Streptogramin

1349.48346

1348.601563

234-244-6

246121

Reddish-yellow powder

D - Dermatologicals|J - Antiinfectives for systemic use

363.76000

4.99230

155 °C (approx)

Poorly soluble in water

MW: 499.6 to 1038; log Kow -1.0 to 3.2; Henry's Law constant: negligible to 2.8X10-23 Pa-L/mol (Polypeptides e.g. avermectin, bacitracin, ivermectin, virginamycin)

Amorphous|Solubility in water: 45 mg/L at 25 °C; log Kow: 1.52; VP: 9.63X10-22 mm Hg at 25 °C (est) /Virginiamycin M1/|Colorless lath from ethyl acetate, mp: 203-205 °C. MW: 525.59. Specific optical rotation: -218 deg at 20 °C/D (c = 0.34 in ethanol). UV max (ethanol) 228 nm (log epsilon 4.51) /Virginiamycin M1/|Solubility in water: 53.41 mg/L at 25 °C; log Kow: 0.32; VP: 1.83X10-26 mm Hg at 25 °C (est) /Virginiamycin S1/|Crystals from methanol, mp: 240-242 °C. MW: 823.89. Specific optical rotation: -28 deg at 20 °C/D (c = 1 in ethanol). UV max (ethanol) 305 nm (log epsilon 3.85) /Virginiamycin S1/

SRP: Expired or waste pharmaceuticals shall carefully take into consideration applicable DEA, EPA, and FDA regulations. It is not appropriate to dispose by flushing the pharmaceutical down the toilet or discarding to trash. If possible return the pharmaceutical to the manufacturer for proper disposal being careful to properly label and securely package the material. Alternatively, the waste pharmaceutical shall be labeled, securely packaged and transported by a state licensed medical waste contractor to dispose by burial in a licensed hazardous or toxic waste landfill or incinerator.

The Generic Animal Drug and Patent Restoration act requires that each sponsor of an approved animal drug must submit to the FDA certain information regarding patents held for the animal drug or its method of use. The Act requires that this information, as well as a list of all animal drug products approved for safety and effectiveness, be made available to the public. Virginiamycin is included on this list.|Tolerances for residues of new animal drugs in food. The ADI for total residues of virginiamycin is 250 micrograms per kilogram of body weight per day.|Tolerances for residues of new animal drugs in food. Tolerances: (1) Swine. Tolerances are established for residues of virginiamycin in uncooked edible tissues of 0.4 part per million (ppm) in kidney, skin, and fat, 0.3 ppm in liver, and 0.1 ppm in muscle. (2) Broiler chickens and cattle. A tolerance for residues of virginiamycin is not required.|New animal drugs for use in animal feeds. Virginiamycin.

|Danger|H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]|P261, P264, P270, P272, P280, P301+P312, P302+P352, P305+P351+P338, P310, P321, P330, P333+P313, P363, and P501|Aggregated GHS information provided by 2 companies from 2 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Virginiamycin concentration in secondarily treated effluent from a 17.5 million gallon/day municipal waste water treatment plant serving 120,000-150,000 residents near Phoenix, AZ was reported as below the detection limit of 0.1 ug/L(1). A leachate plume downgradient of the Norman landfill in central Oklahoma was analyzed in 2000 for pharmaceuticals and other organic waste water. Virginiamycin was not detected; reporting limit 0.10 ug/L(2).|Veterinary pharmaceuticals are commonly administered to animals for disease control, and added into feeds at subtherapeutic levels to improve feeding efficiency. As a result of these practices, a certain fraction of the pharmaceuticals are excreted into animal manures. Land application of these manures contaminates soils with the veterinary pharmaceuticals, which can subsequently lead to contamination of surface and groundwaters. Information on the occurrence and fate of pharmaceuticals in soil and water is needed to assess the potential for exposure of at-risk populations and the impacts on agricultural ecosystems. ...|Commercial feedlots for beef cattle finishing are potential sources of a range of trace chemicals which have human health or environmental significance. To ensure adequate protection of human and environmental health from exposure to these chemicals, the application of effective manure and effluent management practices is warranted. The Australian meat and livestock industry has adopted a proactive approach to the identification of best management practices. Accordingly, this review was undertaken to identify key chemical species that may require consideration in the development of guidelines for feedlot manure and effluent management practices in Australia. Important classes of trace chemicals identified include steroidal hormones, antibiotics, ectoparasiticides, mycotoxins, heavy metals and dioxins. These are described in terms of their likely sources, expected concentrations and public health or environmental significance based on international data and research. Androgenic hormones such as testosterone and trenbolone are significantly active in feedlot wastes, but they are poorly understood in terms of fate and environmental implications. The careful management of residues of antibiotics including virginiamycin, tylosin and oxytetracycline appears prudent in terms of minimising the risk of potential public health impacts from resistant strains of bacteria. Good management of ectoparasiticides including synthetic pyrethroids, macrocyclic lactones, fluazuron, and amitraz is important for the prevention of potential ecological implications, particularly towards dung beetles. Very few of these individual chemical contaminants have been thoroughly investigated in terms of concentrations, effects and attenuation in Australian feedlot wastes.

