Chinese Japanese Germany Korea


Mode of action A second-line anti-TB drug Chemical properties Uses Production process
D-Cycloserine structure
Chemical Name:
pa94;106-7;NJ-21;PA 94;I-1431;Closina;E-733-A;Cyclorin;Closerin;Oxymycin
Molecular Formula:
Formula Weight:
MOL File:

D-Cycloserine Properties

Melting point:
147 °C (dec.)(lit.)
111 º (C=5, 2N NaOH)
Boiling point:
191.38°C (rough estimate)
1.3516 (rough estimate)
refractive index 
1.5110 (estimate)
storage temp. 
water: soluble50mg/mL, clear, colorless to light yellow
pKa 4.5 (Uncertain)
white to off-white
optical activity
[α]20/D +115.0±5.0°, c = 2% in H2O
Water Solubility 
Air Sensitive
CAS DataBase Reference
68-41-7(CAS DataBase Reference)
NIST Chemistry Reference
  • Risk and Safety Statements
Hazard Codes  Xn
Risk Statements  5-20
Safety Statements  38-36/37-24/25
WGK Germany  2
RTECS  NY2975000
HS Code  29419090

D-Cycloserine price More Price(19)

Manufacturer Product number Product description CAS number Packaging Price Updated Buy
Sigma-Aldrich 30020 D-Cycloserine ≥96.0% (NT) 68-41-7 1g $68.5 2018-11-20 Buy
Sigma-Aldrich 1158005 Cycloserine United States Pharmacopeia (USP) Reference Standard 68-41-7 250mg $352.8 2018-11-20 Buy
TCI Chemical C1189 D-(+)-Cycloserine >98.0%(HPLC)(T) 68-41-7 1g $48 2018-11-22 Buy
TCI Chemical C1189 D-(+)-Cycloserine >98.0%(HPLC)(T) 68-41-7 5g $169 2018-11-22 Buy
Alfa Aesar A18000 D-Cycloserine, 98+% 68-41-7 5g $201 2018-11-13 Buy

D-Cycloserine Chemical Properties,Uses,Production

Mode of action

The first three amino acids of the pentapeptide chain of muramic acid are added sequentially, but the terminal d-alanyl-d-alanine is added as a dipeptide unit. To form this unit the natural form of the amino acid, l-alanine, is first racemized to d-alanine and two molecules are then joined by d-alanyl-d-alanine ligase. Both of these reactions are blocked by the antibiotic cycloserine, which is a structural analog of d-alanine.

A second-line anti-TB drug

D-cycloserine is a broad-spectrum polypeptide antibiotic produced by Streptomyces lavendulae and Streptomyces orchidaceus or synthesized by chemical methods. As white crystals with strong hygroscopic nature, it is soluble in water, slightly soluble in lower alcohols, acetone and dioxane, and hardly soluble in chloroform and petroleum ether. It is relatively stable in alkaline solution and decomposes rapidly in acidic or neutral solutions. As a broad-spectrum antibiotic, cycloserine is inhibitive against most Gram-positive and Gram-negative bacteria, rickettsia and some protozoa, with the exception of Mycobacterium tuberculosis., It is also effective on some of the Mycobacterium tuberculosis strains with tolerance to streptomycin, vinactane para-aminosalicylic acid, isoniazid and pyrazinamide. Cycloserine slightly synergizes with isoniazid in the inhibition of Mycobacterium tuberculosis H37RV, but it neither synergizes nor antagonizes against streptomycin. The product is a bacteriostatic agent, and thus won’t exert bactericidal effect even when increasing the dose or prolonging the action time with bacteria.
The Mechanism of D-cycloserine’s antibacterial action is to inhibit the biosynthesis of peptidoglycan of the cell wall. As it is a structural analog of D-alanine, D-cycloserine can competitively inhibit the activities of alanine racemase and D-alanyl-D-alanine synthetase, which are two important enzymes in peptidoglycan synthesis. D-cycloserine shows weak inhibitive activity against Mycobacterium tuberculosis which is only 1/10 to 1/20 that of streptomycin. The advantage of the product is that it is effective on drug-resistant Mycobacterium tuberculosis strains and less likely to induce drug resistance. The product can be used with other anti-tuberculosis drugs in the treatment of tuberculosis caused by drug-resistant Mycobacterium tuberculosis.
Cycloserine is a second-line anti-tuberculosis drug. It can inhibit the growth of Mycobacterium tuberculosis, but the effect is relatively weaker than that of the first-line drugs. Its efficacy in tuberculosis treatment is relatively low. Use the drug alone may produce drug resistance, but the resistance occurs slowly compared with that of other anti-tuberculosis drugs. No cross-resistance has been found between cycloserine and other anti-tuberculosis drugs. The mechanism of its antibacterial action is to inhibit the synthesis of peptidoglycan of bacterial cell wall, causing defective in cell wall architecture. The main structural component of the bacterial cell wall is peptidoglycan, which is composed of N-acetylglucosamine (GNAc) and N-acetylmuramic acid (MNAc). N-acetylmuramic acid is linked with pentapeptide and connects N-acetylglucosamine in a reduplicated and alternative manner. The formation of cytoplasmic peptidoglycan precursor may be hampered by cycloserine, as the latter can hinder the racemase and the synthetase of D-alanine, and thus blocks the formation of N-acetylmuramic acid.

