Dietary Supplements for Male Infertility: A Critical Evaluation of Their Composition.

Dietary supplements (DS) represent a possible approach to improve sperm parameters and male fertility. A wide range of DS containing different nutrients is now available. Although many authors demonstrated benefits from some nutrients in the improvement of sperm parameters, their real effectiveness is still under debate. The aim of this study was to critically review the composition of DS using the Italian market as a sample. Active ingredients and their minimal effective daily dose (mED) on sperm parameters were identified through a literature search. Thereafter, we created a formula to classify the expected efficacy of each DS. Considering active ingredients, their concentration and the recommended daily dose, DS were scored into three classes of expected efficacy: higher, lower and none. Twenty-one DS were identified. Most of them had a large number of ingredients, frequently at doses below mED or with undemonstrated efficacy. Zinc was the most common ingredient of DS (70% of products), followed by selenium, arginine, coenzyme Q and folic acid. By applying our scoring system, 9.5% of DS fell in a higher class, 71.4% in a lower class and 19.1% in the class with no expected efficacy. DS marketed in Italy for male infertility frequently includes effective ingredients but also a large number of substances at insufficient doses or with no reported efficacy. Manufacturers and physicians should better consider the scientific evidence on effective ingredients and their doses before formulating and prescribing these products.

Aerosticca soli gen. nov., sp. nov., an aerobic gammaproteobacterium isolated from crude oil-contaminated soil.

An aerobic bacterium, designated strain Dysh456T, was isolated from a crude oil-contaminated soil. Cells of strain Dysh456T were rod-shaped, motile, and Gram-stain-negative. Strain Dysh456T grew at 13-48 °C and pH 4.3-7.9. Major cellular fatty acids were iso-C15:0 (42.5%), iso-C17:0 (15.3%) and summed feature 9 (iso-C17:1 ω9c/C16:0 10-methyl [13.7%]). Major respiratory quinone was ubiquinone-8. The genome of strain Dysh456T consists of a single circular chromosome of 2,874,969 bp in length with G + C content of 68.3%. Phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain Dysh456T belongs to the family Rhodanobacteraceae, but none of the existing genera can accommodate this novel isolate. On the basis of physiological, chemotaxonomic, and genomic properties, strain Dysh456T (= NBRC 112897T = DSM 105662T) is proposed as the type strain representing a novel species of novel genus, for which the name Aerosticca soli gen. nov., sp. nov. is proposed.

ß-RA reduces DMQ/CoQ ratio and rescues the encephalopathic phenotype in Coq9R239X mice.

Coenzyme Q (CoQ) deficiency has been associated with primary defects in the CoQ biosynthetic pathway or to secondary events. In some cases, the exogenous CoQ supplementation has limited efficacy. In the Coq9R239X mouse model with fatal mitochondrial encephalopathy due to CoQ deficiency, we have tested the therapeutic potential of ß-resorcylic acid (ß-RA), a structural analog of the CoQ precursor 4-hydroxybenzoic acid and the anti-inflammatory salicylic acid. ß-RA noticeably rescued the phenotypic, morphological, and histopathological signs of the encephalopathy, leading to a significant increase in the survival. Those effects were due to the decrease of the levels of demethoxyubiquinone-9 (DMQ9) and the increase of mitochondrial bioenergetics in peripheral tissues. However, neither CoQ biosynthesis nor mitochondrial function changed in the brain after the therapy, suggesting that some endocrine interactions may induce the reduction of the astrogliosis, spongiosis, and the secondary down-regulation of astrocytes-related neuroinflammatory genes. Because the therapeutic outcomes of ß-RA administration were superior to those after CoQ10 supplementation, its use in the clinic should be considered in CoQ deficiencies.

Paraburkholderia panacihumi sp. nov., an isolate from ginseng-cultivated soil, is antagonistic against root rot fungal pathogen.

