A New Process for Drug Loaded Nanocapsules Preparation Using a Membrane Contactor

In this paper, we describe a new process for the preparation of drug loaded nanocapsules using a membrane contactor which may be scaled up for industrial applications. Nanocapsules are prepared according to the nanoprecipitation method. The organic phase (solvent, polymer, oil, and drug) is pressed through the pores of an ultrafiltration membrane via the filtrate side. The aqueous phase (water and surfactant) circulates inside the membrane module, and sweeps away the nanocaspules forming at the pore outlets. Two model drugs are selected for the preparation of drug loaded nanocapsules: indomethacin and vitamin E. It is shown that indomethacin loaded nanocapsules with a mean diameter of 240 nm and vitamin E loaded nanocapsules with a mean diameter of 230 nm are obtained with a 150,000 daltons ultrafiltration membrane, a transmembrane pressure of 3 bar, and a crossflow rate of 1.7 m.s(- 1). High fluxes are also obtained (around 0.6 m3/h.m2), leading to the preparation of 1.8 10(- 3) m3 drug loaded nanocapsules in 8 min. The advantage of this membrane contactor compared to other processes for drug loaded nanocapsules preparation is shown to be its scale-up ability.

Protective effects of vitamin glycosides on gamma-radiation and H2O2-induced decomposition of thymine in aqueous solutions

Effects of ascorbic acid (AA), ascorbic acid glycoside (AAG) and alpha-tocopherol monoglycoside (TMG) on radiation - and H(2)O(2)-induced decomposition of thymine in aqueous solutions were investigated. Of the three compounds studied, AAG was found to possess the most marked protector properties. An explanation of this phenomenon has been given in terms of differences in molecular structures of AA and AAG, as well as properties of radical adducts formed during their interaction with OH radicals.

Nutritional composition of frog (Rana esculanta) waste meal

In the present study, the waste obtained from the frozen frog leg industry was used for the production of frog waste meal, and its proximate, amino acids, fatty acids, mineral and vitamin compositions were evaluated to determine the nutritional quality. In addition, the total bacterial count, Salmonella, total volatile basic nitrogen (TVB-N, mgN/100g) and thiobarbituric acid (TBA, mg malonaldehyde/kg) were also measured to determine the microbiological and chemical quality of frog waste meal (FWM). The crude protein, fat and ash content of FWM on a dry weight basis were 68.6%, 17.0% and 13.2%, respectively. The amino acid profiles were found to be fairly close to those of fish meal in terms of protein sources and rich in the glutamic acid, glycine, proline, arginine, and methionine. The proportions of fatty acid composition in FWM were analysed and findings were 26.7% for total saturated fatty acid (SFA), 42.5% for total monounsaturated fatty acid (MUFA), 17.0% for total n - 6 and 3.3% for n - 3 ratio. The major SFA, MUFA and PUFA in FWM were palmitic acid (19.1%), oleic acid (26.0%) and linoleic acid (16.7%), respectively. FWM was found to be high in mineral content, especially Zn, K, Cu, Mn, and Mg and high level of some vitamins such as folic acids and thiamin. The total bacterial count was found to be 2.9x10(4) CFU/g, and Salmonella was not observed. TVB-N and TBA in FWM was determined to be 157.4+/-5.8 mg N/100g and 1.2+/-0.1 mg malonaldehyde/kg, respectively.

Physico-mechanical analysis of free ethyl cellulose films comprised with novel plasticizers of vitamin resources

This research was conducted to investigate the physico-mechanical characteristics of the EC-based coating membranes plasticized with two informal ingredients of vitamin resources, cholecalciferol and alpha-tocopherol, with respect to the commercial plasticizer DBS. Proceeding the experiment, free thin polymer sheetings of the sample formulations, incorporating incremental weight percents of the individual plasticizers were prepared employing a revised casting method of delayed solvent evaporation whereby similar flat specimens of standard dimensions were subjected to tensile loadings and extensions. The data were analyzed through the known equations of membrane theory in spherical subjects considering the complete symmetry of assumingly spherical pellets and/or granules. The relative tensile parameters of the experimental and commercial plasticizers in the resilient region were also estimated to fairly decide on a moderate explanation of a strong, hard, and tough structure among the specimens. The results implied the great compatibility of the oily soluble vitamins in EC networks projecting higher factors of safety and greater ultimate strength, toughness, and young coefficient of the formulations compared to the specimens plasticized with the commercial DBS within a concentration range of 40-50% (w/w) of the polymer solids. alpha-Tocopherol represented supremacy over colecalciferol to result in relatively a 2-fold (and practically a 4-fold with respect to DBS) greater increase in the modulus of resilience. The vitamin compounds and in essential alpha-tocopherol, in consequence, can properly be applied at concentrations of 40-50% (w/w) as efficient plasticizers to provide a greater protection of the structure against sudden fractures of dynamic and continuously increasing environmental and biological stresses.

