1
|
Synthetic, structural and pharmacological studies on some isonicotinohydrazide and benzohydrazide analogues. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.jopr.2013.06.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
2
|
Yamada K, Murakami M, Yamamoto A, Takada K, Muranishi S. Improvement of Intestinal Absorption of Thyrotropin-releasing Hormone by Chemical Modification with Lauric Acid. J Pharm Pharmacol 2011; 44:717-21. [PMID: 1360521 DOI: 10.1111/j.2042-7158.1992.tb05506.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Abstract
Intestinal absorption of 125I-labelled lauryl thyrotropin-releasing hormone (Lau-TRH), a novel lipophilic derivative of TRH, was examined by rat in-situ closed intestinal loops. At a dose of 1 μmol per rat into the small intestine, a significant increase in percent of dose in plasma radioactivity of Lau-TRH was observed in comparison with that of TRH. A dose-dependent decrease in percent of dose in plasma radioactivity of TRH was noted, suggesting a saturable process of TRH transport. In contrast, the percent of dose in plasma radioactivity of Lau-TRH increased with increasing dose of Lau-TRH. The stability of TRH and Lau-TRH was studied in plasma and rat small intestinal homogenates. Lau-TRH was more stable than TRH in rat plasma. These results suggest that chemical modification of TRH with lauric acid may not only increase the lipophilicity of TRH but also reduce the degradation of TRH, resulting in the increased plasma radioactivity of TRH. On the other hand, Lau-TRH was gradually converted to TRH in the intestinal mucosal homogenate. These findings indicate that chemical modification of TRH with lauric acid might be a useful approach for improving the intestinal absorption of this peptide.
Collapse
Affiliation(s)
- K Yamada
- Department of Biopharmaceutics, Kyoto Pharmaceutical University, Japan
| | | | | | | | | |
Collapse
|
3
|
Senthilkumar P, Long J, Swetha R, Shruthi V, Wang RR, Preethi S, Yogeeswari P, Zheng YT, Sriram D. Synthesis of zidovudine derivatives with anti-HIV-1 and antibacterial activities. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2009; 28:89-102. [PMID: 19219739 DOI: 10.1080/15257770902736442] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Twelve novel zidovudine derivatives were prepared by modifying 5 '-hydroxyl group of sugar moiety (1-8) and 5-methyl group of thymidine nucleus (9-12) and characterized spectrally. The compounds were evaluated for anti-HIV-1, antitubercular and antibacterial activities. Compound (3-azido-tetrahydro-5- (3,4-dihydro-5-methyl-2,4-dioxopyrimidin-1(2H)-yl)furan-2-yl)methyl 7-(4-(2-phenylacetoyloxy)-3,5- dimethylpiperazin-1-yl)-5-(2-phenylacetoyloxyamino)-1-cyclopropyl-6,8-difluoro-1,4-dihydro-4-oxoquinoline-3-carboxylate (5) was found to be the most potent anti-HIV-1 agent with EC(50) of 0.0012 microM against HIV-1(IIIB) and CC(50) of 34.05 microM against MT-4 with selectivity index of 28,375. Compound 5 inhibited Mycobacterium tuberculosis with MIC of 1.72 microM and inhibited four pathogenic bacteria with MIC of less than 1 microM.