The novel species DCY115T was isolated from ginseng-cultivated soil in Gochang province, Republic of Korea. The isolated strain was assigned to the genus Paraburkholderia due to its 16S rRNA gene sequence proximity to Paraburkholderia xenovorans LB400T (98.8%), Paraburkholderia terricola LMG 20594T (98.4%), Paraburkholderia graminis C4D1MT (98.2%), Paraburkholderia rhynchosiae WSM3937T (98.1%), and Paraburkholderia phytofirmans PsJNT (98.1%). Strain DCY115T is gram-negative, facultative aerobic, rod-shaped, non-motile, non-flagellated, and oxidase and catalase positive. The predominant isoprenoid quinone of DCY115T is ubiquinone Q-8. The major cellular fatty acids are C16:0, cyclo-C17:0, cyclo-C19:0 ω8c, summed feature 3 (C16:1 ω7c and/or C16:1 ω6c) and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c). The major polar lipids include diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), and an unknown amino lipid (AL1). The genomic DNA G + C content is 61.3 mol%. Phenotypic tests and chemotaxonomic analysis place strain DCY115T in the genus Paraburkholderia. DNA-DNA hybridization values between strain DCY115T and closely related reference strains were lower than 51%. The low DNA relatedness data in combination with phylogenetic and biochemical tests showed that strain DCY115T could not be assigned to any recognized species. Finally, strain DCY115T showed antagonistic activity against Fusarium solani (KACC 44891T) and Cylindrocarpon destructans (KACC 44660T), which are two root rot fungal pathogens of ginseng. In conclusion, the results in this study support strain DCY115T as a novel species within the genus Paraburkholderia for which the name Paraburkholderia panacihumi is proposed. The type strain is DCY115T (= KCTC 52952T = JCM 32099T).

Low-cost and disposable sensors for the simultaneous determination of coenzyme Q10 and α-lipoic acid using manganese (IV) oxide-modified screen-printed graphene electrodes.

In this work, for the first time, manganese (IV) oxide-modified screen-printed graphene electrodes (MnO2/SPGEs) were developed for the simultaneous electrochemical detection of coenzyme Q10 (CoQ10) and α-lipoic acid (ALA). This sensor exhibits attractive benefits such as simplicity, low production costs, and disposability. Cyclic voltammetry (CV) was used to characterize the electrochemical behavior of the analyte and investigate the capacitance and electroactive surface area of the unmodified and modified electrode surfaces. The electrochemical behavior of CoQ10 and ALA on MnO2/SPGEs was also discussed. Additionally, square wave anodic stripping voltammetry (SWASV) was used for the quantitative determination of CoQ10 and ALA. Under optimal conditions, the obtained signals are linear in the concentration range from 2.0 to 75.0 µg mL-1 for CoQ10 and 0.3-25.0 µg mL-1 for ALA. The low limits of detection (LODs) were found to be 0.56 µg mL-1 and 0.088 µg mL-1 for CoQ10 and ALA, respectively. Moreover, we demonstrated the utility and applicability of the MnO2/SPGE sensor through simultaneous measurements of CoQ10 and ALA in dietary supplements. The sensor provides high accuracy measurements, exhibiting its high potential for practical applications.

Novel HPLC-UV Method for Simultaneous Determination of Fat-soluble Vitamins and Coenzyme Q10 in Medicines and Supplements.

A precise, accurate and rapid HPLC-UV method for simultaneous determination of fat-soluble vitamins (vitamin D3, E-acetate, K1, ß-carotene, A-palmitate) and coenzyme Q10 was developed and validated according to ICH guidelines. Optimal chromatographic separation of the analytes in minimal analysis time (8 min) was achieved on a Luna C18 150 × 4.6 mm column using a mixture of acetonitrile, tetrahydrofuran and water (50:45:5, v/v/v). The described reversed phase HPLC method is the first published for quantification of these five fat-soluble vitamins and coenzyme Q10 within a single chromatographic run. The method was further applied for quantification of the analytes in selected liquid and solid dosage forms, registered as nutritional supplements and prescription medicines, which confirmed its suitability for routine analysis.