Formulation and thermal sterile stability of a less painful intravenous clarithromycin emulsion containing vitamin E

The purpose of this study is to develop a less painful intravenous clarithromycin emulsion (ClaE) and investigate its thermal sterile stability. The formulation of ClaE is composed of clarithromycin 0.25% (w/v), vitamin E 5% (w/v), medium chain triglyceride (MCT) 10% (w/v), egg lecithin 1.0% (w/v), Cremophor EL-40 (EL-40) 2% (w/v), Pluronic F-68 (F-68) 0.2% (w/v), Tween80 0.2% (w/v), glycerol 2.5% (w/v) and L-cysteine 0.05% (w/v) in water. High-pressure homogenization, photon correlation spectroscopy (PCS) and electrophoretic light scattering (ELS) technology, light microscopy and high-performance liquid chromatography (HPLC) methods were used in the preparation and evaluation of ClaE. Investigation of thermal sterile stability included the effects of different thermal sterile methods, thermal sterile time, drug concentrations and pH values. Sterilization in a 100 degrees C rotating water bath for 30 min was finally adopted as the sterilization method. The drug remaining was 98.6% and 96.5%, respectively, before and after thermal sterilization. Moreover, the pH value, particle size distribution (PSD), zeta-potential and entrapment efficiency (EE) of ClaE after sterilization were 7.95, 213.6 nm, -22.29 mV and 96.35%, respectively. This showed that ClaE had sufficient physicochemical stability to resist the sterilization process. Tests using animal models demonstrated that there was a marked pain reduction following the injection of ClaE compared with clarithromycin solution. Overall, ClaE described in this paper may be very suitable for industrial-scale production and clinical application.

Differentiation of 2-alkylthioorotic acids, methyl and ethyl 2-alkylthioorotates and hydrazides of 2-alkylthioorotic acids by using electron ionization mass spectra

Electron ionization mass spectra of 12 derivatives of 2-thioorotic acid have been discussed and general fragmentation routes of their molecular ions have been proposed. The compounds under discussion were three groups of four chemical species (2-alkylthioorotic acid, methyl 2-alkylthioorotate, ethyl 2-alkylthioorotate and 2- alkylthioorotic hydrazide) each with the same relative molecular mass. The comparison of selected ions relative abundances and their correlation with the abundance of molecular ions enable differentiation between isomeric or isobaric species in this class of compounds.

Cupric ion reducing antioxidant capacity assay for food antioxidants: vitamins, polyphenolics, and flavonoids in food extracts

Antioxidants are health beneficial compounds through their combat with reactive oxygen and nitrogen species and free radicals that may cause tissue damage leading to various diseases. This work reports the development of a simple and widely applicable antioxidant capacity index for dietary polyphenols, vitamins C and E, and plasma antioxidants utilizing the copper(II)-neocuproine (Cu(II)-Nc) reagent as the chromogenic oxidizing agent. This novel method based on an electron-transfer mechanism was named by our research group as 'cupric reducing antioxidant capacity', abbreviated as the CUPRAC method. The method is comprised of mixing the antioxidant solution with aqueous copper(II) chloride, alcoholic neocuproine, and ammonium acetate aqueous buffer at pH 7, and subsequently measuring the developed absorbance at 450 nm after 30 min. Since the color development is fast for compounds like ascorbic acid, gallic acid, and quercetin but slow for naringin and naringenin, the latter compounds are assayed after incubation at 50 degrees C on a water bath for 20 min. The flavonoid glycosides are hydrolyzed to their corresponding aglycones by refluxing in 1.2 M: HCl-containing 50% MeOH so as to exert maximal reducing power towards Cu(II)-Nc. The CUPRAC antioxidant capacities of synthetic mixtures are equal to the sum of individual capacities of antioxidant constituents, indicating lack of chemical deviations from Beer's law. Tests on antioxidant polyphenols demonstrate that the highest CUPRAC capacities are observed for epicatechin gallate, epigallocatechin gallate, quercetin, fisetin, epigallocatechin, catechin, and caffeic acid in this order, in accord with the number and position of the -OH groups as well the conjugation level of the molecule. The parallelism of the linear calibration curves of pure antioxidants in water and in a given complex matrix (plant extract) demonstrates that there are no chemical interactions of interferent nature among the solution constituents, and that the antioxidant capacities of the tested antioxidants are additive, in conformity to the Beer's law. For individual determination of ascorbic acid in fruit juices with a modified CUPRAC procedure, flavonoids are pre-extracted as their La(III) complexes prior to assay. For apricot extracts, a modified version of the CUPRAC assay based on anion exchange separation at pH 3 is applied, since sulfited-dried sample extracts contain the hydrosulfite anion interfering with the determination. For herbal tea infusions, the standard CUPRAC protocol is applied. The CUPRAC reagent is stable, easily accessible, low-cost, and is sensitive toward thiol-type antioxidants unlike FRAP. The reaction is carried out at nearly physiological pH as opposed to the acidic pH of FRAP or to the alkaline pH of Folin methods, constituting a basic advantage for the realistic assay of biological fluids.

