Synthetic lipids containing a tripeptide moiety have been found to form aggregates not only in water but organic solvents as well. Aggregate structure was examined in this study by Fourie transform infrared spectroscopy and surface structure by atomic force microscopy. Tripeptide-containing lipids were found to form a supramolecular structures possessing numerous parallel β-sheets. The supramolecule should prove useful as a model of amyloid fibers whose accumulation causes fatal diseases such as Alzheimer's dementia. The diversity of surface structure of air-dried film of peptide-containing lipids indicates the possibility of the formation of a new molecular architecture system.

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Cholic acid derivatives form crystalline inclusion compounds with various organic substances. More than two hundred their crystal structures have been used in the study of molecular recognition through their assemblies. Host molecules were noted to combine via intermolecular hydrogen bonds to produce diversible assemblies comprised of layers and helices. The explanation for these assemblies is that the hosts have characteristic facial structures with chirality, directionality and amphiphilicity. Multiple hydrogen bonding groups are essential to the formation of the assemblies. Slight change in the host and guest molecules may frequently lead to great change in the assemblies due to exchange of the corresponding hydrogen bonding network. Different intermolecular hydrogen bonding networks produced polymorphic crystals, depending on the particular guest components. The hosts exhibited very different inclusion ability toward aliphatic alcohols due to additional hydrogen bonding groups situated between host and guest molecules rather than among host molecules. Inclusion spaces are effective as fields for enantioselective resolution and polymerization reactions. This study has demonstrated on analogy between cholic acid derivatives and proteins, and on the basis of which, chiral and sequential carbon chains may be concluded to express their information through molecular assemblies with multiple hydrogen bonds.

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This paper reviews the synthesis and applications of DNA/synthetic polymer conjugates. The conjugates have been applied to the separation of DNA-binding molecules and nucleic acids. One principle advantage of conjugates is that an affinity reaction can be carried out in homogeneous solution with high efficiency. The conjugates were used as DNA probes to augment detection sensitivity. Synthetic polymers carrying multiple reporter groups conjugated with DNA. In an antisense and antigene strategy, conjugation of oligonucleotide (ODN) with synthetic polymer may be an effective molecular design. The functions of synthetic polymers in a conjugate are to protect ODN from nuclease degradation and cover the ODN anionic charge. DNA has been found useful in supramolecular chemistry as programmable molecular glue and template for molecular alignment. A hydrogel, polymeric micelle structure and (conjugated DNA/native DNA) -tandemly connected molecules have been constructed through use of DNA/synthetic polymer conjugates.

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Hydrophobized polysaccharides such as cholesterol group-bearing pullulan (CHP) were noted to spontaneously form hydrogel nanoparticles in dilute aqueous solution by intra-and/or intermolecular self-aggregation. The size, density and colloidal stability of the nanoparticle could be controlled by changing the degree of the hydrophobe substitution and hydrophobicity. In the semi-dilute region of a polymer, a macro-gel was produced through association of nanoparticles. The association and dissociation of hydrophobized polysaccharides were controlled by host-guest interactions with cyclodextrin (CD). Self-assembled nanoparticles bound various hydrophobic substances and soluble proteins. Protein thermal stability increased with complexation and that of an enzyme was enhanced by a molecular chaprone-like two-step mechanism : capture of heat-denatured unfolded protein and release of the refolded form by CD addition. Hydrophobized polysaccharides became coated on liposomes, oil-in-water emulsions and protoplast cells. The supramolecular assemblies have been shown to have broad application in biotechnology and medicine.

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Hydrophobic cavities of cyclodextrins render them capable of accommodating various guest molecules of not only lower molecular weight compounds but certain polymers with consequent inclusion complex formation. This review presents our recent studies : polymeric functions based on supramolecular-structured cyclodextrin. Polyrotaxanes as supramolecular-structured polymers were characterized for usefulness as drug carriers, implantable material, and stimuli-responsive material. Polyrotaxanes may be defined as many cyclodextrins threaded onto a polymeric chain capped with bulky-end groups. The important features of the polyrotaxanes are (i) non-covalent bonds between CDs and linear polymeric main chains, (ii) rod-like structures and (iii) chemical modification of CDs in polyrotaxanes. These chemical characteristics of noncovalent bonds give rise to supramolecular dissociation when terminal blocking-groups are eliminated and to sliding of CDs along linear polymeric main chains. New molecular architectures such as polyrotaxanes are found in the present study to be important for the expressing of polymeric functions in biomedical and smart materials.

