No abstract

This study relates to the modification of 2-benzylamino-4-methyl-6-trifluoromethyl-1,3,5-triazine. New 1,3,5-triazine compounds with an electron-withdrawing carboxyl group, e.g. ester group, substituted for the trifluoromethyl group, were synthesized and assayed for activity to inhibit photosynthetic electron transport (PET) in thylakoids of spinach as well as both atrazineresistant and wild-type Chenopodium album. Among the compounds with an alkylamino group, 2-ethoxycarbonyl-4-isopropylamino-6-methyl-1,3,5-triazine was the most potent PET-inhibitor, exhibiting a pI 50 of 6.11. The inhibitory activity was generally more potent with 2-alkoxycarbonyl-4-(branched alkyl)amino-6-methyl-1,3,5-triazines than amino-analogues with straight chain alkyl groups or unsaturated alkyl groups.

The effect of 2-benzylamino-1,3,5-triazines on photosynthetic electron transport (PET) was measured with thylakoids isolated from atrazine-resistant, wild-type Chenopodium album, and spinach to find novel 1,3,5-triazine herbicides bearing a strong PET inhibition. The PET inhibition assay with Chenopodium (wild-type and resistant), yielded a resistance ratio (R/ W = I 50 (resistant)/I 50 (wild-type)) of 324 for atrazine while for benzylamino-1,3,5-triazine derivatives of diamino-1,3,5-triazines a R/W of 11 to 160 was found. The compounds having a benzylamino group at one of the amino groups in the diamino-1,3,5-triazines have a resistant ratio down to one half to 1/30 of the atrazine value. The average resistance ratio of 21 benzylamino derivatives of monoamino-1,3,5-triazines was found to be about 4.0. The inhibition of 21 benzylamino-1,3,5-triazines assayed with atrazine-resistant Chenopodium thylakoids, indicated by pI 50 (R) -values, correlated well with the PET inhibition pI 50 (W) of wildtype thylakoids from Chenopodium.

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Bei Behandlung des Brom‐adenosins (I) mit NaH in Dioxan entsteht das Cyclonucleosid (II) (Abbildung von ORD‐ und CD‐Kurven), aus dem durch Erhitzen in n Schwefelsäure das ungeschützte Cyclonucleosid (III) und das Hydroxyadenosin (IVa) und durch Erhitzen in 0,1 Schwefelsäure die Adenyl‐ribose (V) entstehen.