Advances in functional research of antioxidants and organoleptic traits in berry crops

Berry species are economically-important crops worldwide and represent an invaluable source of vitamins and other health-related compounds. Species belonging to the families Rosaceae, Ericaceae and Grossulariaceae provide the most popular fruits, showing a strong diversity in natural and breeding populations as to berry traits (fruit type, size, color, flavor, antioxidant capacity), resistance to a/biotic stress, adaptation to different environment/culture conditions. The small genome size of most diploid berry genera is a remarkable feature for last-generation genomics technologies, molecular genetics and functional studies. This review will cover the literature dealing with molecular research in berry crops, focusing on antioxidant- and flavor-related compounds.

[Study of the arsenate reducted by common reducing agents]

OBJECTIVE

To study the role of glutathione (GSH), cysteine (Cys), vitamin C (VC) and ferrous ion (Fe2+) in the reduction of arsenate [As (V)] and the characteristic of reduction.

METHODS

The reaction conditions [(37 degrees C, pH7.0 phosphate buffer) and the concentrations of As (V) (3 micromol/L), GSH (60 mmol/L), Cys (60 mmol/L), VC (0-30 mmol/L) and Fe2+ (0-40 mmol/L)] were simulated in vitro. Arsenite[As(III)] and [As(V)] were determined by the high performance liquid chromatography-hydride generation-atomic fluorescence spectrometry (HPLC-HG-AFS).

RESULTS

The reduction, of As(V) and As(III) formation, increased with the concentration, of GSH (0-60 mmol/L), and reached a maximum values at the concentration of 60 mmol/L GSH, then decreased with the concentration of (60-80 mmol/L) GSH. -SH in sulfhydryl compound, could play an important role in the reduction of As(V), and at the concentration of 60 mmol/L -SH (both GSH and Cys) could reduce 60%, of As(V) to As(III) for 30 min. VC or Fe2+ could not reduce As(V) alone, but when the concentration of VC or Fe2+ reached to 10 mmol/L or 20 mmol/L, they could have a significantly synergistic effect with 60 mmol/L -SH on the reduction of As(V) (P < 0.01).

CONCLUSION

SH could reduce As(V) alone without any reductase. VC and Fe2+ could have a synergistic effect with -SH on the reduction of As(V).

The stability of choline ascorbate

The stability of choline ascorbate was studied considering concentration, temperature, and pH of the drug solution. Our results revealed that choline ascorbate is almost fully stable with respect to these parameters. Practically no loss was observed when 3 x l0(-1) (50%) drug solution is preserved in the refrigerator, at ambient temperature, or at 37 degrees C for one year, a finding that favors the high stability of this compound. Choline ascorbate was also found to be more stable in comparison to vitamin C and crystalline ascorbic acid. Its dilution within a vitamin B solution did not modify the amount of ascorbic acid within 120 min at ambient temperature. We conclude that the choline ascorbate form of ascorbic acid appears to be more reliable and promising when the quality of therapy with this agent is concerned.

