The diarylheptanoid constituents of the titled plants and their close plants were reviewed. Many new diarylheptanoids and their glycosides named acerogenin and aceroside were isolated from the stem bark of Acer nikoense, A. griseum and A. triflorum. Myricanone, myricanol and its five new glycosides were isolated from the stem bark of Myrica rubra, and myricanone and galeon, from the stem of M. gale var. tomentosa. The structures of these compounds were determined on the basis of chemical and spectral evidence, and chemotaxonomy of the above plants was briefly discussed. In addition biosynthesis of acerogenin A, revision of the structure for isomyricanone derived from myricanone, and some biological activities of A. nikoense and M. rubra were described.
Our investigation on the chemistry of biologically active natural products during the last 40 years since 1953 are reviewed in this paper. The following subjects are discussed : I. photochemical relationship between rhodopsin and compounds related to areca alkaloid, II. furanoid diterpenoid constituents from dioscoreaceae plants and colombo root, III. field desorption and fast atom bombardment mass spectrometry of biologically active natural glycosides and glycosphingolipids, IV. investigation of biologically active marine natural products, 1) constituents of steroid glycoside sulfates from Asteroidea, 2) spine toxins from Acanthaster planci, 3) constituents of triterpenoid glycoside sulfates from Holothuroidea, 4) constituents of isoprenoids from Opisthobranchia and Octocorallia, 5) constituents of glycosphingolipids from Asteroidea.
A series of 3-O-alkyl-1, 2-O-isopropylidene-α-D-glucofuranoses (3-7), 6-deoxy-3-O-dodecyl-6-halo-1, 2-0-isopropylidene-α-D-glucofuranoses (9-11), and 6-deoxy-3-O-dodecyl-6-halo-D-glucopyranoses (12-14) were prepared from 1, 2 ; 5, 6-di-O-isopropyridene-α-D-glucofuranose and their antibacterial activities were evaluated. The compounds having C12 and C14 alkylchains at C-3 of 1, 2-0-isopropylidene glucoses were the most effective in vitro antibacterial screening, of which the structure-activity relationships are also discussed.
A 3β-hydroxysteroid dehydrogenase/Δ4-Δb-isomerase (3β-HSD/isomerase) has been purified to homogeneity from the pig adrenal microsomes by solubilization with sodium cholate, followed by some conventional column chromatographies. The molecular weight of the enzyme was estimated to be 42000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The Km value for pregnenolone as the substrate of the purified enzyme was higher than that of the microsomal enzyme. The purified enzyme was less stable for heat treatment than the microsomal binding enzyme. The microsomal enzyme was treated with various agents or enzymes which destroyed the membrane structure. Lipid peroxidation with Fe2+, digestion with phospholipase A2 or C, and the addition of various free fatty acids, imidazole containing compounds and polymyxin B were utilized for the membrane destruction. Consequently, the 3β-HSD/isomerase activity was significantly reduced in all cases, and the Km value of the 3β-HSD/ isomerase for pregnenolone increased. And the Vmax and Vmax/Km values significantly decreased. Therefore, it is strongly suggested that the normal membrane structure plays an important role in the maintenance of the 3β-HSD/isomerase activity.
Epidermal growth factor (EGF) in the milk fat globule membrane (MFGM) emulsion enhanced the absorption of this factor from the intestine, especially to the intestinal lymph. Most of the radioactive EGF administered was degraded to small molecular weight materials. These degraded materials were absorbed and appeared in both the intestinal lymph and portal vein blood. However, a certain portion of EGF, although small, appeared in the lymph maintaining the original molecular mass. The MFGM emulsion used enhanced the lymphatic absorption of intact EGF, suggesting that this dosage form increased the absorption of EGF, protected the degradation of EGF in the intestine or promoted the absorption of intact EGF. The enhancing effect on the absorbed dose percentage of EGF recovered using MFGM emulsion was also observed in the portal vein plasma. However, the effect on the absorption of intact EGF was much larger in the lymph than in the portal vein.
Whether or not resistance to macrolide-lincosamide-streptogramin type B antibiotics (MLS) can be induced by many macrolide antibiotics (Mac), was inquired in Bacillus lichenformis EMR. Resistance to MLS in the strain was induced by erythromycin, oleandomycin, clarithromycin, roxithromycin, narbomycin, picromycin, kujimycin A or B, mycinamicin I, or rosamicin. On the contrary, josamycin, spiramycin, tylosin, rokitamycin, midecamycin, and miokamycin as well as lincosamide and streptogramin type B antibiotics could not induce MLS-resistance. The results suggest that two common chemical residues of the inducer Mac, that is, 1) a single monosaccharide at C5 in the 14- and 16-membered lactone rings, and 2) one polar group such as dimethylamino or methoxyl at C3' in the sugar, are likely to be responsible for showing the activity of MLS-resistance inducer in Bacillus licheniformis EMR.