The glucocorticoid receptor gene polymorphism N363S predisposes to more severe toxic side effects during pediatric acute lymphoblastic leukemia (ALL) therapy.

The survival rates in childhood acute lymphoid leukemia (ALL) have improved dramatically; however, patients still suffer from a variety of drug-related toxicities. Individualized therapy regimens promise the least toxic therapy regimen with the best hematologic outcome. Our aim was to investigate whether increased individual glucocorticoid sensitivity due to the N363S polymorphism of the glucocorticoid receptor increased susceptibility to steroid-related toxicities during ALL therapy. A total of 346 pediatric ALL patients were involved in the present study. N363S carrier status was investigated by allele-specific PCR. Clinical and laboratory signs of glucocorticoid-related toxicities, Day 8 prednisone response, and 5-year event-free survival were analyzed and compared retrospectively. Thirty-two of the 346 patients were heterozygous carriers (9.2 %). Hepatotoxicity (31.3 vs. 11.2 %, p = 0.004, carriers and non-carriers, respectively) and glucose metabolism abnormalities (18.8 vs. 3.8 %, p = 0.001, carriers and non-carriers, respectively) were significantly more frequent among carriers. There was no difference in the incidence of hypertension and encephalopathy/psychosis among carriers and non-carriers. Carriers were also more prone to have a combination of toxicities. All 363S carriers were good prednisone responders (100 %) and had significantly better 5-year event-free survival rates (93.1 vs. 71.86 %, p = 0.012), whereas among non-carriers there were more poor prednisone responders (8.28 %) and worse 5-year event-free survival rates. Patients with the N363S polymorphism in the glucocorticoid receptor are more prone to steroid-related toxicity during ALL therapy and should be monitored more closely. Patients with N363S polymorphism of the glucocorticoid receptor may be appropriate candidates for inclusion in the design of individualized therapies.

Effects of 28 days of beta-alanine and creatine monohydrate supplementation on aerobic power, ventilatory and lactate thresholds, and time to exhaustion.

The effect of beta-alanine (beta-Ala) alone or in combination with creatine monohydrate (Cr) on aerobic exercise performance is unknown. The purpose of this study was to examine the effects of 4 weeks of beta-Ala and Cr supplementation on indices of endurance performance. Fifty-five men (24.5 +/- 5.3 yrs) participated in a double-blind, placebo-controlled study and randomly assigned to one of 4 groups; placebo (PL, n = 13), creatine (Cr, n = 12), beta-alanine (beta-Ala, n = 14), or beta-alanine plus creatine (CrBA, n = 16). Prior to and following supplementation, participants performed a graded exercise test on a cycle ergometer to determine VO(2peak), time to exhaustion (TTE), and power output, VO(2), and percent VO(2peak) associated with VT and LT. No significant group effects were found. However, within groups, a significant time effect was observed for CrBa on 5 of the 8 parameters measured. These data suggest that CrBA may potentially enhance endurance performance.

Effects of beta-alanine supplementation on the onset of neuromuscular fatigue and ventilatory threshold in women.

This study examined the effects of 28 days of beta-alanine supplementation on the physical working capacity at fatigue threshold (PWCFT), ventilatory threshold (VT), maximal oxygen consumption (VO2-MAX), and time-to-exhaustion (TTE) in women. Twenty-two women (age+/-SD 27.4+/-6.1 yrs) participated and were randomly assigned to either the beta-alanine (CarnoSyn) or Placebo (PL) group. Before (pre) and after (post) the supplementation period, participants performed a continuous, incremental cycle ergometry test to exhaustion to determine the PWCFT, VT, VO2-MAX, and TTE. There was a 13.9, 12.6 and 2.5% increase (p<0.05) in VT, PWCFT, and TTE, respectively, for the beta-alanine group, with no changes in the PL (p>0.05). There were no changes for VO2-MAX (p>0.05) in either group. Results of this study indicate that beta-alanine supplementation delays the onset of neuromuscular fatigue (PWCFT) and the ventilatory threshold (VT) at submaximal workloads, and increase in TTE during maximal cycle ergometry performance. However, beta-alanine supplementation did not affect maximal aerobic power (VO2-MAX). In conclusion, beta-alanine supplementation appears to improve submaximal cycle ergometry performance and TTE in young women, perhaps as a result of an increased buffering capacity due to elevated muscle carnosine concentrations.

