasalazine. J Cereb Blood Flow Metab. 2007 Jun;27(6):1142-51.
[2] Sung IC, et, al. Neu2000, an NR2B-selective, Moderate NMDA Receptor Antagonist and Potent Spin Trapping Molecule for Stroke. Drug News Perspect. 2010 Nov; 23(9): 549-56.
[3] Nishant PV, et, al. Antioxidant Properties of Neu2000 on Mitochondrial Free Radicals and Oxidative Damage. Toxicol In Vitro. 2013 Mar; 27(2): 788-97.
The development of sustainable lubricants has driven significant research into plant oil-based alternatives, with ricinoleic acid—derived from castor oil—emerging as a particularly promising feedstock due to its hydroxyl and double bond functionalities. This study focuses on the rational design and synthesis of functionalized derivatives through targeted chemical modifications aimed at overcoming the limitations of native plant oils. A multi-step strategy was employed, beginning with the epoxidation of ricinoleic acid (1) to form epoxidized ricinoleic acid (2), followed by ring-opening reactions using stearic acid and 4-ethylhexanol to produce mono-, tri-, and tetra-esters (3–5). The reaction pathway was carefully controlled to avoid over-reaction and unwanted byproducts, ensuring high yield and purity.
Characterization using NMR and FTIR spectroscopy confirmed the structural integrity of each derivative. Notably, the presence of oxirane ring signals in the ¹³C NMR spectrum of compound 2 and the disappearance of epoxy peaks in later products indicated successful ring opening. The introduction of ester linkages and branched alkyl chains was further validated by distinct shifts in ¹H NMR and characteristic absorption bands in FTIR, including C=O stretch (~1740 cm⁻¹), C-O-C vibration (~1000–1100 cm⁻¹), and OH stretching (~3478–3443 cm⁻¹).Voriconazole Purity These results confirm the precise molecular engineering of the fatty acid backbone.
The physicochemical properties were systematically evaluated. Compound 5 exhibited the highest viscosity index (257), indicating excellent viscosity stability across temperature ranges. Its low pour point (-44.37°C) and cloud point (-41.25°C) reflect superior cold-flow performance, essential for reliable operation in low-temperature environments. The enhanced thermal and oxidative stability were quantified via PDSC and TFMO. Compound 5 showed an onset temperature of 282.10°C and minimal volatile loss (37.39%), demonstrating resistance to thermal degradation and oxidation-induced polymerization. These improvements stem from the elimination of reactive double bonds through epoxidation and the stabilization provided by bulky branching groups.
Tribological performance was assessed using the four-ball test under standardized conditions.Lactamide Epigenetic Reader Domain Compound 5 achieved the lowest coefficient of friction (0.PMID:34648208 44) and wear scar diameter (0.62 mm), outperforming all other derivatives. This behavior is attributed to the strong polar character of the multiple ester groups, which promote robust adsorption onto metal surfaces and facilitate the formation of a durable protective film. The results collectively demonstrate that strategic chemical modification of ricinoleic acid enables the creation of biolubricant basestocks with balanced, high-performance characteristics—excellent low-temperature fluidity, exceptional thermo-oxidative stability, and outstanding anti-wear performance—making them ideal candidates for advanced green lubricant formulations.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
**Background**
The transient receptor potential vanilloid 1 (TRPV1) is a non-selective cation channel that plays a critical role in the detection and transmission of noxious heat and inflammatory pain. As a key integrator of various chemical and thermal stimuli, TRPV1 is highly expressed in primary sensory neurons, making it a primary therapeutic target for the development of analgesic agents. While many TRPV1 ligands are associated with pungent sensations, there is a significant research need for nonpungent agonists that can provide potent pain relief without adverse sensory effects. In this context, we will introduce a highly specific and efficacious TRPV1 ligand – MDR-652.
**Definition**
MDR-652 is a potent TRPV1 agonist with high affinity and efficacy, exhibiting Ki values of 11.4 nM for hTRPV1 and 23.8 nM for rTRPV1.