Collapse
Affiliation(s)
- Palaniappan Senthilkumar
- Medicinal Chemistry & Antimycobacterial Research Laboratory, Pharmacy Group, Birla Institute of Technology & Science-Pilani, Hyderabad, Andhra Pradesh, India
| | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Sriram D, Yogeeswari P, Babu NR, Kurre PN. Synthesis and in vitro anti-HIV activities of didanosine prodrugs. J Enzyme Inhib Med Chem 2008; 22:51-5. [PMID: 17373547 DOI: 10.1080/14756360600988831] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
A series of prodrugs of didanosine were synthesized in an effort to enhance the anti-HIV activity. The 5'-OH function of didanosine was esterified with different aryl piperazine acetic acid derivatives and evaluated for anti-HIV-1 activity in MT-4 cell line using the MTT assay method. Among the synthesized compounds, (tetrahydro-5-(1,6-dihydro-6-oxopurin-9-yl)furan-2-yl)methyl 2-(4-(4-chlorophenyl)piperazin-1-yl)acetate (4b) was found to be the most potent compound with EC50 of 0.64 microM and was not toxic to the MT-4 cells up to 1000 microM with a selectivity index of > 1562. Compound 4b was found to be seven times more potent than the parent drug didanosine (EC50 of 4.8 microM) in vitro. In vitro hydrolysis of the various esters in human plasma indicated that these agents were relatively stable toward plasma esterases with t1/2 ranging from 20-60 min.
Collapse
Affiliation(s)
- Dhrmarajan Sriram
- Medicinal Chemistry Research Laboratory, Pharmacy group, Birla Institute of Technology and Science, Pilani 333031, India.
| | | | | | | |
Collapse
|
5
|
Synthesis and Stability in Biological Media of 1H-Imidazole-1-carboxylates of ROS203, an Antagonist of the Histamine H3 Receptor. Chem Biodivers 2008; 5:140-52. [DOI: 10.1002/cbdv.200890004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
6
|
Morty RE, Bulau P, Pellé R, Wilk S, Abe K. Pyroglutamyl peptidase type I from Trypanosoma brucei: a new virulence factor from African trypanosomes that de-blocks regulatory peptides in the plasma of infected hosts. Biochem J 2006; 394:635-45. [PMID: 16248854 PMCID: PMC1383713 DOI: 10.1042/bj20051593] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Peptidases of parasitic protozoans are emerging as novel virulence factors and therapeutic targets in parasitic infections. A trypanosome-derived aminopeptidase that exclusively hydrolysed substrates with Glp (pyroglutamic acid) in P1 was purified 9248-fold from the plasma of rats infected with Trypanosoma brucei brucei. The enzyme responsible was cloned from a T. brucei brucei genomic DNA library and identified as type I PGP (pyroglutamyl peptidase), belonging to the C15 family of cysteine peptidases. We showed that PGP is expressed in all life cycle stages of T. brucei brucei and is expressed in four other blood-stream-form African trypanosomes. Trypanosome PGP was optimally active and stable at bloodstream pH, and was insensitive to host plasma cysteine peptidase inhibitors. Native purified and recombinant hyper-expressed trypanosome PGP removed the N-terminal Glp blocking groups from TRH (thyrotrophin-releasing hormone) and GnRH (gonadotropin-releasing hormone) with a k(cat)/K(m) value of 0.5 and 0.1 s(-1) x microM(-1) respectively. The half-life of TRH and GnRH was dramatically reduced in the plasma of trypanosome-infected rats, both in vitro and in vivo. Employing an activity-neutralizing anti-trypanosome PGP antibody, and pyroglutamyl diazomethyl ketone, a specific inhibitor of type I PGP, we demonstrated that trypanosome PGP is entirely responsible for the reduced plasma half-life of TRH, and partially responsible for the reduced plasma half-life of GnRH in a rodent model of African trypanosomiasis. The abnormal degradation of TRH and GnRH, and perhaps other neuropeptides N-terminally blocked with a pyroglutamyl moiety, by trypanosome PGP, may contribute to some of the endocrine lesions observed in African trypanosomiasis.