Potential advantage of N363S glucocorticoid receptor polymorphism in 21-hydroxylase deficiency.

OBJECTIVE: Congenital adrenal hyperplasia (CAH) shows a range of severity which is explained in part by the different mutations of the CYP21 gene. To better understand the incomplete concordance between genotype and phenotype in CAH the role of the sensitizing N363S polymorphism of the glucocorticoid receptor (GR) was examined in CAH patients. DESIGN: CAH patients were screened for N363S. Laboratory findings and clinical characteristics of carriers and non-carriers were analyzed retrospectively. METHODS: The CYP21 gene of 200 CAH patients was analyzed by allele-specific PCR. The GR gene was tested for N363S by PCR followed by restriction fragment length polymorphism. Antropometric data (height, weight), degree of intrauterine virilization, hormone concentrations (17-OH-progesterone, dehydroepiandrosterone (DHEA), aldosterone, testosterone, plasma renin activity), substitution doses and clinical course were analyzed. RESULTS: The carrier frequency of N363S in CAH patients was equivalent to that of the general Hungarian population (6% vs 7.8%). Interestingly, none of the non-classical CAH (NC-CAH) patients were carriers of the polymorphism. Carrier girls had milder genital virilization than mutation-matched non-carrier controls. There was no significant difference between the carriers and non-carriers in either the substitution doses, the hormonal, or the auxiological parameters. CONCLUSIONS: The association of sensitizing the GR variant with impaired cortisol production in CAH might be compensatory in mild NC-CAH and may prevent severe intrauterine virilization in classical form. Although the exact role of N363S in extrauterine life should be further investigated, the consideration of certain genetic polymorphisms of CAH patients may lead to better, individualized therapeutic regimes.

Indinavir uncovers different contributions of GLUT4 and GLUT1 towards glucose uptake in muscle and fat cells and tissues.

AIMS/HYPOTHESIS: Insulin-dependent glucose influx in skeletal muscle and adipocytes is believed to rely largely on GLUT4, but this has not been confirmed directly. We assessed the relative functional contribution of GLUT4 in experimental models of skeletal muscle and adipocytes using the HIV-1 protease inhibitor indinavir. METHODS: Indinavir (up to 100 micro mol/l) was added to the glucose transport solution after insulin stimulation of wild-type L6 muscle cells, L6 cells over-expressing either GLUT4myc or GLUT1myc, 3T3-L1 adipocytes, isolated mouse brown or white adipocytes, and isolated mouse muscle preparations. RESULTS: 100 micro mol/l indinavir inhibited 80% of both basal and insulin-stimulated 2-deoxyglucose uptake in L6GLUT4myc myotubes and myoblasts, but only 25% in L6GLUT1myc cells. Cell-surface density of glucose transporters was not affected. In isolated soleus and extensor digitorum longus muscles, primary white and brown adipocytes, insulin-stimulated glucose uptake was inhibited 70 to 80% by indinavir. The effect of indinavir on glucose uptake was variable in 3T3-L1 adipocytes, averaging 45% and 67% inhibition of basal and maximally insulin-stimulated glucose uptake, respectively. In this cell, fractional inhibition of glucose uptake by indinavir correlated positively with the fold-stimulation of glucose uptake by insulin, and was higher with sub-maximal insulin concentrations. The latter finding coincided with an increase only in GLUT4, but not GLUT1, in plasma membrane lawns. CONCLUSION/INTERPRETATION: Indinavir is a useful tool to assess different functional contributions of GLUT4 to glucose uptake in common models of skeletal muscle and adipocytes.

