National Center for Pharmaceutical Crops (NCPC), Arthur Temple College of Forestry and Agriculture

1. Identification of Bioactive Agents from Plants       2. Development of Pharmaceutical Crops
Researchers at NCPC have focused on identifying anti-cancer and antiviral compounds from plants, particularly native plants in Texas since 1994. To date, over 1,100 species of vascular plants representing 138 families found in Texas were collected for the identification of bioactive agents. From 26 species, over 600 pure compounds, including 108 new compounds, have been isolated. Several compounds have shown promising results in initial tests by using mechanism-directed activity screening and in human tumor cell culture assays.

1.1 Identification of novel anti-cancer compounds from Camptotheca (Camptotech, Inc. and private funds, since 2001).

Happytrees (Camptotheca) is the major source of promising anti-cancer drugs camptothecins (CPTs). Two CPT drugs have received FDA approval with over $1 billion of annual sales: Hycamtin® and Camptosar®. Orathecin and 13 other CPT analogs are being investigating in clinical trials in the U.S. Since the anti-tumor activity of CPT was discovered in 1958, Camptotheca acuminata, the previously only-known species has been studied extensively worldwide in terms of chemical contents. In addition to the existing 12 known natural CPT analogues, we have recently identified two new CPT analogues and two other new compounds from C. acuminata.
Camptotheca acuminata

1.2 Discovery and development of anti-tumor saponins from plants (USDA 2008 to 2011).

The objective of the project is to identify novel anti-cancer agents with high efficacy and low toxicity from 6,000 samples representing approximately 2,000 selected species of native and invasive plants in Texas, which have been largely ignored by modern medicine. To date, over 130 triterpenoid saponins were isolated. Examples: from buttonbush (Cephalanthus occidentalis L.), a common American wetland species, six new triterpenoid saponins, together with 29 known compounds were isolated and identified; from red buckeye (Aesculus pavia L.), a shrubby or small tree species commonly distributed in the southeastern U.S., we have isolated 31 compounds including 25 new saponins. Several compounds showed potent cytotoxicity in vitro against human prostate, lung, and pancreatic tumors and inhibition of human DNA topoisomerase I (Topo I). Structure modification and biotransformation via fungi and bacteria of active saponins showed initial promising results. The structure-activity relationships of over 120 bioactive saponins have been investigated.
Aesculus pavia

1.3 Identification of antiviral agents from plants (US CDC R01 CI000315-01, 2004-2007; SFASU 2006-2008).

The primary objectives of the project are to discover promising bioactive compounds that may serve as “leads” for the development of effective solutions to control potential bioterrorism agents and for new pharmaceuticals to fight infectious diseases. Pure compounds are isolated from active extracts through the application of chromatographic techniques. From common invasive bullnettle (Cnidoscolus texanus (Muell.-Arg.) Small), 26 compounds, including 15 flavonoids, three coumarins, three coumaric acid derivatives, four triterpenoids, and one phytosterol have been isolated with three new flavonoids. Recently, 14 compounds were isolated from cotton weed (Froelichia floridana (Nuttall) Moquin-Tandon) including five new phytoecdysteroid glycosides and one new phenylpropanoid ester of sucrose, 11 compounds from yellow Jessamine (Gelsemium sempervirens (L.) Jaume Saint-Hilaire) including 3 new steroids, and 15 compounds from Liatris elegans (Walt.) Michx including two new compounds. Our investigations had also involved pteridophytes (ferns and allies). Actually, most of the 10,000 species of pteridophytes in the world have never been scientifically investigated for their chemical constituents and bioactivity, and therefore their potential medical values have been ignored. Of the 74 genera and 439 species of native and exotic pteridophytes in North America, 46 genera and 87 species are shared with China where some have been traditionally used to treat influenza. We expect to extensively investigate the chemical constituents of at least 25 species. To date, 33 compounds have been isolated from six fern species. In future, we plan to investigate about 200 species of plants in Texas.
Cnidoscolus texanus


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