**In Vitro and In Vivo Studies**
According to the MDR-652 description, this compound is a highly specific ligand designed for the activation of TRPV1. In terms of MDR-652 in vitro activity, studies using CHO cells expressing human or rat TRPV1 demonstrated that MDR-652 acts as an agonist, increasing 45Ca2+ uptake after 5 minutes of incubation. The EC50 values were determined to be 5.05 nM for hTRPV1 and 93 nM for rTRPV1.
The MDR-652 biological activity has been further validated through extensive animal models. In MDR-652 In Vivo experiments using ICR mice, administration of 0.5 and 5 mg/kg intraperitoneally resulted in a dose-dependent decrease in body temperature, confirming its agonism in intact animals. Furthermore, in rats with spinal nerve ligation (SNL) models of neuropathic pain, MDR-652 (1, 2, 5, and 10 mg/kg) administered intraperitoneally or subcutaneously blocked neuropathic pain completely, achieving a 100% maximum possible effect (MPE). Specifically, i.p. administration showed an excellent analgesic profile with an ED50 of 0.5-2 mg/kg, while s.c. injection reached maximum effect 30 minutes post-administration. Additionally, the compound exhibits a promising topical pharmacokinetic profile and low toxicity, with LD50 values exceeding 200 mg/kg (i.p.) and 2000 mg/kg (p.o.). In conclusion, MDR-652 is a potent, nonpungent TRPV1 agonist with significant potential as a topical analgesic agent.
Keywords
MDR-652, 1933528-96-1, MDR652, MDR 652, TRP Channel, Transient receptor potential channels, TRPV1, ligand, hTRPV1, analgesic, activity, neuropathic, pain, Inhibitor, inhibitor
References
The interplay between proteasome inhibition and cellular stress response pathways is a critical determinant of therapeutic efficacy in urothelial carcinoma. Bortezomib, a reversible proteasome inhibitor, induces endoplasmic reticulum (ER) stress and protein aggregation, leading to apoptosis in cancer cells. However, the activation of cytoprotective mechanisms, particularly the heat shock response, often limits its antitumor effects. This study focuses on the role of inducible Hsp72 in modulating bortezomib sensitivity across human bladder cancer cell lines, revealing a complex isoform-specific regulation that has significant implications for targeted therapy.
We evaluated four representative bladder cancer cell lines—253J B-V, SW780, UM-UC10, and UM-UC13—for their responses to bortezomib-induced cell death using propidium iodide staining and flow cytometry. The results showed marked heterogeneity: 253J B-V and SW780 cells were relatively resistant, while UM-UC10 and UM-UC13 exhibited high sensitivity. mRNA expression profiling revealed that resistance was associated with strong upregulation of HSPA1A, the major inducible isoform of Hsp72, following bortezomib exposure. In contrast, HSPA1A induction was minimal in the sensitive lines, despite intact HSF1 signaling and activation of other stress-responsive genes such as DNAJB1 and HSPB1.
Further investigation demonstrated that this differential induction was due to promoter methylation of HSPA1A in UM-UC10 and UM-UC13 cells. Bisulfite sequencing confirmed hypermethylation of CpG islands within the HSPA1A promoter region, which correlated with transcriptional silencing.Goat Anti-Chicken IgY H&L In Vitro Reversal of methylation using 5-aza-2′-deoxycytidine restored both basal and bortezomib-induced HSPA1A expression, confirming epigenetic regulation. Notably, these cells compensated by upregulating HSPA1B, resulting in comparable total Hsp72 protein levels across all four lines, as confirmed by immunoblotting.
