Quantification of Structurally Alert Mutagenic Impurities in Meropenem Trihydrate Drug Substance by Liquid Chromatography with High Resolution Mass Spectrometer (LC-HRMS)

Potential mutagenic impurities in Active Pharmaceutical Ingredient, Meropenem Trihydrate were assessed and a novel analytical method for their quantification was developed and validated. This Liquid Chromatographic method using High Resolution Mass Spectrometer (LC-HRMS) technique is proved to be suitable for simultaneous quantification of all ten identified impurities with required specificity, sensitivity, resolution, precision, accuracy, and other method characteristics as per ICH Guidelines. The acceptable limit of less than 2.9 μg/g was considered for evaluations, based on drug substance dosage and duration of treatment. The method stands most sensitive with a Limit of Detection of 0.35 μg/g, considering the challenge full acceptance criteria as per current regulatory standards.

Mutagenic Potential of Medicinal Polyherbal Preparations

Extracts of twelve medicinal polyherbal preparations in powder form sold at retail shops were tested for mutagenicity using Ames in vitro test. Five of the polyherbal preparations were found to be mutagenic (p ≤ 0.05) at 250 μg/ml. Two mutagenic preparations comprised of traditionally used medicinal plants with no mutagenicity property being reported. However, one polyherbal preparation which contained one mutagenic plant was found not mutagenic. Under the conditions of this study, it can be concluded that some polyherbal preparations were potentially mutagenic and mutagenicity of polyherbal preparation cannot always be deduced from the mutagenicity status of each individual plant components of the polyherbal preparations.

A Comparative Study on Mutagenic Effects of Space Flight and Irradiation of γ-rays on Rice

The experiment was conducted to study the mutagenic effects of space environment on seedling growth in M1 generation and plant height and heading date in M2 generation in rice. Two types of lines of growth promotion （GP） and growth suppression （GS） were selected from the recombinant inbred lines （RILs） derived from a cross between a sensitive japonica Lemont and a nonsensitive indica Teqing to compare the mutation frequency and mutagenic efficiency for plant height and heading date in the M2 generation. Space environment resulted in 34.9% higher seedling height （SH） in the GP group than in the control, and 39.1% lower in the GS group than in the control, and there was no difference in seed fertility （SF） between the two groups. In M2, mutants of plant height and heading date can be induced by space treatment in both the two groups with lower mutation frequency and mutagenic efficiency in the GP group than in the GS group. There were no significant differences in the physiological damages in M1 between the two groups after γ-rays irradiation treatment. Mutation frequency and mutagenic efficiency of heading date in M2 were higher in the GS group than in the GP group, and the opposite was true for mutagenic efficiency of plant height although the mutation frequency varied between the two groups. The mutation frequencies of plant height and heading date induced by space environment were obviously lower than those by γ-rays irradiation, but the mutagenic efficiency was the opposite for most of the traits. For the GP and GS of seedlings induced by space environment, the GS had higher mutation frequency and mutagenic efficiency for plant height and heading date than the GP in M2.

Antimutagenicity of Propolis Against Some 0Mutagens in vivo and in vitro

Objective To evaluate the antimutagenicity of propolis in vivo and in vitro. Methods Salmonella typhimurium strains TA98 and TA100 were used as a test model in vitro against a direct mutagen DMC and an indirect mutagen 2AF with or without S9 mix, and MN formation of mice bone marrow cell and CAs induction of mice testicle cell were applied as a test model in vivo against two mutagens CP and MMC. Results The present study clearly demonstrated that propolis could inhibit mutagenicity of both DMC and 2AF directly in a dose-dependent manner, and significant antimutagenic effects (P<0.05) were obtained in TA98 strain at 2000 and 3000 mg/plate. It also could inhibit mutagenicity of both DMC and 2AF to TA98 strain in a dose-dependent manner, with significant antimutagenic effects (P<0.05) appeared at 1000, 2000, and 3000 mg/plate. The results of antimutagenicity test in vivo revealed that propolis could inhibit MN formation significantly (P<0.05) at the doses of 45.0 and 135.0 mg/kg b. w., and decrease the frequency of chromosome aberrants and chromosome aberrant cells significantly (P<0.05) only at the dose of 135.0 mg/kg b. w. Conclusion The propolis is a good inhibitor for mutagencity of DMC and 2AF in vitro, as well as for CP and MMC in vivo.

