HCTU is a highly efficient aminium-based coupling reagent widely utilized in solid-phase and solution-phase peptide synthesis.

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HCTU is a highly efficient aminium-based coupling reagent widely utilized in solid-phase and solution-phase peptide synthesis. As a 6-chloro derivative of HBTU, HCTU exhibits superior reactivity and faster reaction kinetics, facilitating robust amide bond formation even in sterically hindered sequences with minimal racemization. HCTU reagent demonstrates excellent solubility in water or 1% acetic acid, making it a versatile and indispensable tool for high-yield automated synthesis and complex macromolecular assemblies.

Complete Stock Solution Preparation Table

Desoxyrhaponticin, a stilbene glycoside from rhubarb, is a potent BACE1 inhibitor with an IC50 value of 1.213µM.

Products are for research use only. Not for human use. We do not sell to patients.

Desoxyrhaponticin, a stilbene glycoside from rhubarb, is a potent BACE1 inhibitor with an IC50 value of 1.213µM [1]. Desoxyrhaponticin improves insulin resistance (IR) and reduces lipid accumulation through the PI3K/AKT/mTOR signaling pathway[2]. Desoxyrhaponticin is widely used as an internal standard to develop high-speed counter-current chromatography (HSCCC) methods for the large-scale separation and identification of related compounds[3].

In vitro, Desoxyrhaponticin treatment for 4 days significantly inhibited the proliferation of H1299 cells and HBE cells, with IC50 values of 86.68µM and 58.83µM, respectively[4]. Treatment with 400µM Desoxyrhaponticin for 24 hours strongly inhibited the expression of Fatty acid synthase (FAS) in MCF-7 cells and the activity of FAS within the cells, and promoted cell apoptosis[5]. Treatment with 10µM Desoxyrhaponticin for 48 hours significantly inhibited the accumulation of triglycerides (TG) in 3T3-L1 preadipocytes and increased the level of PPARγ[6].

In vivo, Desoxyrhaponticin treatment via a single oral administration at a dose of 300mg/kg for 2 hours significantly reduced postprandial hyperglycemia in diabetic rats[7].

References:

[1] Oh J M, Kim S H, Pandey B P, et al. A stilbenoid, rhapontigenin, isolated from the root of Rheum palmatum L. acts as a potent BACE1 inhibitor[J]. Fitoterapia, 2025, 182: 106484.

[2] Gao Y, Wu Y, Tie F, et al. Stilbenoids from fenugreek seeds alleviate insulin resistance by regulating the PI3K/AKT/mTOR signaling pathway in a type 2 diabetes zebrafish model[J]. Heliyon, 2024, 10(13).

[3] Wang X, Wang H, Ding C, et al. One‐step preparative separation of two polyhydroxystilbenes from Rheum likiangense sam. by high‐speed counter‐current chromatography[J]. Phytochemical Analysis, 2012, 23(6): 684-688.

[4] Fan M, Liu Q, Ma X, et al. ZNF131-BACH1 transcriptionally accelerates RAD51-dependent homologous recombination repair and therapy-resistance of non-small-lung cancer cells by preventing their degradation from CUL3[J]. Theranostics, 2024, 14(18): 7241.

[5] Li P, Tian W, Wang X, et al. Inhibitory effect of desoxyrhaponticin and rhaponticin, two natural stilbene glycosides from the Tibetan nutritional food Rheum tanguticum Maxim. ex Balf., on fatty acid synthase and human breast cancer cells[J]. Food & function, 2014, 5(2): 251-256.

[6] Li G, Luan G, He Y, et al. Polyphenol Stilbenes from Fenugreek (Trigonella foenum-graecum L.) Seeds Improve Insulin Sensitivity and Mitochondrial Function in 3T3‐L1 Adipocytes[J]. Oxidative Medicine and Cellular Longevity, 2018, 2018(1): 7634362.

[7] Li J M, Che C T, Lau C B S, et al. Desoxyrhaponticin (3, 5-dihydroxy-4′-methoxystilbene 3-O-β-d-glucoside) inhibits glucose uptake in the intestine and kidney: In vitro and in vivo studies[J]. The Journal of pharmacology and experimental therapeutics, 2007, 320(1): 38-46.

Protocol

Chemical Properties

Complete Stock Solution Preparation Table

VcMMAE is a drug-linker conjugate used in the synthesis of antibody-drug conjugates (ADCs), consisting of the microtubule inhibitor monomethyl auristatin E (MMAE) and a cleavable valine-citrulline (vc) linker.