[Natural or synthetic vitamin C? A new substance's precarious status behind the scenes of World War II]

Today, thousands of tons of vitamin C (l-ascorbic acid) is synthesized every year by the pharmaceutical industry. Synthetically produced vitamin C is widely accepted as having the same physiological effects as vitamin C isolated from natural sources. This is an important difference compared to the 1930s when vitamin C was synthesized for the first time. The identity of synthetic vitamin C with natural vitamin C had to be established. First of all, the scientific community had to accept that artificial I-ascorbic acid and natural vitamin C were chemically identical and had the same physiological effects. Second, other communities like food manufacturers, military health officials, and the broader public also had to be persuaded that these substances were equal. This article demonstrates how Hoffmann-La Roche, a Swiss pharmaceutical company and world-leading producer of synthetic vitamins in the 20th century, tried to coax its adversaries into supporting artificial vitamin C. In doing so, synthetic vitamin C was naturalized in different ways. In the case of Switzerland during the Second World War era, the mentality of national defense and the quest for products supporting autarchy helped to convince perspective consumers. Thus in order to sell a new chemical substance, cultural meaning had to be attached to it.

Transgenic strategies for the nutritional enhancement of plants

The nutrients in the human diet ultimately come from plants. However, all our major food crops lack certain essential vitamins and minerals. Although a varied diet provides adequate nutrition, much of the human population, particularly in developing countries, relies on staple crops, such as rice or maize, which does not provide the full complement of essential nutrients. Malnutrition is a significant public health issue in most of the developing world. One way to address this problem is through the enhancement of staple crops to increase their essential nutrient content. Here, we review the current strategies for the biofortification of crops, including mineral fertilization and conventional breeding but focusing on transgenic approaches which offer the most rapid way to develop high-nutrient commercial cultivars.

Compounding of vitamin A, D3, E and K3 supplements for cystic fibrosis patients: formulation and stability study

BACKGROUND AND OBJECTIVE

Cystic fibrosis (CF) patients suffer from malabsorption of fat-soluble vitamins (A, D, E and K). These vitamins are available as water-dispersible (A, D(3) and E) or water-soluble grades (K(3)), which is favoured in CF patients as they fail to absorb oil-based products. The objective of this study was to determine stability of these raw materials after opening the original package and to develop a compounded formulation of acceptable quality, stability and taste, allowing flexible dose adaptation and being appropriate for administration to children and elderly people.

METHODS

The raw materials were stored after opening their original package for 8 months at 8 degrees C and room temperature (RT). Stability was assessed using a validated HPLC method after extraction of the vitamin from the cold water-soluble matrix (vitamin A acetate, D(3) and E) or using a spectrophotometrical method (vitamin K(3)). These materials were mixed with an appropriate lactose grade (lactose 80 m for vitamins A and D(3); lactose 90 m for vitamin E, lactose very fine powder for vitamin K(3)) and filled in hard gelatin capsules. Mass and content uniformity were determined and stability of the vitamins in the capsules was assessed after 2 months storage at 8 degrees C and RT.

RESULTS

All raw materials showed good stability during storage in the opened original package for 8 months storage at 8 degrees C as well as RT (>95% of the initial content). The compounded formulations complied with the requirements of the European Pharmacopoeia for mass and content uniformity and can be stored for 2 months at 8 degrees C or RT while maintaining the vitamin content between 90% and 110%.

CONCLUSIONS

As these fat-soluble vitamins are not commercially available on the Belgian market, compounded formulations are a valuable alternative for prophylactic administration of these vitamins to CF patients, i.e. a stable formulation, having an acceptable taste, allowing flexible dose adaptation and being appropriate for administration to children and elderly people.

Vitamin-loaded electrospun cellulose acetate nanofiber mats as transdermal and dermal therapeutic agents of vitamin A acid and vitamin E

The present contribution reports the use of mats of electrospun cellulose acetate (CA; acetyl content=39.8%; Mw=30,000 Da) nanofibers as carriers for delivery of the model vitamins, all-trans retinoic acid or vitamin A acid (Retin-A) and alpha-tocopherol or vitamin E (Vit-E). The amounts of Vit-E and Retin-A loaded in the base CA solution [17% w/v in 2:1 v/v acetone/N,N-dimethylacetamide (DMAc)] were 5 and 0.5 wt% (based on the weight of CA), respectively. Cross-sectionally round and smooth fibers were obtained. The average diameters of these fibers ranged between 247 and 265 nm. The total immersion of the vitamin-loaded as-spun CA fiber mats in the acetate buffer solutions containing either 0.5 vol % Tween 80 or 0.5 vol % Tween 80 and 10 vol % methanol was used to arrive at the cumulative release of the vitamins from the fiber mat samples. The same was also conducted on the vitamin-loaded solution-cast CA films for comparison. In most cases, the vitamin-loaded as-spun fiber mats exhibited a gradual and monotonous increase in the cumulative release of the vitamins over the test periods (i.e., 24 h for Vit-E-loaded samples and 6 h for Retin-A-loaded ones), while the corresponding as-cast films exhibited a burst release of the vitamins.