Pharmaceuticals are emerging contaminants with potential risks to the environment and human health. A liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was developed for determination of the antimicrobials virginiamycin, monensin, salinomycin, narasin and nicarbazin in poultry litter and soil. This method involves methanol extraction and clean-up of extracts through glass microfibre filters, introduction of the extracts and separation of compounds on a Zorbax Eclipse XDB C8 column, and compound detection in a Quattro Micro Micromass spectrometer. For litter samples, Method Detection Limits ranged from 0.1-0.6 ug/kg, while Limit of Quantitation (LOQ) /was/ 2 ug/kg for virginiamycin in litter and soil. Application of the LC-MS-MS method for detection of veterinary pharmaceuticals in litter collected from commercial poultry farms showed that compounds were present at concentrations ranging from 10-11,000 ug/kg.

LD50 Mouse subcutaenous 2500 mg/kg|LD50 Mouse intraperitoneal 350 ug/kg|LD50 Mouse oral 2100 mg/kg

Virginiamycin is one of the streptograms produced by a Streptomyces virginiae. The two principal components are referred to as M1 and S1(1).

Virginiamycin's production and use as a veterinary antibiotic and animal feed supplement(1) may result in its release to the environment through various waste streams(SRC). The commercial product contains about 75% of the fraction M1 and 5% of the fraction S1(2).

TERRESTRIAL FATE: The commercial product virginiamycin contains about 75% of the fraction M1 and 5% of the fraction S1(1). Based on a classification scheme(2), estimated Koc values of 980 and 1.6X10+5 for M1 and S1, respectively(SRC), determined from a structure estimation method(3), indicate that virginiamycin mobility is expected to be low to immobile in soil(SRC). Volatilization of virginiamycin from moist soil surfaces is expected to be an important fate process(SRC) given a negligible Henry's Law constant(4). Virginiamycin is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure for the M1 fraction of 9.6X10-22 mm Hg at 25 °C(SRC), determined from a fragment constant method(5). Half-lives ranging from 83 to 175 days in soil(4) indicate that biodegradation may be an important environmental fate process in soil(SRC).|AQUATIC FATE: The commercial product virginiamycin contains about 75% of the fraction M1 and 5% of the fraction S1(1). Based on a classification scheme(2), estimated Koc values of 980 and 1.6X10+5 for M1 and S1, respectively(SRC), determined from a structure estimation method(3), indicates that virginiamycin is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(4) based upon negligible Henry's Law constant(5). According to a classification scheme(6), an estimated BCF of 5 for M1(SRC), from an estimated log Kow of 1.52(7) and a regression-derived equation(8), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation data in water were not available(SRC, 2012).|ATMOSPHERIC FATE: The commercial product virginiamycin contains about 75% of the fraction M1 and 5% of the fraction S1(1). According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(2), virginiamycin M1, which has an estimated vapor pressure of 9.6X10-23 mm Hg at 25 °C(SRC), determined from a fragment constant method(3), is expected to exist solely in the particulate phase in the ambient atmosphere. Particulate-phase virginiamycin may be removed from the air by wet or dry deposition(SRC). Virginiamycin M1 and virginiamycin S1 absorb light at 228 nm and 305 nm, respectively(4), suggesting that virginiamycin may be susceptible to direct photolysis by sunlight(SRC).