Products are for research use only. Not for human use. We do not sell to patients.

VcMMAE is a drug-linker conjugate used in the synthesis of antibody-drug conjugates (ADCs), consisting of the microtubule inhibitor monomethyl auristatin E (MMAE) and a cleavable valine-citrulline (vc) linker[1-2]. In the ADC structure, VcMMAE is covalently linked to the antibody via the maleimide group of its linker. Upon specific cleavage by cancer cell lysosomes, VcMMAE releases the cytotoxic MMAE, thereby inhibiting tubulin polymerization and inducing tumor cell apoptosis[3-4].

In vitro, when conjugated with the anti-HER2 antibody H32 (0.02–0.78nM) and applied to HER2-positive cancer cells such as N87, SK-BR-3, and BT474 for 16 hours, VcMMAE significantly inhibited cancer cell viability and induced apoptosis[5]. The conjugate of VcMMAE with Rituximab (100–1000ng/mL) treatment of CD20-positive Raji cells for 48–72 hours markedly reduced cell viability and induced cell death[6].

In vivo, the conjugate of VcMMAE with the chimeric monoclonal antibody cAC10 targeting CD30 (1-30mg/kg), administered via tail vein injection every 4 days to tumor-bearing SCID mice, significantly suppressed the growth of CD30-positive anaplastic large cell lymphoma (Karpas 299) and Hodgkin's disease (L540cy) xenografts, leading to complete tumor regression[7]. The conjugate of VcMMAE with the anti-CD22 monoclonal antibody HB22.7 (7.5mg/kg), administered as a single intraperitoneal injection to tumor-bearing ICR-SCID mice, significantly inhibited the growth of DoHH2 (transformed follicular lymphoma) and Granta 519 (mantle cell lymphoma) xenografts and induced complete tumor regression[8].

References:

[1] Best RL, LaPointe NE, Azarenko O, et al. Microtubule and tubulin binding and regulation of microtubule dynamics by the antibody drug conjugate (ADC) payload, monomethyl auristatin E (MMAE): Mechanistic insights into MMAE ADC peripheral neuropathy. Toxicol Appl Pharmacol. 2021 Jun 15;421:115534.

[2] Pollack VA, Alvarez E, Tse KF, et al. Treatment parameters modulating regression of human melanoma xenografts by an antibody-drug conjugate (CR011-vcMMAE) targeting GPNMB. Cancer Chemother Pharmacol. 2007 Aug;60(3):423-35.

[3] Vaklavas C, Forero A. Management of metastatic breast cancer with second-generation antibody-drug conjugates: focus on glembatumumab vedotin (CDX-011, CR011-vcMMAE). BioDrugs. 2014 Jun;28(3):253-63.

[4] Zhang J, Li M, Li W, et al. Mechanistic Insights into Anti-Nectin4-VcMMAE-Induced Ocular Toxicity: From Cellular Uptake Pathways to Molecular Modification. Int J Mol Sci. 2025 May 22;26(11):4996.

[5] Chiang ZC, Chiu YK, Lee CC, et al. Preparation and characterization of antibody-drug conjugates acting on HER2-positive cancer cells. PLoS One. 2020 Sep 28;15(9):e0239813.

[6] Abdollahpour-Alitappeh M, Hashemi Karouei SM, Lotfinia M, et al. Amanzadeh A, Habibi-Anbouhi M. A developed antibody-drug conjugate rituximab-vcMMAE shows a potent cytotoxic activity against CD20-positive cell line. Artif Cells Nanomed Biotechnol. 2018;46(sup2):1-8.

[7] Francisco JA, Cerveny CG, Meyer DL, et al. cAC10-vcMMAE, an anti-CD30-monomethyl auristatin E conjugate with potent and selective antitumor activity. Blood. 2003 Aug 15;102(4):1458-65.

[8] Abuhay M, Kato J, Tuscano E, et al. The HB22.7-vcMMAE antibody-drug conjugate has efficacy against non-Hodgkin lymphoma mouse xenografts with minimal systemic toxicity. Cancer Immunol Immunother. 2016 Oct;65(10):1169-75.

Protocol

Chemical Properties

Complete Stock Solution Preparation Table

FM1 43 is a water-soluble styryl dye with strong lipophilicity, and FM1-43 is widely used as a fluorescent membrane probe in biological research..

Products are for research use only. Not for human use. We do not sell to patients.

