4-Hydroxykigelin and 6-Demethylkigelin, Root Growth Promoters, Produced by Aspergillus terreus

Abstract

Root growth promoters, 4-hydroxykigelin (1) and 6-demethylkigelin (2), together with 6- hydroxymellein (3) were isolated from cultures of the fungus Aspergillus terreus and their structures were identified by spectroscopic analysis. The biological activities of the three dihydroisocoumarins, 1, 2, and 3, have been examined using a bioassay method with lettuce seedlings. Furthermore, interactions between the dihydroisocoumarins and indole-3-acetic acid against the root growth have been examined.

Citrinolactones A, B and C, and Sclerotinin C, Plant Growth Regulators fromPenicillium citrinum

“…4). [4][5][6] Compounds 1, 3 and 4 did not show any effect on hypocotyl elongation in the concentration range of 3-300 mg/l, but 2 completely inhibited hypocotyl elongation at a concentration of 300 mg/l. Compounds 1 and 4 increased root growth in proportion to their concentration from 3 to 300 mg/l.…”

“…The length of the hypocotyls and roots treated with the compounds was measured, and the mean length values were compared with an untreated control. [4][5][6] All experiments were triplicated.…”

“…6,8,9) The C-9-(R) and C-9-(S)-MTPA esters of 2 were synthesized, and their 1 H-NMR spectra were recorded in CDCl 3 . Positive Á values ( S -R ) in the 1 H-NMR spectra were observed for H-5, H-12 and OH-8, while negative Á values were located at H-7, H-9, H-10 and H-11 (Fig.…”

Rubralactone, Rubralides A, B and C, and Rubramin Produced byPenicillium rubrum

“…The length of the hypocotyls and roots treated with the compounds was measured, and the mean length values were compared with an untreated control. [4][5][6] All experiments were triplicated.…”

Plant Growth Activities of Aspyran, Asperentin, and its Analogues Produced by the Fungus Aspergillus sp.

“…So far, we have isolated and characterized chloroisosulochrin (Shimada et al, 2001), myxostiol (Kimura et al, 2002), 4-hydroxykigelin (Shimada et al, 2004), brevicompanine C (Kimura et al, 2005), citrinolactone A (Kuramata et al, 2007), and rubralactone . In the course of our screening search for new plant growth regulators, using bioassays with lettuce and rice seedlings suitable for developing new herbicides, we found plant growth regulators in the culture fi ltrate of the fungus Aspergillus sp.…”