Selectivity of folate conjugated polymer micelles against different tumor cells

Folate or folic acid has been employed as a targeting moiety of various anticancer agents to increase their cellular uptake within target cells since folate receptors are vastly overexpressed in several human tumors. In this study, a biodegradable polymer poly(d,l-lactide-co-glycolide)-poly(ethylene glycol)-folate (PLGA-PEG-FOL) was used to form micelles for encapsulating anticancer drug doxorubicin (DOX). The drug loading content, encapsulation efficiency and in vitro release were characterized. To evaluate the targeting ability of the folate conjugated micelles, the cytotoxicity and cellular uptake of DOX-loaded micelles on three cancer cell lines with different amount of folate receptors (KB, MATB III, C6) and normal fibroblast cells (CCL-110) were compared. The cytotoxicity of PLGA-PEG-FOL micelles to cancer cells was found to be much higher than that of normal fibroblast cells, demonstrating that the folate conjugated micelles has the ability to selectively target to cancer cells. For normal cells, the cellular uptake of PLGA-PEG-FOL micelles was similar to PLGA-PEG micelles without folate conjugation, and was substantially lower than that of cancer cells. In addition, the cell cycle analysis showed that the apoptotic percentage of normal fibroblasts was substantially lower compared with the cancer cells after exposing to DOX-loaded PLGA-PEG-FOL micelles. An optimal folate amount of approximately 40-65% on the micelles was found to be able to kill cancer cells but, at the same time, to have very low effect to normal cells.

Contents of selected B vitamins in NIST SRM 3280 multivitamin/multielement tablets by liquid chromatography isotope dilution mass spectrometry

There is increased interest in accurately assessing the total dietary intake of vitamins from all sources, including foods and dietary supplements. Consequently, a Dietary Supplement Ingredient Database (DSID), based upon analytical values, is being established by USDA with support of the Office of Dietary Supplements (ODS), NIH. The DSID necessitated the development of a new SRM, 3280--Multivitamin/Multimineral Tablets, by the National Institute of Standards and Technology (NIST), with support from the ODS. As a continuation of a long-term project to develop and validate new methods of determining water-soluble B vitamins in foods and dietary supplements, and as part of a collaborative effort with NIST to characterize SRM 3280, values for the vitamin contents of SRM 3280 have been generated by a liquid chromatographic isotope dilution mass spectrometric (LC/IDMS) method. Isotope-labeled ((13)C and/or (2)H) B vitamins (B1-thiamine, B6-pyridoxine, B3-nicotinamide, and B5-pantothenic acid) were obtained from commercial sources, with the support of the ODS/NIH. Our LC/IDMS method uses a C18 reversed phase column, an Agilent 1100 HPLC system, and a Quattro Micro triple-quad mass spectrometer (MS). B vitamin determination was achieved using a gradient LC profile combined with MS/MS detection in multiple reaction monitoring mode. Stock solutions of the isotope-labeled vitamins were calibrated against USP standard solutions. The SRM tablets, with added amounts of the four isotope-labeled B vitamins, were extracted and the vitamins simultaneously determined in a single LC run, in contrast with the single-component determinations performed via IDMS. Unknown vitamin concentrations were calculated by comparing the ratios of the integrated LC peaks at the different masses of the unlabeled and labeled vitamins.

