How Antibiotics Halt Bacterial Protein Synthesis (With Representative Products and a Selection Guide)

1) Why is “inhibiting protein synthesis” a classic antibacterial strategy?

For bacteria to grow, divide, repair damage, and express virulence factors, they must continuously make new proteins. The key machine that “translates” mRNA into protein is the bacterial ribosome. Once translation is stalled, bacteria struggle to keep proliferating and adapting, and infection progression is often markedly slowed—or even halted.

It’s considered a “classic strategy” mainly because of three advantages:

1. Essential process, fast and direct impact

Protein synthesis is a fundamental life process for all cells. In bacteria, translation shutdown rapidly affects the supply of metabolic enzymes, cell-wall–associated proteins, stress-response proteins, and more—so the antibacterial effect is usually very clear. Many commonly used clinical bacteriostatic agents primarily work by inhibiting protein synthesis: first “hold the bacteria in place” (stop them from growing), then let the host immune system clear them.

2. Clear basis for selectivity: bacterial ribosomes differ from human ones

Bacterial ribosomes are 70S (30S + 50S) and differ structurally from the 80S (40S + 60S) cytosolic ribosomes of eukaryotic cells. Many drugs exploit these differences to preferentially bind key regions of bacterial ribosomes, achieving relatively selective inhibition. (This also helps explain why a few drugs can cause toxicity—e.g., due to effects on mitochondrial ribosomes.)

Note: Bacterial ribosomes are 70S (30S + 50S; “S” is the Svedberg sedimentation coefficient and is not arithmetically additive); eukaryotic cytosolic ribosomes are 80S (40S + 60S).

3. Many “bindable” functional centers—easy for small molecules to precisely disrupt

The ribosome is not a “smooth protein block.” It contains multiple functional hotspots—such as the decoding center (30S), the peptidyl transferase center and peptide exit tunnel (50S), and the GTPase center—that are naturally suited for small-molecule binding and blockage. As a result, many mechanistically diverse antibiotic classes can be developed (e.g., blocking tRNA entry, inhibiting bond formation, preventing translocation, plugging the exit tunnel), giving broad coverage.

Summary: Protein synthesis inhibition is “classic” because it hits the bacteria’s most essential production line, offers multiple precisely targetable functional centers, and leverages exploitable differences from human structures—balancing efficacy with relative selectivity.

2) “Protein synthesis”: bacterial translation as a four-stage production line

Stage	What happens in this stage	Key players (bacteria)	How A/P/E stations are used	Memory hook
Initiation (Start)	Align mRNA to the start site, load the first “raw material,” and assemble a working ribosome	30S → 70S; IF1/IF2/IF3; fMet-tRNAᶠᴹᵉᵗ; mRNA	The initiator tRNA is positioned directly in the P site (not starting from A)	“Fix the first piece in P, then start the line”
Elongation (Build)	Cycle: add substrate → form bond → translocate	aa-tRNA enters A site; EF-Tu/GTP (delivery + proofreading); peptidyl transferase center (large subunit catalytic core) forms peptide bond; EF-G/GTP drives translocation by one codon	tRNA generally moves A → P → E; hybrid A/P and P/E states can occur	“Add—link—shift one step”
Termination (Stop)	Stop codon triggers release of the peptide	RF1/RF2 (recognize stop); RF3 (recycling)	A stop codon appears in the A site; release factors “cut the product off the line”	“STOP isn’t a raw material—swap in release factors”
Recycling (Reset)	Disassemble and reset the machine for the next round	RRF + EF-G (split/recycle); IF3 etc.	70S dissociates into 30S/50S; clear and reset	“Disassemble—clear—restart”

Quick notes:

(a) A (Aminoacyl) = input/loading site: new aa-tRNA enters

(b) P (Peptidyl) = chain-holding site: holds the growing peptide

(c) E (Exit) = exit site: used tRNA leaves

3) Why do they “hurt bacteria more, and humans less”?