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Potato-dextrose-agar plates are widely used as stock culture medium. While screening fungus producing highly unsaturated fatty acids, many different filamentous fungi, such as genus Mortierella, were found to grow best in the medium containing potato extract and accumulate lipids present at 35% dry cell weight. Potato protein powder is now available commercially and thus was used into present study as the solid and liquid medium cultivation of Mortierella alpina in place of potato extract. But this brought about no significant change in morphology and harvest in either case. Optimum concentrations of potato protein powder were 0.25-0.50% and 1.0-2.0% for the two media respectively. A comparison of lipid content of the fungus in the liquid medium with that of the fungus in the soy flour-dextrose liquid medium indicated use of the potato protein powder to have resulted in 50-100% more lipid production by the fungus. Examination of the various components of the media indicated amino acid composition, or other substances to possibly have been factor for this.

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Potato protein and dextrose are ideal media for cultivation of Mortierella alpina, that produces arachidonic acid. Corn peptide-dextrose medium is not suitable for growth of the fungus although amino acid compositions of the two are similar. Thus, to corn peptide- dextrose medium was added metallic salt containing quasi-major element, sodium, calcium, magnesium, phosphor, or potassium in amounts from 0.050.30% and used for liquid cultivation at 20°C in a 500-mL shake flask for 14 days. Cell growth was greatly enhanced but the lipid accumulation ratio of methyl esters (g) /dry cell weight (g) reached only 70% that of lipid in cells grown in potato-dextrose medium. Iron, copper, zinc, or manganese was then added at 2×10^-51×10^-3% to corn peptide-dextrose medium on top of phosphor and potassium for cultivation. Iron and manganese increased the lipid accumulation ratio to essentially the same extent as above with nitrogen content in the medium the same. Phosphor and potassium may be concluded essential for the growth of M. alpina and iron and manganese to have significant roles in lipid synthesis.

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We screened the inner contents of Japanese pearl oyster Pinctada fucata for surfactants which may be commercially useful as cosmetic material. Total lipids extracted were separated into total neutral lipid, glycolipid and phospholipid fractions, and the total phospholipid fraction was further fractionated into five subfractions by silica gel column chromatography. Surface tension of the total phospholipid fraction and subfractions 4 and 5 which were eluted with solvents of higher polarity was 4048 mN/m and comparable to those of commercially available surfactants for cosmetic use. Contrastingly, the surface tension values for subfractions 1 and 3 were about 30 mN/m and much lower than those of commercial surfactants.

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Examination was made of the condensation of citral (1), (R) -l-Perillaldehyde (2) and l-Myrtenal (3) using N, N-dialkylamine compounds (dimethylamine, diethylamine and di-n-propylamine) to obtain dialkylamide compounds (7a) (9c) in 2856% yield in three steps. Nine terpene derivatives obtained were tested for growth-inhibitory activity in plants. These dialkylamine derivatives, (8a), (9a) and (9b) each at a pot concentration of 500g/10a were found to express herbicidal activity toward Cyperus difformis and annual broadleaf weeds in the paddy field.

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On treating 4-biphenylyl-4'-methyl benzoate (1) with anhydrous aluminum chloride (AlCl₃) in o-dichlorobenzene at reflux temperature, 4-hydroxy-4'-methyl-3-biphenylyl phenyl ketone (3) was obtained as a rearrangement product with 4'-methyl-4-biphenylol (5). Then a rearrangement product 4-hydroxy-4'-methyl-3-biphenylyl methyl ketone (4) was obtained with 5 from 4-biphenylyl-4'-methyl acetate (2) under the same reaction conditions. The 4-biphenylyl ester 2 proceeded firster than other ester 1 in o-dichlorobenzene and toluene. A methyl group on 4'-position of 1 and 2 appeared to lose the reaction rate compared to 4-biphenylyl benzoate and 4-biphenylyl acetate. The Fries rearrangement of 1 may possibly proceed via an intramolecular pathway that involved some intermolecularity. Compoud 2 apparently proceeded via intramolecular rearrangement.

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