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13C-NMR spectra of isoechinulins A, B and C, metabolites from Aspergillus ruber, were fully assigned on the basis of chemical shifts and multiplicities and comparison with their analogues. Taking advantage of the symmetrical structure of the diketopiperazine ring, the stereochemistry of the trisubstituted carbon-carbon double bond in a dehydrotryptophyl moiety was determined as Z (cis) by measuring the coupling constants, , in the proton nondecoupled spectrum of isoechinulin B.

The structures of ezomycins A1. and A2, antifungal antibiotics produced by a strain of Streptomyces, were determined as 1 and 2, respectively, by degradative and spectrometric studies.

From 1.2 × 106 male adult heads of the silkworm, Bombyx mori, 0.16 mg of bombyxin-IV was isolated, which was a novel molecular species of bombyxin, previously called 4K-prothoracicotropic hormone. Injection of 0.1 ng of bombyxin-IV into a dauer pupa of the Eri-silkworm, Samia cynthia ricini, evoked adult development. Microsequencing, chemical modification, enzymatic digestion, and fast atom bombardment mass spectrometry showed that bombyxin-IV consisted of two heterogeneous peptides linked by disulfide bonds and had a considerable sequence homology (62.5%) with bombyxin-II.

Twelve new quarternary ammonium compounds were synthesized and their plant growth retarding activities were examined. Among the candidates, N,N,N-trimethyl-l-methyl-3-(3′,3′5′-trimethylcyclohexyl)- and N,N,N-trimethyl-l-methyl-3-(3′,3′,5′,5′-tetramethylcyclohexyl)-2-propenylammonium iodides were the most effective to suppress the growth of rice and cucumber seedlings, and their activities were far stronger than those of any growth retardants hitherto known.

From the phytopathogenic fungus, Colletotrichum nicotianae, three phytotoxic substances have been isolated and named colletotrichin, colletotrichins B and C (1, 2 and 3). The structures of these compounds have been elucidated from the physical and chemical evidence. When applied on the tobacco leaves, colletotrichins induced the symptom similar to that of the tobacco anthracnose caused by C. nicotianae. The compounds were also toxic to the lettuce and rice seedlings.

A new insecticidal cyclodepsipeptide, bassianolide (1), was isolated from the mycelia of two entomophagous fungi and its structure was elucidated. Silkworm larvae exhibited an atonic symptom and were killed by administration of 1.

Three acidic growth inhibitors were isolated from leaves of peanut and were identified as ferulic acid, p-cumaric acid and salicylic acid, respectively.

The solution conformations of protodestruxin, desmethyldestruxtn B and destruxin B, insecticidal cyclodepsipeptides, in DMSO-d6 have been studied through the use of 100–MHz proton NMR spectroscopy. Proton-deuteron exchange and temperature dependence of the peptide proton chemical shift were used to delineate peptide protons in terms of exposure to solvent. The results defined the β-alanine and isoleucine peptide protons of desmethyldestruxin B and destruxin B as solvent-shielded. A rigid conformation of desmethyldestruxin B and destruxin B, in which there are two hydrogen-bonded rings of ten atoms, is proposed. Protodestruxin seems to have a mobile conformation in DMSO–d6. The results indicate that the biological N-methylation of the alanine peptide proton in protodestruxin decreases the number of possible conformations which are stabilized by intramolecular hydrogen bonding and, as the result, fixes the molecule in a specific conformation.

Five alkaloids were isolated from ripe fruits of Evodia rutaecarpa Hook, f.et Thoms. Four of these were found to be indoloquinazoline type alkaloids: rutecarpine (I), evodiamine (II) and two new alkaloids, dihydrorutecarpine (IV) and its 14-formyl derivative (III). The remaining one was a new quinolone alkaloid, 1-methyl-2-nonyl-4(1H)-quinolone (V). The synthesis of II, III and IV was also achieved.

One molecular species of prothoracicotropic hormone with a molecular weight of about 22, 000 (22K-PTTH) of the silkworm, Bombyx mori, was isolated from 5 × 105 adult heads. The purification procedure consisted of 16 steps including defatting, salt-extraction, fractional precipitations, conventional column chromatographies, and high performance liquid chromatographies. An approximately 5 × 106-fold purification was attained to yield 5.4 μg (0.25 nmol) of the pure hormone with a recovery of 3.3%. Injection of 0.11 ng of the purified 22K-PTTH could elicit adult development in a brainless Bombyx pupa. 22K-PTTH is a basic protein (pI 7.7 ~ 8.7) containing disulfide bond(s). The amino-terminal amino acid sequence of 22K-PTTH was determined to be Gly-Asn-Ile-Gln-Val-Glu-Asn-Gln-Ile-Pro-Asp-Pro-.

A peptidyl factor named α substance-IA, which induces sexual agglutinability in a type cells of the heterothallic Saccharomyces cerevisiae, was found to be composed of twelve amino acid residues. Further, the amino acid sequence was elucidated by the combined application of the Edman-dansyl procedure and the cleavage reaction with cyanogen bromide to be H- His-Trp-Leu-Gln-Leu-Lys-Pro-GIy-Gln-Pro-Met-Tyr-OH.