One-sentence summary: Selectivity ≈ (target differences) + (differences in bacterial exposure/accumulation) − (mitochondrial similarity exceptions)

Source of selectivity (3 layers)	Plain-language analogy	Key point	Common misunderstanding
① Target differences	“Different machine models”	Bacterial 70S (30S+50S) differs from human cytosolic 80S (40S+60S) in structure and binding pockets → provides room for selective binding	Not “completely harmless,” but “relatively more bacteria-leaning”
② Entry & accumulation	“Can the drug enter the factory—and stay inside?”	Bacterial envelopes, permeability, porins, and efflux determine effective intracellular drug levels (Gram-negative outer membrane/porins/efflux are especially impactful)	Same target ≠ same sensitivity; poor entry can look like “insensitivity/resistance”
③ Mitochondrial exception	“Humans have a ‘workshop’ that resembles bacteria”	Mitochondrial translation is evolutionarily closer to bacteria → some translation inhibitors may affect mitochondria and cause adverse effects	Not all ribosome inhibitors strongly damage mitochondria

Summary: To “hurt bacteria more,” a drug must both “jam bacterial ribosomes more effectively” and “accumulate better inside bacteria”; mitochondria are a common selectivity loophole.

4) Which key steps do antibiotics mainly “jam”?

“Production-line map”:

Upstream supply cut (aaRS) → Initiation → Elongation〔Decoding (30S) → Bond formation (50S-PTC) → Translocation (factors/energy) → Exit tunnel (50S)〕 → Termination/Recycling

“Jamming site”	Which step	Consequence
30S decoding center (codon reading / A-site entry)	Elongation (decoding/input)	Either “can’t load” or “reads wrong”: aa-tRNA fails to enter A site or mistranslation increases
50S PTC peptidyl transferase center (bond formation)	Elongation (bond formation)	“Can’t weld”: peptide bond formation or proper A-site positioning is blocked
50S exit tunnel (product-out channel)	Elongation (peptide extension/export)	“Product stuck in the tunnel”: extension stalls or becomes sequence-dependent stalling
Translocation/energy system (factor-driven shifting)	Elongation (translocation)	“Can’t move”: ribosome stalls mid-cycle; next round can’t proceed
Upstream supply cut: aaRS (load raw materials onto tRNA)	Upstream supply	“Raw materials never reach the line”: lack of correctly aminoacylated tRNA

5) Typical representative drugs—by “which step they jam”

Jamming site	Typical family / representative drug (examples)	Main target	Resulting outcome	Usual effect
Upstream supply (feeding)	Mupirocin	Inhibits IleRS → tRNA can’t be charged with isoleucine	Supply cut → translation stalls	Mostly bacteriostatic
Start button (initiation)	Oxazolidinones: linezolid	Binds key 50S region → inhibits 70S initiation complex formation	Line can’t be assembled	Mostly bacteriostatic
A-site entry / loading (elongation—input)	Tetracyclines: doxycycline, etc.	Blocks aa-tRNA entry into 30S A site	Loading fails → elongation stalls	Mostly bacteriostatic
Decoding accuracy (elongation—decoding)	Aminoglycosides: gentamicin/amikacin, etc.	Binds 30S decoding region (near 16S rRNA) → mistranslation ↑ (and can disturb elongation/translocation)	“Typos” → abnormal proteins ↑, translation collapses	Often bactericidal
Welding point (elongation—bond formation)	Chloramphenicol	Inhibits 50S PTC peptidyl transfer reaction	Peptide bond formation impaired → chain can’t grow	Mostly bacteriostatic
Exit channel (elongation—exit)	Macrolides: erythro-/azithro-, etc.	Binds 50S exit tunnel (NPET), causing elongation pausing (may be sequence-dependent)	Peptide “stuck in tunnel” → elongation blocked/paused	Mostly bacteriostatic

Note: “Mostly bacteriostatic / mostly bactericidal” depends on organism, concentration, and growth state.

6) Why does resistance often center on these sites?

These “sites” are the translation hotspots most commonly bound and disrupted by antibiotics—such as the 30S decoding center, the 50S peptidyl transferase center (PTC) and nascent peptide exit tunnel, and upstream aminoacyl-tRNA synthetase (aaRS) active sites. They are the “critical components” of the translation machine. Under long-term antibiotic pressure, bacterial countermeasures commonly fall into two broad directions: making the drug unable to enter/stay, or ensuring that even if it gets in, it can’t hit/push the target.

The table below summarizes “common bacterial resistance mechanisms.” The key idea: bacteria either reduce the effective intracellular drug concentration, alter/protect the target, or chemically inactivate the drug.