FM1-43 is a water-soluble styrene dye with strong lipophilicity. FM 1-43 membrane probe is a reagent that can specifically bind to cell membranes and inner membrane organelles to generate fluorescence.  FM1-43 is widely used as endocytosis and excision membrane structure markers, and can be used to identify actively firing neurons and research Mechanisms of activity-dependent vesicle cycling[1]. In actively releasing neurotransmitters, the FM1-43 dye is internalized into recycled synaptic vesicles, causing the nerve terminals to become brightly stained. Non-specific staining of cell surface membranes from FM1-43 can be simply washed off before observation[2]. FM1-43 is nontoxic to cells, barely fluoresces in aqueous media, but fluoresces strongly after insertion into the outer leaflet of the cell membrane. FM1-43 also reduces the ototoxic effects of the aminoglycoside antibiotic neomycin sulfate[3].

References:

[1]. Audrey C Brumback, et al. Using FM1-43 to study neuropeptide granule dynamics and exocytosis.2004 Aug;33(4):287-94. doi: 10.1016/j.ymeth.2004.01.002.

[2]. J J Renger,C Egles, G Liu. A developmental switch in neurotransmitter flux enhances synaptic efficacy by affecting AMPA receptor activation.2001 Feb;29(2):469-84. doi: 10.1016/s0896-6273(01)00219-7.

[3]. J E Gale, et al. FM1-43 dye behaves as a permeant blocker of the hair-cell mechanotransducer channel. J Neurosci. 2001 Sep 15;21(18):7013-25.

Protocol

This protocol provides a guide only and should be modified according to your specific needs.

1. Preparation of FM1-43 cell membrane staining solution

(1) Prepare DMSO storage solution: the storage solution is prepared with DMSO at a concentration of 1-5mM.

Note: Store the unused stock solution in aliquots at -20°C or -80°C in the dark and avoid repeated freezing and thawing.

(2) Preparation of working solution: Use an appropriate buffer (such as: serum-free medium, HBSS or PBS) to obtain a 5-20 μM FM working solution[1].

Note: The final concentration of the working solution needs to be optimized according to different cell lines and experimental systems. It is recommended to start from the recommended concentration and explore the optimal concentration in the range of 10 times.

2. Suspension Cell Staining with FM1-43 Dye

(1) The suspended cells were centrifuged at 4°C, 1000-1500rpm for 3-5 minutes, and the supernatant was discarded. Wash twice with PBS for 5 minutes each.

(2) Add 1mL of FM1-43 working solution (recommended concentration: 10μM), incubate at room temperature for 5-30 minutes, the optimal incubation time is different for different cells.

(3) The cell test tube was centrifuged at 1000-1500 rpm for 5 minutes.

(4) After the incubation, centrifuge at 1000-1500rpm for 5 minutes, remove the supernatant, add PBS to wash 2-3 times, 5 minutes each time.

(5) Resuspend the cells with serum-free cell culture medium or PBS. Observed by fluorescence microscopy or flow cytometry.

3. FM1-43 Dye Staining of Adherent Cells

(1) Culture adherent cells on sterile coverslips.

(2) Remove the coverslip from the medium, aspirate excess medium, and place the coverslip in a humid environment.

(3) Add 100uL of FM1-43 working solution from one corner of the cover slip, shake gently to make the dye evenly cover all the cells.

(4) Incubate at room temperature for 5-30 minutes, and the optimal incubation time is different for different cells.

(5) Discard the working solution, and wash the coverslip 2-3 times with the culture medium.

4. Microscopic examination: FM1-43 excitation/emission light is 480/598nm respectively[2].

Note:

1) Fluorescent dyes have quenching problems, please try to avoid light to slow down fluorescence quenching.

2) For your safety and health, please wear a lab coat and disposable gloves for operation.

References:

[1]. J J Renger,C Egles, G Liu. A developmental switch in neurotransmitter flux enhances synaptic efficacy by affecting AMPA receptor activation.2001 Feb;29(2):469-84. doi: 10.1016/s0896-6273(01)00219-7.

[2]. Adriana Della Pietra, Nikita Mikhailov, Rashid Giniatullin. FM1-43 Dye Memorizes Piezo1 Activation in the Trigeminal Nociceptive System Implicated in Migraine Pain. 2023 Jan 14;24(2):1688. doi: 10.3390/ijms24021688.

Chemical Properties

Complete Stock Solution Preparation Table

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