Herbicidal action of 2‐hydroxy‐3‐alkyl‐1,4‐naphthoquinones

Abstract

The main mode of herbicidal activity of 2-hydroxy-3-alkyl-1,4-naphthoquinones is shown to be inhibition of photosystem II (PSII). The herbicidal and in vitro activities have been measured and correlated with their (Log)octanol/water partition coefficients (Log Ko/w). The length of the 3-n-alkyl substituent for optimal activity differed between herbicidal and in vitro activity. The maximum in vitro activity was given by the nonyl to dodecyl homologues (Log Ko/w between 6.54 and 8.12), whereas herbicidal activity peaked with the n-hexyl compound (Log Ko/w = 4.95). The effect of chain branching was also investigated using isomeric pentyl analogues substituted at position 3. All exhibited similar levels of in vitro activities but herbicidal activities differed, albeit moderately, with the exception of one analogue that was much less phytotoxic. Other modes of action were also investigated using two representative compounds. They did not show any activity on photosystem I or mitochondrial complex I, or generate toxic oxygen radicals by redox cycling reactions. Only moderate activity was found against mitochondrial complex III from plants, in contrast to much higher corresponding activity using an insect enzyme.

Activity of Quinones on Colletotrichum Species

“…Naturally occurring quinones are known for their biological activities. They possess antitumor, antiinflammatory, antiparasitic, antimicrobial, insecticidal, herbicidal, and fungicidal activities ( − ). Quinones are known to inhibit electron transport involved in mitochondrial respiration ().…”

Biological activities of 1,4-naphthoquinones derivatives against T. cruzi and L. amazonensis

“…The biological activity of 1,4-naphthoquinones derivatives have been reported to exhibit a variety of pharmacological properties involving antimicrobial [16], anticancer [17], antioxidant [18], trypanocidal [19], leishmanicidal [20], anti-inflammatory [21], herbicidal [22], antiplasmodial [23], fungicidal [24].…”

“…3 ), 1.00-1.50 (m, 24H, CH 2 ), 1.54 (m, 2H, CH 2 ), 2.81 (t, J = 9.0 Hz, 2H, CH 2 ), 7.08-7.73 (m, 2H, CH), 8.06-8.15 (m, 2H, CH).13 C NMR (75 MHz, CDCl 3 ): δ = 14.0 (CH 3 ),22.6 (CH 2 ), 27.7 (CH 2 ), 31.6 (CH 2 ), 29.0-30.0 (CH 2 ), 31.9 (CH 2 ), 127.0 (CH), 127.4 (CH), 131.2 (C), 131.6 (C), 133.8 (CH), 134.0 (CH), 138.6 (C), 152.2 (C), 177.7 (C=O), 181.7 (C=O). MS (EI + ): m/z (%) 448,30 [M +• +2] (56,91); 447,30 [M 2-Bromo-3-heptadecyl-[1,4]naphthoquinone (3b) Compound was prepared according to general procedure.…”

Novel Algicidal Substance (Naphthoquinone Group) from Bio-derived Synthetic Materials against Harmful Cyanobacteria, Microcystis and Dolichospermum

“…및 미생물 (Streptococcus faecalis etc.) 내 존재하는 천연물로서, 다양한 기능을 갖고 있어 의약품 (medical supplies), 제초제 (herbicide), 살균제 (antimicrobial agent) (O'Brien 1991, Monks et al 1992, Schrader et al 2003, Dong et al 2009, Menna-Baretto et al 2009 (Biggins et al 1990, Jewess et al 2002…”