Isolation and structure of bacterial sex pheromone, cPD1

The Streptococcus faecalis sex pheromone cPD1, which induces a mating response in cells harboring the conjugative plasmid pPD1, has been isolated and its structure determined. It was found to have a molecular weight of 912, and its amino acid sequence was H-Phe-Leu-Val-Met-Phe-Leu-Ser-Gly-OH. A synthetic octapeptide showed the same biological activity and chromatographic behavior as the isolated cPD1. Pheromone activity was detectable at a concentration of approximately 4 X 10(-11)M.

Terrecyclic acid A, a new antibiotic from Aspergillus terreus. III. 13C NMR spectrum of terrecyclic acid A

Assignment of the fifteen carbons of terrecyclic acid A, C15H20O3, a new sesquiterpene antibiotic, in the 13C NMR spectrum was performed by 13C-[1H] selective proton decoupling experiments, comparison with spectra of its derivatives and chemical shifts.

Isolation and some characterization of the prothoracicotropic hormone from Bombyx mori

The prothoracicotropic hormone (PTTH) was isolated from adult heads of Bombyx mori. Fifty micrograms of pure PTTH was obtained from 648,000 heads through a 15-step purification procedure with a 2 X 10(6)-fold purification and an 8% recovery. Chemical analyses of this PTTH have shown that it is a single-chain peptide consisting of 40-43 amino acid residues (MW, 4330-4740), the N-terminus of which is glycine. As little as 0.1 ng of PTTH elicited adult development in a debrained pupa of Samia cynthia ricini. Five picograms of PTTH directly stimulated the prothoracic glands in vitro so as to enhance ecdysone release. The hemolymph ecdysteroids of brainless Samia pupae that were developed by PTTH injection increased with essentially the same pattern as in developing normal pupae.

Isolation of tremerogens A-9291-I and A-9291-II, novel sex hormones of tremella brasiliensis

Two hormones, tremerogens A-9291-I and A-9291-II, that induce conjugation tube formation in a-type cells of Tremella brasiliensis were isolated from the culture filtrate of A-type cells. Both hormones are peptides and they have similar amino acid compositions. The N-terminal amino acids of these peptides are aspartic acid or asparagine.

Inhibitory effect of bassianolide, a cyclodepsipeptide, on drug-induced contractions of isolated smooth muscle preparations

Bassianolide (BASS) is a cyclodepsipeptide isolated from cultured mycelia of Beauveria bassiana and is pathogenic to insects. In a longitudinal muscle preparation from guinea pig ileum, 10(-6) M BASS almost irreversibly inhibited an isotonic contraction induced by acetylcholine (ACH) and made the dose-response curve shift in parallel to the right (pA2: 7.6). It also inhibited the contractions induced by carbachol, pilocarpine, histamine, 5-hydroxytriptamine (5-HT) and prostaglandin E2, but did not inhibit the contraction induced by barium or a high concentration (40-60 mM) of potassium (high K). When applied to the guinea pig vas deferens, 10(-8) - 10(-7) M BASS inhibited an isometric contraction induced by norepinephrine (NE) (3 x 10(-6) - 10(-5) M), phenylephrine (3 x 10(-6) - 10(-5) M) or ACH (10(-6) - 10(-5) M). When the contractions of the three agonists exceeded the concentrations mentioned above, BASS failed to exert an inhibitory effect upon any of these agonists. It also inhibited the contraction caused by carbachol and histamine, but did not inhibit that induced by barium or high K. BASS itself failed to cause the contraction or relaxation of both muscle preparations. From these results, it is suggested that BASS inhibits the contraction induced by an agonist which acts upon selective sites of smooth muscle cells, but which does not inhibit a contraction induced by an agonist that has an effect on non-selective sites of cells.

Large-scale purification of prothoracicotropic hormone of the silkworm (Bombyx mori)

Prothoracicotropic hormone has been successfully extracted from as many as 2,800,000 silkworm male adult heads and purified partially through an 8-step procedure. Approximately 7 microgram of the crude preparation ("crude PTTH") shows activity in the debrained Samia pupa test. A further 4-step chromatographic purification of the "crude PTTH" derived from 100,000 Bombyx heads yields 3.4 mg of purified preparation ("highly purified PTTH"), of which 7 ng causes adult development in a debrained Samia pupa.