Somatostatin receptor

This work is devoted to the large-scale solid-phase synthesis (SPS) of Atosiban, Mpa1-D-Tyr(OEt)-Ile-Thr-Asn-Cys6-Pro-Orn-Gly-NH2 cyclic 1,6 disulfide, the only clinically used oxytocin receptor antagonist. The conditions have been selected for the closure of the disulfide bond (S–S) in the Atosiban molecule both in the solution and solid phase with the minimal formation of by-products. A comparative assessment of the formation of the S–S bond was carried out under various conditions. The formation of by-products during the closure of the disulfide bond has been studied both in solution and on the polymer support. The developed technique allows for the synthesis of Atosiban on an enlarged scale (10–20 mmol) involving the cyclization of a protected intermediate with the formation of the S–S bond during solid-phase synthesis with the minimal formation of by-products [1].

Reduced hepatic glycogenesis is one of the most important causes of metabolic abnormalities in non‑alcoholic fatty liver disease. Octreotide, a somatostatin analogue, has been demonstrated to promote weight loss and improve metabolic disorders in mice with high fat diet (HFD)‑induced obesity. However, whether octreotide affects hepatic glycogenesis is unknown. The aim of the present study was to verify the effects of octreotide on hepatic glycogenesis in rats with HFD‑induced obesity. Male Sprague‑Dawley rats were fed a standard diet or a HFD for 24 weeks. Obese rats from the HFD group were further divided into a HFD‑control group and an octreotide‑administered group. Rats in the latter group were injected with octreotide for 8 days. Glucose and insulin tolerance tests were performed, and the area under the curve (AUC) was calculated. Following sacrifice, their body weights and lengths, fasting plasma glucose (FPG), fasting insulin (FINS), serum triglyceride (TG), total cholesterol (TC), free fatty acid (FFA), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were measured. In addition, Lee's index and the homeostatic model assessment index were calculated. Hepatic TG, FFA levels and glycogen content were first determined. Hepatic steatosis in the obese rats was assessed based on hematoxylin and eosin and Oil Red O staining. Human hepatoblastoma HepG2 cells were divided into a control group, a palmitate (PA)‑treated group and a PA + octreotide‑treated group. Establishment of the in vitro fatty liver model using HepG2 cells was confirmed by Oil Red O staining. The expression of phosphorylated Akt and glycogen synthase kinase 3β (GSK3β) was detected by western blotting, and glycogen synthase (GS) mRNA levels were detected by reverse transcription‑quantitative polymerase chain reaction. Compared with the control group, the body weight, Lee's index, AUC of the intraperitoneal glucose tolerance test and intraperitoneal insulin tolerance test, levels of FPG, FINS, TG, TC, FFA, ALT and AST, and HOMA index values were significantly increased in the obese rats. The body weight, levels of FPG and FINS, and the HOMA index were significantly reduced following octreotide treatment, whereas the decrease in Lee's index, the blood levels of ALT, AST, TC, TG and FFA, and the AUC did not reach statistical significance. Hepatic TG and FFA levels were significantly increased and hepatic glycogen content was significantly decreased in rats with HFD‑induced obesity when compared with those in the control group. Octreotide intervention restored these alterations. The expression levels of phosphorylated Akt and GSK3β protein expression, as well as GS mRNA levels in the HFD group were lower when compared with those in the control group, whereas octreotide treatment reversed these reductions. The in vitro experiments demonstrated that the reduced levels of phosphorylated Akt and GSK3β protein, and GS mRNA in the PA‑treated group were significantly reversed by octreotide treatment. In conclusion, the results indicate that octreotide improved hepatic glycogenesis and decreased FPG concentration in rats with HFD‑induced obesity. These mechanisms may be associated with increased GS activity via the promotion of GSK3β phosphorylation. Therefore, octreotide may be regarded as a novel therapeutic strategy for HFD‑induced obesity and obesity‑associated metabolic disorders [2].