Removal effect on Mesocyclops leukarti and mutagenicity with chlorine dioxide

Mesocyclops leukarti of zooplankton propagates excessively in eutrophic water body and it cannot be effectively inactivated by the conventional drinking water treatment process. In order to tackle this problem, a study of removal effect on Mesocylops leukarti with chlorine dioxide in a waterworks was performed. The results showed that Mesocyclops leukarti could be effectively removed from water by 1.0 mg/L chlorine dioxide prcoxidation combined with the conventional drinking water treatment process. Higher oxidizability and molecular state of chlorine dioxide in water is the key to the inactivation of Mesocyclops leukarti. The chlorite, disinfection by-products （DBPs） of chlorine dioxide, was stable at 0.45 mg/L, which is lower than that critical value of the USEPA. GC-MS examination showed that the quantity of organic substance in the water treated by chlorine dioxide obviously decreased. Ames test further revealed that the mutagenicity was reduced by chlorine dioxide with respect to prechlorine. The propagation ofMesocyclops leukorti can be inactivated effectively and safely by chlorine dioxide pre-oxidation.

MUTAGENICITY AND CARCINOGENICITY OF FISH SAUCE FROM A COUNTY WITH THE HIGH RISK FOR GASTRIC CANCER IN CHINA

The mutagenicity and carcinogenicity of fish sauce (FS) sample from Changle County, a high gastric cancer mortality (113.20/105) area, were investigated with the biologic short-term tests and laboratory animal experiment. The results showed that the extract of FS was markedly direct mutagenic toward S. typhimurium TA100, induced high sister chromatid exchanges (SCE) and micronucleus (MN) in V79 cells after nitrosation with sodium nitrite. But the non-nitrosated FS did not. The nitrosated fish sauce (NFS) also induced SOS in E. coli PQ37 and alkylation of calfthymus DNA. The potency of NFS to induce unscheduled DNA synthesis (UDS) in human normal gastric mucosal cells was increased about fivefold compared with FS. When the NFS extract was given to newborn rats by gavage, dys-plasia and adenocaroinoma were induced in the glandular stomach in the 4th and 16th experimental week, respectively. N-nitrosamides were also found in NFS, which may account for the mutagenicity and carcinogenicity of NFS. It is indicated that FS, a traditional daily eaten seasoning, may contribute to the causes of the high gastric cancer mortality for the local residents.

Thiolsulfonate functionalized polystyrene resin:Preparation and application in the isolation and identification of electrophilic mutagens

A new approach for isolation and identification of elecrtophilic mutagens from complex matrix was developed. Thiosulforfic anion was immobilized onto polystyrene beads and used as separation media. Potassium polystyryl-thiosulfonate, prepared from polystyryl- sulfonyl chloride and KHS, was observed to selectively react with model electrophilic mutagens such as alkyl halides, ct-chloroketones and α-chloroesters to produce polystyryl-thiosulfonlc esters. After separation from other nonreactive organic compounds, the beads then reacted with ethanethiol to produce unsymmetrical ethyl disulfides which are easily detected by GC/MS. For one mutagenic compound, only one unsymmetrical disulfide was found to contain its structure part. Thus, the structure of the parent mutagens could be deduced from that of the unsymmetrical disulfides. The degree of functionalization of the potassium polystyryl-thiosulfonate resin was 1.11 mmol/g. Its reactivity was discussed and its recycling method was reported here.

