WARNING: This product is for research use only, not for human or veterinary use.

MedKoo CAT#: 202242

CAS#: 149402-51-7

Description: Photochlor, also known as HTTP, is a lipophilic, second-generation, chlorin-based photosensitizer. Upon intravenous administration, HPPH selectively accumulates in the cytoplasm of cancer or pre-cancerous cells. When laser light is applied, a photodynamic reaction between HPPH and oxygen occurs, resulting in the production of cytotoxic free radicals and singlet oxygen and free radical-mediated cell death. Compared to the first-generation photosensitizer porfimer sodium, HPPH shows improved pharmacokinetic properties and causes only mild skin photosensitivity which declines rapidly within a few days after administration.

Chemical Structure

CAS# 149402-51-7

Theoretical Analysis

MedKoo Cat#: 202242
Name: Photochlor
CAS#: 149402-51-7
Chemical Formula: C39H48N4O4
Exact Mass: 636.36756
Molecular Weight: 636.82
Elemental Analysis: C, 73.56; H, 7.60; N, 8.80; O, 10.05

Price and Availability

Size Price Availability Quantity
5.0mg USD 190.0 Ready to ship
10.0mg USD 350.0 Ready to ship
25.0mg USD 750.0 Ready to ship
50.0mg USD 1350.0 Ready to ship
100.0mg USD 2350.0 Ready to ship
200.0mg USD 4150.0 Ready to ship
10.0mM * 1 mL DMSO USD 350.0 Ready to ship
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Synonym: HPPH; Photochlor; 2-(1-Hexyloxyethyl)-2-devinyl pyropheophorbide-a; 2-(1'-hexyloxyethyl)-2-devinylpyropheophorbide-a.

IUPAC/Chemical Name: (3S,4S)-14-Ethyl-9-[1-(hexyloxy)ethyl]-4,8,13,18-tetramethyl-20-oxo-3-phorbinepropanoic acid


InChi Code: InChI=1S/C39H50N4O4/c1-8-10-11-12-15-47-24(7)36-22(5)30-17-29-21(4)26(13-14-35(45)46)38(42-29)27-16-34(44)37-23(6)31(43-39(27)37)18-32-25(9-2)20(3)28(40-32)19-33(36)41-30/h17-19,21,24,26,31,40-41,43H,8-16H2,1-7H3,(H,45,46)/b28-19-,29-17-,32-18-/t21-,24?,26-,31?/m0/s1

SMILES Code: O=C(O)CC[C@@H]([C@@H]/1C)C2=NC1=C/C3=C(C)C(C(OCCCCCC)C)=C(N3)/C=C4C(C)=C(CC)/C(N/4)=C/C5C(C)=C6C(N5)=C2CC6=O

Appearance: Black solid powder

Purity: >95% (or refer to the Certificate of Analysis)

Shipping Condition: Shipped under ambient temperature as non-hazardous chemical. This product is stable enough for a few weeks during ordinary shipping and time spent in Customs.

Storage Condition: Dry, dark and at 0 - 4 C for short term (days to weeks) or -20 C for long term (months to years).

Solubility: Soluble in DMSO, not in water

Shelf Life: >2 years if stored properly

Drug Formulation: This drug may be formulated in DMSO

Stock Solution Storage: 0 - 4 C for short term (days to weeks), or -20 C for long term (months).

HS Tariff Code: 2934.99.9001

Preparing Stock Solutions

The following data is based on the product molecular weight 636.82 Batch specific molecular weights may vary from batch to batch due to the degree of hydration, which will affect the solvent volumes required to prepare stock solutions.

Recalculate based on batch purity %
Concentration / Solvent Volume / Mass 1 mg 5 mg 10 mg
1 mM 1.15 mL 5.76 mL 11.51 mL
5 mM 0.23 mL 1.15 mL 2.3 mL
10 mM 0.12 mL 0.58 mL 1.15 mL
50 mM 0.02 mL 0.12 mL 0.23 mL

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1: Sun G, Anderson MA, Gorospe EC, Leggett CL, Lutzke LS, Wong Kee Song LM, Levy M, Wang KK. Synergistic effects of photodynamic therapy with HPPH and gemcitabine in pancreatic cancer cell lines. Lasers Surg Med. 2012 Nov;44(9):755-61. doi: 10.1002/lsm.22073. Epub 2012 Sep 27. PubMed PMID: 23018618.

2: Nava HR, Allamaneni SS, Dougherty TJ, Cooper MT, Tan W, Wilding G, Henderson BW. Photodynamic therapy (PDT) using HPPH for the treatment of precancerous lesions associated with Barrett's esophagus. Lasers Surg Med. 2011 Sep;43(7):705-12. doi: 10.1002/lsm.21112. PubMed PMID: 22057498; PubMed Central PMCID: PMC3218433.

3: Srivatsan A, Ethirajan M, Pandey SK, Dubey S, Zheng X, Liu TH, Shibata M, Missert J, Morgan J, Pandey RK. Conjugation of cRGD peptide to chlorophyll a based photosensitizer (HPPH) alters its pharmacokinetics with enhanced tumor-imaging and photosensitizing (PDT) efficacy. Mol Pharm. 2011 Aug 1;8(4):1186-97. doi: 10.1021/mp200018y. Epub 2011 Jul 1. PubMed PMID: 21702452; PubMed Central PMCID: PMC3148296.