Collapse
Affiliation(s)
- Rory E Morty
- Department of Internal Medicine, University Hospital Giessen and Marburg, Aulweg 123, D-35392 Giessen, Germany.
| | | | | | | | | |
Collapse
|
7
|
Sriram D, Yogeeswari P, Myneedu NS, Saraswat V. Abacavir prodrugs: microwave-assisted synthesis and their evaluation of anti-HIV activities. Bioorg Med Chem Lett 2006; 16:2127-9. [PMID: 16458506 DOI: 10.1016/j.bmcl.2006.01.050] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2005] [Revised: 01/02/2006] [Accepted: 01/16/2006] [Indexed: 11/16/2022]
Abstract
The synthesis of a new series of abacavir prodrugs involving N2-substitution with various substituted benzaldehyde and ketone derivatives is described. The in vitro anti-HIV activities indicated that compound (3-(2-(4-methylaminobenzylideneamino)-6-(cyclopropylamino)-9H-purin-9-yl)cyclopentyl)methanol (3) was found to be most potent compound with EC50 of 0.05 microM and CC50 of >100 microM with selectivity index of >2000. Compound 3 was found to be 32 times more potent than the parent drug (EC50 of 1.6 microM). At pH 7.4, 37 degrees C, the hydrolytic t1/2 ranged between 120 and 240 min.
Collapse
Affiliation(s)
- Dharmarajan Sriram
- Medicinal Chemistry Research Laboratory, Pharmacy Group, Birla Institute of Technology and Science, Pilani-333031, India.
| | | | | | | |
Collapse
|
8
|
Sriram D, Yogeeswari P, Madhu K. Synthesis and in vitro antitubercular activity of some 1-[(4-sub)phenyl]-3-(4-{1-[(pyridine-4-carbonyl)hydrazono]ethyl}phenyl)thiourea. Bioorg Med Chem Lett 2006; 16:876-8. [PMID: 16303302 DOI: 10.1016/j.bmcl.2005.11.004] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2005] [Revised: 10/18/2005] [Accepted: 11/02/2005] [Indexed: 11/24/2022]
Abstract
Various isonicotinyl hydrazones were prepared by reacting isonicotinyl hydrazide [INH] with 1-(4-acetylphenyl)-3-[(4-sub)phenyl]thiourea and were tested for their antimycobacterial activity in vitro against Mycobacterium tuberculosis H37Rv and INH-resistant M. tuberculosis using the BACTEC 460 radiometric system. Among the synthesized compounds, 1-(4-fluorophenyl)-3-(4-{1-[(pyridine-4-carbonyl)-hydrazono]ethyl}phenyl)thiourea (4d) was found to be the most potent compound with a minimum inhibitory concentration of 0.49 microM against M. tuberculosis H37Rv and INH-resistant M. tuberculosis. When compared to INH, 4d was found to be 3 and 185 times more active against M. tuberculosis H37Rv and INH-resistant M. tuberculosis, respectively, with a selectivity index of >300.
Collapse
Affiliation(s)
- Dharmarajan Sriram
- Medicinal Chemistry Research Laboratory, Pharmacy group, Birla Institute of Technology and Science, Pilani 333031, India.
| | | | | |
Collapse
|
9
|
Sriram D, Yogeeswari P, Madhu K. Synthesis and in vitro and in vivo antimycobacterial activity of isonicotinoyl hydrazones. Bioorg Med Chem Lett 2005; 15:4502-5. [PMID: 16115763 DOI: 10.1016/j.bmcl.2005.07.011] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2005] [Revised: 07/05/2005] [Accepted: 07/07/2005] [Indexed: 11/16/2022]
Abstract
The purpose of this study was to prepare various isoniazid derivatives by introducing the isoniazid pharmacophore into several molecules and screening for antimycobacterial activity. Ortho-hydroxy acetophenone reacts with isoniazid to form acid hydrazones. The C-Mannich bases of the above acid hydrazones were prepared by reacting them with formaldehyde and various secondary amines. The synthesized compounds were screened against M. tuberculosis H(37)R(v) using the alamar blue susceptibility test. The synthesized compounds inhibit Mycobacterium tuberculosis strain H(37)R(v) with minimum inhibitory concentrations ranging from 0.56 to 4.61 microM. Compound N'-{1-[2-hydroxy-3-(piperazin-1-ylmethyl)phenyl]ethylidene}isonicotinohydrazide 8 was found to be the most active compound with an MIC of 0.56 microM, and was more potent than isoniazid (MIC of 2.04 microM). After 10 days of treatment, compound 8 decreased the bacterial load in murine lung tissue by 3.7-log10 as compared to controls, which was equipotent to isoniazid. The results demonstrate the potential and importance of developing new isoniazid derivatives against mycobacterial infections.