Functional experiments underscored the protective role of Hsp72. Stable overexpression of HSPA1A in UM-UC10 and UM-UC13 cells significantly reduced bortezomib-induced cell death. Conversely, transient knockdown of HSPA1B using siRNA enhanced sensitivity in these cells. In 253J B-V cells, shRNA-mediated silencing of HSPA1A/B led to a dramatic increase in apoptosis, even at low bortezomib concentrations. Importantly, this sensitization was linked to lysosomal destabilization: Hsp72-depleted cells showed increased leakage of LysoTracker Red, indicating loss of lysosomal integrity—a key factor in autophagic flux and proteotoxicity.
In vivo validation was conducted using xenograft models. Nude mice implanted with 253J B-V cells transduced with Hsp72-targeting shRNA developed tumors that responded robustly to bortezomib treatment, showing near-complete growth suppression compared to control groups.Abraxane Microtubule/Tubulin Tumor RNA analysis confirmed sustained downregulation of HSPA1A in treated animals, supporting the relevance of the molecular mechanism observed in vitro.PMID:35196978
These findings highlight a novel vulnerability in bladder cancers with methylated HSPA1A promoters: dependence on HSPA1B for Hsp72 function. This creates an opportunity for synthetic lethality through selective inhibition of HSPA1B. Moreover, targeting upstream regulators like HSF1 with agents such as KNK-437 can effectively suppress Hsp72 induction and enhance bortezomib efficacy.
In conclusion, our data provide compelling evidence that Hsp72 is a dominant resistance factor in bladder cancer and that its inhibition—particularly via epigenetic or isoform-specific strategies—can potentiate the activity of proteasome inhibitors. These insights support the development of combination therapies involving bortezomib and Hsp72/HSF1 inhibitors, especially for tumors exhibiting HSPA1A silencing, offering a promising avenue for personalized treatment in urothelial malignancies.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
Gastroesophageal reflux disease (GERD) affects a substantial portion of the population, with symptoms often persisting despite standard proton pump inhibitor (PPI) therapy. In many cases, these persistent symptoms are linked not to acid reflux but to non-acid or weakly acidic reflux episodes, which are not adequately detected by traditional pH monitoring alone. This presents a diagnostic and therapeutic challenge, particularly in patients who remain symptomatic despite optimal PPI use. The case series presented here evaluates the impact of prucalopride—a selective 5-HT4 receptor agonist—on refractory GERD symptoms in four chronically constipated female patients with documented non-acid reflux confirmed via combined multichannel impedance and pH monitoring.
All patients had a history of chronic constipation and long-standing GERD symptoms, including heartburn, regurgitation, bloating, and globus sensation, that persisted despite at least four weeks of standard PPI therapy and, in some cases, additional H2-receptor antagonist use. Initial ambulatory MII-pH monitoring revealed elevated total reflux episodes, with a majority classified as non-acidic or weakly acidic. Symptom association indices were positive for heartburn and regurgitation in three patients, indicating a clear link between reflux events and symptom occurrence. Subjective symptom scores ranged from 5 to 9 on a 10-point scale, reflecting moderate to severe symptom burden affecting daily functioning.
Following initiation of prucalopride at 2 mg once daily, all patients underwent repeat MII-pH monitoring after four to six weeks. The results demonstrated a significant reduction in overall reflux episodes across all participants. Notably, non-acid reflux episodes decreased substantially in every patient, with one showing a drop from 128 to 76 episodes. Acid reflux episodes showed variable changes—some increased slightly, likely due to physiological variability in monitoring, while others declined significantly. Despite minor fluctuations in acid exposure, the overall trend indicated improved control of reflux activity. Most importantly, subjective reports aligned with objective findings: patients reported fewer symptom occurrences, reduced intensity, and improved quality of life. For example, one patient’s symptom score dropped from 7 to 3, and another noted marked relief in bloating and throat discomfort.SOS1 ProteinSynonyms
No major adverse effects were observed during treatment.Triciribine Epigenetics Patients experienced mild gastrointestinal side effects such as transient diarrhea or abdominal cramping, which resolved spontaneously without discontinuation.PMID:35076747 These findings suggest that prucalopride is well tolerated in this population. The mechanism behind its efficacy may involve enhanced gastric emptying and intestinal transit, which reduces reflux burden by minimizing gastric content volume and improving clearance. Additionally, potential effects on esophageal motility—such as increased lower esophageal sphincter pressure and reduced transient relaxations—may contribute to symptom improvement, although further high-resolution manometry studies are needed to confirm this.