Analysis of Closely Related Antioxidant Nutraceuticals Using the Green Analytical Methodology of ANN and Smart Spectrophotometric Methods.

Two new, simple, and specific green analytical methods are proposed: zero-crossing first-derivative and chemometric-based spectrophotometric artificial neural network (ANN). The proposed methods were used for the simultaneous estimation of two closely related antioxidant nutraceuticals, coenzyme Q10 (Q10) and vitamin E, in their mixtures and pharmaceutical preparations. The first method is based on the handling of spectrophotometric data with the first-derivative technique, in which both nutraceuticals were determined in ethanol, each at the zero crossing of the other. The amplitudes of the first-derivative spectra for Q10 and vitamin E were recorded at 285 and 235 nm respectively, and correlated with their concentrations. The linearity ranges of Q10 and vitamin E were 10-60 and 5.6-70 µg⋅mL-1, respectively. The second method, ANN, is a multivariate calibration method and it was developed and applied for the simultaneous determination of both analytes. A training set of 90 different synthetic mixtures containing Q10 and vitamin E in the ranges of 0-100 and 0-556 µg⋅mL-1, respectively, was prepared in ethanol. The absorption spectra of the training set were recorded in the spectral region of 230-300 nm. By relating the concentration sets (x-block) with their corresponding absorption data (y-block), gradient-descent back-propagation ANN calibration could be computed. To validate the proposed network, a set of 45 synthetic mixtures of the two drugs was used. Both proposed methods were successfully applied for the assay of Q10 and vitamin E in their laboratory-prepared mixtures and in their pharmaceutical tablets with excellent recovery. These methods offer advantages over other methods because of low-cost equipment, time-saving measures, and environmentally friendly materials. In addition, no chemical separation prior to analysis was needed. The ANN method was superior to the derivative technique because ANN can determine both drugs under nonlinear experimental conditions. Consequently, ANN would be the method of choice in the routine analysis of Q10 and vitamin E tablets. No interference from common pharmaceutical additives was observed. Student's t-test and the F-test were used to compare the two methods. No significant difference was recorded.

Health-promoting effects of red palm oil: evidence from animal and human studies.

The fruit of the oil palm tree (Elaeis guineesis) is the source of antioxidant-rich red palm oil. Red palm oil is a rich source of phytonutrients such as tocotrienols, tocopherols, carotenoids, phytosterols, squalene, and coenzyme Q10, all of which exhibit nutritional properties and oxidative stability. Mutagenic, nutritional, and toxicological studies have shown that red palm oil contains highly bioavailable ß-carotene and vitamin A and is reasonably stable to heat without any adverse effects. This review provides a comprehensive overview of the nutritional properties of red palm oil. The possible antiatherogenic, antihemorrhagic, antihypertensive, anticancer, and anti-infective properties of red palm oil are examined. Moreover, evidence supporting the potential effectiveness of red palm oil to overcome vitamin A deficiency in children and pregnant women, to improve ocular complications of vitamin A deficiency, to protect against ischemic heart disease, to promote normal reproduction in males and females, to aid in the management of diabetes, to ameliorate the adverse effects of chemotherapy, and to aid in managing hypobaric conditions is presented.

Coenzyme Q10 analytical determination in biological matrices and pharmaceuticals.

In recent years, the analytical determination of coenzyme Q10 (CoQ10) has gained importance in clinical diagnosis and in pharmaceutical quality control. CoQ10 is an important cofactor in the mitochondrial respiratory chain and a potent endogenous antioxidant. CoQ10 deficiency is often associated with numerous diseases and patients with these conditions may benefit from administration of supplements of CoQ10. In this regard, it has been observed that the best benefits are obtained when CoQ10 deficiency is diagnosed and treated early. Therefore, it is of great value to develop analytical methods for the detection and quantification of CoQ10 in this type of disease. The methods above mentioned should be simple enough to be used in routine clinical laboratories as well as in quality control of pharmaceutical formulations containing CoQ10. Here, we discuss the advantages and disadvantages of different methods of CoQ10 analysis.