Collapse
Affiliation(s)
- Dharmarajan Sriram
- Medicinal Chemistry Research Laboratory, Pharmacy Group, Birla Institute of Technology and Science, Pilani 33031, India.
| | | | | |
Collapse
|
10
|
Iwai K, Hasegawa T, Taguchi Y, Morimatsu F, Sato K, Nakamura Y, Higashi A, Kido Y, Nakabo Y, Ohtsuki K. Identification of food-derived collagen peptides in human blood after oral ingestion of gelatin hydrolysates. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2005; 53:6531-6. [PMID: 16076145 DOI: 10.1021/jf050206p] [Citation(s) in RCA: 239] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
In the present study, we identified several food-derived collagen peptides in human blood after oral ingestion of some gelatin hydrolysates. Healthy human volunteers ingested the gelatin hydrolysates (9.4-23 g) from porcine skin, chicken feet, and cartilage after 12 h of fasting. Negligible amounts of the peptide form of hydroxyproline (Hyp) were observed in human blood before the ingestion. After the oral ingestion, the peptide form of Hyp significantly increased and reached a maximum level (20-60 nmol/mL of plasma) after 1-2 h and then decreased to half of the maximum level at 4 h after the ingestion. Major constituents of food-derived collagen peptides in human serum and plasma were identified as Pro-Hyp. In addition, small but significant amounts of Ala-Hyp, Ala-Hyp-Gly, Pro-Hyp-Gly, Leu-Hyp, Ile-Hyp, and Phe-Hyp were contained.
Collapse
Affiliation(s)
- Koji Iwai
- Department of Food Sciences and Nutritional Health, Kyoto Prefectural University, 1-5 Shimogamo Kyoto 606-8522, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Kissel T, Werner U. Nasal delivery of peptides: an in vitro cell culture model for the investigation of transport and metabolism in human nasal epithelium. J Control Release 1998; 53:195-203. [PMID: 9741927 DOI: 10.1016/s0168-3659(97)00253-8] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We investigated the transport- and metabolism properties of three peptides in monolayers of human nasal epithelial cells. The effective permeability coefficients of thyrotropin-releasing hormone, met-enkephalin and human recombinant insulin were found to be 4.5, 4.4 and 0.4 x 10(-7) cm/s, respectively. The permeability was inversely proportional to the molecular weight and one order of magnitude lower than in excised nasal mucosa of rabbits. The metabolic cleavage of thyrotropin-releasing hormone (TRH) to the free acid by cytosolic prolyl-endopeptidase was also detected in human nasal cell monolayers, suggesting that ca. 10% of the total amount of TRH is transported via a transcellular pathway. Met-enkephalin is a substrate for aminopeptidases, located on the apical membrane of nasal epithelial cells. Metabolites and enzyme activity are comparable with literature data. Our studies demonstrate that not only morphological, but also functional properties of human nasal epithelial cells are preserved under in vitro conditions. Such a cell culture model based on human nasal cells could be beneficial for the characterization of peptide transport on a cellular level and for investigation of the absorption enhancer mechanism. Further studies are necessary, however, to establish correlations between in vitro permeabilities in cell cultures and nasal drug absorption in animals and humans.
