Untargeted Metabolomic Analysis of Human Milk from Mothers of Preterm Infants

The application of metabolomics in neonatology offers an approach to investigate the complex relationship between nutrition and infant health. Characterization of the metabolome of human milk enables an investigation into nutrients that affect the neonatal metabolism and identification of dietary interventions for infants at risk of diseases such as necrotizing enterocolitis (NEC). In this study, we aimed to identify differences in the metabolome of breast milk of 48 mothers with preterm infants with NEC and non-NEC healthy controls. A minimum significant difference was observed in the human milk metabolome between the mothers of infants with NEC and mothers of healthy control infants. However, significant differences in the metabolome related to fatty acid metabolism, oligosaccharides, amino sugars, amino acids, vitamins and oxidative stress-related metabolites were observed when comparing milk from mothers with control infants of ≤1.0 kg birth weight and >1.5 kg birth weight. Understanding the functional biological features of mothers’ milk that may modulate infant health is important in the future of tailored nutrition and care of the preterm newborn.     

Automatic analytical approach for the determination of 12 illicit drugs and nicotine metabolites in wastewater using on-line SPE-UHPLC-MS/MS

In this study, we developed a novel on-line solid phase extraction (SPE)-ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS)-based analytical method for simultaneously quantifying 12 illicit drugs and metabolites (methamphetamine, amphetamine, morphine, codeine, 6-monoacetylmorphine, benzoylecgonine, 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxyamphetamine, cocaine, ketamine, norketamine, and methcathinone) and cotinine (COT) in wastewater samples. The analysis was performed by loading 2 mL of the sample onto an Oasis hydrophilic-lipophilic balance cartridge and using a cleanup step (5% methanol) to eliminate interference with a total run time of 13 min. The isotope-labeled internal standard method was used to quantify the target substances and correct for unavoidable losses and matrix effects during the on-line SPE process. Typical analytical characteristics used for method validation were sensitivity, linearity, precision, repeatability, recovery, and matrix effects. The limit of detection (LOD) and limit of quantification (LOQ) of each target were set at 0.20 ng/L and 0.50 ng/L, respectively. The linearity was between 0.5 ng/L and 250 ng/L, except for that of COT. The intra- and inter-day precisions were <10.45% and 25.64%, respectively, and the relative recovery ranged from 83.74% to 162.26%. The method was used to analyze various wastewater samples from 33 cities in China, and the results were compared with the experimental results of identical samples analyzed using off-line SPE. The difference rate was between 19.91% and −20.44%, and the error range could be considered acceptable. These findings showed that on-line SPE is a suitable alternative to off-line SPE for the analysis of illicit drugs in samples.     

南海软珊瑚Lobophytum sp.中二萜类化合物的研究

目的 对海洋来源软珊瑚Lobophytum sp.中的化学成分结构多样性及生物活性进行研究。方法 利用硅胶、十八烷基硅烷键合硅胶（ODS-C18）、凝胶Sephadex LH-20和半制备高效液相（semi-HPLC）等色谱学方法对软珊瑚乙酸乙酯提取物中的化学成分进行分离;利用紫外（UV）、核磁共振波谱（NMR）、质谱（MS）等波谱学方法,结合与文献的数据对比确定化合物的结构。结果 从软珊瑚的乙酸乙酯提取物中分离鉴定了10个西松烷型二萜类化合物,分别为sarcomililatins B（1）、lobophytins A（2）、isosarcophine（3）、sarcophytoxide（4）、isosarcophytoxide（5）、(+)-11,12-epoxyepoxy-11,12-dihydrocembrene-C（6）、cherbonnolide B（7）、sarcomililatins A（8）、sarcophytonin B（9）和3,4-dihydro-4α-hydroxy-?2-sarcophine（10）。其中化合物7和8为首次从该属软珊瑚中分离得到。化合物1和3在20 μmol/L 浓度下对LPS诱导NO产生的抑制率分别为31.5%和28.6%。结论 从南海软珊瑚Lobophytum sp.中分离得到了化合物1~10,其中化合物1和3对LPS诱导NO产生具有一定的抑制作用。     

Elucidating the role of blood metabolites on pancreatic cancer risk using two-sample Mendelian randomization analysis

Pancreatic ductal adenocarcinoma (PDAC) is an uncommon but highly fatal malignancy. Identifying causal metabolite biomarkers offers an opportunity to facilitate effective risk assessment strategies for PDAC. In this study, we performed a two-sample Mendelian randomization (MR) study to characterize the potential causal effects of metabolites in plasma on PDAC risk. Genetic instruments were determined for a total of 506 metabolites from one set of comprehensive genome-wide association studies (GWAS) involving 913 individuals of European ancestry from the INTERVAL/EPIC-Norfolk cohorts. Another set of genetic instruments was developed for 483 metabolites from an independent GWAS conducted with 8299 individuals of European ancestry from the Canadian Longitudinal Study on Aging (CLSA) cohort. We analyzed GWAS data of the Pancreatic Cancer Cohort Consortium (PanScan) and the Pancreatic Cancer Case-Control Consortium (PanC4), comprising 8275 PDAC cases and 6723 controls of European ancestry. The association of metabolites with PDAC risk was assessed using the inverse-variance weighted (IVW) method, and complemented with sensitivity analyses of MR-Egger and MR-PRESSO tests. Potential side effects of targeting the identified metabolites for PDAC intervention were further evaluated by a phenome-wide MR (Phe-MR) analysis. Forty-four unique metabolites were identified to be significantly associated with PDAC risk, of which four top-ranking metabolites (X: 12798, X: 11787, X: 11308 and X: 19141) showed replication evidence when using instruments developed from both two cohorts. Our results highlight novel blood metabolites related to PDAC risk, which may help prioritize metabolic features for PDAC mechanistic research and further evaluation of their potential role in PDAC risk assessment.     

