Acylated and non-acylated flavonol monoglycosides from the Indian minor spice Nagkesar (Mammea longifolia)

A methanol extract of nagkesar (buds of Mammea longifolia), which showed strong radical scavenging activity, yielded 13 compounds by separations using column chromatography and HPLC. Structure elucidation of these compounds was achieved by (1)H and (13)C NMR, including DQF-COSY, TOCSY, DEPT, HMQC, HSQC, and HMBC. They include two new compounds, quercetin 3-O-(2' ',4' 'di-E-p-coumaroyl)-alpha-L-rhamno-pyranoside and quercetin 3-O-(3' ',4' '-di-E-p-coumaroyl)-alpha-L-rhamnopyranoside, along with known compounds kaempferol, quercetin, the isopropylidenedioxy derivative of shikimic acid, kaempferol 3-O-(2' ',4' '-di-E-p-coumaroyl)-alpha-L-rhamnopyranoside, kaempferol 3-O-(3' ',4' '-di-E-p-coumaroyl)-alpha-L-rhamnopyranoside, kaempferol 3-O-alpha-L-rhamnopyranoside, quercetin 3-O-alpha-L-rhamnopyranoside, shikimic acid, kaempferol 3-O-beta-D-glucopyranoside, quercetin 3-O-beta-D-glucopyranoside, and beta-sitosterol 3-O-beta-D-glucopyranoside.     

A specific and potent inhibitor of brassinosteroid biosynthesis possessing a dioxolane ring

Screening for brassinosteroid biosynthesis inhibitors was performed to find azole derivatives that induced dwarfism, to resemble brassinosteroid-deficient mutants in Arabidopsis, and which could be rescued by brassinosteroid. Through this screening experiment, propiconazole fungicide was selected as a likely inhibitor of brassinosteroid biosynthesis and, thus, propiconazole derivatives with optimized activity and selectivity were synthesized. The biological activity of these compounds was evaluated by examining cress stem elongation. Among the compounds tested, 2RS,4RS-1-[2-(4-trifluoromethylphenyl)-4-n-propyl-1,3-dioxolan-2-ylmethyl]-1H-1,2,4-triazole (12) showed the most potent capability to retard cress stem elongation in the light. The compound-induced hypocotyl dwarfism was restored by the coapplication of 10 nM brassinolide but not by 1 microM gibberellin. These results suggest that 12 should affect brassinosteroid biosynthesis. The potency and specificity of 12 were greater than those of brassinazole, a previously reported brassinosteroid biosynthesis inhibitor.     

Reduced immunogenicity of beta-lactoglobulin by conjugation with carboxymethyl dextran differing in molecular weight

To reduce the immunogenicity of beta-lactoglobulin (beta-LG), two beta-LG-carboxymethyl dextran (CMD) conjugates (Conj. 40 and Conj. 162) were prepared by using water-soluble carbodiimide (EDC). The molar ratios of beta-LG to CMD in Conj. 40 and Conj. 162 were 8:1 and 7:1, respectively. Each conjugate maintained approximately 50% of the retinol binding activity of beta-LG. Structural analyses by intrinsic fluorescence, CD spectra, and ELISA with monoclonal antibodies indicated that the surface of beta-LG in each conjugate was covered by CMD without great disruption of native conformation. By conjugation with CMD, the antibody response to beta-LG was reduced in BALB/c, C3H/He, and C57BL/6 mice, which was eminent in Conj. 162. The results of B cell epitope scanning using overlapping synthesized peptides showed that the linear epitope profiles of the conjugates were similar to those of beta-LG, whereas the antibody response to each epitope was reduced, which was eminent in Conj. 162. It was concluded that conjugation with CMD of higher molecular weight is effective in reducing the immunogenicity of beta-LG and that masking of epitopes by CMD is responsible for the reduced immunogenicity.     

Iodine desorption from rice paddy soil

Laboratory experiments on the desorption phenomena of iodine from rice paddy soil under waterlogged conditions, with a special reference to soil redox potential (Eh) and pH, have been conducted. Radioiodine tracer (1251), added to the soil, was readily sorbed on it. At the beginning of the waterlogging, the iodine desorption was low. However, iodine was desorbed into soil solution with time. The iodine desorption was enhanced markedly by the addition of organic substances such as straw pieces and glucose to the soil. Cultivation of rice plants in soil also affected the iodine desorption, suggesting root exudates and/or root autolysis might be participating in the desorption process. Eh dropped considerably after soil was waterlogged due to microbial metabolisms. Particularly low Eh values were observed in soils with plants and also with added organic substances. A negative correlation was seen between the desorption and soil Eh. High desorption was frequently observed when the Eh dropped to about -100 mV or below. Due to the reducing conditions (low Eh) by waterlogging, iodine in soil was leached into the soil solution; consequently total iodine concentration in paddy soil was considerably lower than forest and upland field soils. These iodine desorption phenomena under anaerobic conditions should be considered in assessing transfer of the long-lived radioiodine (129I) in the environment, especially in rice fields and marshland.     

