Camptothecin Accumulation and Variations in Camptotheca

Abstract

Camptotheca (Nyssaceae) is a major source of anticancer camptothecin (CPT). It is imperative to understand CPT accumulation and variations in Camptotheca in order to develop CPT production strategies for endangered germplasm. Our study results showed that CPT is primarily accumulated in glandular trichomes of leaves and stems, and CPT content varies among species and varieties but even more significantly within the plant (with different tissues, tissue ages, and seasons). Because of higher CPT yield and desirable biological and ecological features, ‘Hicksii’ and ‘Katie’ should be considered the major management germplasm as CPT sources in the future. Young leaves and mature fruits have higher CPT contents than other tissues in the plants. Young photosynthetic leaves and stems contain higher CPT contents than old ones, but ‘sink’ tissues such as wood, roots, and fruits show different patterns. CPT content also shows a great seasonal change, but is less influenced by tree age. Intact clipping of young leaves and stems should be managed for harvest for CPT production. Preservation and treatment methods influence the CPT extraction. CPT is better preserved in fresh or freeze-dried material than in air or oven-dried material. CPT can be more efficiently extracted after homogenizer treatment of plant materials because more trichome walls can be broken to allow solvent extraction.

Key words

Camptotheca - Nyssaceae - trichome - camptothecin - accumulation - variation

References

• 1 Li S Y, Adair K T. Camptotheca acuminata Decaisne, Xi Shu, a promising anti-cancer and anti-viral tree for the 21st century. A Henry M. Rockwell monograph. Stephen F. Austin State University Nacogdoches, Texas; 1994
• 2 Li S Y, Wang Y J, Beasley R S, Northrup K. Anti-cancer happytrees (Camptotheca Decaisne). Research Report. Arthur Temple College of Forestry, Stephen F. Austin State University Nacogdoches, Texas; 2000
• 3 Liu Z, Adams J. Seed source variation in camptothecin concentrations of nursery-grown Camptotheca acuminata seedlings.  New Forests. 1998;  16 167 - 75
• 4 Liu Z, Carpenter S B, Bourgeois W J, Yu Y, Constantin R J, Falcon M J, Adams J C. Variations in the secondary metabolite camptothecin in relation to tissue age and season in Camptotheca acuminata .  Tree Physiology. 1998;  18 265 - 70
• 5 Liu Z, Adams J. Camptothecin yield and distribution within Camptotheca acuminata trees cultivated in Louisiana.  Canadian Journal of Botany. 1996;  74 360 - 5
• 6 Lopez-Meyer M, Nessler C L, McKnight T D. Sites of accumulation of the antitumor alkaloid camptothecin in Camptotheca acuminata .  Planta Medica. 1994;  60 558 - 60
• 7 Hsu J S, Chao T Y, Lin L T, Hsu C F. Chemical constituents of the anticancer plant Camptotheca acuminata Decne. II. Chemical constituents of the fruits of Camptotheca acuminata Decne.  Acta of Chimica Sinica. 1977;  35 193 - 200
• 8 Hsu J S, Chao T Y, Hsu C F. Chemical constituents of the anticancer plant Camptotheca acuminata Decne (I).  Acta Chimica Sinica. 1977;  35 227 - 31
• 9 Li S Y. Camptotheca lowreyana, a new species of anti-cancer happytrees (Camptotheca Decaisne).  Bulletin of Botanical Research. 1997;  17 348 - 52
• 10 Wang Y J. Genetic diversity and camptothecin variation in Camptotheca Decaisne. Ph. D. Dissertation. Stephen F. Austin State University Nacogdoches, Texas; 2001
• 11 Li S Y. Camptotheca lowreyana tree named ‘Katie’. US Patent 2001: PP11,959
• 12 Wall M E, Wani M C, Cook C E, Palmer K H, McPhail A T, Sim G A. Plant antitumor agents. I. The isolation and structure of camptothecin, a novel alkaloidal leukemia and tumor inhibitor from Camptotheca acuminata .  Journal of American Chemical Society. 1966;  88 3888-90
• 13 Tien H J, Tien J M, Yeh M Y, Wu T S, Huang C M. Studies on the constituents of Camptotheca acuminata Done (I). The constituents of leaves.  Chemistry. 1977;  2 51-4
• 14 Perdue R E, Smith R L, Wall M E, Hartwell J L, Abbott B J. Camptotheca acuminata Decaisne (Nyssaceae) source of camptothecin, and antileukemic alkaloid. Agricultural Research Series USDA Technical Bulletin No. 1415 1977
• 15 Kawamura F, Kikuchi Y, Ohira T, Yatagai M. Accelerated solvent extraction of paclitaxel and related compounds from the bark of Taxus cuspidata .  Journal of Natural Products. 1999;  62 244 - 7