A biological test for vitamin P activity

Synthesis and biological activity of vitamin D3-sulfate.

Vitamin D3-3 beta-sulfate has been synthesized using pyridine sulfur trioxide as the sulfate donor. It has been shown to be pure by high performance liquid chromatography and spectral methods. Unlike previous reports, the product has been identified unambiguously as the 3 beta-sulfate ester of vitamin D3 by its ultraviolet, nuclear magnetic resonance, infrared, and mass spectra. The biological ...

Citrus Vitamin P - Ii. the Antibiotic Activity of Citrus Bioflavonoids

color that occurred during storage of the packs of canned grapefruit sections collected from plant A during the 1953-54 season, it was decided to obtain samples from two other plants during the following season in order to confirm such results. However, when this was done, the data obtained, as shown in Tables 2 and 3, indicated that the differences found after storage at 90 °F. for six months ...

Ccxciii. Vitamin a Determination: Rela- Tion between the Biological, Chemical and Physical Methods of Test

Synthesis, Characterization, and Biological Activity Studies on Fanlizhicyclopeptide A

The synthesis of a proline-rich cyclic heptapeptide, fanlizhicyclopeptide A (8), previouslyisolated from the fruits of Annona squamosa (sugar-apples), is described via coupling oftetrapeptide l-prolyl-l-tyrosyl-l-leucyl-l-proline methyl ester with tripeptide Boc-glycyl-lvalyl-l-proline followed by cyclization of the linear fragment having seven amino acid units.Structure of the synthesized cycl...

A Recursive Test for P-matrices

The time complexity for testing whether an n-by-n real matrix is a P-matrix is reduced from O( 2 n ) to O( 2 ) by applying recursively a criterion for P-matrices based on Schur complementation. A Matlab program implementing the associated algorithm is provided. AMS subject classification: 15A48, 90-08, 15A15.