Status of methodology for the determination of fat-soluble vitamins in foods, dietary supplements, and vitamin premixes

Fat-soluble vitamins (FSVs) include vitamin A, carotenoids, vitamins D, E, and K. New legislation is being introduced in many countries to reinforce regulatory compliance of declared concentrations of vitamins and other micronutrients in food products and dietary supplements. The levels of FSVs are likely to be more closely scrutinized due to their potential health risks associated with overdosing, in particular of vitamin D. However, a proviso of stricter regulatory compliance is that analytical methods must be fit-for-purpose, providing adequate accuracy and precision. Official methods have been published by organizations such as AOAC INTERNATIONAL, European Committee for Standardization, International Dairy Federation, U.S. Pharmacopeia, and International Organization for Standardization. The methods available for foods, dietary supplements, and vitamin premixes are evaluated in this review. In general, these methods show adequate precision for regulatory compliance; however, the field of application has not often been evaluated for a sufficiently large range of food matrixes. Gaps have been noted in the range of published official procedures, particularly for carotenoids and vitamin premixes. The potential of some recent developments in sample preparation and chromatographic techniques were evaluated to provide improved procedures for FSV analysis the future.

QSPR modeling of octanol/water partition coefficient for vitamins by optimal descriptors calculated with SMILES

Simplified molecular input line entry system (SMILES) has been utilized in constructing quantitative structure-property relationships (QSPR) for octanol/water partition coefficient of vitamins and organic compounds of different classes by optimal descriptors. Statistical characteristics of the best model (vitamins) are the following: n=17, R(2)=0.9841, s=0.634, F=931 (training set); n=7, R(2)=0.9928, s=0.773, F=690 (test set). Using this approach for modeling octanol/water partition coefficient for a set of organic compounds gives a model that is statistically characterized by n=69, R(2)=0.9872, s=0.156, F=5184 (training set) and n=70, R(2)=0.9841, s=0.179, F=4195 (test set).

Methyl substitution of the 25-hydroxy group on 2-methylene-19-nor-1α,25-dihydroxyvitamin D3 (2MD) reduces potency but allows bone selectivity

The discovery of 2-methylene-19-nor-1alpha,25-dihydroxyvitamin D3 (2MD) as a bone selective and bone anabolic form of vitamin D has stimulated an investigation of structure/function of bone selectivity. Four new 2-substituted-19-norvitamin D analogs 3-6 have been developed to study the structure-activity relationship at C-25. As predicted, removing the 25-hydroxy group (compound 3) from the very potent analog 2MD and its 2-methyl derivatives (5 and 6) dramatically reduces in vitro activities, but biological potency is nearly fully restored in vivo likely due to in vivo 25-hydroxylation. The introduction of a methyl group at C-25 (compound 4) that blocks in vivo 25-hydroxylation reduces biological activity both in vitro and in vivo. However, analog 4 retains bone selectivity making it interesting as a possible therapeutic for bone loss diseases.

Hydroxypropyl-beta-cyclodextrin enhanced determination for the Vitamin B12 by fluorescence quenching method

A novel fluorescence quenching method for the determination of Vitamin B12(VB12) had been developed. It was based on that the fluorescence intensity of erythrosine sodium(ES) could be enhanced by Hydroxypropyl-beta-cyclodextrin(HP-beta-CD) due to the formation of inclusion complex (HP-beta-CD-ES), while the fluorescence intensity of HP-beta-CD-ES was diminished after adding VB12 into the system, and there was a linear relationship between the fluorescence quenching value of the system (DeltaF) and the concentration of VB12 (c). The mechanism of the determination of VB12 was discussed. The results showed that under the optimal conditions, the linear range of calibration curve for the determination of VB12 was 0.0 approximately 2.1 x 10(-5) mol/L, and the detection limit was 1.8 x 10(-7) mol/ L. It could be satisfactorily applied to the determination of VB12 in injections.

Biodegradation of methylthio-s-triazines by Rhodococcus sp. strain FJ1117YT, and production of the corresponding methylsulfinyl, methylsulfonyl and hydroxy analogues

A novel bacterial strain FJ1117YT was isolated from an enrichment culture with the herbicide simetryn. The isolate was capable of degrading the herbicide supplied as the sole sulfur source in an aquatic batch culture. The strain FJ1117YT was identified as that belonging to Rhodococcus sp. on the basis of comparative morphology, physiological characteristics and comparison of the 16S rRNA gene sequence. The biodegradation pathway of simetryn was established by isolating the methylsulfinyl analogue as the first metabolite and by identification of the methylsulfonyl intermediate and the hydroxy analogue by liquid chromatography-mass spectrometry (LC-MS) and/or nuclear magnetic resonance (NMR) analysis. The results indicate that the methylthio group was progressively oxidised and hydrolysed by the strain FJ1117YT. The same strain is also able to metabolise other methylthio-s-triazines such as ametryn, desmetryn, dimethametryn and prometryn through similar pathways.