Limited value of serum steroid measurements in identification of mild form of 21-hydroxylase deficiency.

BACKGROUND: ACTH stimulation test is widely used as a basic diagnostic method for non-classical congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD). However, the interpretation of this test has not been definitely established. To determine the cut-off values of basal and post-ACTH serum 17-OHP concentrations, data of patients with suspected 21-OHD has been analysed. PATIENTS AND METHODS: Two hundred and eighty-seven patients with postnatal/peripubertal virilization were investigated. Serum steroid concentrations were measured by RIA, urinary steroid profile was determined by capillary gas chromatography and mutation analysis of CYP21 gene was performed by allele specific PCR. 21-OHD was diagnosed by elevated serum 17-OHP concentrations, high level of the urinary 17-OHP metabolites and/or homozygosity for CYP21 mutations. RESULTS: Twenty-one patients of the total of 287 subjects (7.3 %) were identified as having 21-OHD. The numbers of 21-OHD patients compared to total numbers of patients with different ranges of serum 17-OHP were as follows: basal values below 3.5 ng/ml (mean + 1 SD) 0/225; between 3.5 - 6.6 ng/ml 3/41; above 6.6 ng/ml (mean + 2 SD) 18/21. Post-ACTH values below 6.4 ng/ml (mean + 1 SD) 0/226, between 6.4 - 10.3 ng/ml 0/35, above 10.3 ng/ml (mean + 2 SD) 21/26. CONCLUSION: There are patients with inappropriate peripubertal virilization who have slightly elevated 17-OHP concentrations. In this subgroup of patients more sensitive and specific methods are needed to establish the diagnosis of 21-OHD. Therefore we suggest performing an ACTH stimulation test in patients with a morning 17-OHP level above 3.5 ng/ml. Furthermore, urinary steroid profile and/or CYP21 gene analysis are needed in patients with a stimulated 17-OHP value between 10 and 30 ng/ml. These tests will distinguish between patients with non-classical 21-OHD and patients with other disorders.

Effects of an external nasal dilator on the work of breathing during exercise.

PURPOSE: The effect of an external nasal dilator on the work of breathing (WOB) was measured during exercise in 14 untrained college students (age, 23 +/- 2.7 yr). METHODS: Two maximal, incremental ergometer tests were performed to exhaustion. Subjects wore a placebo or an active nasal dilator strip, in random order, during each test. An esophageal balloon was placed through each of the subject's mouth into the esophagus for measurement of inspiratory elastic work (INEW), inspiratory resistive work (INRW), and expiratory resistive work (EXRW). Subjects breathed through a Hans Rudolph(R) face mask that covered both the mouth and nose during both tests. Measured variables included oxygen uptake (VO2), ventilation (VE), tidal volume (VT), frequency of breathing (f), INEW, INRW, and EXRW (work expressed in joules). An alpha level was set at P < 0.05. RESULTS: No significant differences were found in INEW, INRW, and EXRW between conditions at 70% of VO2max (mean +/- SD; Placebo: INEW, 25.6 +/- 17.8 J.min-1; INRW, 22.4 +/- 15.8 J.min-1; EXRW, 16.7 +/- 12.3 J.min-1; Active: INEW, 24.7 +/- 12.9 J.min-1; INRW, 19.7 +/- 11.9 J.min-1; EXRW, 15.2 +/- 8.6 J.min-1; P > 0.05). No difference was found in INEW, INRW, and EXRW at maximal exercise between conditions (mean +/- SD; Placebo: INEW, 50.2 +/- 29.9 J.min-1; INRW, 67.3 +/- 42.3 J.min-1; EXRW, 102.3 +/- 78.4 J.min-1; Active: INEW, 45.7 +/- 19.6 J.min-1; INRW, 62.6 +/- 36.7 J.min-1; EXRW, 86.3 +/- 50.9 J.min-1; P > 0.05). There were no differences in VO2, VE, VT, or f between conditions. CONCLUSION: Wearing an external nasal dilator does not significantly reduce the work of breathing during exercise.