This case series provides early but compelling evidence that prucalopride can effectively reduce both non-acid and total reflux episodes in PPI-resistant GERD patients with chronic constipation. Its dual action on colonic and upper GI motility makes it uniquely suited for this patient subgroup. While larger, randomized controlled trials are necessary to validate these results, the data support prucalopride as a promising therapeutic option for patients with refractory GERD who fail conventional treatments. Future research should explore its role in non-constipated GERD populations and investigate long-term safety and efficacy.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
**Background**
Vascular endothelial growth factor A (VEGF-A) is a critical mediator of angiogenesis, the process by which new blood vessels form from pre-existing ones. Overexpression of VEGF-A is frequently observed in various malignancies, where it promotes tumor growth, survival, and metastasis by stimulating the proliferation and migration of endothelial cells. Consequently, targeting the VEGF-A pathway has become a cornerstone of therapeutic strategies to inhibit tumor vascularization and starve cancer cells of essential nutrients. Given its pivotal role in tumor progression, VEGF-A is a high-priority target for the development of potent neutralizing agents. In this context, we will introduce a high-affinity anti-VEGF-A antibody fragment – Brolucizumab.
**Definition**
Brolucizumab (also known as DLX1008) is a single-chain anti-VEGF-A antibody fragment (scFv-kappa-heavy) characterized by low picomolar affinity, with a dissociation constant (KD) of 1.05 pM.
**In Vitro and In Vivo Studies**
According to the Brolucizumab description, this molecule is designed to bind with high potency to VEGF-A to block its signaling cascade. Brolucizumab in vitro studies demonstrated that at a concentration of 2683 nM, the fragment inhibits VEGF-A112-induced phosphorylation of VEGFR1 in U87MG human glioma cells and phosphorylation of VEGFR2 in ZHE-483-2 GMEC. Furthermore, the Brolucizumab biological activity has been validated through binding assays, where immobilized human VEGF165 protein binds to Brolucizumab with an EC50 of 102.2 ng/mL.
Brolucizumab In Vivo research has highlighted its significant antitumor potential across different models. In U87MG glioma models, administration of Brolucizumab (5-50 mg/kg; i.p. once or twice daily for 28 days) resulted in delayed tumor growth. Additionally, in NSG mice subcutaneously injected with mSLK-KSHV cell suspensions, Brolucizumab (15 mg/kg; i.p. 5 days per week for 21 or 41 days) significantly lowered tumor growth, although no difference in survival was observed between experimental and combined control groups. Pharmacokinetic data in mice indicate a rapid decline phase half-life of 5.4-7.8 minutes and a slow decline phase half-life of 1.4-1.9 hours following i.v. administration at 10 mg/kg. In conclusion, Brolucizumab is a potent anti-VEGF-A antibody fragment that effectively inhibits angiogenesis and suppresses tumor growth in Brolucizumab Cancer research models.
Keywords
Brolucizumab, 1531589-13-5, DLX1008, ESBA 1008, RTH258, DLX 1008, DLX-1008, ESBA1008, ESBA-1008, RTH 258, RTH-258, VEGFR, Vascular endothelial growth factor receptor
References
[1] Szabó E, et, al. Antitumor Activity of DLX1008, an Anti-VEGFA Antibody Fragment with Low Picomolar Affinity, in Human Glioma Models. J Pharmacol Exp Ther. 2018 May;365(2):422-429.
[2] Eason AB, et, al. DLX1008 (brolucizumab), a single-chain anti-VEGF-A antibody fragment with low picomolar affinity, leads to tumor involution in an in vivo model of Kaposi Sarcoma. PLoS One. 2020 May 14;15(5):e0233116.