Chemical properties

Colorless needle or leafy crystals, or amorphous powder; melting point 155-156℃ (decomposition). Soluble in water; slightly soluble in methanol, ethanol, butanol, propylene glycol, isopropyl alcohol and acetone; and hardly soluble or insoluble in toluene, chloroform, ether, pyridine, benzene and carbon disulfide.


Used as an antibiotic medicine in the treatment of drug-resistant Mycobacterium tuberculosis infection.
Biochemical research

Production process

D-Cycloserine can be obtained through fermentation technique or through direct synthesis. The bacteria used in the fermentation is Actinomyces laven-dulae. The fermentation medium consists of dextrin, dextrose, starch, soybean powder, yeast powder, ammonium sulfate, ammonium nitrate, calcium carbonate, sodium chloride, magnesium sulfate and soybean oil. In the synthesis process, D-cycloserine is obtained from β-aminooxy alanine ethyl ester hydrochloride by reaction with potassium hydroxide in a cyclization reaction.

Chemical Properties

White to pale yellow cryst. powder


antibacterial (tuberculostatic)


D-Cycloserine inhibits cell wall biosynthesis (D-Ala peptide bond formation). D-Cycloserine also prevents conversion of D-Ala to L-Ala. D-Cycloserine is an bacteriostatic. D-Cycloserine is an antibiot ic against Gram-negative bacteria.


Cycloserine is a broad-spectrum antibiotic produced by Streptomyces orchidaceus. It is structural analogue of Dalanine and acts through a competitive inhibition of the D-alanine that is involved in bacterial cell wall synthesis. Cycloserine is inhibitory to M. tuberculosis and active against Escherichia coli, S. aureus, and Enterococcus, Nocardia, and Chlamydia spp. It is used in the treatment of MDR tuberculosis and is useful in renal tuberculosis, since most of the drug is excreted unchanged in the urine.

brand name

Seromycin (Lilly).

Pharmaceutical Applications

A fermentation product of Strep. orchidaceus and other related organisms now produced synthetically. Aqueous solutions are stable at pH 7.8 but the agent is rapidly destroyed in acid conditions. It is active against a wide range of Gram-negative and Grampositive bacteria, including Staphylococcus aureus, streptococci, including Enterococcus faecalis, various enterobacteria, Nocardia and Chlamydia spp. M. tuberculosis is inhibited by 8–16 mg/L. Some environmental mycobacteria, including M. avium, are also susceptible. Its action is specifically antagonized by d-alanine, from which media for in-vitro tests should be free. Its use is limited by neurological and psychiatric side effects. Primary resistance in M. tuberculosis is rare and develops only slowly in patients treated with cycloserine alone. Its inclusion in combinations deters the development of resistance to other drugs. There is no cross-resistance with other therapeutic antibiotics.
It is well absorbed when given orally, achieving a concentration of c. 10 mg/L 3–4 h after a 250 mg dose. Doubling the dose approximately doubles the plasma level. Some accumulation occurs over the first 3 or 4 days of treatment. In children receiving 20 mg/kg orally, plasma levels of 20–35 mg/L have been found. It is widely distributed throughout the body fluids, including the CSF. About 50% is excreted unchanged in the glomerular filtrate over 24 h and 65–70% over the subsequent 2 days. The remainder is metabolized. There is no tubular secretion and no effect of probenecid. Cycloserine accumulates in renal failure, reaching toxic levels if dosage is uncontrolled. It can be removed by hemodialysis.
Evidence of central nervous system toxicity, including headache, somnolence, vertigo, visual disturbances, confusion, depression, acute psychotic reactions and tremors, may develop over the first 2 weeks of treatment. The effects may be exacerbated by alcohol and can be reduced, to some extent, by administering pyridoxine. Treatment should be stopped promptly if any mental or neurological signs develop. Convulsions are said to occur in about 50% of patients when the plasma concentration exceeds 20–25 mg/L, but the relationship to dose is not particularly close. No permanent damage appears to be caused. Cycloserine inhibits mammalian transaminases and this and the convulsant effects of the drug have been attributed to a metabolite, amino-oxyalanine. Use of the drug should be avoided in patients with previous fits or other neurological or psychiatric abnormalities. Rare side effects include rashes, cardiac arrhythmia and deficiency in folate and vitamin B12 leading to peripheral neuritis.
It is occasionally used in MDR tuberculosis (with other antituberculosis drugs) and other mycobacterioses (with appropriate additional drugs).