Spectral analysis of heart rate variability and pulmonary responses to topical applications of 2% aminophylline-based thigh cream.

OBJECTIVE: Noninvasive assessment of the immediate and delayed cardiopulmonary response to a 2% aminophylline-based topical thigh reducing cream. DESIGN: Prospective, double-blind, randomized, counterbalanced study with application of: no cream (NC), placebo cream (PC) or 2% aminophylline cream (AC). SUBJECTS: Nine healthy women (aged: 23+/-3 y; weight: 58+/-3 kg; height: 165+/-7 cm; body fat: 19+/-6%; estimated maximal aerobic fitness VO2max): 40+/-4 ml/kg/min). MEASUREMENTS: Medical history, skin patch test, skinfolds, YMCA submaximal cycle ergometry test, psychological evaluations (POMS and Speilberger STAI-1). Pulmonary function and spectral analysis on heart rate variability, measured immediately post-and 4 h post-treatment, on three separate days within a three-week period. RESULTS: Pulmonary function did not change. The averaged R-R interval (ms) was significantly lower for the immediate post AC treatment, but returned to baseline in 4 h. CONCLUSION: Application of a 2% aminophylline-based thigh cream does not affect pulmonary function, however, it may cause a temporary, transient reduction in the averaged R-R interval.

Exaggerated blood pressure response to exercise: importance of resting blood pressure.

Normotensive individuals who exhibit an exaggerated blood pressure (BP) response to exercise have an increased risk of future hypertension. However, previous studies failed to control for resting BP despite the fact that an elevated resting BP in the normotensive range is also a strong predictor of future hypertension. Therefore, we determined whether maximal systolic BP is associated with resting BP. Resting BP was measured in 68 healthy normotensive men on three separate days. The subjects then performed a graded, maximal exercise test on a Monark cycle ergometer. Maximal systolic BP was strongly correlated with resting systolic BP (r = 0.64, P < 0.0001). Subjects with elevations in systolic BP during maximal exercise (> 220 mmHg) also had higher (P < 0.005) resting BP than those without (< 220 mmHg). When stepwise regression analyses were performed, systolic BP at rest was a significant independent predictor of maximal systolic BP, explaining over 40% of the variability. These results suggest that exaggerated BP response as a predictor of future hypertension reported in previous studies may be little more than a simple reflection of elevated resting BP. Specifically, these studies should not be interpreted as demonstrating that exercise BP is a better predictor of future hypertension than resting BP alone. In the future, defining the BP 'response' to exercise as a change score (i.e. maximal BP minus resting BP) may be advantageous as it permits the effects of exercise to be examined independently of the level of resting BP.

Skeletal muscle fibre type and capillary density in college-aged blacks and whites.

The purpose of this study was to compare muscle fibre type proportions and capillary density in untrained, college-aged blacks (n = 14) and whites (n = 14). Both groups were similar in terms of peak oxygen uptake (VO2peak), measured during cycle ergometry (blacks: 42.6 +/- 4, whites: 44.3 +/- 4 ml.kg-1 min-1, mean +/- SD). Muscle samples were obtained from the quadriceps femoris (vastus lateralis) by the needle biopsy technique. Fibre type was determined by myosin ATPase stain (pH = 4.54) and capillaries were identified by amylase-periodic acid Schiff (PAS) stain. The percentage of type I, IIa, and IIb fibres in the blacks was 39.5 +/- 11.5, 40.0 +/- 8.4, and 22.8 +/- 9.8, respectively. In whites the percentage of type I, IIa, and IIb fibres was 44.9 +/- 8.5, 36.6 +/- 6.9, and 18.3 +/- 9.6, respectively. No significant differences were noted between the two racial groups for type I, IIa, or IIb fibres. Capillary density was 277 +/- 39/mm2 in the blacks compared to 289 +/- 32/mm2 in the whites. Capillary density was positively correlated to percentage of type I fibres (r = 0.497) and negatively correlated to percentage of type IIa fibres (r = -0.389), in the overall study population. These data suggest that if racial differences in fibre type do exist, such differences are small compared to the variability in this measure.