Resistance category	Specific strategy	Typical examples	Direct outcome
Lower intracellular drug level (can’t enter / can’t stay)	Reduced permeability; efflux pumps	Outer membrane/porin changes; efflux system upregulation	Intracellular level too low to reach effective dose
Alter or shield the target (can’t hit)	Target mutation; rRNA modifications such as methylation	erm → 23S rRNA methylation (reduces macrolide binding); some 16S rRNA methylation affects aminoglycosides	Drug present, but binding pocket changed/blocked
Drug inactivation/modification (disable the drug)	Enzymatic modification or degradation	Aminoglycoside-modifying enzymes (acetylation/phosphorylation, etc.)	Chemical structure altered → activity reduced/lost
Target protection (push drug off)	Protection proteins interfere with ribosome–drug interaction	Tet(M)/Tet(O); ABC-F protection mechanisms	Even if bound, inhibition is relieved or drug is displaced

7) How can you “see” protein synthesis inhibition in experiments?

1. SUnSET (non-radioactive): Apply a short puromycin pulse to cells. Puromycin incorporates into nascent peptide chains and causes premature termination. Then use an anti-puromycin antibody (WB/FACS/immunofluorescence) to detect changes in total “newly synthesized peptides” as a readout of global translation level.

2. Classical incorporation assays: Such as radioactive amino acid incorporation or click-chemistry labeling of nascent proteins—also commonly used to quantify changes in translation rate (choose based on the system).

8) Navigation Table | Products Related to Protein Synthesis Inhibition (Tables 1–3)

Typical scenario	Which table to check first	Why this table is the best fit	Common keywords / examples
Running bacterial bacteriostatic/antibacterial experiments and looking for classic, widely used “ribosome inhibitors” as controls or for screening	Table 1 (mainly 30S) + Table 2 (50S / other links)	The core targets on the bacterial 70S ribosome are mainly distributed on 30S or 50S; these two tables cover the most commonly used antibiotic families (aminoglycosides, tetracyclines, macrolides, lincosamides, oxazolidinones, pleuromutilins, streptogramins, etc.)	“30S/50S”, “bacteriostatic control”, “MIC”, “Gram-positive/Gram-negative”, “resistance mechanisms”
You already know you want a major class (e.g., “aminoglycosides” or “tetracyclines”) as a control and want to choose within that class	Table 1 (mainly 30S)	Table 1 groups aminoglycosides/aminocyclitols/tetracycline lineages together, making within-class comparisons easier (salt form, potency, cell-culture grade, etc. are listed per row)	Kanamycin / Gentamicin / Amikacin; Tetracycline / Doxycycline / Minocycline / Tigecycline
Planning experiments around 50S inhibitors (e.g., macrolide resistance, MLS_B phenotype, initiation-complex inhibition, etc.)	Table 2 (50S / other links)	Table 2 concentrates canonical 50S-targeting drugs: macrolides/ketolides, lincosamides, oxazolidinones, pleuromutilins, streptogramins, etc.	Erythromycin / Azithromycin / Clarithromycin; Clindamycin; Linezolid / Tedizolid; Dalfopristin + Quinupristin
Mechanism validation/controls where you want to block protein synthesis without directly targeting the ribosome	Table 2 (50S / other links)	Table 2 includes typical “pathway targets,” such as EF-G (fusidic acid) and IleRS (mupirocin), useful for distinguishing “ribosomal vs non-ribosomal” mechanisms	EF-G, aaRS, IleRS, translocation factor, mechanism validation
Cell-culture selection (stable cell line selection): eliminate non-transfected cells or maintain selection pressure	Check first: Table 2 (includes Puromycin / Blasticidin S); also see Table 1 (includes Hygromycin B / Gentamicin, etc.)	Common stable-selection antibiotics include Puromycin / Blasticidin S / Hygromycin B, etc.	Puromycin, Blasticidin S, Hygromycin B, “cell culture/low endotoxin/ready-made”
Not working with bacteria—want rapid translation shutoff in mammalian/eukaryotic systems as a research tool (transcription–translation dependence, ribosome profiling, etc.)	Table 3 (eukaryotic translation inhibitor tools)	Table 3 is dedicated to eukaryotic translation inhibitors (e.g., Cycloheximide, Harringtonine, Anisomycin) to avoid mixing them with “antibacterial drugs” and causing misuse	Cycloheximide, Harringtonine, Anisomycin, Ribo-seq, translation shutoff

Table 1 | Mainly 30S-Targeting (Aminoglycosides / Aminocyclitols / Tetracycline Lineages, etc.)