Sphingomonas parvus sp. nov. isolated from a ginseng-cultivated soil.

Strain GP20-2(T) was isolated from a soil cultivated with ginseng in Korea. The 16S rRNA gene sequence of this strain showed the highest sequence similarity with Sphingomonas daechungensis CH15-11(T) (96.7%) and Sphingomonas sediminicola Dae 20(T) (96.2%) among the type strains. The strain GP20-2(T) was a strictly aerobic, Gram-negative, non-motile, rod-shaped bacterium that formed very tiny colonies, less than 0.3 mm in diameter after 10 days on R2A agar. The strain grew at 10-35-C (optimum, 35-C), at a pH of 5.0-8.0 (optimum, pH 6.0), and in the absence of NaCl. The DNA G+C content of strain GP20-2(T) was 67.2 mol%. It contained ubiquinone Q-10 as the major isoprenoid quinone, and summed feature 8 (C18:1ω6c and/or C18:1ω7c, 49.8%) and C16:0 (17.0%) as the major fatty acids. On the basis of evidence from our polyphasic taxonomic study, we concluded that strain GP20-2(T) should be classified as a novel species of the genus Sphingomonas, for which the name Sphingomonas parvus sp. nov. is proposed. The type strain is GP20-2(T) (=KACC 12865(T) =DSM 100456(T)).

A novel non-invasive sampling method using buccal mucosa cells for determination of coenzyme Q10.

Coenzyme Q10 (CoQ10) is an important cofactor in the mitochondrial respiratory chain and a potent endogenous antioxidant. CoQ10 deficiency is often associated with numerous diseases, and patients can benefit from CoQ10 supplementation, being more effective when diagnosed and treated early. Due to the increased interest in CoQ10 deficiency, several methods for CoQ10 analysis from plasmatic, muscular, fibroblast, and platelet matrices have been developed. These sampling techniques are not only highly invasive but also too traumatic for periodic clinical monitoring. In the present work, we describe the development and validation of a novel non-invasive sampling method for quantification of CoQ10 in buccal mucosa cells (BMCs) by microHPLC. This method is suitable for using in a routine laboratory and useful for sampling patients in pediatry. CoQ10 correlation was demonstrated between BMCs and plasma levels (Spearman r, 0.4540; p < 0.001). The proposed method is amenable to be applied in the post treatment monitoring, especially in pediatric patients as a non-invasive sample collection. More studies are needed to assess whether this determination could be used for diagnosis and if this matrix could replace the traditional ones.

Quantitative determination of coenzyme Q10 from dietary supplements by FT-NIR spectroscopy and statistical analysis.

A novel, time- and money-sparing method has been developed and validated for the quantitative determination of coenzyme Q10 (CoQ10) from several dietary supplements. FT-NIR spectroscopy was applied for the examination, and a calibration model was built by partial least-square regression (PLS-R) using 50 dietary supplements. The combination of FT-NIRS and multivariate calibration methods is a very fast and simple way to replace the commonly used HPLC-UV method; because in contrast with the traditional techniques, sample pretreatment and reagents are not required and no wastes are produced. The calibration models could be improved by different variable selection techniques (for instance interval PLS, interval selectivity ratio, genetic algorithm), which are very fast and user-friendly. The R(2) (goodness of calibration) and Q(2) (goodness of validation) of the variable selected models are highly increased, the R(2) values being over 0.90 and the Q(2) values being over 0.86 in every case. Fivefold cross-validation and external validation were applied. The developed method(s) could be used by quality assurance laboratories for routine measurement of coenzyme Q10 products.