Comparative 5-HT4 receptor antagonist activity of LY353433 and its active hydroxylated metabolites

LY353433 is a selective, potent, and orally active 5-HT₄ receptor antagonist with a long duration of pharmacological activity following its oral administration to rats. After oral administration of LY353433 (100 mg/kg) to rats, peak plasma concentration of the parent material was approximately 25 ng/ml and rapidly declined such that 4 h after administration, plasma concentration of the parent material was barely detectable. However, two additional peaks (LY343031 and LY343032) were observed in plasma via HPLC and subsequently identified as hydroxylated metabolites of LY353433. Peak plasma concentrations of LY343031 (approximately 50 ng/ml) and of LY343032 (approximately 150 ng/ml) were achieved within 1 h after the oral administration of LY353433. Furthermore, plasma concentrations of these metabolites were maintained for several hours and declined more slowly than plasma concentrations of the parent material. Both metabolites inhibited esophageal 5-HT₄ receptors in a concentration range similar to that observed with LY353433. In addition, the receptor selectivity profiles for LY343031 and LY343032 were similar to that of LY353433 at α₁, α₂, β, Dopamine D₁, Dopamine D₂, benzodiazapine, histamine H₁, GABA_A, 5-HT₂, and muscarinic receptors. Thus, these hydroxylated derivatives of LY353433 were potent and selective 5-HT₄ receptor antagonists in vitro. Lastly, using ex vivo esophageal relaxation to serotonin to assess 5-HT₄ receptor antagonism, these compounds were less active after oral administration to rats than LY353433. Thus, the long duration of pharmacological activity observed after oral administration of LY353433 is likely related not only to the 5-HT₄ receptor antagonist activity of the parent molecule, but also to the 5-HT₄ receptor antagonist activity associated with its two hydroxylated metabolites. Drug Dev. Res. 43:193–199, 1998. © 1998 Wiley-Liss, Inc.     

Urinary excretion of methylated catecholamine metabolites in a child with neuroblastoma maturing into ganglioneuroma

Neuroblastomas are malignant tumors derived embryonically from the neural crest. Biological diagnosis relies on assay of urinary excretion of homovanillic acid (HVA), vanillylmandelic acid (VMA), and dopamine (DA). Spontaneous regression of these neoplasms has been reported by numerous investigators. The authors report the case of a child with neuroblastoma that illustrates the relationship between catecholamine metabolites and tumor maturation. At 1 month of age, this infant presented an adrenal neuroblastoma with multiple metastases (stage IV); the initial histological diagnosis based on examination of cutaneous metastases was neuroblastoma. At the age of 6 months, after chemotherapy, the primary tumor was resected; hepatic metastases were discovered at laparotomy. The histological diagnosis for all lesions was highly differentiated, mature ganglioneuroma-like tissue. The main biochemical abnormality at the time of diagnosis was an elevation in normetanephrine (NMN). HVA was only slightly increased but rose progressively during chemotherapy; it dropped back to normal levels after the sixth course. This case illustrates the potential benefits of separate assays of urinary methylated catecholamine metabolites for biochemical diagnosis and therapeutic management of neuroblastoma in addition to assays of HVA, VMA, and DA. Case findings suggest existence of a transformation process with maturation of the tumor involving enzymatic regulation and expression of MAO. © 1996 Wiley-Liss, Inc.     

Structure-activity relationships in the mutagenicity and cytotoxicity of putative metabolites and related analogs of benzene derived from the valence tautomers benzene oxide and oxepin