Category	CAS No.	Aladdin Cat. No.	Name	Specification / Purity	Product features & applications
Aminoglycosides (30S)	25389-94-0	K742567	Kanamycin sulfate	Potency ≥750 IU/MG	Aminoglycoside; binds 30S causing misreading and protein synthesis errors; commonly used for bacterial inhibition and kanR plasmid selection.
Aminoglycosides (30S)	31282-04-9	H432611	Hygromycin B	From Streptomyces hygroscopicus	Aminoglycoside-like antibiotic; inhibits ribosomal elongation/translocation; widely used for eukaryotic cell HygR selection (common for stable line selection).
Aminoglycosides (30S)	3810-74-0	S432671	Streptomycin sulfate	Powder	Aminoglycoside; 30S binding interferes with initiation and induces misreading; commonly used for bacterial inhibition and as an experimental antibiotic mix (e.g., anti-contamination).
Aminoglycosides (30S)	65710-07-8	A106706	Apramycin sulfate	Analytical standard	Apramycin; aminoglycoside; 30S binding; commonly used in veterinary antibacterial applications and aprR selection systems.
Aminoglycosides (30S)	1405-10-3	N109017	Neomycin sulfate	PharmPure™, USP, 600 I.U./mg	Neomycin; aminoglycoside; 30S binding; used for antibacterial purposes and often as a neoR/aph-related control (G418 is more common for mammalian selection).
Aminocyclitols (30S)	22189-32-8	S117923	Spectinomycin hydrochloride pentahydrate	Potency: ≥603 IU/mg	Spectinomycin; aminocyclitol; inhibits 30S translocation; commonly used for bacterial inhibition and spectR plasmid selection.
Aminoglycosides (30S)	1405-41-0	G100392	Gentamicin sulfate	Potency: ≥590 μg gentamicin per mg	Gentamicin sulfate; aminoglycoside; 30S misreading; used for cell-culture anti-contamination/bacterial inhibition and as a gentR-system control.
Aminoglycosides (30S)	32986-56-4	T100847	Tobramycin	Moligand™, ≥98%, Potency ≥900uG/mg	Tobramycin (base); aminoglycoside; 30S misreading; commonly used against Pseudomonas aeruginosa etc., also as a cell-culture antibiotic control.
Aminoglycosides (30S)	56391-57-2	N304005	Netilmicin sulfate	Moligand™, ≥98%	Netilmicin; aminoglycoside; 30S misreading; suitable for aminoglycoside controls and resistance studies.
Aminoglycosides (30S)	1403-66-3	G302822	Gentamicin	Moligand™, ≥900 IU/mg (Microbiological assay of antibiotics, Dried Basis)	Gentamicin (base); aminoglycoside; 30S misreading; suitable for antibacterial/cell-culture antibiotic controls (note potency/dry-basis conversion).
Aminoglycosides (30S)	1263-89-4	P431666	Paromomycin sulfate salt	BioReagent, for plant cell culture	Paromomycin; aminoglycoside; 30S misreading; commonly used in protozoan/plant systems and as an aminoglycoside control.
Aminoglycoside-like (Kasugamycin, 30S)	19408-46-9	K118340	Kasugamycin hydrochloride	Analytical standard, ≥90%(HPLC)	Kasugamycin; primarily inhibits translation initiation (30S); commonly used in plant-pathogenic bacteria studies / antibacterial control.
Aminoglycosides (30S)	79645-27-5	T133599	Tobramycin sulfate	≥98%	Tobramycin sulfate; aminoglycoside; 30S misreading; commonly used for antibacterial applications and as resistance/culture system controls.
Aminoglycosides (30S)	49842-07-1	T275622	Tobramycin sulfate	≥98%	Tobramycin sulfate; aminoglycoside; 30S misreading; similar to above—choose by salt form/potency.
