Kunikatsu Shirahata

Isolation and characterization of chum salmon growth hormone

Two molecular forms of salmon growth hormone (sGH), sGH I and II, have been isolated from the pituitary glands of the chum salmon (Oncorhynchus keta); a two-step extraction procedure, under alkaline (pH 10) conditions, subsequent to acid-acetone extraction was employed for extraction of the sGHs. They were then purified by iso-electric precipitation at pH 5.6, gel filtration on Sephadex G-100, and high-performance liquid chromatography on ODS. Intraperitoneal injection of sGH I and a combination of sGH I and II at doses of 0.01 microgram/g body wt at different intervals resulted in a significant increase in body weight and length of juvenile rainbow trout. The GH producing cells in the pituitary of mature chum salmon were identified in the proximal pars distalis immunocytochemically with a specific antiserum; no cross-reactivity was seen in the prolactin cells in the rostral pars distalis. A molecular weight of 22,000 was estimated for both sGHs by gel electrophoresis in sodium dodecyl sulfate. Isoelectric points, by gel electrofocusing, of 5.6 and 6.0 were estimated for sGH I and II, respectively, with differences present in the amino acid composition and the N-terminal residue, suggesting that they may be genetic variants coded on two separate genes. The partial amino acid sequences of sGH I at both terminal regions have been determined.

Isolation of two forms of growth hormone secreted from eel pituitaries in vitro

Two forms of growth hormone (GH) were purified by chromatofocusing of medium from cultured Japanese eel (Anguilla japonica) pituitaries. The pituitaries were organ-cultured in Eagles minimum essential medium with Earles salts. Following polyacrylamide gel electrophoresis of the medium at pH 9.5, two prominent bands were seen with Rf 0.36 and 0.29; they were designated as eGHI and eGHII, respectively. Seven-hundred fifty milliliters of medium, in which 260 pituitaries were cultured for 6-10 weeks, was concentrated by DIAFLO membrane (YM-5) and subjected to gel filtration on a Sephadex G-75 column and to chromatofocusing on a PBE-94 column. eGHI and II were finally purified by gel filtration on a Sephadex G-75 column, yielding 2.0 mg of eGHI and 1.3 mg of eGHII. Both eGHI and eGHII were equipotent to ovine GH in promoting growth of juvenile rainbow trout. The putative GH-producing cells in the proximal pars distalis of the eel pituitary were stained specifically with antisera raised against eGHI or eGHII; no cross-reactivity was seen in the follicular prolactin cells in the rostral pars distalis. As determined by gel isoelectric focusing, eGHI and eGHII have isoelectric points of 6.3 and 6.7, respectively. Identical molecular masses of 23,000 Da were determined by sodium dodecyl sulfate gel electrophoresis. Their amino acid compositions strongly resembled each other; comparison of the partial N-terminal amino acids indicates that sequence 1 to 36 of GHII is exactly the same as 4 to 39 of GHI.

Constituents of genus petasites—IV : Bakkenolide-A, a sesquiterpene of novel carbon skeleton

Abstract A group of a new type of sesquiterpene, named bakkenolide-A, B, C, D, and E was isolated from the buds of Petasites japonicus (Sieb. et Zucc.) Maxim. subsp. giganteus (Fr. Schm.) Kitam. (Japanese name, Akita-buki). They have a novel spiro-γ-lactone grouping. The structure and stereochemistry including absolute configuration was established for bakkenolide-A (B-A) ( 1 ) on the basis of chemical degradations (Chart 1, 2) and physical measurements. The C 11 -dicarboxylic acid ( 5 ), a main degradation product of B-A during potassium permanganate oxidation, was instrumental in determination of the full structure. The absolute configuration was based on the transformation of B-A to the known perhydroindanone derivative ( 12 ).

The structure of tetronolide, the aglycone of antitumor antibiotic tetrocarcin

Abstract X-ray analysis has determined the structure of tetronolide, which has a unique spiro γ-lactone group.

STRUCTURE OF A NOVEL Ca2+ AND CALMODULIN-DEPENDENT CYCLIC NUCLEOTIDE PHOSPHODIESTERASE INHIBITOR K-259-2

The structure of K-259-2, a potent inhibitor of Ca2+ and calmodulin-dependent cyclic nucleotide phosphodiesterase, was determined to be 3-(2Z-2-ethyl-2-butenyl)-1,6,8-trihydroxy-anthraquinone-2-carboxyl ic acid by chemical conversion and spectral studies.

Mass spectra of bakkenolides and their derivatives

Abstract Mass spectra (including high resolutions) of bakkenolides and their derivatives (I–X) were measured and the common fragmentation patterns discussed with the help of metastable ions. Fragmentation of B-A(I) is characterized by a McLafferty-type rearrangement, whereas oxygen functions at 1 and 9-positions of B-A take part in the fragmentation of bakkenolides-B, C, D and E.

Improved Synthesis of Mitomycin G

Abstract Mitomycin G 2 was derived from mitomycin B 5 by 3 steps in an overall yield of 43 %.

X-Ray determination of the molecular structure of the novel antibiotic DC-52-d, 6-hydroxymethyl-3,12-imino-7-methoxy-13-methyl-1,2,3,4-tetrahydroazepino[1,2-b]isoquinoline-1-carboxylic acid

The molecular geometry of the title compound has been determined by X-ray diffraction. The molecule has a novel tetracyclic skeleton. Crystallographic data are a= 11.185(2), b= 15.878(2), c= 11.1184(9)A, Z= 4, space group P212121. Diffractometer intensity measurements were made with Mo-Kα radiation and least-squares adjustment of the atomic parameters converged at Rw 0.069 for 1 793 |F0| values.