The commercial product virginiamycin contains about 75% of the fraction M1 and 5% of the fraction S1(1). Virginiamycin M1 and virginiamycin S1 absorb light at 228 nm and 305 nm, respectively(2), suggesting that virginiamycin may be susceptible to direct photolysis by sunlight(SRC).

The commercial product virginiamycin contains about 75% of the fraction M1 and 5% of the fraction S1(1). An estimated BCF of 5 was calculated in fish for virginiamycin M1(SRC), using an estimated log Kow of 1.52(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).|(14C)-Labelled virginiamycin (VM) and related factors were fed during 15 days to rainbow trout /Salmo gairdneri/ at the following concentration: 40 ppm for VM, 35 ppm for virginiamycin M (M) and 12 ppm for viginiamycin S (S). The experiments were conducted at 14 °C and repeated at 6 °C for VM only. At the end of the treatment, part of the trout were fed a control diet and the other fish were starved. At these doses, the apparent digestibility of M was 98% whereas it was in the 75-79% range for S. No evidence of accumulation of VM, M, S or metabolites was observed in tissues, carcass and viscera of medicated fish. The highest concentration of residues was found in gall bladder and viscera. After 15 days of treatment, less than 10 ng of VM equivalents were detected per gram of muscle. Five days after withdrawal, only gall bladder and viscera contained residual amounts of radioactivity. Starvation seems to delay the discharge of residues. Probably because the residue levels in trout fed VM are very low, the effect of temperature on these levels is weak or even non-existent. In liver, the extractable residues accounted for less than 20% of the total radioactivity, suggesting that unchanged virginiamycin was not a major tissue residue.

The commercial product virginiamycin contains about 75% of the fraction M1 and 5% of the fraction S1(1). The Koc of virginiamycin M1 is estimated as 980(SRC), determined from a structure estimation method(2). According to a classification scheme(3), this estimated Koc value suggests that virginiamycin is expected to have low mobility in soil. Using a 2.4 meter soil column, treated effluent was applied to the top of the column over 23 days, simulating a recharge condition similar to those in arid or semiarid climates. The soil used was a Mohall-Laveen sandy loam from an area northwest of Phoenix, AZ with no known history of cultivation or irrigation. Secondarily treated effluent from a 17.5 million gallon/day municipal waste water treatment plant serving 120,000-150,000 residents near Phoenix, AZ was employed. Virginiamycin concentration in the treated effluent was reported as below the detection limit of 0.1 ug/L(4).

The Henry's Law constant for virginiamycin falls in the range of negligible to 2.8X10-23 Pa-L/mol(1). This Henry's Law constant indicates that virginiamycin is expected to be essentially nonvolatile from water and moist soil surfaces(2). The commercial product contains about 75% of the fraction M1 and 5% of the fraction S1(3). Virginiamycin is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 9.6X10-22 mm Hg for the M1 component(SRC), determined from a fragment constant method(4).

GROUNDWATER: Virginiamycin is one of the drugs earmarked by the US Geological Survey for inclusion in a survey of 80 groundwater sources(1).|DRINKING WATER: Virginiamycin M (21411-53-0) was not detected in finished drinking water from a US facility in a heavily populated, highly urbanized drainage basin as part of a USGS/CDC survey; reporting level of 0.10 ug/L(1).|SURFACE WATER: Virginiamycin is one of the many pharmaceuticals tested for in surface waters(1). In a survey conducted by the United States geological Survey, virginiamycin was not detected (0.10 ug/L reporting level) in 104 water samples from a network of US streams across 30 states during 1999-2000(2). Virginiamycin M (21411-53-0) was not detected in 76 water samples collected in 2001 upstream and downstream of select towns and cities in Iowa under low, normal, and high flow conditions; reporting limit = 0.10 ug/L(3). Virginiamycin was tested for, not detected in samples collected in March, April and August 2004 at 18 sites on seven selected streams in Arkansas(4). The compound was not detected in all 143 surface water samples from various locations in the Great Lakes Basin(5). Virginiamycin was reported at a concentration of less than 100 ng/L in 2 of 2 sampling sites along Assunpink Creek in the vicinity of Trenton, NJ. This watershed is predominantly agricultural in its headwaters and becomes heavily urbanized in the lower reaches with a major municipal wastewater treatment plant located near the center of the watershed. Site one was approximately 100 yards downstream from the treatment plant with site 2 approximately 2 miles further downstream. Assunpink Creek is a tributary to the Delaware River(6).