Aminoglycosides (30S)	53179-09-2	S303909	Sisomicin sulfate	≥98%	Sisomicin; aminoglycoside; 30S misreading; commonly used for aminoglycoside controls and resistance research.
Aminoglycosides (30S)	39831-55-5	A129422	Amikacin sulfate	≥97%	Amikacin sulfate; aminoglycoside; 30S misreading; commonly used as a control in studies on resistant Gram-negative bacteria.
Tetracyclines & derivatives (30S)	13614-98-7	M657411	Minocycline hydrochloride	No animal-derived components, low endotoxin, for cell culture, Moligand™, ≥98%	Tetracycline class; blocks aminoacyl-tRNA entry into the 30S A site; cell-culture grade/low endotoxin—suitable for antibacterial controls or Tet-regulated systems (depending on the system).
Tetracyclines & derivatives (30S)	64-73-3	D113714	Demeclocycline hydrochloride	≥90%(HPLC)	Tetracycline class; blocks 30S A-site tRNA binding; used for antibacterial controls / resistance mechanism studies.
Tetracyclines & derivatives (30S)	64-75-5	T105494	Tetracycline hydrochloride	Analytical standard	Tetracycline class; 30S A-site inhibition; commonly used as an antibacterial control and in Tet-system/resistance controls (per experimental design).
Tetracyclines & derivatives (30S)	24390-14-5	D111943	Doxycycline hydrochloride	Moligand™, ≥98%	Doxycycline HCl; tetracycline class 30S inhibition; commonly used for antibacterial work, cell/animal experiments, and Tet-on/off induction systems (choose by system).
Tetracyclines & derivatives (30S)	64-72-2	C103022	Chlortetracycline hydrochloride	PharmPure™, USP, ≥80%(HPLC)	Chlortetracycline HCl; tetracycline class; commonly used for antibacterial/resistance work and tetracycline-lineage controls.
Tetracyclines & derivatives (30S)	389139-89-3	A125972	Omadacycline	Moligand™, ≥98%	Omadacycline (newer tetracycline derivative); 30S inhibition; suitable as a comparator for “tetracycline-resistance bypass/new drug” studies.
Tetracyclines & derivatives (30S)	10118-90-8	M611887	Minocycline	Moligand™, ≥98%	Minocycline; tetracycline class; 30S inhibition; commonly used for antibacterial work and as a tetracycline-lineage control.
Tetracyclines & derivatives (30S)	79-57-2	O304654	Oxytetracycline	Moligand™, ≥98%	Oxytetracycline; tetracycline class; 30S inhibition; commonly used for antibacterial work and tetracycline controls.
Tetracyclines & derivatives (30S)	564-25-0	D304007	Doxycycline	Moligand™, ≥97%	Doxycycline; tetracycline class; 30S inhibition; commonly used for antibacterial work, inducible expression systems, and resistance controls (system-dependent).
Tetracyclines & derivatives (30S)	60-54-8	T501080	Tetracycline	Moligand™, ≥96%	Tetracycline; classic 30S A-site inhibitor; standard reference drug for antibacterial work and mechanism/resistance studies.
Tetracyclines & derivatives (30S)	220620-09-7	E129449	Tigecycline	Moligand™, ≥96%	Tigecycline (glycylcycline); 30S inhibition; commonly used as a comparator in multidrug-resistant bacteria research.
Tetracyclines & derivatives (30S)	127-33-3	D329445	Demeclocycline	Moligand™	Demeclocycline; tetracycline class; 30S inhibition; used as a tetracycline-lineage control.