Analysis of the Phenotype and the Restriction Enzyme Mapping Level of Mutations Induced by the New Mutagen Glycidyl Methacrylate

Glycidyl methaerylate (GMA) is a recently recognized chemical mutagen. In order to explore the mutagenicity and mutagenic process of GMA, plasmid pBR322 was used for in vitro binding, mutant screening, and restriction enzyme mapping. The binding between GMA and DNA in vitro has been verified by means of a spectrophotometric method. When pBR322 and GMAbound pBR322 were used to transform Eschenchia coli HB101, the following results were obtained: (1) The transformation efficiency of GMA-bound pBR322 was much lower than that of pBR322 alone. (2) GMA-bound pBR322 induced phenotype changes in competent cells (i.e., tetracycline-resistance inactivation or ampicillin-resistance inactivation). There were two mutants of pBR322, Ap~RTc~S and Ap~STc~R, in the transformants and a deductive mutant Ap~STc~S in the nontranstormants. (3) All of the selected mutants were stable and heritable. (4) When restriction enzyme maps were used to analyze the mutant Ap~RTc~S, four of seven maps were changed. some sites were shifted to other resistant gene regions, for example, sites of Bgll, EcoRl, Ilindlll. Hinclll, etc., and there was a new recognition site for Hindi (252). We did not observe any DNA fragment insertion or deletion on any maps. Our results suggest that when GMA is covalently linked to the plasmid DNA, it gives rise to a premutagenic lesion of DNA that is converted in vivo into a point mutation. (C)1990 Academic Press, Inc.

Comparison of the Mutagenicity of Exhaust Emissions From Motor Vehicles Using Leaded and Unleaded Gasoline as Fuel

While Unleaded gasoline has the advantage of eliminating lead from automobile exhaust, its potential to reduce the exhaust gas and particles, merits further examination. In the present studies,the concentrations of hydrocarbons (HC) and earbon monoxides (CO) in emissions were analyzed on Santana engine Dynamometer under a standard test cycle, and total exhaust particles were collected from engines using leaded and unleaded gasoline. It was found that unleaded gasoline reduced the emissions of CO and HC, and decreased the quantity of vehicle exhaust particulate matters by 60%.With the unlead gasoline, only 23 kinds of organic substances, adsorbed in the particles, were identified by gas chromatography/mass spectrometer (GC/MS) while 32 components were detected using the leaded gasoline. The results of in vitro Salmonella/ microsomal test and micronucleus induction assay in CHL cells indicated that both types of gasoline increased the number of histidine-independent colonies and the frequencies of micronucleus induction; no significant differellce was found in their mutagenicity.

INDUCTION OF MUTAGENIC EFFECT IN SOMATIC AND GERM CELLS BY ENRICHED URANIUM

Enriched uranium(UO2F2) accumulated in organism could cause chromosome aberrations in somatic cells, its rates on bone marrow cells were elevated when the dose of 235UO2F2 was increased. Among the types of induced aberrations, chromatid breakage was predominant, accompanied with a few chromosome breakage and translocation. At the same time mitosis index of metaphase cells was depressed. Chromatid delation and chromatid exchange were induced in peripheral blood lymphocytes. The important type of aberrations in spermatogonia was break. For primary spermatocytes the most significant aberration was multivalents which resulted either from chromatid interchanges or reciprocal translocations. 235UO2F2 could result in DNA breakage in germ cells. The sensitivity of germ cells at various stages to 235UO2F2. was different. At 12d after exposure the amount of sperm DNA eluted reached the peak. When the treating time was fixed, elution of sperm DNA from treated animals increased with the increasing doses. 235UO2F2. could also result in sperm abnormalities. Especially at 13 to 36 d after treatment the rates of sperm abnormalities were significantly elevated.

ADPRT-MEDIATED DECREASE OF CELLULAR NAD CONTENT AND THE DETECTION OF CHEMICALLY INDUCED DNA DAMAGE DEVELOPMENT OF A NEW SHORT-TERM SCREENING TEST FOR MUTAGENS