Cardiovascular and plasma catecholamine response to static exercise in normotensive blacks and whites.

OBJECTIVES: The objectives of the present study were (1) to evaluate the pressor response to an isometric handgrip exercise in normotensive black and white males; (2) to measure plasma catecholamine levels pre- and post-exercise, as an index of sympathetic nervous system activity; and (3) to quantify the pressor response to bolus intravenous injections of phenylephrine (an alpha-specific agonist). METHODS: Cardiovascular and catecholamine responses to an isometric handgrip exercise (3 minutes at 30% MVC) were measured in 15 normotensive blacks and whites. In another phase of the study, pressor responses to bolus injections of phenylephrine were assessed to evaluate alpha-adrenergic sensitivity. RESULTS: The blood pressure in the blacks increased from 119/69 to 160/120 mm HG during isometric exercise, while in the whites it increased from 118/67 to 153/110 mm HG. The blacks exhibited a greater diastolic blood pressure reactivity, as evidenced by a significant race x time interaction (p < 0.05). The heart rate responses were not significantly different between the two groups. The plasma levels of norepinephrine were similar at rest, but were 25% lower in the blacks than in the whites following isometric exercise (p < 0.01). Black subjects also demonstrated an increased pressor response to intravenous injections of phenylephrine at rest (p < 0.05). CONCLUSIONS: The enhanced vascular sensitivity to norepinephrine may have contributed to the greater exercise pressor response in the blacks.

Analysis of amino acids in biological fluids by pentafluorobenzyl chloroformate derivatization and detection by electron capture negative ionization mass spectrometry.

Pentafluorobenzyl chloroformate (PFBCF) has been utilized as a derivatization reagent for amino acids (AAs) in biological fluids with susequent detection by electron capture negative ionization mass spectrometry (ECNI/MS). AAs were derivatized in one step in aqueous solution, plasma, and whole blood at room temperature. To demonstrate quantitative analysis, phenylalanine concentrations were determined in human plasma. AAs were derivatized in one step using PFBCF and a mixture of water, ethanol, and pyridine/dimethylaminopyridine. The N-pentafluorobenzyloxycarbonyl amino acid ethyl esters (f phi-AA-OEt) exhibited good GC properties and the ECNI mass spectra are dominated by the [M-181]- ion. The f phi-AA-OEt derivatives can be easily detected at the femtomole level by selected ion monitoring. Phenethyl alcohol was also derivatized, using anhydrous conditions, and the resulting PFB carbonate's ECNI mass spectrum was dominated by the [M-181]- ion. The ECNI molar response of the PFB carbonate derivative is two times that of the corresponding pentafluorobenzoate.

Syntheses and antimalarial activities of N-substituted 11-azaartemisinins.

A two-step reaction sequence between artemisinin and methanolic ammonia followed by treatment with Amberlyst 15 yielded 11-azaartemisinin in 65% yield. Substituting a variety of primary alkyl- and heteroaromatic amines for ammonia in the reaction sequence yields N-substituted 11-azaartemisinins in similar or greater yield. When Amberlyst 15 is replaced by a mixture of sulfuric acid/silica gel, both 11-azaartemisinin and the expected metabolite, 10-azadesoxyartemisinin, are formed in 45% and 15% yields, respectively. In vitro and in vivo test data for a number of novel N-substituted 11-azaartemisinins, against drug-resistant strains of Plasmodium falciparum, show they possess antimalarial activities equal to or greater than that of artemisinin. The most active derivative, N-(2'-acetaldehydo)-11-azaartemisinin, 17, was 26 times more active in vitro and 4 times more active in vivo than artemisinin.

Desaturation and oxygenation of 1,2-dihydronaphthalene by toluene and naphthalene dioxygenase.

