https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

National Institute of Standards and Technology における超伝導研究及び生活

Plant essential oils for pest and disease management

Biological effects of resveratrol.

Resveratrol, trans-3,5,4'-trihydroxystilbene, was first isolated in 1940 as a constituent of the roots of white hellebore (Veratrum grandiflorum O. Loes), but has since been found in various plants, including grapes, berries and peanuts. Besides cardioprotective effects, resveratrol exhibits anticancer properties, as suggested by its ability to suppress proliferation of a wide variety of tumor cells, including lymphoid and myeloid cancers; multiple myeloma; cancers of the breast, prostate, stomach, colon, pancreas, and thyroid; melanoma; head and neck squamous cell carcinoma; ovarian carcinoma; and cervical carcinoma. The growth-inhibitory effects of resveratrol are mediated through cell-cycle arrest; upregulation of p21Cip1/WAF1, p53 and Bax; down-regulation of survivin, cyclin D1, cyclin E, Bcl-2, Bcl-xL and clAPs; and activation of caspases. Resveratrol has been shown to suppress the activation of several transcription factors, including NF-kappaB, AP-1 and Egr-1; to inhibit protein kinases including IkappaBalpha kinase, JNK, MAPK, Akt, PKC, PKD and casein kinase II; and to down-regulate products of genes such as COX-2, 5-LOX, VEGF, IL-1, IL-6, IL-8, AR and PSA. These activities account for the suppression of angiogenesis by this stilbene. Resveratrol also has been shown to potentiate the apoptotic effects of cytokines (e.g., TRAIL), chemotherapeutic agents and gamma-radiation. Phamacokinetic studies revealed that the target organs of resveratrol are liver and kidney, where it is concentrated after absorption and is mainly converted to a sulfated form and a glucuronide conjugate. In vivo, resveratrol blocks the multistep process of carcinogenesis at various stages: it blocks carcinogen activation by inhibiting aryl hydrocarbon-induced CYP1A1 expression and activity, and suppresses tumor initiation, promotion and progression. Besides chemopreventive effects, resveratrol appears to exhibit therapeutic effects against cancer. Limited data in humans have revealed that resveratrol is pharmacologically quite safe. Currently, structural analogues of resveratrol with improved bioavailability are being pursued as potential therapeutic agents for cancer.

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Role of Resveratrol in Prevention and Therapy of Cancer: Preclinical and Clinical Studies

Inhibition of acetylcholinesterase (AChE) activity by 17 kinds of monoterpenoids (hydrocarbons, alcohols, and ketones) with p-menthane skeletons was studied. Inhibition of AChE was measured by the colorimetric method. The terpene ketones showed stronger inhibition than the terpene alcohols. The terpene hydrocarbon compounds showed identical inhibitory activity with the terpene alcohols, but α-terpinene and (+)-p-menth-1-ene were equally strong inhibitors as the terpene ketones. Monoterpenoids used in this study were found to be competitive inhibitors. Keywords: Acetylcholinesterase; monoterpenoids; p-menthane skeleton; inhibition of enzyme activity; competitive inhibitor

Inhibition of Acetylcholinesterase Activity by Monoterpenoids with a p-Menthane Skeleton

A methanol extract from the flower heads of Chrysanthemum morifolium showed a suppressive effect on umu gene expression of the SOS response in Salmonella typhimurium TA1535/pSK1002 against the mutagen 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (furylfuramide). The methanol extract was re-extracted with hexane, chloroform, ethyl acetate, butanol, and water. The ethyl acetate fraction showed a suppressive effect. Suppressive compounds in the ethyl acetate fraction were isolated by silica gel column chromatography and identified as the flavonoids acacetin (1), apigenin (2), luteolin (3), and quercetin (4) by EI-MS, IR, and (1)H and 13C NMR spectroscopy. Compounds 1-4 suppressed the furylfuramide-induced SOS response in the umu test. Compounds 1-4 suppressed 60.2, 75.7, 90.0, and 66.6% of the SOS-inducing activity at a concentration of 0.70 micromol/ml. The ID50 (50% inhibitory dose) values of 1-4 were 0.62, 0.55, 0.44, and 0.59 micromol/ml. These compounds had the suppressive effects on umu gene expression of the SOS response against other mutagens, 4-nitroquinolin 1-oxide (4NQO) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), which do not require liver-metabolizing enzymes. These compounds also showed the suppression of SOS-inducing activity against the other mutagens aflatoxin B1 (AfB1) and 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), which require liver-metabolizing enzymes, and UV irradiation. In addition to the antimutagenic activities of these compounds against furylfuramide, Trp-P-1 and activated Trp-P-1 were also assayed by the Ames test using S. typhimurium TA100.

