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The syntheses of novel rigid dendritic ligands and their ruthenium complexes, in which 1,3,5-phenylene-based hydrocarbon dendron units were directly connected to a phenanthroline ligand at the 3 and 8 positions, are described. Preliminary absorption and fluorescence results are indicative of highly efficient energy transfer within the rigid metallodendrimers.

A main component of ganglioside M5 from egg of the sea urchin, Anthocidaris crassispina, Neu5Gcα2 → 6Glcβ1 → 1Cer (1), which has N-glycolyl group in neuraminic acid part, as well as phytosphingosine and saturated nonhydroxy fatty acid in ceramide part was first synthesized starting from N-acetylneuraminic acid.

The isomers of sialic acid with 6-acetylamino group, 1a and 1b were synthesized from furanose 3a and 3b respectively obtained by aldol condensation of D -glucose with oxalacetic acid.

N-Acetylneuramimic acid (sialic acid) 1 was synthesized through relatively short steps from d -glucose via a key intermediate 1,5-lactone derivative obtained from the pyranose isomer of the aldol condensation products of d -glucose with oxalacetic acid.

Nephritogenoside (1), proposed as a nephritogenic triglycosylhenicosapeptide with asparagine N-α-glycoside linkage, was first synthesized by the coupling of triglycosyldipeptide active ester with the nonadecapeptide (3–21) using allyloxycarbonyl group as the final protecting group. A β-anomeric glycopeptide was also prepared.

A lysophosphatidylserine with 19:4 acyl group proposed as a candidate of DLIS-2, an endogenous digoxin-like substance was chemically synthesized. The synthetic compound showed a significant activity of Na + ,K + -ATPase inhibition, which has been accepted as a major indicator activity for the essential hypertension.

A site-specific ring opening reaction for the antifungal depsipeptide aureobasidin A occurred on treatment with HF at room temperature for 1 hour. The open-chain peptide thus obtained was recyclized to afford the original aureobasidin A without any modification.

The structure of the lipid A component of E. coli lippopolysaccharide was determined by means of chemical and 2D-NMR methods unequivocally to be a glucosamine β(1′-6)-disaccharide 1,4′-diphosphate acylated at the two hydroxyl (positions C-3 and −3′) and the two amino groups.

Title compounds ( 1a,b ) and an analogous disaccharide ( 2a ) were synthesized via a reaction of a ketosidic fluoride of 3-deoxy-D- manno -2-octulosonic acid (KDO) ( 3 ) with phosphorylated acyl glucosamine di- and monosaccharides.

Total Synthesis of antibiotic althiomycin has been achieved starting from D-cysteine. The imide bond between thiazoline and the pyrrolinone part was constructed by coupling reaction of sodium salt of pyrrolinone with cysteine active ester or by photoreaction with diketene. The hydroxymethyl group attached on the carbon adjacent to C-2 of the thiazoline ring, was introduced by aldol condensation posterior to the thiazoline ring formation. The thiazole part was introduced in a final step in whole process of the total synthesis of the antibiotic. The synthetic althiomycin was identical with the natural antibiotic in all respects.

A synthetic route was established to construct the proposed structure of lipid A which consists of β (1–6) glucosamine disaccharide 1,4′-diphosphate O,N-acylated with (R)-3-hydroxy- or (R)-3-acyloxytetradecanoic acid.

The first total synthesis of streptothricin F was achieved and its structure was unequivocally confirmed.

Dityromycin is a peptide antibiotic isolated from the culture broth of the soil microorganism, Streptomyces sp. strain No. AM-2504, showing activities against Bacillus, Corynebacterium, and Clostridium. Dityromycin was clarified to be composed of N-MeVal, Pro, Val, Phenylglycine, CH3NH2, N,N-Me2Thr and di-α-amino acid containing diphenylether moiety. The peptide sequence except one labile amino acid residue was determined by partial hydrolysis, chemical cleavage, and the Edman degradation. The unknown amino acid was finally deduced to be the dehydroamino acid containing epoxide, resulting in an elucidation of whole structure of the antibiotic.

The structure of the oligosaccharide portion of an E.coli Re lipopolysaccharide was determined as α-KDO-(2→4)-α-KDO-(2→6)-β-GlcN-α(1→6)-α-GlcN, bisphosphorylated at positions 1 and 4′. Taking into account the previous determination of the acylation pattern of the GlcN disaccharide, the total structure of E.coli Re LPS was thus established.

6- O -(2-Deoxy-2-myristoylamino-6- O -myristoyl-β-D-glucopyranosyl)-2-deoxy-2-myristoylamino-3,4-di- O -myristoyl-D-glucopyranose ( 2 ) was prepared in a synthetic approach to lipid A which is the active center of bacterial endotoxin.

1-α-Monophosphate ( 2 ), 4′-monophosphate ( 3 ), and 1-α, 4′-diphosphate ( 4 ) of 6-0-(2-deoxy-2-tetradecanoylamino-6-0-tetradecanoyl-β-D-glucopyranosyl) -2-deoxy-2-tetradecanoylamino-3, 4-di -0-tetradecanoyl-D-glucopyranose were prepared in order to elucidate the role of phosphate moieties in endotoxic activity of lipid A.