4: Sunar U, Rohrbach D, Rigual N, Tracy E, Keymel K, Cooper MT, Baumann H, Henderson BH. Monitoring photobleaching and hemodynamic responses to HPPH-mediated photodynamic therapy of head and neck cancer: a case report. Opt Express. 2010 Jul 5;18(14):14969-78. doi: 10.1364/OE.18.014969. PubMed PMID: 20639983; PubMed Central PMCID: PMC2964147.

5: Spernyak JA, White WH 3rd, Ethirajan M, Patel NJ, Goswami L, Chen Y, Turowski S, Missert JR, Batt C, Mazurchuk R, Pandey RK. Hexylether derivative of pyropheophorbide-a (HPPH) on conjugating with 3gadolinium(III) aminobenzyldiethylenetriaminepentaacetic acid shows potential for in vivo tumor imaging (MR, Fluorescence) and photodynamic therapy. Bioconjug Chem. 2010 May 19;21(5):828-35. doi: 10.1021/bc9005317. PubMed PMID: 20387862; PubMed Central PMCID: PMC2874103.

6: Zheng X, Morgan J, Pandey SK, Chen Y, Tracy E, Baumann H, Missert JR, Batt C, Jackson J, Bellnier DA, Henderson BW, Pandey RK. Conjugation of 2-(1'-hexyloxyethyl)-2-devinylpyropheophorbide-a (HPPH) to carbohydrates changes its subcellular distribution and enhances photodynamic activity in vivo. J Med Chem. 2009 Jul 23;52(14):4306-18. doi: 10.1021/jm9001617. PubMed PMID: 19507863; PubMed Central PMCID: PMC2913405.

7: Weston MA, Patterson MS. Simple photodynamic therapy dose models fail to predict the survival of MLL cells after HPPH-PDT in vitro. Photochem Photobiol. 2009 May-Jun;85(3):750-9. doi: 10.1111/j.1751-1097.2008.00494.x. Epub 2008 Dec 18. PubMed PMID: 19140895.

8: Kim YC, Kang HE, Lee MG. Pharmacokinetics of phenytoin and its metabolite, 4'-HPPH, after intravenous and oral administration of phenytoin to diabetic rats induced by alloxan or streptozotocin. Biopharm Drug Dispos. 2008 Jan;29(1):51-61. PubMed PMID: 18022993.

9: Brinkmann C, García F, Morey JV, McPartlin M, Singh S, Wheatley AE, Wright DS. Stepwise nucleophilic substitution of manganocene, syntheses and structures of the dimer [CpMn(hpp)]2 and the unusual manganate cage [LiMn(hpp)3]2 (hppH = 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2,a]pyrimidine). Dalton Trans. 2007 Apr 28;(16):1570-2. Epub 2007 Mar 15. PubMed PMID: 17426857.

10: Bellnier DA, Greco WR, Nava H, Loewen GM, Oseroff AR, Dougherty TJ. Mild skin photosensitivity in cancer patients following injection of Photochlor (2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a; HPPH) for photodynamic therapy. Cancer Chemother Pharmacol. 2006 Jan;57(1):40-5. Epub 2005 Nov 5. PubMed PMID: 16001178.

Additional Information

Clinical trial results: Photochlor is currently producing promising results in Phase II clinical trials. Forty-eight patients enrolled in Phases 1 and 2 clinical trials underwent two or more exposures to four graded doses (44.4, 66.6, 88.8 or 133.2 J/cm2) of artificial solar-spectrum light (SSL) before and after administration of Photochlor at a dose of 2.5, 3, 4, 5 or 6 mg/m2 . RESULTS: The most severe skin response, experienced by only six of the subjects, was limited to erythema without edema and could only be elicited by exposure to the highest light dose. Conversely, eight subjects had no discernible reaction to SSL at any light dose. For nearly all the patients, the peak skin response was obtained when the interval between sensitizer injection and exposure to SSL was 1 day and, generally, their sensitivity to SSL decreased with increasing sensitizer-light interval. For example, a 2-day sensitizer-SSL interval resulted in less severe reactions than those obtained with the 1-day interval in 79% of the subjects, while 90% of the subjects exposed to SSL 3 days after Photochlor infusion had responses that were less severe than those obtained with either the 1- or 2-day sensitizer-SSL interval. CONCLUSIONS: Photochlor, at clinically effective antitumor doses, causes only mild skin photosensitivity that declines rapidly over a few days. [source: Cancer Chemother Pharmacol. 2006 Jan;57(1):40-5. Epub 2005 Nov 5.]
Photochlor is considered a second-generation photosensitizer because of its improved properties over Photofrin®. These two photosensitizers have closely related molecular structures but significantly different photophysical properties. Clinical studies have shown that Photochlor stays in the tumor for a long time and clears faster from the rest of the system and does not show any significant skin phototoxicity, a main drawback associated with most of the porphyrin-based compounds, including Photofrin. Photochlor also offers the advantage of long wavelength absorption that increases light penetration and minimizes the number of laser fibers needed to deliver light within the tumor. These properties are important for treating large and deep-seated tumors. [ soucre: Ravendra K. Pandey: Lighting Up the Lives of Cancer Patients by Developing Drugs for Tumor Imaging and Photodynamic Therapy:A “See and Treat” Approach, Oncology, 2008, 22-23]