Successful reversal of propionic acidaemia associated cardiomyopathy: evidence for low myocardial coenzyme Q10 status and secondary mitochondrial dysfunction as an underlying pathophysiological mechanism.

Dilated cardiomyopathy is a rare complication in propionic acidaemia (PA). Underlying pathophysiological mechanisms are poorly understood. We present a child of Pakistani consanguineous parents, diagnosed with late-onset PA at 18months of age. He presented a mild phenotype, showed no severe further decompensations, normal growth and psychomotor development on a low protein diet and carnitine supplementation. At 15years, a mildly dilated left ventricle was noticed. At 17years he presented after a 2-3month history of lethargy and weight loss with severe decompensated dilated cardiomyopathy. He was stabilised on inotropic support and continuous haemofiltration; a Berlin Heart biventricular assist device was implanted. He received d,l-hydroxybutyrate 200mg/kg/day, riboflavin and thiamine 200mg/day each and coenzyme Q10 (CoQ10). Myocardial biopsy showed endocardial fibrosis, enlarged mitochondria, with atypical cristae and slightly low respiratory chain (RC) complex IV activity relative to citrate synthase (0.012, reference range 0.014-0.034). Myocardial CoQ10 was markedly decreased (224pmol/mg, reference range 942-2738), with a marginally decreased white blood cell level (34pmol/mg reference range 37-133). The dose of CoQ10 was increased from 1.5 to 25mg/kg/day. Cardiomyopathy slowly improved allowing removal of the external mechanical cardiac support after 67days. We demonstrate for the first time low myocardial CoQ10 in cardiomyopathy in PA, highlighting secondary mitochondrial impairment as a relevant causative mechanism. According to these findings, a high-dose CoQ10 supplementation could be a potential adjuvant therapeutic to be considered in PA-related cardiomyopathy.

Enhanced production of coenzyme Q10 by self-regulating the engineered MEP pathway in Rhodobacter sphaeroides.

Fine-tuning the expression level of an engineered pathway is crucial for the metabolic engineering of a host toward a desired phenotype. However, most engineered hosts suffer from nonfunctional protein expression, metabolic imbalance, cellular burden or toxicity from intermediates when an engineered pathway is first introduced, which can decrease production of the desired product. To circumvent these obstacles, we developed a self-regulation system utilizing the trc/tac promoter, LacI(q) protein and ribosomal binding sites (RBS). With the purpose of improving coenzyme Q10 (CoQ10 ) production by increasing the decaprenyl diphosphate supplement, enzymes DXS, DXR, IDI, and IspD were constitutively overexpressed under the control of the trc promoter in Rhodobacter sphaeroides. Then, a self-regulation system combining a set of RBSs for adjusting the expression of the LacI(q) protein was applied to tune the expression of the four genes, resulting in improved CoQ10 production. Finally, another copy of the tac promoter with the UbiG gene (involved in the ubiquinone pathway of CoQ10 biosynthesis) was introduced into the engineered pathway. By optimizing the expression level of both the upstream and downstream pathway, CoQ10 production in the mutants was improved up to 93.34 mg/L (7.16 mg/g DCW), about twofold of the wild-type (48.25 mg/L, 3.24 mg/g DCW).

Rapid determination of coenzyme Q10 in food supplements using 1H NMR spectroscopy.

A methodology utilizing 1H NMR spectroscopy has been developed to measure the concentration of coenzyme Q10 (CoQ10) in dietary supplements. For sample preparation, a very simple dilution with deuterated chloroform and addition of internal standard is sufficient. CoQ10 produces a distinct peak of the CH groups in the isoprene side chain of the molecule in the δ 5.15 - 5.05 ppm range, where it can be distinguished from other matrix compounds. The method was shown to be of adequate sensitivity with a limit of detection (LOD) of 7.8 mg/L, to control the CoQ10 content in the majority of the products. The precision expressed as relative standard deviation was around 5 %; linearity was observed from 14 to 2000 mg/L (R = 0.99). The developed methodology was applied for the analysis of 21 food supplements (capsules, tablets, and liquid products). On the basis of the labeled amounts, only two products contained substantially lower concentrations of CoQ10 (57 % and 51 %). All other concentrations varied between 83 % and 190 % with respect to labeling. The developed NMR method may be used by quality assurance laboratories for routine control of CoQ10 products.

