The bicyclic retinoates (VII) and (XII) were synthesised.

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High performance liquid chromatography (HPLC) separation of the SDS-solubilized membrane proteins of Halobacterium halobium S9 was investigated with a gel permeation column, TSK G3000 or 4000 SW. When sodium phosphate buffer (pH 7.0) containing 0.1% SDS was used for elution, both the elution volume and the elution profile of protein peaks were highly dependent on the buffer concentration. On increasing the buffer concentration, the elution volume for each increased and the resolution was also improved. Protein was recovered quantitatively from the column in the buffer concentration range between 0.01 to 0.2 M. In contrast to the phosphate buffer system, the elution profile of the membrane protein was almost independent of the salt concentration when Tris-HCl (pH 7.0) buffer containing 0.1% SDS and various amounts of NaCl was used for elution. The best separation conditions finally determined for the membrane proteins of H. halobium using SW columns were as follows : 0.2 M Tris-HCl (pH 7.0) containing 0.1 M NaCl and 0.1% SDS as an elution buffer system, at a flow rate of 0.6 ml per min. Under the above elution conditions, nine major protein peaks could be determined in the SDS-solubilized plasma membrane preparation of H. halobium S9 within 40 min when the absorbance was recorded at 280 nm. The resolution obtained is comparable to that of SDS-PAGE.

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The applicability of chitosan as a vehicle for sustained-release preparations of water-soluble drugs was examined. Propranolol hydrochloride was selected as a model substance for this evaluation. Zero-order controlled release of propranolol hydrochloride from tablets containing chitosan was obtained in JP X disintegration medium No. 1 and in disintegration medium No. 2 following exposure to No. 1. Chitosan could be a useful vehicle for the controlled release of water-soluble drugs.

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As a part of a series of studies on pharmaceutical applications of chitin and chitosan, the fluidity and compressibility of combined powders of mannitol with chitin and chitosan, as well as the disintegration properties of tablets made from these powders were investigated in comparison with those of crystalline cellulose with mannitol. The fluidity of the combined powders with chitin and chitosan was a little greater than that of the powder with crystalline cellulose. At more than 30% addition of chitin, chitosan or crystalline cellulose, tablets were easily formed. Tablets containing less than 60% chitin or chitosan passed the disintegration test of JP X. It is suggested that chitin and chitosan, as well as crystalline cellulose, may be suitable as diluents for chewable, sublingual or oral mucosal tablets prepared by direct compression processes.

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From the fresh leaves of polypodium someyae eupha-7, 24-diene and from the fresh rhizomes of P. fauriei (20R)-dammara-13 (17), 24-diene were obtained and characterized. These hydrocarbons are the first derivation from a natural source. They are rather unstable in the air.

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Along with the known hydrangenosides C and D, new glucosides of the same series, hydrangenosides E, F, and G, have been isolated from Hydrangea scandens and their absolute structures have been established. These glucosides were found to consist of secologanin and a shikimate-malonate derived C-13 unit. Hydrangenoside G is considered to be a biogenetic intermediate of the other glucosides.

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N-Alkylthiocarbonyl tryptophan (Ia-f) and tryptamine (Ig-j) derivatives can be converted into the corresponding 3, 4-dihydro-β-carbolines (3) under mild and non-acidic conditions by use of alkylating reagents.

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New hydrolyzable tannins, rugosin A (1), B (2), C (3) from Rosa rugosa, and 3 and praecoxin A (7) from Stachyurus praecox, were isolated, and their structures, including the valoneoyl group, were elucidated.

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Four new hydrolyzable tannins, rugosin D (1), E (2), F (3) and G (4), were isolated from Rosa rugosa, and their dimeric and trimeric structures, linked via a valoneoyl group, were elucidated.

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Using the common bicyclic compound 1-oxabicyclo [3. 2. 1] octan-2-one (1), two isomeric monoterpenes, semburin (6) and isosemburin (7) isolated from Swertia japonica Makino, have been synthesized stereoselectively in racemic forms.

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1-Acylimidazoles could be highly activated for acylation by the quarternizing with benzyl halides. 1-Acyl-3-benzylimidazolium halides [I] were powerful acylating agents. Alcohols, phenols, and amines were converted to the corresponding esters and amides in excellent yields under mild conditions.

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Two new dimeric ellagitannins, gemin B (2) and C (3), and a monomeric tannin, gemin D (4), have been isolated from Geum japonicum. Their structures were elucidated on the basis of NMR analysis and partial hydrolysis. Gemin D was isolated also from Camellia japonica.

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