Pristinamycin IA (also known as Mikamycin B; Mikamycin IA), a naturally occuring and biologically active decapeptide isolated from the skin of the Australian frog Hyla caerulea, is a novel and potent cholecystokinetic agent which acts as a cholecystokinin receptor agonist.

Physicochemical Properties

Molecular Formula	C45H54N8O10
Molecular Weight	866.957860000001
Exact Mass	866.396
CAS #	3131-03-1
Related CAS #	Pristinamycin;270076-60-3
PubChem CID	11136668
Appearance	Light yellow to yellow solid powder
Density	1.38g/cm3
Boiling Point	1202.1ºC at 760mmHg
Flash Point	680.8ºC
LogP	2.132
Hydrogen Bond Donor Count	4
Hydrogen Bond Acceptor Count	12
Rotatable Bond Count	7
Heavy Atom Count	63
Complexity	1700
Defined Atom Stereocenter Count	7
InChi Key	YGXCETJZBDTKRY-UHFFFAOYSA-N
InChi Code	InChI=1S/C45H54N8O10/c1-6-31-42(59)52-22-11-14-32(52)43(60)51(5)34(24-27-16-18-29(19-17-27)50(3)4)44(61)53-23-20-30(54)25-33(53)39(56)49-37(28-12-8-7-9-13-28)45(62)63-26(2)36(40(57)47-31)48-41(58)38-35(55)15-10-21-46-38/h7-10,12-13,15-19,21,26,31-34,36-37,55H,6,11,14,20,22-25H2,1-5H3,(H,47,57)(H,48,58)(H,49,56)
Chemical Name	N-[3-[[4-(dimethylamino)phenyl]methyl]-12-ethyl-4,16-dimethyl-2,5,11,14,18,21,24-heptaoxo-19-phenyl-17-oxa-1,4,10,13,20-pentazatricyclo[20.4.0.06,10]hexacosan-15-yl]-3-hydroxypyridine-2-carboxamide
Synonyms	Mikamycin B; Mikamycin IA
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

Targets	Ribosome (specifically induces transient ribosome stalling) [2]
ln Vitro	Pristinamycin IA (100 μM, 0–4 h) suppresses the disruption of [3H]vinblastine in Caco-2 cells [1]. Pristinamycin IA (4.614 μM) stimulates the ribosome-supporting ribose regulatory factor (LRR), and Pristinamycin IA (100 μM) and [3H]vinblastine rescue in Caco-2 cell monolayers [2]. Pristinamycin IA (Pnm) was identified as one of the ribosome-targeting antibiotics that can markedly induce the "on" state of the LRR attenuator in Bacillus thuringiensis BMB171. In an assay measuring β-galactosidase activity (LacZ reporter), treatment with Pristinamycin IA at 4 µg/mL (4.614 µM) significantly increased LacZ expression compared to the no-antibiotic control, indicating it can effectively activate the LRR-mediated gene expression switch. [2] The fold-change in LacZ expression induced by Pristinamycin IA (4 µg/mL) was reported, although the exact numerical fold-change from this specific antibiotic is not separately listed in the provided figures/tables; it is grouped among other effective inducers like retapamulin, virginiamycin, chloramphenicol, and linezolid. [2] The activity of Pristinamycin IA (as well as other antibiotics like retapamulin, chloramphenicol, tetracycline, and virginiamycin) in activating the LRR attenuator was also tested in Escherichia coli using an RFP reporter system. The expression level of RFP increased when Pristinamycin IA was added, demonstrating that LRR (and thus the ribosome-stalling mechanism) functions in this Gram-negative bacterium as well. [2]
Cell Assay	For antibiotic-induction experiments in B. thuringiensis, strains carrying the reporter plasmid (e.g., pB-PLR with lacZ) were grown overnight, diluted, and then treated with Pristinamycin IA (at 4 µg/mL final concentration) for a specified period (e.g., 6 hours). Cells were harvested, and β-galactosidase activity was measured to quantify gene expression. The assay involved cell disruption, incubation with ONPG substrate, and measurement of absorbance at 420 nm to calculate Miller units. [2] For testing in E. coli, the strain BL21 harboring plasmid pET-LRR-RFP was cultured with or without Pristinamycin IA (4 µg/mL) at 37°C for 10 hours. Cells were collected, washed, and resuspended in PBS. Fluorescence intensity (excitation 584 nm, emission 607 nm) was measured and normalized to cell density (OD600) to determine RFP expression levels. [2]
References	[1]. Interaction of pristinamycin IA with P-glycoprotein in human intestinal epithelial cells. Eur J Pharmacol. 1995 Jan 16;288(2):187-92. [2]. Attenuator LRR - a regulatory tool for modulating gene expression in Gram-positive bacteria. Microb Biotechnol. 2021 Nov;14(6):2538-2551.
Additional Infomation	Pristinamycin IA is a cyclodepsipeptide that is (together with pristinamycin IIA) a component of pristinamycin, an oral streptogramin antibiotic produced by Streptomyces pristinaespiralis. Pristinamycin exhibits bactericidal activity against Gram positive organisms including methicillin-resistant Staphylococcus aureus. It has a role as an antibacterial drug, an antimicrobial agent and a bacterial metabolite. Pristinamycin IA has been reported in Streptomyces pristinaespiralis with data available. A specific streptogramin group B antibiotic produced by Streptomyces graminofaciens and other bacteria. Pristinamycin IA is a ribosome-targeting antibiotic. [2] It is one of the several antibiotics (including retapamulin, virginiamycin, chloramphenicol, and linezolid) that can induce transient ribosome stalling, leading to a conformational change in the LRR attenuator RNA, which switches from a terminator to an anti-terminator structure, thereby upregulating downstream gene expression. [2] The study focuses on the use of Pristinamycin IA as an inducer for a synthetic biology tool (the LRR attenuator) to control gene expression in various bacterial hosts, including B. thuringiensis, B. subtilis, B. cereus, B. amyloliquefaciens, and E. coli. [2] The concentration used for induction in B. thuringiensis was 4 µg/mL (4.614 µM). [2]

Solubility Data

Solubility (In Vitro)

DMSO : ~33.33 mg/mL (~38.44 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 3 mg/mL (3.46 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 30.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. Solubility in Formulation 2: ≥ 3 mg/mL (3.46 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 30.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly. 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. Solubility in Formulation 3: ≥ 3 mg/mL (3.46 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 30.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	1.1535 mL	5.7673 mL	11.5346 mL
	5 mM	0.2307 mL	1.1535 mL	2.3069 mL
	10 mM	0.1153 mL	0.5767 mL	1.1535 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.