Insecticidal Activities And Active Components On Juglans Mandshurica Maxim.

Juglans mandshurica Maxim. is the most suitable species for timber production and pharmacy resources in northeast of China. This study provides the theoretical proofs of the exploitation and utilization of Juglans mandshurica. The study showed that total flavonoid amount and jugione amount of extracts from leaves,' bark and green peel of Juglans mandshurica were determined by UV-VIS and HPLC; and insecticidal activities, antifungal activities and allelopathy of the extracts from leaves, bark and green peel of Juglans mandshurica and bioactivities of juglone were studied by the determination methods of bioactivity; and chemical components, chemical structures and relative contents of the extracts from leaves, bark and green peel of Juglans mandshurica were determined by GC-MS; and juglone product was isolated and depurated from bark of JugIans mandshurica by ultrasonic method and vacuum distillation; and stability of the extracts from leaves, bark and green peel ofJuglans mandshurica was studied by HPLC. The study results were as below:(1) Extractions of total flavonoid and juglone from leaves, bark and green peel of Juglans mandshurica were carried out by three extracting methods respectively, including common method, reflux method and ultrasonic method. UV-VIS spectroscopy was used for determining the amount of total flavonoid, and HPLC was used for determining the amount of juglone. Results showed that amounts of total flavonoid and juglone by ultrasonic method were both more than common method and reflux method. The amounts of total flavonoid extracted by ultrasonic method were: 50.0 mg'g^-1 for leaves, 41.7 mg'g^-1 for bark, 30.5 mg'g^-1 for green peel, respectively. The amounts of juglone extracted by ultrasonic method were: 0.209 mg'g^-1 for leaves, 0.131 mg'g^-1 for bark, 0.229 mg'g^-1. for green peel, respectively.(2) Insecticidal activities, antifungal activities and allelopathy of the extracts from leaves, green peel of Juglans mandshurica were studied by the determination methods of bioactivity. Results showed that the extracts had insecticidal activities on Lymantria dispar L. and Mamestra brassicae L.. The insecticidal activities of the alcohol extracts showed more efficient than both of the chloroform parts and the acetic ether parts of the extracts. The mechanism of insecticidal activities of the extracts was poisoning action. The extracts had antifungal activities on Alternaria alternate Ft. and Sphaeropsis sapinea Fr., and also allelopathy on Brassica chinesis L., Medicago sativa L. and Sorghum pacesetter L.. The insecticidal activities, antifungal activities and allelopathy of the extracts showed the order of green peel extracts more efficient than leaves extracts, and leaves extracts more efficient than bark extracts.(3) Chemical components, chemical structures and relative contents of the extracts from leaves, bark and green peel of Juglans mandshurica were determined by GC-MS. Resultsshowed that the major active components in the .extracts were: juglone (5-hydroxy-1,4-naphthaoquinone), Phenol,-2,2'-methylenebis [6-(1,1-dimethylethyl)-4-methyl-], 2-Methoxy-4-vinylphenol, D-Allose, 1,4-Naphthalenedione, 5;8-dihydroxy-, 1,5-Naphthalenediol,Benzofuran, 2,3-dihydro-, 7-Methoxy-1-tetralone, 1-Naphthalenol,.1,4-Naphthalenedione, 8-hydroxy-2-methoxy-, 4-Methyl-2,6-dihydroxyquinoline, 4-Hydroxy-2-methoxycinnamalde-hyde, Vanillin, 1,2,3-Benzenetriol, 2-Furancarboxaldehyde, 5-(hydroxymethyl)-, 1(2H)-Naphthalenone, 3,4-dihydro-6,7-dihydroxy-, Phenol, 2,6-dimethoxy- determined by GC-MS.(4) Juglone product was isolated and-depurated from bark of Juglans mandshurica byultrasonic .method and vacuum distillation. The product was characterized by FT-IR and ¹H-NMR, and chemical components and relative contents of the product were determined by GC-MS. Results showed that the extract ratioof the product was 0.09 %, and the relative contentsin the product were: juglone (5-hydroxy-l,4-naphthaoquinone) 96.42%, 1,4-Naphthalenedione0.70%; 7-Methoxy-1-tetralone 2.88%. This offered a simple and effective method to get highpurity juglone from bark ofJuglans mandshurica.(5) Juglone is the major active component extracted from Juglans mandshurica. Theinsecticidal activities, antifungal activities and allelopathy of juglone were studied by thedetermination methods of bioactivity. Results. showed that juglone had insecticidal activities onLymantria dispar and Mamestra brassicae, and antifungal activities on AIternaria alternateand Sphaeropsis sapinea, and also allelopathy on Brassica chinesis, Medicago sativa andSorghum pacesetter. This provides the theoretical foundation of the syntheses of leadcompounds and exploitation of botanical insecticides for Juglans mandshurica.(6) Stability of the extracts was studied by HPLC. Results showed that the stability of theextracts was reduced with temperature gone up and sunshine, and the stability of the extractswas fine at 4 to 8 for pH value and adding tween 80. The decompositions of the extracts werefirst order reactions with temperature gone up and pH value changed, and the decompositionsof the extracts were zero order reactions with sunshine and adding tween 80. The stability ofthe extracts showed the order of extracts of bark better than extracts of leaves, and extracts ofleaves better than extracts of green peel.