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Nowadays to move toward a more sustainable agriculture, use of pesticide alternatives that have positive effects and play critical roles toward reducing the use of pesticides should be used. Laboratory bioassays were carried out to analyze the bioactivity of tannins isolated from urtica weed leaves (U), bean hull (B), black tea (BT) and green tea (GT) against larvae of cotton leafworm Spodoptera littoralis (Boisduval) using food mixing technique and essential oil isolated from onion against larvae of cotton leafworm, adults of rice weevil and houseflies using fumigation technique. The results showed that during the first week of treatment, tannins extracted from U had the strongest antifeedant activity with an EC50 of 33.034 μg/g followed by tannins extracted from B (EC50 = 47.839 μg/g). In the second and third week, tannins isolated from B depicted highest antifeedant activity (EC50 = 37.733 and 84.828, respectively). Furthermore, the isolated tannins induced notable larval growth inhibition on S littoralis. On the other hand, mortality percentage of onion essential oil on tested insects clearly increased with both increased concentration and exposure time. The LC50 (μg/cm3) at 30 min reflected that the essential oil had a greater toxicity to cotton leafworm with a LC50 = 2.15 μg/cm3 while least toxic to house flies (LC50 = 16.09). The repellency action based on LT50 values was seen to be highly effective in houseflies (LT50 = 1.85 min). The results demonstrated that tannins and essential oil could be applicable in the management of insect pests to decrease ecologically detrimental effects of synthetic insecticides.

Succinate-cytochrome c reductase (SCR) from mouse liver was inhibited strongly and reversibly by an iron (II) macrocyclic complex 3. The inhibition was observed for the enzyme toward the reduction of both 2,6-dichlorophenol indophenol (DCIP) and cytochrome c (cyt c). The inhibition was a mixed type and noncompetitive with respect to the reduction of DCIP and cyt c, respectively. Values of the inhibition constant ranged from 6.6 to 8.3 microM. The IC50 for the complex 3 was found to be 16.6 +/- 0.8 and 12.1 +/- 0.5 microM for the enzyme toward DCIP and cyt c, respectively. The reduced form of complex 3 also exhibited enzyme inhibition but to a less extent. Complex 3, at a lower level, equal to 25% of its LD50 showed about 50% inhibition of the enzyme through in vivo dose-dependent effect. These findings suggested that the structure of the equatorial benzoquinoid macrocyclic ligand of the Fe(II) complex is involved in the enzyme inhibition.

The new amino protecting group PChd has the following advantages: the N‐(PChd) esters (3) are usually formed without racemization and in high selectivity; the group can be removed quantitatively by hydrogenolysis with regeneration of (1) (R  C6H5).