- Biologically active components against Drosophila melanogaster from Podophyllum hexandrum
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In the course of screening for novel naturally occurring insecticides from Chinese crude drugs, a dichloromethane extract of Podophyllum hexandrum was found to give an insecticidal activity against larvae of Drosophila melanogaster Meigen. From the extrac
- Miyazawa, Mitsuo,Fukuyama, Mami,Yoshio, Kimio,Kato, Takenori,Ishikawa, Yukio
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- Decatungstate-Mediated C(sp3)–H Heteroarylation via Radical-Polar Crossover in Batch and Flow
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Photocatalytic hydrogen atom transfer is a very powerful strategy for the regioselective C(sp3)–H functionalization of organic molecules. Herein, we report on the unprecedented combination of decatungstate hydrogen atom transfer photocatalysis with the oxidative radical–polar crossover concept to access the direct net-oxidative C(sp3)–H heteroarylation. The present methodology demonstrates a high functional group tolerance (40 examples) and is scalable when using continuous-flow reactor technology. The developed protocol is also amenable to the late-stage functionalization of biologically relevant molecules such as stanozolol, (?)-ambroxide, podophyllotoxin, and dideoxyribose.
- Capaldo, Luca,Frederick, Michael O.,García-Losada, Pablo,Laudadio, Gabriele,Mateos, Carlos,No?l, Timothy,Nu?o, Manuel,Nyuchev, Alexander V.,Rincón, Juan A.,Wan, Ting
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- Stereoselective synthesis of 4β-acyloxypodophyllotoxin derivatives as insecticidal agents
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As our ongoing work on research of natural-product-based insecticidal agents, some 4α/β-acyloxypodophyllotoxin derivatives were synthesized, and were evaluated against the pre-third-instar larvae of B. mori, A. dissimilis and M. separate in vivo at the co
- Che, Zhi-Ping,Tian, Yue-E,Liu, Sheng-Ming,Jiang, Jia,Hu, Mei,Chen, Gen-Qiang
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p. 1028 - 1041
(2018/07/15)
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- Synthesis of novel 4α-(Acyloxy)-2′(2′,6′)-(di) halogenopodophyllotoxin derivatives as insecticidal agents
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In continuation of our program aimed at the discovery and development of natural-product-based insecticidal agents, we have prepared three series of novel 4α-(acyloxy)-2′(2′,6′)-(di)halogenopodophyllotoxin derivatives modified in the C and E rings of podophyllotoxin, which is a naturally occurring aryltetralin lignan isolated from the roots and rhizomes of Podophyllum hexandrum. Their structures were well characterized by 1H NMR, HRMS, ESI-MS, optical rotation, and mp. The stereochemical configurations of compounds 5s, 6b, 6d, and 7q were unambiguously confirmed by single-crystal X-ray diffraction. Their insecticidal activity was evaluated against the pre-third-instar larvae of oriental armyworm, Mythimna separata Walker, in vivo at a concentration of 1 mg/mL. These derivatives likely displayed the antimolting hormone effect. Among all the derivatives, especially compounds 5a, 5n, 7f, 7n, and 7w exhibited the most potent insecticidal activity with final mortality rates of 70% or so. This suggested that a chlorine or bromine atom introduced at the C2′ or C2′ and C6′ positions on the E ring of podophyllotoxin was necessary for obtaining the potent compounds. This will pave the way for further design, structural modification, and development of podophyllotoxin derivatives as insecticidal agents.
- Che, Zhiping,Yu, Xiang,Zhi, Xiaoyan,Fan, Lingling,Yao, Xiaojun,Xu, Hui
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p. 8148 - 8155
(2013/09/23)
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- Carbon-13 NMR Chemical Shifts of some Podophyllum Lignans and Analogues
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Carbon-13 nmr chemical shifts of a number of podophyllum lignans, podophyllotoxin, 4′-demethylpodophyllotoxin, podophyllotoxone, desoxypodophyllotoxin and their derivatives have been determined. The derivatives include 1-naphthol, quinone, diol and tetrahydrofuran compounds.
- Mitra, Jayati,Mitra, Alok Kumar
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p. 692 - 694
(2007/10/03)
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- BIOSYNTHESIS OF PODOPHYLLUM LIGNANS - I. CINNAMIC ACID PRECURSORS OF PODOPHYLLOTOXIN IN PODOPHYLLUM HEXANDRUM
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Feeding experiments in Podophyllum hexandrum plants have established that phenylalanine, cinnamic acid and ferulic acid are good precursors of the two major aryltetralin lignans podophyllotoxin and 4'-demethylpodophyllotoxin.Sinapic and 3,4,5-trimethoxycinnamic acids were poorly utilized, showing that the substitution pattern of the pendent aryl ring is built up after coupling of the two phenylpropane units.Degradation studies on podophyllotoxin derived from ferulic acid show that the two halves of the lignan molecule are equally labelled supporting a biosynthetic sequence involving oxidative coupling of two similar phenylpropane precursors having the substitution pattern of ferulic acid.Although 3,4-methylenedioxycinnamic acid was readily incorporated, degradative studies prove that this compound is not incorporated intact, but via a metabolic sequence in which the methylenedioxy carbon atom enters the C1-pool and then labels the methylenedioxy and methoxyl substituents of podophyllotoxin.The rest of the skeleton is incorporated via ferulic acid, presumably by way of caffeic acid.Key Word Index - Podophyllum hexandrum; Podophyllaceae; aryltetralin; lignans; biosynthesis; podophyllotoxin.
- Jackson, David E.,Dewick, Paul M.
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p. 1029 - 1036
(2007/10/02)
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- Antitumor agents. LXII: Synthesis and biological evaluation of podophyllotoxin esters and related derivatives
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Synthetic esters of the C-4 hydroxyl group of podophyllotoxin (I) were prepared. In addition, esters were synthesized using the diol system of tetrahydropyranyl podophyllol (XV), produced by reducing the lactone ring of tetrahydropyranyl podophyllotoxin with lithium aluminum hydride. Six compounds, the acrylate (IV), 3,3-dimethyl acrylate (V), phenoxyacetate (IX), and ethyl adipate (XI) and I as well as podophyllol (XIV) and tetrahydropyranyl podophyllol dimesylate (XVIII), showed significant activity when tested using the P-388 lymphocytic leukemia screen at 3 mg/kg/day. None of the esters showed higher activity than that shown by the parent molecule I when tested at the same dosage level.
- Levy,Hall,Lee
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p. 1158 - 1161
(2007/10/02)
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