Bacterial strains expressing toluene and naphthalene dioxygenase were used to examine the sequence of reactions involved in the oxidation of 1,2-dihydronaphthalene. Toluene dioxygenase of Pseudomonas putida F39/D oxidizes 1,2-dihydronaphthalene to (+)-cis-(1S,2R)-dihydroxy-1,2,3,4-tetrahydronaphthalene, (+)-(1R)-hydroxy-1,2-dihydronaphthalene, and (+)-cis-(1R,2S)-dihydroxy-1,2-dihydronaphthalene. In contrast, naphthalene dioxygenase of Pseudomonas sp. strain NCIB 9816/11 oxidizes 1,2-dihydronaphthalene to the opposite enantiomer, (-)-cis-(1R,2S)-dihydroxy-1,2,3,4-tetrahydronaphthalene and the identical (+)-cis-(1R,2S)-dihydroxy-1,2-dihydronaphthalene. Recombinant Escherichia coli strains expressing the structural genes for toluene and naphthalene dioxygenases confirmed the involvement of these enzymes in the reactions catalyzed by strains F39/D and NCIB 9816/11. 1-Hydroxy-1,2-dihydronaphthalene was not formed by strains expressing naphthalene dioxygenase. These results coupled with time course studies and deuterium labelling experiments indicate that, in addition to direct dioxygenation of the olefin, both enzymes have the ability to desaturate (dehydrogenate) 1,2-dihydronaphthalene to naphthalene, which serves as a substrate for cis dihydroxylation.

Synthesis and antimalarial activities of several fluorinated artemisinin derivatives.

The carbonyl groups in several artemisinin derivatives were converted into geminal difluorinated compounds on treatment with diethylaminosulfur trifluoride. A number of other mono- and polyfluorinated artemisinin derivatives were prepared. Their in vitro antimalarial activities were all equal to or greater than the nonfluorinated analogs or precursors.

Cardiovascular responses to exercise in sprinters and distance runners.

The purpose of this study was to examine the cardiovascular responses of sprinters and distance runners to isometric (IE) and dynamic exercise (DE). Normotensive males were selected and grouped according to prior running performance: sprinter (N = 6) or distance runner (N = 6). Each subject completed an incremental DE (cycle ergometry) test (6-min stages) at 20%, 40%, and 60% of VO2peak, and 3 min of isometric handgrip at 30% of MVC. Blood pressure (BP), heart rate (HR), cardiac output (Q), oxygen uptake, and blood lactate were measured, while mean arterial blood pressure (MABP), cardiac index (CI), and systemic vascular resistance (SVR) were calculated during each stage of DE. BP and HR were measured during each minute of IE. Muscle biopsies of the vastus lateralis revealed a significant difference in capillary density (capillaries per mm2 and capillaries per fiber) between the sprinters and distance runners (323 +/- 23 vs 409 +/- 27 and 2.2 +/- 0.2 vs 3.2 +/- 0.3, P < 0.05) and for the percentage of Type I fibers (46.4 +/- 4% vs 64.8 +/- 7%, P < 0.05). The IE challenge elicited a greater BP response at minute 3 in the sprinters, which was associated with a greater HR response. During DE, there were no significant differences in BP or HR between the groups. However, at 60% of VO2peak, the distance runners had a significantly higher cardiac index and a lower systemic vascular resistance than the sprinters (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Desaturation, dioxygenation, and monooxygenation reactions catalyzed by naphthalene dioxygenase from Pseudomonas sp. strain 9816-4.