It was found that the DNA-damaging agents N-methyl-N’-nitro-N-nitrosoguanidine（MNNG）,methyl-methanesulphonate（MMS）and 4-nitroquinoline-N-oxide（4NQO）could stimulate ADP-ribosyl transferase（ADPRT）activity and reduce the cellular NAD content in a dose-dependent way.The reduction of NAD after DNA damage could be partially or completelyprevented by ADPRT inhibitors,3-aminobenzamide or nicotinamide,which showed noinfluence on reduction of NAD induced by metabolic blocking agents.Therefore,a simpleand specific method to detect DNA-damaging mutagens by measuring ADPRT-mediateddecrease of cellular NAD content was explored.Using β-naphthofiavone,a mixed functionoxygenase inducer,together with induced or uninduced human amnion FL cells,it was foundthat aflatoxin B1,benzo（a）pyrene,2-acetylaminofluorene,9,10-dimethylanthracene andethylcarbamate could induce the ADPRT-mediated decrease of cellular NAD content,while4-acetylaminofluorene,anthracene,isopropyl-N-（3-chlorophenyl）-carbamate,β-propiolactone,γ-butyrolactone,cyclophosphamide and safrol could not.The results indicate that this isa cheap and specific method to detect DNA damage caused by chemical carcinogens/mutagenswith a spccificity approaching that of the unscheduled DNA synthesis assay.

Identification and mechanism of formation of certain mutagenic components in the volatile condensates from oxidized and heated edible oils

Edible oils-rapeseed oil, soybean oil and peanut oil are heated in air at 270-280 ℃respectively. The volatile condensates are collected and analyzed by means of GC/MS. Eithercrotonaldehyde or 2-methylacrolein is found respectively in the condensates of rapeseed oil andsoybean oil. Neither crotonaldehyde nor 2-methylacrolein is found in the condensates of peanut oil.Mechanism of formation of crotonaldehyde is discussed.

Studies on Mutagenicity and Teratogenicity of Sarafloxacin

Wistar rats and closed Kunming strain mice were selected to study the genetic toxicity of sarafloxacin. The results indicated that sarafloxacin had no significant toxic effect of an excreted mutagen in S. typhimurium strains, and did not induce significantly higher percentages of polychromatic erythrocytes with micronuclei (MNPCE) in mice. No significant mutagenic activity was observed in dominant lethal assay. At 5 and 50mg/kg b.w. , sarafloxacin did not produce significant effects on the reproductive parameters of litters and fetal growth, and did not induce the teratogenic effects on fetuses. Sarafloxacin induced some toxic effects on body length and skeletal growth in fetuses of 500mg/kg b.w., but had no significant dose - response relationship among the administered dosages of sarafloxacin. The results of the genetic toxicology above indicated that no evidence showing sarafloxacin was mutagenic and potentially teratogenic for animals.

Studies on the Mutagenicity and Teratogenicity of Kuianchun and Its Potential Carcinogenicity Prediction

Kuianchun is a newly synthesized antibacterial and growth-promoting drug. This paper selected a battery of three short-term tests, including Ames test, micronucleus test and sperm abnormality test, to detect the mutagenicity of Kuianchun. The carcinogenicity prediction and battery selection method (CPBS method) was used to determine the probability of carcinogenicity of Kuianchun based upon the results of short-term tests mentioned above. In addition, traditional teratogenic test was selected to study teratogenicity of Kuianchun. In Ames test, Kuianchun showed mutagenic for Salmonella typhimurium strains TA98 and TA100 in the absence and presence of microsomal metabolic activation system (S9-mix). However, the mutagenicity was reduced by the addition of S9-mix. In micronucleus test, Kuianchun was administered intra-peritoneally to male mouse 30 hours and 6 hours before they were killed respectively. The result indicated that there was no significant difference on the number of micronucleated polychromatic erythrocytes (PCEs) in the mouse bone marrow induced by Kuianchun compared with the negative contrast (50% DMSO) (P>0.05). In sperm abnormality test, Kuianchun was administered through a gastric incubation to male mouse as a suspension in 2% Tween-80. The dosage levels were 450, 750, 1000 and 1500mg/kg per day for 5 days. The result indicated that the percentage of abnormal sperms induced by Kuianchun was not significant compared with the negative contrast (P > 0.05). In traditional teratogenic test, Kuianchun was given orally to pregnant mouse at 1730, 1/20 and 1/15 LD50 during 6 - 15days of pregnancy period (the LD50 = 9000mg/kg). No toxicity was found either on mother and embryo in mouse, and teratogenic effects were also not observed at all tested dosages.The probability of carcinogenicity of Kuianchun is 23.8%(6 = 0.238). The result demonstrated that Kuianchun is a non-carcinogen.