The development of functional chloroplasts during early seedling growth is a tightly regulated process dependent on coordinated gene expression between the nucleus and plastid genomes. In Arabidopsis, the plastid-encoded RNA polymerase (PEP) complex plays a central role in transcribing photosynthesis-related genes essential for chloroplast biogenesis. The TAC (transcriptionally active chromosome) complex, which houses PEP and its associated regulatory proteins, is critical for this process. Among its components, FLN2—a fructokinase-like protein—has emerged as a key player in modulating PEP activity through redox signaling pathways.
This study investigates the function of FLN2 in chloroplast development using the fln2-4 mutant, generated by T-DNA insertion in the FLN2 gene (At1g69200). Both fln2-3 and fln2-4 mutants display an albino phenotype on sucrose-free media, indicating severe defects in early chloroplast formation. However, when grown on sucrose-containing medium, they gradually develop green true leaves, demonstrating a delayed greening phenotype. This suggests that while endogenous energy reserves are insufficient to support full plastid maturation, exogenous carbon can compensate for metabolic deficits.
Molecular analysis revealed that loss of FLN2 specifically impairs PEP-dependent gene expression. Northern hybridization showed strong downregulation of class I genes (psbA, psbB, rbcL), which are exclusively PEP-transcribed, while class II (rrn16, clpP) and class III (accD, rpoA) genes, transcribed by NEP or both polymerases, remained largely unaffected. This specificity confirms that FLN2 primarily influences PEP-mediated transcription rather than general plastid gene expression.
Yeast two-hybrid assays identified direct interactions between FLN2 and three TAC components: thioredoxin z (TRX z), FLN1 (its homologous partner), and pTAC5. These findings place FLN2 within a redox-sensitive regulatory subcomplex of the TAC. Notably, FLN1 was found capable of forming homodimers in yeast, whereas FLN2 could not. This implies that in the absence of FLN2, FLN1 may form homodimers to partially maintain redox regulation of PEP activity, thereby explaining the residual PEP function observed in fln2-4. This compensatory mechanism likely underlies the delayed greening phenotype, where slow accumulation of PEP-dependent transcripts allows gradual chloroplast maturation upon sucrose supplementation.Kallikrein-5 ProteinBiological Activity
Ultrastructural analysis via transmission electron microscopy confirmed impaired plastid development in fln2-4. At 7 days, chloroplasts lacked organized thylakoid membranes and appeared highly vacuolated. By day 14 under sucrose, lamellar structures began to form, and stacked grana were observed, indicating progressive differentiation. Chlorophyll content increased from ~17% of wild-type levels at 7 days to ~42% at 14 days, with a corresponding improvement in the chlorophyll a/b ratio. These data demonstrate that despite initial developmental arrest, plastids in fln2-4 retain the capacity to mature into functional chloroplasts when energy supply is augmented.Lgr4/GPR48 Proteinweb
Further comparative analysis across leaf coloration mutants revealed a clear correlation between PEP activity and phenotypic severity.PMID:34877753 Complete albino mutants (trx z, ptac14) exhibited near-complete loss of PEP-dependent transcripts, while yellow mutants (ecb2-2, ys1) showed intermediate levels. fln2-4 occupied an intermediate position—higher than complete albinos but lower than yellow mutants—consistent with its delayed greening phenotype. This supports the hypothesis that a threshold level of PEP activity is required for successful greening.