Occupational exposure to virginiamycin may occur through inhalation and dermal contact with this compound at workplaces where virginiamycin is produced or used. (SRC)

Anti-Bacterial Agents|MEDICATON (VET): Necrotic enteritis is an acute enterotoxemia. The clinical illness is usually very short and often the only signs are a sudden increase in mortality. The disease primarily affects broiler chickens (2-5 wk old) and turkeys (7-12 wk old) raised on litter but can also affect commercial layer pullets raised in cages. ... Because Clostridium perfringens is nearly ubiquitous, it is important to prevent changes in the intestinal microflora that would promote its growth. This can be accomplished by adding antibiotics in the feed such as virginiamycin ... .|MEDICATION (VET): Swine dysentery is a common, mucohemorrhagic diarrheal disease of pigs that affects the large intestine. ... Therapeutic use of antibacterials is effective if started early. ... Virginiamycin /is/ commonly used.|MEDICATION (VET): For use in cattle fed in confinement for slaughter: Improved feed efficiency. Reduction of incidence of liver abscesses. Increased rate of weight gain.|MEDICATION (VET): Efficacy of virginiamycin (22 mg/kg) in combination with no drug, amprolium, carbarsone, halofuginone, or monensin, was studied. Male & female turkeys were raised to market age in five experiments conducted from 1983 to 1987. Body weights & feed:gain responses to virginiamycin for males & females were positive & significant (P less than .05). Virginiamycin resulted in mean 5.2 & 6.3% body weight responses & 3.3 & 2.2% feed:gain responses for males at 19 or 20 wk of age & for females at 16 or 17 wk of age, respectively. Mortality rates were low in all studies, & were not influenced by virginiamycin. In a processing study, virginiamycin in combination with halofuginone did not affect shrinkage, yield, or market grade. Feed was utilized by males & females 3.9 & 3.0%, respectively, more efficiently than expected with dietary virginiamycin, compared with results predicted by a simulation modeling technique. Profitability was considerably greater with dietary virginiamycin using actual data than with simulated feed consumption data.

VET: The effects of dietary supplements of virginiamycin on the behavior and physiology of 17 thoroughbred geldings (five cribbers, six weavers and six control horses) were compared with the effects of a placebo over a period of 16 weeks. Virginiamycin had no effect on the horses' stereotypic behavior, but it reduced their explorative behavior, possibly owing to a reduction in feeding motivation. Virginiamycin increased the water intake of the cribbers and decreased the water intake of the control horses, but it was not possible to eliminate possible confounding factors for this effect. Virginiamycin had no other significant effects on the behavior or physiology of the horses, and had no effect on the digestibility of their diets.|VET: The effect of a peptolide antibiotic virginiamycin on the growth, rumen & blood parameters was followed in 8 milk-fed calves, 4 weeks old initially. Calves were individually housed in metabolic cages. The experiment was ended at the age of 16 weeks. Virginiamycin was supplied at 80 mg per head per day. Calves receiving virginiamycin gained 5.1% more than control calves. Feed intake per 1 kg of body weight gain was higher in control calves. Virginiamycin significantly increased molar percentage of propionate & decreased molar acetate: propionate ratio in rumen fluid. Serum iron, hematocrit & hemoglobin were significantly increased in the treated group in the last period of the trial. Virginiamycin lowered serum protein & urea & tended to decr activity of aminotransferases.|VET: Morphologic studies were carried out on the liver, kidneys, and small intestine of broiler birds that had been given antibiotics with the feed (virginiamycin, 20.0 ppm, flavomycin, 4.8 ppm, and avotan, 10.0 ppm) in the course of 49 days, kept with a group of controls. The liver of the test birds showed protein and fatty dystrophy, and the kidneys--protein dystrophy. The small intestine showed thinning of the wall and increase in the villi intestinales length. The manifestation of the morphologic changes depended on the amount of the antibiotic taken in. Those of the birds that were offered flavomycin had well manifested lesions, while in birds that were given virginiamycin and avotan only the lesions were more slightly expressed.