Table 2 | 50S and Other “Protein Synthesis Pathway” Targets (Including Non-Ribosomal Targets)

Category	CAS No.	Aladdin Cat. No.	Name	Specification / Purity	Product features & applications
Aminonucleoside translation inhibitor (Puromycin)	58-58-2	P432998	Puromycin	For cell culture, Ready Made Solution, from Streptomyces alboniger, 10 mg/mL in H2O	Aminonucleoside antibiotic; mimics aminoacyl-tRNA, causing premature peptide chain termination; widely used for puromycin-resistance selection in mammalian cells / rapid elimination of non-transfected cells.
Nucleoside translation inhibitor (Blasticidin S)	3513-03-9	B276563	Blasticidin S hydrochloride solution	10 mg/mL in 20 mM HEPES	Blasticidin S: binds the large-subunit PTC region, inhibiting peptide elongation and affecting translation termination/turnover; commonly used for mammalian bsd selection (ready-to-use solution).
Cyclic peptide (TB second-line, ribosome)	1405-37-4	C477559	Capreomycin sulfate (from Streptomyces)	Antibacterial peptide	Capreomycin; cyclic peptide; acts on the 70S ribosome to inhibit translocation; used in drug-resistant tuberculosis research and as an antibacterial control.
Phenicol (50S)	56-75-7	C100333	Chloramphenicol	PharmPure™, USP	Chloramphenicol; phenicol; inhibits 50S peptidyl transferase; commonly used for bacterial inhibition and cat (chloramphenicol acetyltransferase) selection.
Phenicol (50S)	15318-45-3	T111416	Thiamphenicol	Moligand™, analytical standard, ≥99%	Thiamphenicol; phenicol; inhibits 50S peptidyl transferase; commonly used for antibacterial work and phenicol-mechanism comparisons.
Phenicol (50S)	73231-34-2	F111293	Florfenicol	≥98%	Florfenicol; phenicol; inhibits 50S peptidyl transferase; common in veterinary/aquaculture contexts—useful as a phenicol-class comparator.
Macrolides/Ketolides (50S)	114-07-8	E105345	Erythromycin	Moligand™, potency ≥850 μg/mg	Erythromycin; macrolide; binds 50S and blocks peptide exit; commonly used for antibacterial work and erm resistance selection/control.
Macrolides/Ketolides (50S)	83905-01-5	A134451	Azithromycin	Moligand™, analytical standard	Azithromycin; macrolide/azalide; 50S elongation inhibition; suitable for macrolide controls and antibacterial assays.
Macrolides/Ketolides (50S)	81103-11-9	C129746	Clarithromycin	Moligand™, ≥98%	Clarithromycin; macrolide; inhibits 50S elongation; commonly used in respiratory pathogen/H. pylori research controls.
Macrolides/Ketolides (50S)	80214-83-1	R129251	Roxithromycin	Moligand™, ≥98%	Roxithromycin; macrolide; inhibits 50S elongation; common macrolide-class comparator.
Macrolides/Ketolides (50S)	8025-81-8	S112803	Spiramycin	Analytical standard	Spiramycin; macrolide; binds 50S to inhibit elongation; commonly used for antibacterial work and macrolide controls.
Macrolides/Ketolides (50S)	16846-24-5	J463189	Josamycin	≥900 U/mg	Josamycin; macrolide; binds the 50S exit tunnel to inhibit peptide elongation; commonly used for Gram-positive and some atypical pathogens.
Macrolides/Ketolides (50S)	1401-69-0	T302817	Tylosin	≥900 u/mg	Tylosin; veterinary macrolide; inhibits 50S elongation; useful as a veterinary macrolide comparator.
Macrolides/Ketolides (50S)	191114-48-4	T305283	Telithromycin	Moligand™, ≥97%	Telithromycin; ketolide; inhibits 50S elongation; useful as a “macrolide-optimized” comparator and for resistance studies.
Lincosamides (50S)	154-21-2	L329314	Lincomycin	Moligand™, ≥98%	Lincomycin; lincosamide; binds 50S and inhibits elongation; used for antibacterial work and as a within-family comparator to clindamycin.
Lincosamides (50S)	18323-44-9	C274627	Clindamycin	Moligand™, ≥99%	Clindamycin; lincosamide; binds 50S and inhibits peptidyl transfer; commonly used for Gram-positive/anaerobe inhibition and MLS_B resistance studies.
Oxazolidinones (50S initiation)	165800-03-3	L126613	Linezolid	Moligand™, ≥99%	Oxazolidinone; inhibits 50S initiation complex formation; commonly used as a comparator in MRSA/VRE resistant-bacteria research.
Oxazolidinones (50S initiation)	856867-55-5	T413160	Tedizolid phosphate	≥98%	Tedizolid phosphate; oxazolidinone; inhibits 50S initiation complex; suitable as an “updated same-target” comparator to linezolid.
