A 33853 (A33853; A-33853), a tetraacetyl that contains an anhydride moiety, is an antibiotic originally isolated from culture broth of Streptomyces sp. The synthetic analog of it was screened for the inhibition of L. donovani, T. b. rhodesiense, T. cruzi, and P. falciparum cultures followed by determination of IC(50) in L. donovani and cytotoxicity on L6 cells revealed one of the analogs compound 31 to be 3-fold more active than miltefosine, a known antileishmanial drug. Other analogs of A 33853 selectively inhibited L. donovani at nanomolar concentrations and showed much lower cytotoxicity.

Physicochemical Properties

Molecular Formula	C20H13N3O6
Molecular Weight	391.33372
Exact Mass	391.08
CAS #	80148-45-4
Related CAS #	80148-45-4
PubChem CID	133379
Appearance	Typically exists as solid at room temperature
Density	1.588 g/cm3
Boiling Point	644.9ºC at 760 mmHg
Flash Point	343.8ºC
LogP	3.324
Hydrogen Bond Donor Count	4
Hydrogen Bond Acceptor Count	8
Rotatable Bond Count	4
Heavy Atom Count	29
Complexity	619
Defined Atom Stereocenter Count	0
SMILES	O=C(C1=C2N=C(C3=CC=CC(O)=C3NC(C4=NC=CC=C4O)=O)OC2=CC=C1)O
InChi Key	LJVDLJDWXVPUAB-UHFFFAOYSA-N
InChi Code	InChI=1S/C20H13N3O6/c24-12-6-1-4-10(15(12)22-18(26)17-13(25)7-3-9-21-17)19-23-16-11(20(27)28)5-2-8-14(16)29-19/h1-9,24-25H,(H,22,26)(H,27,28)
Chemical Name	2-[3-hydroxy-2-[(3-hydroxypyridine-2-carbonyl)amino]phenyl]-1,3-benzoxazole-4-carboxylic acid
Synonyms	A 33853; A33853; A-33853
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

ln Vitro	The primary pathogenic bacteria causing coccidiosis, Eimeria tenella, is inhibited by the antibiotic A-33853, and its minimum inhibitory concentration (MIC) against Trichomonas vaginalis is less than 0.975 μg/mL[1].
ln Vivo	Chicks are not resistant to Mycoplasma gallisepticum to the extent that antibiotic A-33853 (60 mg/kg; subcutaneous injection; single dose) is [1]. Chicks are not resistant to Mycoplasma gallisepticum to the extent that antibiotic A-33853 (70 mg/kg; subcutaneous injection; single dose) is [1]. 300 mg/kg (intraperitoneal injection) is the LD50 value of the acute toxic dose of antibiotic A-33853 in mouse models [1]. [1] Staphylococcus aureus.
References	[1]. In Pursuit of Natural Product Leads: Synthesis and Biological Evaluation of 2-[3-hydroxy-2-[(3-hydroxypyridine-2-carbonyl)amino]phenyl]benzoxazole-4-carboxylic acid (A-33853) and Its Analogues: Discovery of N-(2-Benzoxazol-2-ylphenyl)benzamides as Novel Antileishmanial Chemotypes J. Med. Chem., 2008, 51 (23), pp 7344-7347 [2]. Michel KH, et al. The discovery, fermentation, isolation, and structure of antibiotic A33853 and its tetraacetyl derivative. J Antibiot (Tokyo). 1984 May;37(5):441-5.

Solubility Data

Solubility (In Vitro)

DMSO:10 mM Water:N/A Ethanol:N/A

Solubility (In Vivo)

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. Injection Formulations (e.g. IP/IV/IM/SC) 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). 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) Oral Formulations 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). 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 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.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	2.5554 mL	12.7769 mL	25.5539 mL
	5 mM	0.5111 mL	2.5554 mL	5.1108 mL
	10 mM	0.2555 mL	1.2777 mL	2.5554 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.