A series of putative metabolites and related analogs of benzene, derived from the valence tautomers benzene oxide and oxepin, was tested for mutagenicity (reversions to histidine prototrophy and forward mutations to resistance to 8-azaguanine) and for cytotoxicity by the Ames Salmonella mutagenicity test. Benzene was not mutagenic in either assay. The benzene oxide-oxepin system and benzene dihydrodiol induced point mutations but not frameshifts. 4,5-sym-Oxepin oxide, which is a putative metabolite of the oxepin valence tautomer; 3,6-diazo-cyclohexane-1,6-3,4-dioxide, a synthetic precursor of sym-oxepin oxide; and transoid-4, 11-diox-atricyclo(5.1 0)undeca-1,6-diene, a stable bridgehead diene analog of sym-oxepin oxide, were toxic but not mutagenic in both assays. 4H-Pyran-4-carboxaldehyde, a stable acid catalyzed rearrangement product of sym-oxepin oxide, was not mutagenic and much less cytotoxic than sym-oxepin oxide. Stable analogs of the valence tautomer benzene oxide, namely syn-indan-3a, 7a-oxide and syn-2-hydroxyindan-3a,7a-oxide, were mutagenic and induced point mutations. All compounds were cytotoxic to Salmonella. Firstly, the apparent decay times of these chemicals, especially that of sym-oxepin oxide, were surprisingly longer than expected, as judged by quantitative plate diffusion assays. Secondly, it is concluded that if benzene oxide is further metabolized in its oxepin tautomeric form, toxic but not mutagenic products are formed. Thirdly, the relatively weak mutagenicity of benzene oxide may be mainly due to its instability and corresponding low probability to reach intracellular polynucleotide targets, whereas stable analogs of benzene oxide are relatively more potent mutagens. © 1996 Wiley-Liss, Inc.     

紫红曲代谢产物中的甾体成分

目的:研究药食两用紫红曲Monascuspurpureus的化学成分.方法:应用各种色谱技术分离纯化,用Ms和NMR分析确定化合物结构.结果:从紫红曲乙醇提取物的石油醚部分分离得到8个化合物,分别鉴定为:豆甾-4-烯-3-酮(1),3-oxo-24-methyl-enecycloarane(2),豆甾醇(3),7β-羟基豆甾醇(4),3β-羟基豆甾-5烯-7-酮(5),3β-羟基豆甾-5,22-二烯-7-酮(6),5a,8α-过氧麦角甾-6,22-二烯-3β-醇(7),β-谷甾醇(8).结论:以上8个化合物除化合物3和7外,其余均为首次从红曲菌属代谢产物中分离得到.     

海洋真菌Cladosporium cladosporioides化学成分研究

 目的对来源于红树林的海洋真菌Cladosporium cladosporioides的发酵产物进行化学成分研究。方法采用溶剂提取、硅胶柱色谱及半制备HPLC等分离方法对真菌菌丝体进行分离纯化,通过波谱学方法进行结构鉴定。结果分离得到10个化合物,分别为二十四烷酸(1)、麦角甾-5,7,22-三烯-3β-醇(2)、24-亚甲基羊毛脂甾-8-烯-3β-醇(3)、1-(硬脂酸)-2-(亚油酸)-3-油酸甘油酯(4)、1,2,3-三亚油酸甘油酯(5)、1,3-二油酸甘油酯(6)、肉桂酸(7)、苯丙酸(8)、β-谷甾醇(9)、丁二酸单乙酯(10)。结论化合物1～10均为首次从该菌种分离得到。     

Nitric oxide metabolite levels in preterm labor

AIM: To investigate the role of nitric oxide metabolites as markers of infection in subjects with preterm labor or preterm premature rupture of membranes (PTPROM). PTPROM means that there was spontaneous rupture of fetal membrane before the onset of labor and gestational age was <37 weeks. This occurs because of imbalance between matrix metalloproteinase and tissue inhibitor of matrix metalloproteinase. The cause of this imbalance that leads to degradation of collagen causing PTPROM is infection. The bactericidal, fungicidal, viricidal and tumoricidal activities of macrophages are determined in part by elaboration of nitric oxide, hence nitric oxide levels have been found to be increased in infections. METHODS: During an 18-month period 50 women with preterm labor or PTPROM and 50 controls were enrolled prospectively. Blood and urine samples were obtained for analysis of nitric oxide metabolites. Patients with known causes of preterm labor were excluded. RESULT: The nitric oxide metabolites, which included both nitrite levels and citrulline levels were significantly higher both in blood as well as urine in patients with preterm labor and PTPROM compared to controls. Serum nitrite levels in subjects with preterm labor were 376.5 +/- 345 nmol/L while in subjects with PTPROM they were 295.7 +/- 161.1 nmol/L and in controls the levels were 62.7 +/- 33.9 nmol/L. Serum citrulline levels in subjects with preterm labor were 5293.8 +/- 2916.7 nmol/L; in PTPROM they were 6536.6 +/- 609.91 nmol/L and in controls they were 949.8 +/- 67.1 nmol/L. On comparing patients with preterm labor, those in whom preterm labor could not be inhibited had statistically significant higher levels of nitrite in both serum and urine (482.9 +/- 387.7 nmol/L and 754.5 +/- 336.5 nmol/L, respectively) compared to patients in whom labor could be inhibited (172.2 +/- 61.9 nmol/L and 401.8 +/- 236.9 nmol/L, respectively). The citrulline levels were also higher among the group who delivered preterm for both serum and urine (5355.4 +/- 3229.7 nmol/L and 11 482.8 +/- 2541.4 nmol/L, respectively) compared to patients in whom labor could be inhibited (5260.2 +/- 2897.08 nmol/L and 10 651.4 +/- 1502.7 nmol/L, respectively) but this did not reach statistical significance. CONCLUSION: Higher nitric oxide metabolites in women with preterm labor are marker of subclinical infection.