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Biomedical subjects

H E Hadd

Publications and source records attributed to H E Hadd.

17 recordsLinked to original sources
PubMed1995

The scarlet letter: Reichstein's Substance S. A comparison of the angiostatic properties of 5 alpha-tetrahydro S and 5 beta-tetrahydro S.

5 beta-Tetrahydro-Reichstein's Substance S (3 alpha, 5 beta-THS) from different sources yielded variable bioassay activity in the chick chorio-allantoic membrane assay system. Physical characterization showed impure products. Synthesis of this compound by two different routes yielded active and inactive 3 alpha, 5 beta-THS. Of the other two epimers, 3 beta, 5 beta-THS (epi-THS) and 3 alpha, 5 alpha-THS (allo-THS), only the latter was active. These results suggest that the impurities present in 3 alpha, 5 beta-THS synthesized by reduction of the alpha, beta-unsaturated ketone of Substance S might be either or both the epi-/allo-epimers (3 beta, 5 beta-THS and 3 alpha, 5 alpha-THS, respectively), with only the latter contributing the positive angiostatic activity to the mixture. Of the two synthetically derived compounds, only the latter was shown to maintain the activity, whereas 3 alpha, 5 beta-THS was not antiangiogenic.

Allantois↗
PubMed1983

Synthesis and characterization of the anomeric pair of 17 beta-glucuronides of ethynylestradiol.

The alpha- and beta-anomers of the 17 beta-D-glucuronide conjugate of ethynylestradiol were synthesized by the SnCl4-promoted reaction between beta-acetoxy GAM and the t-17 beta-hydroxyl group of EE2-3-acetate. The conjugates were resolved by crystallization and HPLC. Positive identification was established by u.v. spectrophotometry, i.r. and mass spectrometry and 1H- and 13C-n.m.r. The structure of the beta-anomer was confirmed by X-ray crystallographic analysis. In addition, the alpha-anomer was refractory to hydrolysis by bovine beta-glucuronidase, establishing a biochemical difference between the conjugate pair.

Chromatography, High Pressure Liquid↗
PubMed1978

A new and improved synthesis of 19-iodocholesterol 3-acetate.

19-Iodocholesterol 3-acetate (VI) was synthesized in a single step by iodo group substitution for hydroxyl using either one of two different reagents: (1) carbodiimidonium methiodide (VIII) or (2) triphenyl-phosphine/N-iodosuccinimide (IX). The yields were as satisfactory as those obtained from the two step iodide replacement of a 19-hydroxy group via the 19-tosyloxy group. The principal intermediate, 19-hydroxy cholesterol 3-acetate (V), was derived in appreciable quantities, and relatively inexpensively, through the Pb (OCOCH3) 4 photolytic oxidation of the bromohydrin of cholesterol 3-acetate (III) to the epoxide (IV) thence Zn reduction to the 19-hydroxy compound. A specially designed 12 liter flask was of aid in accomplishing the photolysis reaction. Dry column chromatography with the supportive puncture sampling was integral to achieving the good yields and high purity of 19-iodocholesterol (VIII).

19-Iodocholesterol↗
PubMed1977

The use of tetrahydrocortisone-3-beta-D-glucuronide in the measurement of urinary 17-hydroxycorticosteroids.

THE 3-G was added to H2O and 56 urines, and the recovered THE was measured by the Porter-Silber method. The recovery from H2O was quantitative (98 +/- 2%), but highly variables from urine, ranging from 35 to 100%. The necessity of the proper standard in analysis of urinary steroid glucuronides was demonstrated. The presence in urine of endogenous inhibitors to beta-glucuronidase was confirmed.

17-Hydroxycorticosteroids↗
PubMedDate not supplied

Ethynyl cleavage of 17 alpha-ethynylestradiol in the rhesus monkey.

17 alpha-Ethynylestradiol (EE2)[20,21-14C] and [9,11-3H] were administered by intragastric intubation to three adult female rhesus monkeys. Quantification of the tritium isotope indicated that the peak plasma radioactivity (3.4-6.8% of dose) occurred between 30 and 60 min, whereas 36-39% of the administered tritium appeared in the urine in the first 96 hr. Fecal excretion was 9.17.0% during the same period. Fractionation and isolation of the urinary conjugates were accomplished by chromatography on Sephadex LH-20 followed by HPLC. Cochromatography of radioactive fractions with authentic steroid glucuronide standards gave presumptive evidence for the presence of ethynylestradiol and estrone glucuronides. Following hydrolysis, the tritium-labeled natural estrogens, estrone and estradiol-17 beta, were identified with reverse-isotope recrystallization, demonstrating that the de-ethynylation of EE2 had occurred.

Animals↗