A PRELIMINARY STUDY ON THE ANTIMUTAGENIC EFFECT OF SELENO-MALT

Seleno- malt is an organic Selenium product recently developed in China . Seleno- malt itself is not genotixic. It antagonized the mutagenic effect of aflatoxin B1. The antagonistic activity was, 10- 15 times higher than Seleno-yeast may be used as a food additive in areas with low selenium level for the prevention of Ke- Shan disease and Cancer.

Mutagenic activity in Salmonella typhimurium mutants of the dust organic extract and its five fractions derived from an aluminum electrolytic plant

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TESTING THE MUTAGENICITY OF FIVE PESTICIDES WITH MICRONUCLEUS TECHNIQUE OF TRADESCANTIA PALUDOSA

Applying the micronucleus technique T.adescanlia paludosa, the mutagenicity of five pesticides, Decis, Sumicid, Cypermethrin, Trichlorphon and Diazinon were tested. The testing results showed that 0.64%, 0.32%, 0.16%, 0.08% of Decis, 0.64%, 0.32%, 0. 16%, 0.04% of Trichlorphon and 0.32%, 0.16%, 0.08%, 0.04% of Diazinon all had mutagenicity on Tradescantia paludosa, but Sumicid and Cypermethrin had no such characteristic.

Mutagenic Effects of BM302:GO112 Induced by Low-Energy Ion Beam Implantation

Mutant strains of GO112 and BM302 with a high 2-keto-L-gulonic acid （2KLG） transformation rate induced by ion beam implantation were separately and combinatorially compared with the original strains GO29 and BM80 to study the mutagenic effects of ion beam implantation. Both the sole GOl12 and mixed BM302：GOl12 demonstrated improved SNDH activity and 2KLG yield compared to the original strains. The mutant combinations of BM302：GOl12 showed a longer stationary phase and higher biomass than BM80：GO29. The mutant BM302 exhibited a stronger capacity to maintain a stable pH environment at mixed fermentation with Gluconobacter oxydans （G. oxydans） for 2KLG transformation and facilitated the growth of G. oxydans compared with the original strain BM80. The promotive capacity to L-sorbosone dehydrogenase （L-SNDH） from the supernate of BM302 was 1.6-fold higher than that of BM80. Genes encoded SNDH in GO29 and GOl12 were amplified and sequenced, and mutations including three transitions （CG →TA, CG →TA, GC → AT） and one transversion （AT→ TA） were confirmed from GO29 to GOl12. The corresponding amino acid was changed as Leu →Phe, Arg → Gln and Asn → Lys.

Two chemical mutagens modulate the seed germination,growth,and phenotypic characteristics of Chinese fir(Cunninghamia lanceolata)

Chinese fir(Cunninghamia lanceolata(Lamb.)Hook),a fast-growing and economically important timber tree species in China,is widely used in construction,furniture,and paper manufacture but has a long breeding cycle.Chemical mutagens,such as ethyl methane sulfonate(EMS)and sodium azide(SA),are widely used in crops such as rice,wheat,cotton,soybean and sugarcane but their utility for tree breeding is unknown.In this study we examined the effects of EMS and S A on Chinese fir seed germination and growth.Chinese fir seeds were treated with the two chemical mutagens;were planted in Jiangle County,Fujian Province,China;and their heights were measured from 2011 to2017.The concentrations and durations of treatment with the two chemical mutagens were significantly associated with the Chinese fir seedling and mortality rates,as well as with the heights of trees from the seedling stage to 3 years old.We also generated 127 mutants with abnormal branches and reproductive growth.We report here the effects of two chemical mutagens on Chinese fir breeding;our data will contribute to knowledge of the utility of EMS and SA in forestry.

Mutagenicity Study on Ibopamine: A New Heart Failure Antagonist

Ibopamine(Ibo) is a new effective drug against heart failure. This paper reports the results of mutation tests of chromosome aberration of mammalian cell (Chinese hamster lung cell, CHL) in vitro and reversional mutation test of Salmonella typhimurium bacterium (Ames test) of ibopamine . The results of both tests were negative. Ibo did not have mutagenic effect.