Sphingomonas kyungheensis sp. nov., a bacterium with ginsenoside-converting activity isolated from soil of a ginseng field.

A bacterial strain THG-B283(T), which has ß-glucosidase activity, was isolated from soil of a ginseng field. Cells were Gram-reaction-negative, oxidase- and catalase-positive, aerobic, motile with one polar flagellum and rod-shaped. The strain was subjected to a polyphasic taxonomic study. Strain THG-B283(T) grew optimally at around pH 7.0, at 25-28 °C and in the absence of NaCl on R2A agar. 16S rRNA gene sequence analysis revealed that strain THG-B283(T) belongs to the family Sphingomonadaceae and is closely related to Sphingomonas melonis DAPP-PG 224(T) (98.2 %), S. aquatilis JSS7(T) (98.1 %), S. insulae DS-28(T) (97.6 %), S. mali IFO 15500(T) (97.1 %) and S. pruni IFO 15498(T) (97.0 %). Strain THG-B283(T) contained Q-10 as the predominant ubiquinone. The major fatty acids included summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), C18 : 1ω7c, C14 : 0 2-OH and C16 : 0. The DNA G+C content was 72.2 mol%. The major component in the polyamine pattern was sym-homospermidine. The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidyldimethylethanolamine, phosphatidylcholine, sphingoglycolipid, diphosphatidylglycerol, an unidentified glycolipid, unidentified aminolipids, an unidentified phospholipid and unidentified lipids. Genomic and chemotaxonomic data supported the affiliation of strain THG-B283(T) to the genus Sphingomonas. DNA-DNA relatedness between strain THG-B283(T) and its closest phylogenetic neighbours was below 23 %. On the basis of phenotypic, phylogenetic and genetic data, strain THG-B283(T) represents a novel species of genus Sphingomonas, for which the name Sphingomonas kyungheensis sp. nov. is proposed. The type strain is THG-B283(T) ( = KACC 16224(T) = LMG 26582(T)).

Coenzyme Q10 quantification in muscle, fibroblasts and cerebrospinal fluid by liquid chromatography/tandem mass spectrometry using a novel deuterated internal standard.

RATIONALE: Neurological dysfunction is common in primary coenzyme Q10 (2,3-dimethoxy, 5-methyl, 6-polyisoprene parabenzoquinone; CoQ10 ; ubiquinone) deficiencies, the most readily treatable subgroup of mitochondrial disorders. Therapeutic benefit from CoQ10 supplementation has also been noted in other neurodegenerative diseases. CoQ10 can be measured by high-performance liquid chromatography (HPLC) in plasma, muscle or leucocytes; however, there is no reliable method to quantify CoQ10 in cerebrospinal fluid (CSF). Additionally, many methods use CoQ9 , an endogenous ubiquinone in humans, as an internal standard. METHODS: Deuterated CoQ10 (d6 -CoQ10 ) was synthesised by a novel, simple, method. Total CoQ10 was measured by liquid chromatography/tandem mass spectrometry (LC/MS/MS) using d6 -CoQ10 as internal standard and 5 mM methylamine as an ion-pairing reagent. Chromatography was performed using a Hypsersil GOLD C4 column (150 × 3 mm, 3 µm). RESULTS: CoQ10 levels were linear over a concentration range of 0-200 nM (R(2) = 0.9995). The lower limit of detection was 2 nM. The inter-assay coefficient of variation (CV) was 3.6% (10 nM) and 4.3% (20 nM), and intra-assay CV 3.4% (10 nM) and 3.6% (20 nM). Reference ranges were established for CoQ10 in CSF (5.7-8.7 nM; n = 17), fibroblasts (57.0-121.6 pmol/mg; n = 50) and muscle (187.3-430.1 pmol/mg; n = 15). CONCLUSIONS: Use of d6 -CoQ10 internal standard has enabled the development of a sensitive LC/MS/MS method to accurately determine total CoQ10 levels. Clinical applications of CSF CoQ10 determination include identification of patients with cerebral CoQ10 deficiency, and monitoring CSF CoQ10 levels following supplementation.

