Alkaloids from Cynanchum komarovii with inhibitory activity against the tobacco mosaic virus

An, Tian-Ying; Huang, Run-qiu; Yang, Zhao; Zhang, Dian-kun; Li, Guang-ren; Yao, Yu-cheng; Gao, Jun

doi:10.1016/s0031-9422(01)00382-x

Cited by 112 publications

(86 citation statements)

References 2 publications

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“…Additional compounds have been isolated from sectioned or entire milkweed plants and might occur partly or entirely in the latex. These include pregnane glycosides, alkaloids, cyclitols, and flavonol glycosides found in various Asclepias species and other milkweeds An et al 2001;Haribal & Renwick 1998;Marion 1939;Warashina & Noro 2000). To our knowledge, no information is available on how these diverse chemicals affect monarch larvae.…”

Section: Discussionmentioning

confidence: 99%

Glues or poisons: which triggers vein cutting by monarch caterpillars?

Helmus

Dussourd

2005

Chemoecology

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Late instar larvae of the monarch butterfly (Danaus plexippus L., Lepidoptera: Nymphalidae) deactivate the latex defense of milkweeds by chewing a furrow in the leaf midrib or petiole. The larva then feeds beyond the cut where latex outflow is minimal. If a larva does encounter latex exudate during feeding, it often returns to its initial cut to damage the midrib or petiole more extensively before resuming feeding. We used this response to latex as an assay for testing what cue triggers vein cutting. A sticky solution of polyethylene glycol and a mixture of cardenolides both were ineffective; drops applied to the mouthparts of feeding monarchs failed to elicit renewed vein cutting. Activity resided instead within a methanol extract of the supernatant obtained from centrifuged latex of the milkweed, Asclepias curassavica L. (Asclepiadaceae). Treatment with proteinase K did not eliminate activity documenting that the active compound is unlikely to be proteinaceous. Our results indicate that latex adhesiveness and low polarity cardenolides are relatively unimportant releasers of vein cutting. We propose that milkweeds contain noncardenolide stimulants of vein cutting; these compounds presumably serve a defensive role for milkweeds. Over 50 species of insects are known to employ vein-cutting before feeding on plants with canal-borne exudates; most of these species are dietary specialists like the monarch. Our behavioral assay provides a novel approach for identifying ecologically-significant compounds in the exudates of their diverse host plants.

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Section: Discussionmentioning

confidence: 99%

Glues or poisons: which triggers vein cutting by monarch caterpillars?

Helmus

Dussourd

2005

Chemoecology

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“…On the contrary, few natural inhibitors against plant-infecting viruses were reported except the anti-TMV agent pyrroloisoquinoline alkaloids (28).…”

Section: Discussionmentioning

confidence: 99%

Seco -pregnane steroids target the subgenomic RNA of alphavirus-like RNA viruses

Wang²,

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

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Plants have evolved multiple mechanisms to selectively suppress pathogens by production of secondary metabolites with antimicrobial activities. Therefore, direct selections for antiviral compounds from plants can be used to identify new agents with potent antiviral activity but not toxic to hosts. Here, we provide evidence that a class of compounds, seco-pregnane steroid glaucogenin C and its monosugar-glycoside cynatratoside A of Strobilanthes cusia and three new pantasugar-glycosides of glaucogenin C of Cynanchum paniculatum, are effective and selective inhibitors to alphavirus-like positive-strand RNA viruses including plant-infecting tobacco mosaic virus (TMV) and animal-infecting Sindbis virus (SINV), eastern equine encephalitis virus, and Getah virus, but not to other RNA or DNA viruses, yet they were not toxic to host cells. In vivo administration of the compounds protected BALB/c mice from lethal SINV infection without adverse effects on the mice. Using TMV and SINV as models, studies on the action mechanism revealed that the compounds predominantly suppress the expression of viral subgenomic RNA(s) without affecting the accumulation of viral genomic RNA. Our work suggested that the viral subgenomic RNA could be a new target for the discovery of antiviral drugs, and that seco-pregnane steroid and its four glycosides found in the two medicinal herbs have the potential for further development as antiviral agents against alphavirus-like positive-strand RNA viruses.antiviral drugs ͉ Strobilanthes cusia ͉ Cynanchum atratum V iruses replicate in host cells by hijacking the host-cell metabolic machinery. It is therefore difficult for antiviral therapies to inhibit only viral functions but spare host cellular processes. Nevertheless, great progress has been achieved over the past decades in antiviral research and therapy to reduce morbidity and mortality in virus-infected individuals (1, 2), and many antiviral drugs have been approved in recent years, most of which targeted either viral proteins or host cellular proteins. However, some of these compounds might induce the resistance of viruses to them and cause cell toxicity (3-5). The continuing emergence of highly pathogenic viruses like avian influenza viruses and severe acute respiratory syndrome coronavirus underscores the importance of advancing the search for effective antiviral agents. Plants have evolved constitutive and inducible defense mechanisms by producing a vast array of secondary metabolites against various microbial pathogens (6). Many herbaceous plants have been used in traditional Chinese medicine to treat viral diseases (7). It is conceivable that antiviral compounds would occur in plants as part of their innate defense arsenal, and the vast assortment of secondary metabolites could serve as a large pool for screening for previously undescribed antiviral compounds with a selective target spectrum and nontoxic to the host plants. Here, we provide evidence that a class of compounds, the seco-pregnane steroid and its glycosides from Strobilanthe...

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“…Activity against tobacco mosaic virus (TMV) was tested by the conventional half-leaf method [9,10] compounds possess good antivirus activities. For example, at 500 ppm, inhibition rate of compounds 2, 4b, and DHT to TMV is 40, 45, and 45%, respectively.…”

Section: Antivirus Activitymentioning

confidence: 99%