[1]. Optimal Method for Disulfide Bond Closure in the Synthesis of Atosiban—Antagonist of Oxytocin Receptors. Russian Journal of Bioorganic Chemistry volume 47, pages1241–1248 (2021)
[2]. Effects of octreotide on hepatic glycogenesis in rats with high fat diet?induced obesity. Mol Med Rep. 2017 Jul;16(1):109-118

The developed method can obtain technical-grade atosiban with a purity of over 85% and a dimer content of less than 5%, which makes it possible to introduce the technology into industrial production. [1]

C98H132N20O20S4

2038.48

2151.877

1926163-80-5

145707862

H-D-Phe-Cys(1)-Phe-D-Trp-Lys-Thr-Cys(2)-Thr-ol.H-D-Phe-Cys(1)-Phe-D-Trp-Lys-Thr-Cys(2)-Thr-ol.TFA
D-phenylalanyl-L-cysteinyl-L-phenylalanyl-D-tryptophyl-L-lysyl-L-threonyl-L-cysteinyl-L-threoninol (2->2'),(7->7')-bis(disulfide) compound with D-phenylalanyl-L-cysteinyl-L-phenylalanyl-D-tryptophyl-L-lysyl-L-threonyl-L-cysteinyl-L-threoninol trifluoroacetic acid
({d-Phe}-Cys-Phe-{d-Trp}-Lys-Thr-Cys-{L-threoninol})2 (Disulfide bond: Cys2A-Cys2B; Cys7A-Cys7B)

({d-Phe}-CF-{d-Trp}-KTC-{L-threoninol})2 (Disulfide bond: Cys2A-Cys2B; Cys7A-Cys7B)

Typically exists as solid at room temperature

27

33

34

149

3820

20

C[C@H]([C@H]1C(=O)N[C@@H](CSSC[C@H](NC(=O)[C@@H](NC(=O)[C@@H](NC(=O)[C@H](NC(=O)[C@@H](NC(=O)[C@H](CSSC[C@@H](C(=O)N[C@H](C(=O)N[C@@H](C(=O)N[C@H](C(=O)N1)CCCCN)CC2=CNC3=CC=CC=C32)CC4=CC=CC=C4)NC(=O)[C@@H](CC5=CC=CC=C5)N)NC(=O)[C@@H](CC6=CC=CC=C6)N)CC7=CC=CC=C7)CC8=CNC9=CC=CC=C98)CCCCN)[C@@H](C)O)C(=O)N[C@H](CO)[C@@H](C)O)C(=O)N[C@H](CO)[C@@H](C)O)O.C(=O)(C(F)(F)F)O

LUSPXROKXWWHOM-GZFVIQAPSA-N

InChI=1S/C98H132N20O20S4.C2HF3O2/c1-55(121)77(49-119)111-95(135)81-53-141-142-54-82(96(136)112-78(50-120)56(2)122)116-98(138)84(58(4)124)118-88(128)72(38-22-24-40-100)106-92(132)76(46-64-48-104-70-36-20-18-34-66(64)70)110-90(130)74(44-62-31-15-8-16-32-62)108-94(134)80(114-86(126)68(102)42-60-27-11-6-12-28-60)52-140-139-51-79(113-85(125)67(101)41-59-25-9-5-10-26-59)93(133)107-73(43-61-29-13-7-14-30-61)89(129)109-75(45-63-47-103-69-35-19-17-33-65(63)69)91(131)105-71(37-21-23-39-99)87(127)117-83(57(3)123)97(137)115-81;3-2(4,5)1(6)7/h5-20,25-36,47-48,55-58,67-68,71-84,103-104,119-124H,21-24,37-46,49-54,99-102H2,1-4H3,(H,105,131)(H,106,132)(H,107,133)(H,108,134)(H,109,129)(H,110,130)(H,111,135)(H,112,136)(H,113,125)(H,114,126)(H,115,137)(H,116,138)(H,117,127)(H,118,128);(H,6,7)/t55-,56-,57-,58-,67-,68-,71+,72+,73+,74+,75-,76-,77-,78-,79+,80+,81+,82+,83+,84+;/m1./s1

(4R,7S,10S,13R,16S,19R,24R,27S,30R,33S,36S,39R)-10,33-bis(4-aminobutyl)-19,24-bis[[(2R)-2-amino-3-phenylpropanoyl]amino]-16,27-dibenzyl-4-N,39-N-bis[(2R,3R)-1,3-dihydroxybutan-2-yl]-7,36-bis[(1R)-1-hydroxyethyl]-13,30-bis(1H-indol-3-ylmethyl)-6,9,12,15,18,25,28,31,34,37-decaoxo-1,2,21,22-tetrathia-5,8,11,14,17,26,29,32,35,38-decazacyclotetracontane-4,39-dicarboxamide;2,2,2-trifluoroacetic acid

1926163-80-5; Octreotide trifluoroacetate salt (Dimer, Parallel); MFCD30748663

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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 (Please use freshly prepared in vivo formulations for optimal results.)