Pleuromutilins (50S)	55297-95-5	T114325	Tiamulin	Analytical standard, Moligand™	Pleuromutilin class; binds the 50S peptidyl transferase center to inhibit elongation; common in veterinary/mycoplasma-related work and methodological controls.
Pleuromutilins (50S)	224452-66-8	R125875	Retapamulin	Moligand™, ≥99%	Retapamulin; pleuromutilin; 50S PTC inhibition; often used in skin/topical antibacterial research and within-class comparisons.
Pleuromutilins (50S)	1061337-51-6	L611476	Lefamulin	Moligand™, ≥98%	Lefamulin; pleuromutilin; 50S PTC inhibition; newer systemic-class comparator (common in respiratory pathogen studies).
Pleuromutilins (50S)	101312-92-9	V1418143	Valnemulin	—	Valnemulin; pleuromutilin; 50S PTC inhibition; used in veterinary mycoplasma/porcine respiratory pathogen studies and as a within-class comparator.
Streptogramins (50S)	112362-50-2	D329279	Dalfopristin	Moligand™, ≥98%, mixture of isomers	Dalfopristin (streptogramin A component); synergistic with quinupristin; inhibits 50S elongation; used for mechanism/synergy studies.
Streptogramins (50S)	120138-50-3	Q344294	Quinupristin	Moligand™, ≥97%	Quinupristin (streptogramin B component); synergistic with dalfopristin; inhibits 50S elongation; used for synergy/resistance studies.
Streptogramins (50S)	23152-29-6	V465591	Virginiamycin S₁	≥99%(HPLC)	Virginiamycin S1 (streptogramin B component); inhibits 50S elongation; synergizes with the M component—commonly used for streptogramin research/controls.
Streptogramins (50S)	21411-53-0	V102390	Virginiamycin A	≥97%	Virginiamycin M1 / Pristinamycin IIA (streptogramin A component); synergizes with S component to inhibit 50S; used for component/synergy dissection studies.
Streptogramins (50S)	270076-60-3	P337242	Pristinamycin	≥98%	Pristinamycin (streptogramin mixture); A/B components synergistically inhibit 50S; suitable as an overall streptogramin comparator and for synergy mechanism studies.
Thiopeptides (50S / elongation factors)	1393-48-2	T102394	Thiostrepton	≥98%, from Streptomyces laurentii	Thiostrepton; thiopeptide; targets the 50S GTPase center and inhibits EF-G/EF-Tu–related steps; commonly used in Gram-positive studies and mechanism validation.
Elongation factor inhibitor (EF-G)	6990-06-3	F134821	Fusidic acid	Moligand™, ≥98%	Fusidic acid; inhibits elongation factor EF-G (blocks translocation/GTP cycle); commonly used in S. aureus studies and as a “non-ribosomal site” protein synthesis inhibition control.
Aminoacyl-tRNA synthetase inhibitor (IleRS)	12650-69-0	M102403	Mupirocin	Moligand™, ≥95%	Mupirocin; inhibits isoleucyl-tRNA synthetase (IleRS); commonly used for selective bacterial inhibition and aaRS target validation.

Table 3 | Eukaryotic Translation Inhibitors (Research Tools)

Category	CAS No.	Aladdin Cat. No.	Name	Specification / Purity	Product features & applications
Eukaryotic translation inhibitor (research tool)	66-81-9	C729197	“3-[2-(3,5-dimethyl-2-oxocyclohexyl)-2-carboxyethyl]glutaramide”	Moligand™, ≥98%	Cycloheximide; inhibits eukaryotic 60S elongation (not a typical antibacterial drug); commonly used to inhibit eukaryotic protein synthesis and as a control in transcription/translation-dependence experiments.
Eukaryotic translation inhibitor (research tool)	26833-85-2	H274974	Harringtonine, translation inhibitor	≥98%	Harringtonine: blocks early elongation after initiation, enriching ribosomes near start sites; commonly used in ribosome profiling for start-site studies.
Eukaryotic translation inhibitor (research tool)	22862-76-6	A102397	Anisomycin	≥97%	Anisomycin; eukaryotic translation inhibitor (60S peptidyl transferase inhibition); commonly used for rapid translation shutoff and also as a research tool in JNK/p38 activation studies.

Note: The items above are representative Aladdin products. For additional specifications and more products, please refer to the full product list at the end of the article or search the Aladdin website by product name/CAS.

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