AFRICAAUSTRALIASOUTH AMERICANORTH AMERICA |
©The
World Botanical Associates Web Page
Prepared by Richard W. Spjut
July 1999
April 2003
AFRICAAUSTRALIASOUTH AMERICANORTH AMERICA |
|
Richard Spjut has more than 20 years experience in plant exploration activities, primarily in the acquisition of plant samples for biological screening programs (anticancer, anti-AIDS, antibiotics, chemo-preventive medicine). His undergraduate and graduate training include courses specifically dealing with the taxonomy of bacteria, algae (fresh water), fungi, lichens, bryophytes, aquatic plants, grasses, and general and advanced work in vascular plants (ferns, conifers, flowering plants). This experience has been maintained for all groups of terrestrial plants as a result of collecting plants for the NCI antitumor and anti-viral screening programs (e.g., Spjut et al. 1986, 1988, Spjut 1994, 1995, 1996; Terrell et al. 2000). Prior to collecting plants for the NCI antitumor screening program, Richard Spjut conducted floristic surveys of the Trinity Alps and Yolla Bolly Wilderness areas in the Klamath Region of California. During the summers of his early graduate studies he backpacked with a plant press into these wilderness areas collecting and identifying more than 600 species of vascular plants. He also collected in other areas of the Klamath Region such as along Willow Creek in Humboldt County and along the Smith River in Del Norte County after daily work on Survey Lines for new roads where he had to camp for ten day periods. Consequently he learned to recognize more than 800 species in northern California. This knowledge formed the basic foundation for his later contract work and employment with the USDA as recognized by his peers. During the next ten years the Richard Spjut continued collecting for the NCI program as an employee of the USDA Agricultural Research Service (ARS). From 1973–1977, he obtained recollections of more than 200 species in Africa (Kenya, Tanzania), Australia (Western Australia, Tasmania), Mexico, and throughout the United States. One of his more productive recollection trips was in Tanzania where he re-collected 50–100 kg of fourteen species: Apodytes dimidiata (ws, sb), Boophone disticha (whole plant), Croton macrostachyus (rt, sb, tw-lf), Dais cotiniifolia (st-lf), Ekebergia benguelensis (sb, tw-lf), Garcinia smeathmannii (sb), Podocarpus milijianus (sb), Gnidia glauca (rt, ws, sb, tw-lf), Gnidia kraussiana (whole plant), Hypoxis spp. (whole plant), Maesa lanceolata (sb), Peponium vogellii (aerial parts), Psorospermum febrifugum (rt), and Schefflera volkensii (rt). The active agents of several of these recollections were reported in Cassady et al. (1990). He has also perhaps acquired the most experience of any ethnobotanist in the procurement of massive recollections: 15 tons of Maytenus buchananii stems in Kenya, reconnaissance of Zambia for Maytenus buchananii, reconnaissance of Kenya for 500 pounds of Gnidia subcordata leaves, aerial and ground reconnaissance of Wisconsin and Ontario for 8,000 pounds of Thalictrum dasycarpum seed, 5,000 pounds of Bouvardia ternifolia plants from Coahuilla (Mexico), ~500 pounds of Colubrina californica and C. texensis stems in California and Texas, aerial and ground reconnaissance of Western Australia for Conospermum spp., and certified the identification of massive collections of Taxus brevifolia bark for the NCI. In late 1977 when the NCI modified their extraction methodology and requested that ARS botanists put more emphasis on collecting new taxa, Richard Spjut subsequently targeted medicinal plants and genera not previously collected for the NCI. Geographical areas with concentrations of taxa of interest became the focal point for ‘bio-diversity’ sampling. During 1978–1981, he obtained 1,736 samples, 758 of which were from Western Australia, an area that has ~12,000 species, 80% of which are endemic. One of his samples led to the discovery of the Anti-HIV chemical conocurvone; this was the root of Conospermum unilaterale (Proteaceae). When the NCI terminated their agreement with the ARS in 1982, Richard Spjut continued to collect medicinal plants under a new organization, World Botanical Associates (WBA). As Director, he has procured more than 3,000 samples for pharmaceutical screening and published four reviews on antitumor screening of vascular plants and bryophytes (Spjut 1985, Spjut et al. 1986, 1988, 1992). In one expedition to Baja California (Mexico) he was accompanied by the Dean of the School of Pharmacy at the Ohio State University (John Cassady) for recollections of plants that had shown activity in the KB and ASK bioassays (Spjut & Marin 2000); during a three week period they obtained 8–10 kg recollections of Atamisquea emarginata, Berginia virgata, Bergerocactus emoryi, Forchhammeria watsonii, Gochnatia arborescens, Jatropha cinerea, Krameria parviflora, Mascagnia macroptera, Phaulothamnus spinescens, Stillingia linearifolia, and Xylonagra arborea, and collected 103 general samples from more than 50 species.