Substances that inhibit the growth or reproduction of BACTERIA. (See all compounds classified as Anti-Bacterial Agents.)

The results of residue determinations of the growth promotors carbadox, tylosin, & virginiamycin in kidney, liver, & muscle from pigs in feeding experiments are described as well as the analytical methods used. Residues of the carbadox metabolite quinoxaline-2-carboxylic acid were found in liver from pigs fed 20 mg/kg in the diet with a withdrawal time of 30 days. No residues were detected in muscle with zero withdrawal time. The limit of determination was 0.01 mg/kg for both tissues. No residues of virginiamycin & tylosin were found in pigs fed 50 & 40 mg/kg, respectively, in the diet, even with zero withdrawal time. Residues of tylosin of 0.06 mg/kg & below were detected in liver & kidney from pigs fed 200 or 400 mg/kg & slaughtered within 3 h after the last feeding.

Reduction of virginiamycin S with sodium borohydride produces allo- & normal-dihydro-virginiamycin S. Reduction of the tosylhydrazone of virginiamycin S with sodium cyanoborohydride affords deoxyvirginiamycin S. These compounds are less active than virginiamycin S. Like virginiamycin S they enhance the activity of virginiamycin M1.|Virginiae butanolides (VBs), which are among the butyrolactone autoregulators of Streptomyces species, act as a primary signal in Streptomyces virginiae to trigger virginiamycin biosynthesis & possess a specific binding protein, BarA. To clarify the in vivo function of BarA in the VB-mediated signal pathway that leads to virginiamycin biosynthesis, two barA mutant strains (strains NH1 & NH2) were created by homologous recombination. In strain NH1, an internal 99-bp EcoT14I fragment of barA was deleted, resulting in an in-frame deletion of 33 amino acid residues, including the second helix of the probable helix-turn-helix DNA-binding motif. With the same growth rate as wild-type S. virginiae on both solid & liquid media, strain NH1 showed no apparent changes in its morphological behavior, indicating that the VB-BarA pathway does not participate in morphological control in S. virginiae. In contrast, virginiamycin production started 6 hr earlier in strain NH1 than in the wild-type strain, demonstrating for the first time that BarA is actively engaged in the control of virginiamycin production & implying that BarA acts as a repressor in virginiamycin biosynthesis. In strain NH2, an internal EcoNI-SmaI fragment of barA was replaced with a divergently oriented neomycin resistance gene cassette, resulting in the C-terminally truncated BarA retaining the intact helix-turn-helix motif. In strain NH2 & in a plasmid-integrated strain containing both intact & mutated barA genes, virginiamycin production was abolished irrespective of the presence of VB, suggesting that the mutated BarA retaining the intact DNA-binding motif was dominant over the wild-type BarA. These results further support the hypothesis that BarA works as a repressor in virginiamycin production & suggests that the helix-turn-helix motif is essential to its function. In strain NH1, VB production was also abolished, thus indicating that BarA is a pleiotropic regulatory protein controlling not only virginiamycin production but also autoregulator biosynthesis.|Previous findings suggest the location of the central loop of domain V of 23S rRNA within the peptidyltransferase domain of ribosomes. This enzymatic activity is inhibited by some antibiotics, including type A (virginiamycin M or VM) & type B (virginiamycin S or VS) synergimycins, antibiotics endowed with a synergistic action in vivo. In the present work, the ability of VM & VS to modify the accessibility of 23S rRNA bases within ribosomes to chemical reagents has been explored. VM afforded a protection of rRNA bases A2037, A2042, G2049 & C2050. Moreover, when ribosomes were incubated with the two virginiamycin components, the base A2062, which was protected by VS alone, became accessible to dimethyl sulphate (DMS). Modified reactivity to chemical reagents of different rRNA bases located either in the central loop of domain V or in its proximity furnishes experimental evidence for conformational ribosome alterations induced by VM binding