Coenzyme Q10 deficiency in mitochondrial DNA depletion syndromes.

We evaluated coenzyme Q10 (CoQ) levels in patients studied under suspicion of mitochondrial DNA depletion syndromes (MDS) (n=39). CoQ levels were quantified by HPLC, and the percentage of mtDNA depletion by quantitative real-time PCR. A high percentage of MDS patients presented with CoQ deficiency as compared to other mitochondrial patients (Mann-Whitney-U test: p=0.001). Our findings suggest that MDS are frequently associated with CoQ deficiency, as a possible secondary consequence of disease pathophysiology. Assessment of muscle CoQ status seems advisable in MDS patients since the possibility of CoQ supplementation may then be considered as a candidate therapy.

Argan oil-contained antioxidants for human mitochondria.

The powerful antioxidant capacity of virgin argan oil is attributed to its content of antioxidant molecules. Recent investigations have identified CoQ10 and melatonin as some of these antioxidant molecules. In this review, we summarize the most recent data about the content of CoQ10 and melatonin in virgin argan oil and the differences found in samples extracted by the traditional and half-industrialized methods. We also emphasize the importance of these two molecules for human health, focusing on their actions in mitochondria. Finally, we refer to other abundant antioxidants in virgin argan oil: tocopherols and polyphenols.

Sphingomonas ginsengisoli sp. nov. and Sphingomonas sediminicola sp. nov.

Two novel bacteria, designated strains Gsoil 634(T) and Dae 20(T), were isolated in South Korea from soil of a ginseng field and freshwater sediment, respectively and were characterized by a polyphasic approach to clarify their taxonomic positions. Phylogenetic analysis based on 16S rRNA gene sequences indicated that, although they probably represented two distinct species (indicated by a sequence similarity of 96.6 %), both strain Gsoil 634(T) and strain Dae 20(T) belonged to the genus Sphingomonas and were most closely related to 'Sphingomonas humi' PB323 (97.8 % and 96.7 % sequence similarity, respectively), Sphingomonas kaistensis PB56(T) (96.8 % and 96.7 %), Sphingomonas astaxanthinifaciens TDMA-17(T) (96.6 % and 95.4 %) and Sphingomonas jaspsi TDMA-16(T) (95.6 % and 95.8 %). For both novel strains, the major ubiquinone was Q-10, the major polyamine was homospermidine, the major cellular fatty acids included summed feature 7 (C(18 : 1)ω7c, C(18 : 1)ω9t and/or C(18 : 1)ω12t), C(17 : 1)ω6c and C(16 : 0), and the polar lipids included sphingoglycolipid. These chemotaxonomic data supported the affiliation of both strains to the genus Sphingomonas. However, the DNA-DNA relatedness value between strain Gsoil 634(T) and 'Sphingomonas humi' PB323(T) was 31 %. Moreover, the results of physiological and biochemical tests allowed the phenotypic differentiation of strains Gsoil 634(T) and Dae 20(T) from established members of the genus Sphingomonas. Based on these data, the two isolates represent two novel species in the genus Sphingomonas, for which the names Sphingomonas ginsengisoli sp. nov. (type strain Gsoil 634(T) = KCTC 12630(T) = DSM 18094(T) = LMG 23739(T)) and Sphingomonas sediminicola sp. nov. (type strain Dae 20(T)  = KCTC 12629(T) = DSM 18106(T) = LMG 23592(T)) are proposed.