Besides vascular plants, Richard Spjut has conducted studies on lichens in which he (Spjut 1995b) has described one new genus (Vermilacinia) and more then 50 new species in Niebla and Vermilacinia of California and Baja California (Spjut 1996), and supplied lichen samples for antiviral, antitumor and carotenoid screening (Czeczuga et al. 1997). He also initiated collection of bryophytes for
antitumor screening that led to the first discovery of P-388 activity in
mosses, Claopodium crispifolium (Spjut et al. 1986).
Because Dean Cassady's group was not obtaining consistent
bioassay results with recollections, Spjut re-examined his vouchers and
suggested that the antitumor active agent might be the product of an
associated organism, in particular a species of Nostoc that he
identified in the samples (Spjut et al. 1988). Consequently, he
submitted samples of Nostoc to the NCI for which they reported
significant P-388 activity (Spjut et al. 1988). This, along with other
independent studies, led the NCI to procure more samples of blue-green
algae from marine and fresh water habitats.
Cryptophycin, a dioxadiazacyclohexa-decenetetrone, was later
isolated from a species of Nostoc, a novel anticancer
chemotherapeutic agent that has less drug treatment resistance than
vincristine, colchicine and taxol (Smith et al. 1994), while Boyd et al.
(1997) have also discovered an antiviral agent Cyanovirin from N.
ellipsosporum. However, ansamacrolids were isolated from Claopodium
crispifolium, suggesting activity may be due to actinomycetes
(Cassady et al. 1990; Suwanborirux et al. 1990). The moss microbial
association is perhaps analogous to that in the movie “Medicine Man”
where the active agent turned out not in the plant that was initially
thought to contain the chemical, but in another organism (species of
ant) that happened to be with the plant at the time it was extracted.
Other recollections of bryophytes by the PI, however, have led to the
isolation of active agents that are clearly a product of the moss
(Cassady et al. 1990) or liverwort (Chonigming et a. 1997). Richard Spjut's collection of bryophytes for the NCI certainlyinfluenced the writing of his major professor’s wife, Carol Norris. One of her many romantic novels, Lost Letters (Fig. 4), was about a fictitious botanist—Brandy who collected bryophytes in California for the NCI, including a recollection of Plagiomnium, a moss that Spjut had recollected 100 kg from near Willow Creek, California. It is interesting that Carol Norris also mentioned taxol as a successful drug for treating cancer, discovered from “Taxus occidentalis,” a name also used by the botanist Nuttall (1849) who described the species. It was not until 1990 (Rowinsky et al.. 1990) that taxol actually became recognized as a drug (paclitaxel). Richard Spjut's contribution to the discoveries of antitumor agents in bryophytes has been recognized by a moss named in his honor, Orthotrichum spjutii Norris & Vitt, a species that is known only from the eastern slopes of the Sierra Nevada, California. Finally, he is working on publishing a taxonomic revision of Taxus. The information he provided to NCI as a result of his review of the distribution and ecology of T. brevifolia for the USDA in 1977 became part of the contract solicitation that was distributed by the NCI during the late 1980’s and early 1990’s. He has subsequently presented his taxonomic concepts of the genus at many international meetings (Spjut 1992, 1993, 1998, 2000; Spjut et al. 1993) and submitted a paper to the editor of Sida Miscellany that is currently under revision. His taxonomic characters for the North American Flora have been accepted (Hils 1993).
|
The
wide variety of plants collected by Richard Spjut has allowed him to
gain an in-depth knowledge of the taxonomy of many families of vascular
plants. This is clearly evident in his book on