Collapse
Affiliation(s)
- T Kissel
- Department of Pharmaceutics and Biopharmacy, Philipps University of Marburg, Germany.
| | | |
Collapse
|
12
|
Visich JE, Byron PR. High-pressure liquid chromatographic assay for the determination of thyrotropin-releasing hormone and its common metabolites in a physiological salt solution circulated through the isolated perfused rat lung. J Pharm Biomed Anal 1996; 15:105-10. [PMID: 8895081 DOI: 10.1016/0731-7085(96)01807-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A specific and sensitive assay for TRH (L-pyroglutamyl-L-histidyl-L-proline amide), 3H-TRH (L-proline 3,4-3H(N), histidyl-3-3H(N)), and four possible metabolites of TRH, present in the recirculated perfusate of an isolated perfused rat lung preparation, was developed. Unlike previous methods, the method developed does not require extraction of the analytes from the biological matrix. The crude sample was adjusted to a pH of 3.2 with concentrated trifluoroacetic acid and injected on to a PRP-1 (polystyrene divinylbenzene) column (10 microns, 25 cm x 4.6 mm i.d.). The mobile phase was 10% v/v acetonitrile and 90% v/v 0.75 g l-1 1-hepantanesulfonic acid in 0.004 M trifluoroacetic acid, adjusted to a pH of 2.4 with concentrated NaOH. The flow rate was 0.5 ml min-1 and the analytes were detected by UV absorption at a wavelength of 26 nm and by radiochemical detection utilizing a liquid scintillation counter. The nominal retention times for L-PRO, L-PRO-NH2, TRH, cyclo(HIS-PRO) and TRH-OH were 4.0 +/- 0.9, 10.0 +/- 0.2, 15.5 +/- 0.4, 19.2 +/- 0.5 and 25.3 +/- 0.5 min respectively. The assay performs well in terms of precision and accuracy as indicated by linear regression and intra-assay variability analysis.
Collapse
Affiliation(s)
- J E Visich
- Department of Pharmacy and Pharmaceutics, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0533, USA
| | | |
Collapse
|
13
|
Walter E, Kissel T. Transepithelial transport and metabolism of thyrotropin-releasing hormone (TRH) in monolayers of a human intestinal cell line (Caco-2): evidence for an active transport component? Pharm Res 1994; 11:1575-80. [PMID: 7870674 DOI: 10.1023/a:1018953603301] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Cell culture models for gastrointestinal transport and metabolism are important mechanistic tools. Our studies of Caco-2 monolayers demonstrate heterogeneity in transport characteristics depending on passage number and origin of the cells. In accordance with data obtained in animals and humans, TRH shows a carrier-mediated, saturable transport component, which operates parallel to a passive pathway in Caco-2 cells at passage number 89-99. At low TRH concentrations (< 3 mM) active transport becomes prominent, as demonstrated by the temperature dependence of TRH transport and inhibition experiments. The Michaelis-Menten parameters of the active, saturable transport component are: Km = 1.59 mM and Vmax = 1.84 microM/min. The pH optimum was determined to be at pH 6.0. On the other hand an exclusively paracellular passive route was found with Caco-2 cells at passage number 30-34. These results are also in agreement with observations made by others in cell culture experiments. The aspect of rigorously characterizing the specific Caco-2 clone under investigation is emphasized, especially when active transport mechanisms are suspected.