Cycloserine is readily absorbed orally and distributes throughout body fluids including the cerebrospinal fluid. The concentrations of cycloserine in tissues, body fluids, and the cerebrospinal fluid are approximately equal to the plasma level. Cycloserine is partially metabolized, and 60 to 80% is excreted unchanged by the kidney.

Clinical Use

Neurological symptoms, which tend to appear in the first week of therapy, consist of dizziness, confusion, irritability, psychotic behavioral changes, and even suicidal ideation. Cycloserine is contraindicated in patients with underlying psychiatric and seizure disorders.Other side effects include occasional peripheral neuropathy and low magnesium levels.

Clinical Use

D-(+)-4-Amino-3-isoxazolidinone (Seromycin) is an antibioticthat has been isolated from the fermentation beer of threedifferent Streptomyces species: S. orchidaceus, S. garyphalus,and S. lavendulus. It occurs as a white to pale yellow crystallinematerial that is very soluble in water. It is stable in alkaline,but unstable in acidic, solutions. The compoundslowly dimerizes to 2,5-bis(aminoxymethyl)-3,6-diketopiperazinein solution or standing.
The structure of cycloserine was reported simultaneouslyby Kuehl et al. and Hidy et al.81 to be D-( +)-4-amino-3-isoxazolidinone. It has been synthesized byStammer et al. and by Smart et al.83 Cycloserine is stereochemicallyrelated to D-serine. However, the L-form hassimilar antibiotic activity.
Although cycloserine exhibits antibiotic activity invitro against a wide spectrum of both Gram-negative andGram-positive organisms, its relatively weak potency andfrequent toxic reactions limit its use to the treatment of tuberculosis.It is recommended for patients who fail to respondto other tuberculostatic drugs or who are known tobe infected with organisms resistant to other agents. It isusually administered orally in combination with otherdrugs, commonly isoniazid.

Purification Methods

Purify cycloserine by recrystallisation from aqueous EtOH or MeOH or aqueous NH3/EtOH or isoPrOH. Also recrystallise it from aqueous ammoniacal solution at pH 10.5 (100mg/mL) by diluting with 5 volumes of isopropanol and then adjusting to pH 6 with acetic acid. An aqueous solution, buffered to pH 10 with Na2CO3, can be stored in a refrigerator for 1week without decomposition. UV: max at 226nm (A1cm 1% 4.02). The tartrate salt has m 165-166o (dec), 166-168o (dec), and [] D 24 -41o (c 0.7, H2O). [Stammer et al. J Am Chem Soc 79 3236 1959, UV: Kuehl J Am Chem Soc 77 2344 1955, Beilstein 27 III/IV 5549.]

D-Cycloserine Preparation Products And Raw materials

Raw materials

Preparation Products

D-Cycloserine Suppliers

Global( 344)Suppliers
Supplier Tel Fax Email Country ProdList Advantage
Shenzhen Sendi Biotechnology Co.Ltd.
0755-23311925 18102838259
0755-23311925 CHINA 3194 55
Henan DaKen Chemical CO.,LTD.
+86-371-55531817 CHINA 21714 58
Taizhou Tianhong Biochemistry Technology Co., Ltd.
0523-86201489 CHINA 217 60
Shanghai Bojing Chemical Co.,Ltd.
+86-21-37127788 CHINA 493 55
Henan Tianfu Chemical Co.,Ltd.
0371-55170693 CHINA 20672 55
Mainchem Co., Ltd.
+86-0592-6210733 CHINA 32447 55
Hangzhou FandaChem Co.,Ltd.
0086 158 5814 5714 (Mobile; WhatsApp; Telegram)
+86-571-56059825 CHINA 2883 55
+86 21 5161 9050/ 5187 7795
+86 21 5161 9052/ 5187 7796 CHINA 24191 60
career henan chemical co
+86-371-86658258 CHINA 30002 58
Jinan Chenghui-Shuangda Chemical Co.,Ltd
+86-531-58897093 CHINA 146 58

View Lastest Price from D-Cycloserine manufacturers

Image Release date Product Price Min. Order Purity Supply Ability Manufacturer
2019-04-03 D-Cycloserine in stock GMP Factory
US $1.00 / KG 1KG GMP Factory in China Top 3 largest production capacity Factory Chemwill Asia Co.,Ltd.
2018-08-20 D-Cycloserine
US $1.00 / KG 1G 98% 100KG career henan chemical co

D-Cycloserine Spectrum

68-41-7(D-Cycloserine)Related Search:

Copyright 2017 © ChemicalBook. All rights reserved