Streptolidine (roseonine, geamine) (1), a guanidino amino acid component of the streptothricin group antibiotics, was synthesized starting from D-ribose (8). The epimino compound (11b) was prepared from 8 in five synthetic steps. Azidolysis of 11b gave the arabino-type compound (12b), which in turn was converted to the key intermediate tribenzyloxycarbamido lactone (23b) by oxidation of C-1. The lactone 23b was rearranged to the free lactam (4) after deprotection, and then guanidinated with cyanogen bromide. The identity of the hydrolysis product of this guanidino lactam with natural streptolidine in all respects certified the proposed structure involving the steric configurations.

The first total synthesis of E. coli lipid A ( 1 ) is described. The synthetic compound was identical with a natural specimen and exhibited the full endotoxic activity. It was thus conclusively proved by this chemical synthesis that lipid A is the active principle of bacterial endotoxin.

A total synthesis of 2,2′-N; 3,3′-O-tetraquis[(R)-3-hydroxytetradecanoyl]-β(1–6)-D-glucosamine disaccharide 1,4′-diphosphate is described. This is the first confirmation of the fundamental structure of lipid A since the synthetic compound exhibited most of the characteristic biological activities of natural endotoxin.

1-Dephospho E. coli lipid A ( 3 ) was synthesized and shown to be identical with the corresponding derivative isolated from bacterial cells. This provides the unequivocal evidence supporting the structure of E. coli lipid A ( 2 ) recently proposed by us.

Total synthesis of a lanthionine peptide nisin was successfully achieved for the first time by application of new methods for preparations of dehydroalanine and lanthionine moieties, resulting in a confirmation of the proposed structure.

The structure of ancovenin, a new peptide inhibitor of angiotensin I converting enzyme, was determined to be a unique tricyclic peptide which comprises sixteen amino acid residues including dehydroalanine and three sulfide amino acids as unusual components.

Two new phospholipids, 2-N; 3-O-bis (R)-3-hydroxytetradecanoyl-glucosamine 1-phosphate and 2-N-(R) -3-hexadecanoyloxytetradecanoyl-3-O-(R)-3-hydroxytetradecanoylglucosamine 1-phosphate, were synthesized and identified with natural lipid X and lipid Y respectively.

To elucidate the stereospecificity of the selenium-containing hydrogenase from Methanocuccus vannielii , ( R ) - and ( S ) - [4- 2 H 1 -3,4-dihydro-7-hydroxy-1-hydroxyethylquinolinone were synthesized as authentic samples for comparison with the compound which was derived from the enzymic reaction product.

Long-chain acyl derivatives of the disaccharide dipeptide, which is a common building unit of bacterial cell walls, were synthesized in order to test their immunostimulating activity.

α-Ketopyranosyl fluorides, 2 and 3, of 4,5:7,8-di-O-isopropylidene KDO methyl and benzyl esters were prepared and shown to act as effective glycosyl donors. X-Ray structure analysis of 2 and 1H NMR study established the boat (B3,6) conformation of the di-O-isopropylidene derivatives of KDO and enabled the assignment of their anomeric configurations.

A new cyclopropyl amino acid, carnosadine, was isolated from red alga Grateloupia carnosa and the structure was determined to be 1-amino-2-guanidino-methylcylopropane-1-carboxylic acid from the results of NMR, mass spectrometry and coloring tests.

Lepidopteran, self-defence substance produced by silkworm (Bombyx mori), was synthesized by the solution method for confirmation of the proposed structure.

Bulgecinine, a new proline type amino acid in bulgecins, was synthesized stereospecifically by use of D -glucose as a chiral precursor.

The chemical structure of E. coli lipid A was elucidated to be 2 by determination of the nature of the individual acyl groups bound to the two hydroxyl groups in positions 3,3′ and the two amino groups of the D-glucosamine disaccharide phosphate backbone.

An acylated tetrasaccharide phosphate 1 was synthesized and identified with the corresponding natural derivative obtained from LPS of E. coli Re mutant by cleavage of the glycosidic phosphate group. The proposed structure of the natural Re LPS was thus confirmed.

The dehydroxymethyl analog of bulgecin A was synthesized in order to establish a synthetic route of bulgecin A.

The structure of lanthiopeptin, a new lanthionine peptide effective against Herpes virus, was newly determined. It has a unique tetracyclic sequence which is very similar to but different from the proposed structure for Ro 09-0198. However, Ro 09-0198 was found to be quite the same compound as lanthiopeptin in all respects.

A new spider toxin NSTX-3 was chemically synthesized for confirmation of the proposed structure and use in the investigation of neuroscience.

Optically active carnosadine, a new cyclopropyl amino acid from red alga Grateloupia carnosa , was synthesized and its absolute structure was determined.