Collapse
Affiliation(s)
- E Walter
- Department of Pharmaceutics and Biopharmacy, University of Marburg, Germany
| | | |
Collapse
|
14
|
Jørgensen L, Bechgaard E. Intranasal permeation of thyrotropin-releasing hormone: in vitro study of permeation and enzymatic degradation. Int J Pharm 1994. [DOI: 10.1016/0378-5173(94)90439-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
15
|
Chapter 30. Peptide Stability in Drug Development: in vitro Peptide Degradation in Plasma and Serum. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 1993. [DOI: 10.1016/s0065-7743(08)60900-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
|
16
|
Banks WA, Kastin AJ, Jaspan JB. Orally administered cyclo(His-Pro) reduces ethanol-induced narcosis in mice. Pharmacol Biochem Behav 1992; 43:939-41. [PMID: 1448489 DOI: 10.1016/0091-3057(92)90428-i] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cyclo(His-Pro) (cHP) is an endogenous, enzymatically resistant, biologically active peptide. We examined its ability to be absorbed after oral administration. cHP radioactively labeled with 125I (I-cHP) was fed to adult mice, and blood and tissue samples were taken 15-90 min later. Radioactivity quickly appeared in blood at levels about one half to one fourth those previously found after IV injection. The highest concentrations were in the kidney and liver, but the testes, muscle, lung, and brain also contained more radioactivity than was accounted for by their vascular spaces. Between 25-32% of the radioactivity recovered from blood 30 min after feeding eluted on high-performance liquid chromatography in the position of intact peptide. Oral cHP reversed ethanol-induced narcosis, an effect previously found to occur within the brain. These results show that cHP can be absorbed orally in amounts sufficient to affect the CNS.
Collapse
Affiliation(s)
- W A Banks
- Veterans Affairs Medical Center, New Orleans, LA 70146
| | | | | |
Collapse
|
17
|
|
18
|
|
19
|
Lundin S, Møss J, Bundgaard H, Artursson P. Absorption of thyrotropin-releasing hormone (TRH) and a TRH prodrug in a human intestinal cell line (Caco-2). Int J Pharm 1991. [DOI: 10.1016/0378-5173(91)90282-s] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
20
|
Møss J, Bundgaard H. Prodrugs of peptides. 12. Bioreversible derivatization of thyrotropin-releasing hormone (TRH) by N-phthalidylation of its imidazole moiety. Int J Pharm 1991. [DOI: 10.1016/0378-5173(91)90409-h] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
21
|
Prodrugs of peptides. 7. Transdermal delivery of thyrotropin-releasing hormone (TRH) via prodrugs. Int J Pharm 1990. [DOI: 10.1016/0378-5173(90)90382-e] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
22
|
Møss J, Buur A, Bundgaard H. Prodrugs of peptides. 8. In vitro study of intestinal metabolism and penetration of thyrotropin-releasing hormone (TRH) and its prodrugs. Int J Pharm 1990. [DOI: 10.1016/0378-5173(90)90398-n] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
23
|
Bundgaard H, Møss J. Prodrugs of peptides. 6. Bioreversible derivatives of thyrotropin-releasing hormone (TRH) with increased lipophilicity and resistance to cleavage by the TRH-specific serum enzyme. Pharm Res 1990; 7:885-92. [PMID: 2122435 DOI: 10.1023/a:1015933504191] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Bioreversible derivatization of TRH (pGlu-His-Pro-NH2) to protect the tripeptide against rapid enzymatic inactivation in the systemic circulation and to improve the lipophilicity of this highly hydrophilic peptide was performed by N-acylation of the imidazole group of the histidine residue with various chloroformates. Whereas TRH was rapidly hydrolyzed at its pGlu-His bond in human plasma by a TRH-specific pyroglutamyl aminopeptidase serum enzyme, the N-alkoxycarbonyl derivatives were resistant to cleavage by the enzyme. On the other hand, these derivatives are readily bioreversible as the parent TRH is formed quantitatively from the derivatives by spontaneous hydrolysis or by plasma esterase-catalyzed hydrolysis. In addition to protecting the parent TRH against rapid inactivation in the circulation and hence potentially prolonging the duration of action of TRH in vivo, the N-alkoxycarbonyl prodrug derivatives were much more lipophilic than TRH as assessed by octanol-buffer partitioning. This property may enhance prodrug penetration of the blood-brain barrier and various other biomembranes compared to the parent peptide.
Collapse
Affiliation(s)
- H Bundgaard
- Royal Danish School of Pharmacy, Department of Pharmaceutical Chemistry, Copenhagen
| | | |
Collapse
|