Isolation And Structure Elucidation Of 5,7-disubstituted Simple Coumarins In The Fruits Of Heracleum Mantegazzianum.

In addition to bergapten ( 1 ), xanthotoxin ( 2 ), isopimpinellin ( 3 ), imperatorin ( 4 ), and pimpinellin ( 5 ), for the first time 5,7-disubstituted simple coumarins, limettin (5,7-dimethoxycoumarin) ( 6 ) and a new compound 5-methoxy-7-(3,3-dimethylalliloxy)-coumarin ( 7 ), have been isolated from the fruits of Heracleum mantegazzianum Somm. et Lev. The new compound 7 is a derivative of anisocoumarin B.

Microbial transformation of isoprenoid systems by means of fungi of Zoophthora genus--microbial transformation of compounds with alpha-campholenic system by means of fungus Zoophthora (Neopandora) sp.

Unsaturated ketones (4 and 10) and epoxides (2-3 and 8-9) were the main products of biotransformation performed by means of Zoophthora (Neopandora) phyllobii. Enantiospecificity of both reactions leading to these compounds strongly depends on the distance of reacting fragment of molecule from the chiral center at C-1'.

Insect growth regulators. XXV. Chemical approach to the correlation of dynamic structure and biological activity of juvenile hormone analogues.

On the basis of flexibility of the carbon skeleton of a juvenoid molecule, an analysis of its steric properties required to induce a biological effect in insects Dysdercus cingulatus and Tenebrio molitor, is presented. Steric analyses of "branched" juvenoids and some derivatives of farnesoic acid differing in position of the double bonds, are also described.