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Biomedical subjects

X J Jiang

Publications and source records attributed to X J Jiang.

30 records · Page 2Linked to original sources
PubMed1989

[Synthesis of antiviral agents acyclic nucleo-sides of 4-substituted pyrrolo [2,3-d] pyrimidine].

Naturally occurring nucleosides of pyrrolo [2,3-d] pyrimidine, tubercidin, sangivamycin and toyocamycin were known as antibodies not only for their potent antitumor activity but also for their significant antiviral effects. However, none of them was developed to be a useful drug due to their high toxicity. In order to reduce the toxicity of this kind of compounds and reveal the relationship between structure and biological activity, a series of acyclic analogues of tubercidin with varied 4-substituted amino groups were synthesized. 4-chlor-pyrrolo (2,3-d) pyrimidin was used as starting material which reacted with 1,3-dibenzyloxy-glycerol-2-chloro-methylether by direct sodium salt glycosylation procedure provided the key intermediate (IX). After hydrogenation, amination of compound IX gave the final free hydroxy products. All the compounds were tested in vitro against HSV-1 and Cox B6. Only three of them (XI6, XI7, XI9) showed certain activities against Cox B6.

Aminoglycosides↗
PubMedDate not supplied

Effects of cadmium on nutrient uptake and translocation by Indian Mustard.

Plants that hyperaccumulate metals are ideal subjects for studying the mechanisms of metal and mineral nutrient uptake in the plant kingdom. Indian Mustard (Brassica juncea) has been shown to accumulate moderate levels of Cd, Pb, Cr, Ni, Zn, and Cu. In this experiment, 10 levels of Cd concentration treatments were imposed by adding 10-190 mg Cd kg(-1) to the soils as cadmium nitrate [Cd(NO3)2]. The effect of Cd on phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and the micronutrients iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn) in B. juncea was studied. Plant growth was affected negatively by Cd, root biomass decreased significantly at 170 mg Cd kg(-1) dry weight soils treatment. Cadmium accumulation both in shoots and roots increased with increasing soil Cd treatments. The highest concentration of Cd was up to 300 mg kg(-1) d.w. in the roots and 160 mg kg(-1) d.w. in the shoots. The nutrients mainly affected by Cd were P, K, Ca, Fe, and Zn in the roots, and P, K, Ca, and Cu in the shoots. K and P concentrations in roots increased significantly when Cd was added at 170 mg kg(-1), and this was almost the same level at which root growth was inhibited. Zn concentrations in roots decreased significantly when added Cd concentration was increased from 50 to 110 mg kg(-1), then remained constant with Cd treatments from 110 to 190 mg kg(-1). However, Zn concentrations in the shoots seemed less affected by Cd. It is possible that Zn uptake was affected by the Cd but not the translocation of Zn within the plant. Ca and Mg accumulation in roots and shoots showed similar trends. This result indicates that Ca and Mg uptake is a non-specific process.

Biodegradation, Environmental↗
PubMedDate not supplied

Effects of the interactions between selenium and phosphorus on the growth and selenium accumulation in rice (Oryza sativa).

The solution culture, paddy soil culture and the simulation experiments in the laboratory were conducted to clarify the interactions between selenium and phosphorus, and its effects on the growth and selenium accumulation in rice. Results revealed that a suitable supply of selenium could promote rice growth and excessive selenium could injure rice plant, causing lower biomass, especially in the roots. The supply of selenite could enhance the selenium contents of rice shoots and roots in solution culture and in soil culture. The selenium concentrations in roots were much higher than those in shoots supplied with the same rates of selenium and phosphorus. The interaction between selenium and phosphorus was evident. When the phosphorus supply increased to meet the needs of plant growth, phosphorus could promote absorption and accumulation of selenium in the shoots. If the phosphorus supply was excessive, phosphorus could inhibit the accumulation of selenium in the shoots at the lower selenite level (2 micromol l(-1)), but could not at the higher selenite level (10 micromol l(-1)). With the supply of phosphate increased, the selenium concentrations in the roots decreased significantly at both selenite levels. The presence of phosphate could decrease Se sorption on the soil surface and increase the selenium concentration in the soil solution. The concentrations of selenium in shoots and roots supplied with 0.08 g kg(-1) phosphorus were lower than those with no phosphorus supplied. With the increase of phosphorus added to 0.4 g kg(-1), the selenium concentration in shoots and roots increased. The effect of phosphorus on the concentration was statistically significant at all three selenium levels.

Absorption↗