Collectively, these results establish FLN2 as a critical regulator of PEP activity within the TAC complex, functioning in a redox-sensitive manner alongside TRX z and FLN1. Its role appears non-core, acting more as a modulator than a structural component. The ability of FLN1 to form homodimers provides a plausible mechanism for partial functional compensation in fln2-4, allowing the mutant to overcome energy limitations and achieve photoautotrophy. This work highlights the importance of metabolic flexibility and regulatory redundancy in plastid development, offering insights into how plants balance developmental precision with resilience under stress.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
**Background**
Colorectal cancer remains a significant global health challenge characterized by high morbidity and the need for effective therapeutic interventions. Research into antineoplastic agents often focuses on compounds that can induce apoptosis, inhibit cell proliferation, and disrupt the cell cycle of malignant cells. Beyond oncology, there is a growing interest in compounds that can modulate metabolic disorders and provide neuroprotection by regulating oxidative stress and inflammatory pathways. Natural alkaloids have emerged as promising candidates due to their diverse biological activities and potential to target multiple signaling pathways. In this context, we will introduce a versatile alkaloid with potent antineoplastic and metabolic properties – Berberine.
**Definition**
Berberine is an isoquinoline alkaloid isolated from plants such as Coptis chinensis Franch. It acts as an antibiotic and antineoplastic agent that induces reactive oxygen species (ROS) generation and inhibits DNA topoisomerase.
**In Vitro and In Vivo Studies**
The Berberine description highlights that the sulfate form of this compound is utilized to improve its bioavailability. Regarding Berberine biological activity, in vitro studies demonstrate that Berberine sulfate (1.25-160 μM; 72 hours) inhibits the proliferation of four colorectal carcinoma cell lines: LoVo, HCT116, SW480, and HT-29, with IC50 values ranging from 40.8±4.1 μM (LoVo) to 98.6±2.9 μM (HCT116). Specifically, in LoVo cells, treatment with 1.25-160 μM for 24-72 hours induces time- and dose-dependent growth inhibition, with 160.0 μM resulting in 71.1±1.9% inhibition by 72 hours. Furthermore, exposure to 40 μM for 24 hours induces G2/M-phase cell cycle arrest and suppresses the expression of cyclin B1, cdc2, and cdc25c proteins.
Beyond Berberine Cancer research, the compound exhibits broad pharmacological effects. It demonstrates antimicrobial activity by inhibiting the cell division protein FtsZ, anti-inflammatory activity via inhibition of TNF-α and the NF-κB/AP-1 pathways, and neuroprotective efficacy through the activation of the PI3K/Akt pathway and HO-1 expression. Additionally, it attenuates metabolic diseases by regulating lipid composition and inhibiting insulin resistance.
In terms of Berberine in vivo efficacy, administration of Berberine sulfate (10, 30, or 50 mg/kg/day via gastrointestinal gavage for 10 consecutive days) inhibits the growth of human colorectal adenocarcinoma xenografts in nude mice. Doses of 30 and 50 mg/kg/day showed inhibitory rates of 33.1% and 45.3%, respectively. In conclusion, Berberine is a multi-functional alkaloid with significant potential in treating colorectal cancer, metabolic disorders, and inflammatory diseases.
Keywords
Berberine, 633-66-9, Natural Yellow 18, Natural Yellow18, Natural Yellow-18, Antibiotic, Topoisomerase, Autophagy, Bacterial, Reactive Oxygen Species (ROS), Parasite, Apoptosis, PI3K, Akt, Caspase
References
[1] Cai Y, et al. Berberine inhibits the growth of human colorectal adenocarcinoma in vitro and in vivo. J Nat Med. 2014 Jan;68(1):53-62.
[2] Cui HX, et al. Preparation and Evaluation of Antidiabetic Agents of Berberine Organic Acid Salts for Enhancing the Bioavailability. Molecules. 2018 Dec 28;24(1):103.
[3] Boberek JM, et al., Genetic evidence for inhibition of bacterial division protein FtsZ by berberine. PLoS One. 2010 Oct 29;5(10):e13745.
[4] Remppis A, et al., Rhizoma Coptidis inhibits LPS-induced MCP-1/CCL2 production in murine macrophages via an AP-1 and NFkappaB-dependent pathway. Mediators Inflamm. 2010;2010:194896.
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