The intensified agricultural crop production for growing high yield varieties requires the indiscriminate use of pesticides and fertilizers, which protect the crop from pests, thus helps in improving the quality and quantity of crops. The aquatic environment gets contaminated by the application of pesticides through several routes: runoff, spray drift, and leaching, which pose serious health risks to the aquatic ecosystem as well as to human beings. This exposure can directly affect all levels of biological organization, including primary producers, microorganisms, invertebrates, or fish. Thus, monitoring methods should be adopted for controlling the runoff events in the spraying method, such as suspended matter sampler for particle-associated pesticides that can be used for controlling the number of toxic substances in water bodies.

Fast atom bombardment mass spectra of a series of naturally occurring and synthetically modified iridoid glycosides were studied using lithium cationization and collision‐induced dissociation of the resulting [M + Li]+ ions. Lithium cationization leads to the unambiguous determination of the molecular masses of these compounds. Collision‐induced dissociation of the lithiated molecular ions give valuable structural information regarding the nature of the substituent on both the aglycone and the sugar moieties. The characteristic fragmentation pathways identified are (1) elimination of neutral molecules comprising the substituents on either the aglycone or sugar moieties, (2) formation of lithiated aglycone and their fragment ions, (3) formation of lithiated sugar and their fragment ions, (4) fragmentation corresponding to the cleavage of the aglycone or sugar ring and (5) fragmentation characteristic of the substituents present in either the aglycone or sugar parts of the molecule. Elimination of two acyloxy radicals from the lithiated molecular ion is a characteristic fragmentation in the case of acyloxy derivatives. Copyright © 2000 John Wiley & Sons, Ltd.

The effect of substitution of the pyrrolo- and indolo-N atoms in tetrahydronaltrindole (TNTI), tetrahydrooxymorphindole (TOMI), and 17-cyclopropylmethyl-3,14-dihydroxy-4,5-epoxy-4'-phenyl-6,7:2',3'-pyrrolomorphinan (4) is reported. In opioid functional assays 4 were potent deltaopioid receptor (DOR) antagonists while the TNTI derivatives (7) were potent DOR antagonists or low-efficacy DOR partial agonists without substantial selectivity. The TOMI derivatives (8) were DOR agonists with significant selectivity. In vivo the DOR antagonist activity of 7d was confirmed, but the predominant agonist effect of 8d was shown to be mu opioid receptor mediated.

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The benzylimines 15 derived from oxymorphones 14 and generated in situ reacted with Michael acceptors (methyl methacrylate, maleic anhydride, and a-methylene-g-butyrolactone) to give opioid ligands 16, 17, and 19 ± 21 having pyrrole-or pyridine-derived ring systems (see Scheme 3). The product of the reaction with maleic anhydride displayed a surprising preference for the 2-hydroxypyrrole form 19 rather than for the tautomeric 1,6dihydro-2H-pyrrol-2-one form 24, resulting from the stability of the C(6)C(7) bond in oxymorphone and related structures.Scheme 2 i) Maleic anhydride, 0 ± 208, 10 min. ii) Methyl methacrylate, 1008, 3d. iii) Methyl crotonate, 1208, 5d.

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The well-established Nenitzescu reaction of imines of beta-dicarbonyl systems, as their enamine tautomers, with benzoquinone has been applied to a wide range of such imines to give 5-hydroxyindoles, some of which are of significant biological importance. This reaction has now been extended to the benzylimines of simple ketones, including those of the potent mu-opioid receptor antagonists naltrexone and naloxone. The products of the latter reactions, 1'-benzyl-5'-hydroxyindolomorphinans (7), are potent delta-opioid receptor (DOR) antagonists, confirming the enhancement of DOR antagonist potency and selectivity resulting from the introduction of the 1'-benzyl group.

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