The stereospecific oxidation of indan and indene was examined with mutant and recombinant strains expressing naphthalene dioxygenase of Pseudomonas sp. strain 9816-4. Pseudomonas sp. strain 9816/11 and Escherichia coli JM109(DE3)[pDTG141] oxidized indan to (+)-(1S)-indanol, (+)-cis-(1R,2S)-indandiol, (+)-(1S)-indenol, and 1-indanone. The same strains oxidized indene to (+)-cis-(1R,2S)-indandiol and (+)-(1S)-indenol. Purified naphthalene dioxygenase oxidized indan to the same four products formed by strains 9816/11 and JM109(DE3)[pDTG141]. In addition, indene was identified as an intermediate in indan oxidation. The major products formed from indene by purified naphthalene dioxygenase were (+)-(1S)-indenol and (+)-(1R,2S)-indandiol. The results show that naphthalene dioxygenase catalyzes the enantiospecific monooxygenation of indan to (+)-(1S)-indanol and the desaturation of indan to indene, which then serves as a substrate for the formation of (+)-(1R,2S)-indandiol and (+)-(1S)-indenol. The relationship of the desaturase, monooxygenase, and dioxygenase activities of naphthalene dioxygenase is discussed with reference to reactions catalyzed by toluene dioxygenase, plant desaturases, cytochrome P-450, methane monooxygenase, and other bacterial monooxygenases.

Regiospecific and stereoselective hydroxylation of 1-indanone and 2-indanone by naphthalene dioxygenase and toluene dioxygenase.

Volume 60, no. 9, p. 3327, Table 2: footnote b should read "Determined by the intensities of the m/z at (M(sup+) + 2)/[M(sup+) + (M(sup+) + 2)] x 100." [This corrects the article on p. 3323 in vol. 60.].

Pentafluorobenzyl chloroformate derivatization for enhancement of detection of amino acids or alcohols by electron capture negative ion chemical ionization mass spectrometry.

Pentafluorobenzyl chloroformate (PFB-chloroformate) has been utilized as a derivatization reagent to impart electron affinity and provide structurally relevant fragmentation in electron capture negative ion chemical ionization mass spectrometry (ECNICI-MS). Phenylalanine (Phe) and decanol were used as model analytes. The conditions used for their derivatization and the chromatographic and mass spectrometric properties of the derivatives are reported. Phenylalanine in aqueous solution was derivatized in one step by using PFB-chloroformate and a mixture of water, ethanol, and pyridine. The phenylalanine N-pentafluorobenzyl-oxycarbonyl ethyl ester (N-PFBC-Phe-OEt) exhibited good gas chromatographic properties and in ECNICI-MS, a dominant [M - 181](-) fragment carries most of the ion current. Selected ion monitoring experiments on N-PFBC-Phe-OEt resulted in the facile detection of 400 fmol of material. Decanol was derivatized by using anhydrous conditions, and the resultant pentafluorobenzyl carbonate also exhibited a predominant [M - 181](-) ion in ECNICI-MS. Initial results indicate that the ECNICI-MS molar response of the decyl pentafluorobenzyl carbonate derivative is six-fold that of the decyl pentafluorobenzoate.

Characterization of anthraquinone-2-carbonyl chloride as an alcohol derivatization reagent for negative ion chemical ionization mass spectrometry.

Anthraquinone-2-carbonyl chloride has been utilized as a derivatization reagent for alcohols to impart electron affinity and aid in transport via a particle beam liquid chromatography-mass spectrometry (LC/MS) interface. In addition, the gas chromatographic-mass spectrometry, UV, fluorescence, and electrochemical characteristics of the derivatives were determined. A series of model compounds, 2-phenylethanol (phenethyl alcohol), 1-phenyl-2-propanol, 2-methyl-l-phenyl-2-propanol, hexanol, and methyl 2-methylglycerate, were used as analytes.The particle beam LC/MS properties of the resultant anthraquinone carboxylate esters were determined in electron impact (EI) and negative ion chemical ionization (NCI) modes. The NCI responses of these anthraquinone carboxylate esters were compared with the corresponding 3,5-dinitrobenzoate esters. The anthraquinone carboxylate esters exhibited an NCI to EI sensitivity enhancement of 113 and were detected in NCI at a tenfold lower concentration than the corresponding 3,5-dinitrobenzoate esters. A detection limit of 26 pg injected on column was achieved for phenethyl anthraquinone carboxylate in NCI by using selected ion monitoring.