Antimutagenic Activity of Flavonoids from Chrysanthemum morifolium

Inhibition of acetylcholinesterase (AChE) activity by 17 kinds of bicyclic monoterpenoids was investigated. Bicyclic monoterpenoids are contained in many kinds of essential oils. Inhibition of AChE was measured according to the colorimetric method. 3.1.1 and 4.1.0 bicyclic hydrocarbons with allylic methyl group showed strong inhibition. (+)- and (−)-α-pinene and (+)-3-carene were potent inhibitors of AChE. 3.1.1 and 2.2.1 bicyclic alcohols and ketones showed weak inhibition. 3.1.1 and 4.1.0 bicyclic hydrocarbons with allylic methyl group were found to be uncompetitive inhibitors. Keywords: Acetylcholinesterase; bicyclic monoterpenoids; inhibition of enzyme activity; uncompetitive inhibitor

Inhibition of acetylcholinesterase activity by bicyclic monoterpenoids.

Volatile organic compounds (VOC) were extracted and identified from plant growth-promoting fungi (PGPF), Phoma sp., Cladosporium sp. and Ampelomyces sp., using gas chromatography–mass spectrometry (GC-MS). Among the three VOC extracted, two VOC blends (emitted from Ampelomyces sp. and Cladosporium sp.) significantly reduced disease severity in Arabidopsis plants against Pseudomonas syringae pv. tomato DC3000 (Pst). Subsequently, m-cresol and methyl benzoate (MeBA) were identified as major active volatile compounds from Ampelomyces sp. and Cladosporium sp., respectively, and found to elicit induced systemic resistance (ISR) against the pathogen. Molecular signaling for disease suppression by the VOC were investigated by treating different mutants and transgenic Arabidopsis plants impaired in salicylic acid (SA) or Jasmonic acid (JA)/ethylene (ET) signaling pathways with m-cresol and MeBA followed by challenge inoculation with Pst. Results show that the level of protection was significantly lower when JA/ET-impaired mutants were treated with MeBA, and in SA-, and JA/ET-disrupted mutants after m-cresol treatment, indicating the involvement of these signal transduction pathways in the ISR primed by the volatiles. Analysis of defense-related genes by real-time qRT-PCR showed that both the SA-and JA-signaling pathways combine in the m-cresol signaling of ISR, whereas MeBA is mainly involved in the JA-signaling pathway with partial recruitment of SA-signals. The ET-signaling pathway was not employed in ISR by the volatiles. Therefore, this study identified two novel volatile components capable of eliciting ISR that may be promising candidates in biological control strategy to protect plants from diseases.

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Systemic resistance induced by volatile organic compounds emitted by plant growth-promoting fungi in Arabidopsis thaliana.

The methanol extract of Yucca schidigera (YE) showed a suppressive effect on umu gene expression of the SOS response induced by 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) in Salmonella typhimurium TA1535/pSK1002. The suppressive effect of YE was also observed for 2-aminoanthracene and activated Trp-P-1, without a significant effect on bacterial growth. The extract exhibited a weak suppressive effect on SOS-induction by N-methyl-N'-nitro-N-nitrosoguanidine, but not by furylfuramide or 4-nitroquinoline-1-oxide. The antimutagenic activity of YE against Trp-P-1 was demonstrated by Ames assay using Salmonella typhimurium TA98. Isolation and purification of the active component of YE was carried out using SiO2 column chromatography, and 275 mg of antimutagenic compound was isolated from 2.5 kg of dried chips of yucca roots and branches. The compound was identified as 3,4',5-trihydroxystilbene (THS). The SOS suppression and antimutagenicity of THS against Trp-P-1 was determined by umu test and Ames test.

Mitsuo Miyazawa

Papers

Inhibition of Acetylcholinesterase Activity by Monoterpenoids with a p-Menthane Skeleton

Antimutagenic Activity of Flavonoids from Chrysanthemum morifolium

Inhibition of acetylcholinesterase activity by bicyclic monoterpenoids.

Systemic resistance induced by volatile organic compounds emitted by plant growth-promoting fungi in Arabidopsis thaliana.

Antimutagenic effect of resveratrol against Trp-P-1.