Emergency and supportive measures: Maintain an open airway and assist ventilation if necessary. Treat coma, seizures, hypotension, anaphylaxis, and hemolysis if they occur. Replace fluid losses resulting from gastroenteritis with intravenous crystalloids. /Antibacterial agents/|Decontamination: Administer activated charcoal orally if conditions are appropriate. Gastric lavage is not necessary after small to moderate ingestions if activated charcoal can be given promptly. /Antibacterial agents/|Enhanced elimination: Most antibiotics are excreted unchanged in the urine, so maintenance of adequate urine flow is important. The role of forced diuresis is unclear. Hemodialysis is not usually indicated, except perhaps in patients with renal dysfunction and a high level of a toxic agent. /Antibacterial agents/|/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on the left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Poisons A and B/|For more Antidote and Emergency Treatment (Complete) data for VIRGINIAMYCIN (6 total), please visit the HSDB record page.

/CASE REPORTS/ Four cases of eczematous-like drug eruption after oral ingestion of synergistins, pristinamycin (3 cases) & virginiamycin (1 case) /are reported/. The lesions occurred after contact sensitization with topical virginiamycin. The clinical symptoms appeared a few hours after ingestion: a generalized maculopapular eruption, sometimes with general symptoms of anaphylactic reaction. Eczema appeared again on initial areas of contact dermatitis. There is a common allergenic group between these 2 antibiotics, which is a macrocyclic lactone. Physiopathology of this drug eruption is not clear: allergic reaction of the delayed type or anaphylactic reaction. Patients allergic to virginiamycin should be strongly cautioned against oral pristinamycin.|/CASE REPORTS/ A warehouseman aged 31 working in a pharmaceutical factory got an occupational contact dermatitis to virginiamycin (factor M), an antibiotic used as a food additive for pigs & poultry. A review is made of contact dermatitis to virginiamycin & to pristinamycin.

Pristinamycin

Approved in US for swine at therapeutic and sub-therapeutic levels Approved in European Union for turkeys, laying hens, cattle (fattening) calves, sows, pigs. Approved in Australia for pigs, meat poultry. Usage in Denmark as an antimicrobial growth promoter (kg active compound, year): 3837 (1990); 15537 (1992); 2801 (1994); 5055 (1996); 892 (1998); 0 (1999); 0 (2000)

Trade Names: Eskalin /SKB/; Stafac /SKB/; Staphylomycine /SKB/|The commercial product contains about 75% of the fraction M1 and 5% of the fraction S1.|V-MAX 50 (virginiamycin) powder, Active Drug Ingredient Virginiamycin : 11% (Contains 50 g virginiamycin activity per lb) (Phibro Animal Health).

...formerly called staphylomycin, was found in the culture broth of Streptomyces virginiae by De Somer et al of Leuven Unviresity in 1955.|A mixture of two principal components designated virginiamycin M1 (21411-53-0) and virginiamycin S1 (23152-29-6)|Growth promoters are added to animal feed to improve efficiency of food digestion|Virginiamycin is used in feeds in the United States and elsewhere.

Analyte: Virginiamycin; matrix: blood, urine; procedure: high performance liquid chromatography with ultraviolet detection at 227.5 nm|A comprehensive analytical method based on ultra high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) has been developed for the determination of virginiamycin M1 in feeds. The sample was extracted twice by ultrasonic extraction with ace-tonitrile-0.2% (v/v) formic acid (8:2, v/v). The chromatographic separation was achieved with a BEH C18 column and acetonitrile-0. 3% (v/v) formic acid (35: 65, v/v) as the mobile phase. The identification and quantification of the analyte were carried out on electrospray ionization MS/MS in a multiple reaction monitoring (MRM) mode. The correlation coefficient (r) of virginiamycin M1 was 0. 999 5 in the linear range of 0. 3 -226. 6 microg/L. The detection limit (S/ N = 3) and quantification limit (S/N = 10) of virginiamycin M1 were 2 microg/kg and 7 microg/kg, respectively. The average spiked recoveries were in the range of 82. 6% to 102. 7% with the relative standard deviations (RSDs) of 0.9% - 10.5%. The results demonstrate that the proposed method is simple, sensitive, repeatable and suitable for the testing of virginiamycin M, in feeds.

HPLC determination in animal feeds.

Animal Drugs -> FDA Approved Animal Drug Products (Green Book) -> Active Ingredients