On hydrolysis with Dowex 50W, ezomycin A1 (1) C26H40N8O16S gave ezomycin A2 (2) C19H28N6O13 and l-cystathionine (3) as main products. Further acid hydrolysis of 2 afforded an amino uronic acid named ezoaminuroic acid (5), 3-amino-3,4-dideoxy-d-xylohexopyranuroic acid, and cytosine. Ezoaminuroic acid, l-cystathionine and cytosine were found to constitute ezomycin A1.

Three quinolone alkaloids were isolated from fresh leaves and fruits of Evodia rutaecarpa Hook. f. et Thoms. and were structurally elucidated as 1-methyl-2-pentadecyl-4(1H)-quinolone (I), 1-methyl-2-tridecyl-4(1H)-quinolone(dihydroevocarpine,II) and 1-methyl-2-undecyl-4(1H)-quinolone (III) on the basis of spectral measurement and synthesis.

Structures of the antifungal antibiotics, ezomycins B1 (1), B2 (21), C1 (3), C2 (4), D1 (5) and D2 (6), were elucidated by degradative and spectrometric studies. Compound 3 was found to be the α-anomer of 1 and 4 was that of 2. Compounds 2, 4 and 6 were easily interconvertible under weak acidic conditions.

Rhodotorucine A, which induces mating tube formation in Rhodospridium toruloides, was found to be a novel peptide composed of eleven amino acid residues with a lipophilic group at the C-terminus. The amino acid sequence of the peptide was determined by Edman degradation and enzymatic hydrolyses. The C-terminus of rhodotorucine A was revealed to be S-farnesylcysteine by proton magnetic resonance, mass spectrometry and chemical synthesis. We proposed the following structure for rhodotorucine A. H-Tyr-Pro-Glu-Ile-Ser-Trp-Thr-Arg-Asn-Gly-Cys(S-farnesyl)-OH.

Effects of hydrofluorene and hydrophenanthrene compounds derived from dehydroabietic acid on the second leaf sheath growth of rice seedlings were examined in the presence and absence of gibberellin A3(GA3). In the absence of GA3, nineteen compounds at 100 ppm inhibited more than 20% the growth of normal rice seedlings. In the presence of GA3 (1.5 ppm) with dwarf rice seedlings, nine compounds at 500 ppm suppressed the elongation caused by the hormone, and a compound was slightly promotive. Then, three compounds were selected and subjected to the bioassay under various conditions.

From the antifungal ezomycin complex produced by a strain of Streptomyces were isolated six new components named ezomycins B1, B2, C1, C2, D1 and D2. They are novel pseudouridine-type C-C nucleoside antibiotics, of which B1 is the most active.

After twelve steps of purification, a peptidyl factor named rhodotorucine A*1 was isolated in pure form from a culture filtrate of A type cells of Rhodosporidium toruloides. Rhodotorucine A induced the mating tube formation in a cells, opposite mating type cells of the yeast, at a concentration of 8 ng/ml. A factor in the previous papers is now renamed rhodotorucine A.

Rhodotorucine A is a lipophilic undecapeptide having a novel amino acid, S-farnesyl-cysteine, at the C-terminus. Sulfonium salt formation of rhodotorucine A and subsequent hydrolysis afforded trans-trans-farnesol, trans-nerolidol and α-bisabolol. Thus, the geometry of the side chain of S-farnesylcysteine was established unambiguously as all trans. The reaction mechanism was also discussed.

Two lignans were isolated from leaves of Magnolia kobus DC. as growth inhibitors on silkworm larvae and structurally elucidated as sesamin (I) and kobusin (II) which has been hitherto unknown.

A new alkaloid named stemospironine (I) was isolated together with stemofoline (II) as the main insecticidal constituents of leaves and stems of Stemona japonica Miq. The absolute stereostructure of I has been determined by X-ray crystallographic analysis. Stemofoline (II) showed a much stronger activity than I against silkworm larvae (Bombyx mori L.) by oral administration.

A simple procedure for partial purification of silkworm brain hormone starting with heads of Bombyx moths is described. The method is unique in that it can supply samples with a definite activity without chromatography and bioassay during the purification process. The titer of brain hormone in every batch is 30~40 Samia units/head (specific activity, 1~2μg/Samia unit). Some chromatographic behaviors of the hormone are also reported.

Cinnzeylanine (1) and cinnzeylanol (2) were isolated from barks of Cinnamonum zeylanicum Nees (ceylon cinnamon). Chemical properties and NMR spectra of the both compounds are disccused in terms of their structures which were determined by the X-ray analysis and chemical reactions. When administered orally with artificial diet, both 1 and 2 killed larvae of silkworm, Bombyx mori L. at a dose of 16 ppm and inhibited larval ecdysis at 2~ 4 ppm.

A new compound was isolated from leaves of peanut. Its structure was determined as o-(malonylamino)benzoic acid on the basis of physicochemical evidences.

A new gibberellin C20H26O6, tentatively named “bamboo gibberellin”, was isolated from water extract of bamboo shoots (Phyllostachys edulis) through successive purification procedures: countercurren...