Adsorption behavior of heavy metals on biomaterials

We have investigated adsorption of Cd(II) and Pb(II) at pH 2-6.7 onto the biomaterials chitosan, coffee, green tea, tea, yuzu, aloe, and Japanese coarse tea, and onto the inorganic adsorbents, activated carbon and zeolite. High adsorptive capabilities were observed for all of the biomaterials at pH 4 and 6.7. In the adsorption of Cd(II), blend coffee, tea, green tea, and coarse tea have comparable loading capacities to activated carbon and zeolite. Although activated carbon, zeolite, and chitosan are utilized in a variety of fields such as wastewater treatment, chemical and metallurgical engineering, and analytical chemistry, these adsorbents are costly. On the other hand, processing of the test biomaterials was inexpensive, and all the biomaterials except for chitosan were able to adsorb large amounts of Pb(II) and Cd(II) ions after a convenient pretreatment of washing with water followed by drying. The high adsorption capability of the biomaterials prepared from plant materials is promising in the development of a novel, low-cost adsorbent. From these results, it is concluded that heavy metal removal using biomaterials would be an effective method for the economic treatment of wastewater. The proposed adsorption method was applied to the determination of amounts of Cd(II) and Pb(II) in water samples.     

Translation of double-stranded RNA segments 1 and 2 of Chuzan virus in rabbit reticulocyte lysates.

Coding assignments of genome segments 1 and 2 of Chuzan virus strain K-47 were studied in vitro by using rabbit reticulocyte lysates. The double-stranded RNA segment was extracted from sodium dodecyl sulfate (SDS)-polyacrylamide gels by a modified crushing and eluting technique. Translation products labeled with [35S]methionine were resolved by SDS-polyacrylamide gel electrophoresis. The molecular weights of the products from RNA segments 1 and 2 were estimated to be 98 and 95 kilodaltons, respectively.     

Electrophoretic studies on serum proteins in cows with traumatic pericarditis.

Diagnostic significance of electrophoretic findings of serum protein in cows with traumatic pericarditis was evaluated. Affected cows were classified into 3 groups according to autoptical findings: fibrinous, sero-fibrinous, and purulent types. Slight hypoprotenemia, moderate hypo-albuminemia, slight hyper-alpha globulinemia and tendency of hyper-beta globulinemia were commonly observed in the affected cows. The level of gamma globulin tended to be lower in the cows with fibrinous or sero-fibrinous, and higher in purulent pericarditis, than the level in healthy cows. In the serum protein electropherograms of the cows with fibrinous or sero-fibrinous pericarditis, there was pathognostic pattern composed of slender albumin, acute shape of alpha globulin with a broad rising accompanied by double peaks and with main peak migrating toward the albumin side, tendency of rising beta globulin fraction, and large indentation between beta and gamma fractions. These findings except for the slender albumin fraction, however, was not or poorly observed in purulent pericarditis. Electrophoretic findings were subacute inflammatory pattern with non-selective serum protein losing in fibrinous or sero-fibrinous, and chronic inflammatory pattern in purulent pericarditis.     

An aspermia rat mutant (as/as) with spermatogenic failure at meiosis.

A newly identified aspermia rat mutant was investigated on testicular histology and mode of inheritance of the defect. Average testis weight of mutants was about one-third of that of phenotypically normal males. Spermatogenesis was interrupted at meiosis. Pachytene spermatocytes significantly decreased in number. Secondary spermatocytes and few round spermatids were seen, but no elongated spermatids and sperms were observed. A large basophilic inclusion-like body existed in the cytoplasm of late pachytene spermatocytes. Genetic analysis revealed an autosomal recessive transmission of the defect. Aspermia (As) was designated for the locus.     

Inhibitory effects of pesticides on growth and respiration of cultured cells

Effects of various drugs including pesticides on the growth and respiration of cultured cells were evaluated comparatively using cell lines derived from mosquito ovary and subcutaneous mouse tissues. The concentration producing 50% inhibition of cell growth, I₅₀ (M), was determined for each of 42 drugs. Inhibitors of respiration and nucleic acid and protein biosyntheses such as rotenone, piericidin A₁, actinomycin D, and puromycin had very high pI₅₀ values of approximately 8. Except for the compounds known to be uncouplers of oxidative phosphorylation, the drugs suppressed the respiration rate of the cultured cells to various degrees. The pI₅₀ value (and the pEC₁₅₀, 150% enhancement of the control, value for uncouplers) was determined for each compound. By examining the relation of pI₅₀ (and pEC₁₅₀) values between cell growth and respiration, the compounds could be classified into two groups according to their modes of inhibitory action against the cultured cells. One mode relates to the inhibition of energy synthesis and the other, perhaps, to interference with the biosynthesis of biomacromolecules.