Studies On Accumulation Of Camptothecin And Tissue Culture In Camptotheca Acuminata Decne.

Camptothecin (CPT) is an important anti-tumor component extractedfrom Camptotheca acuminata Decne. (Nyssaceae), which distributed in the south of China. In order to recognize the characteristic of CPT accumulation in the plant, researches involving tissue culture, determination of CPT concentration and accumulation & localization of CPT have been carried out.In the tissue culture studying, 6 types of explants were selected, bud, young leaf and young stem were optimal, young stem was the best of them. Meanwhile, the influence of basal culture medium (BDS, MS) and hormone (NAA, 2,4-D 6-BA, KT) on the callus induction and subculture were studied. The results suggest that there were no significant difference on the induction ratio, but BDS improve the growth of callus. And the using hormone in tissue culture with combinatorial way is better than that of single. BDS+2,4-D1.0 mg/L +KT0.6 mg/L, BDS+2,4-D1.5 mg/L +KT0.6 mg/L, BDS+2,4-D2.0 mg/L +KT0.6 mg/L were effective for induction, otherwise BDS+2,4-D0.5mg/L+KT0.6mg/L, BDS+BA2.0mg/L+NAA0.2mg/L, and BDS + NAA 3.0 mg/L + KT 0.6 mg/L were optimal for subculture in all combinatorial formulae.Second part, the CPT and HCPT concentration in 15 samples from south of China were determined by HPLC. The result showed that CPT concentration in fruit from Fujian Province was the highest, and which from Guizhou Province was the lowest in all samples. There was significant difference in CPT concentration between them (P < 0.01). It also found the same result in HCPT. HCPT concentration in fruit from Sichuan was the highest, and was the lowest from Guizhou in all samples. Comparing the CPT and HCPT concentration in 3 samples from different area (Hangzhou Jinhua Pan'an) in Zhejiang, it showed that there was no difference among them. The CPT and HCPT in fruit of fresh and stored 1 year from different areas were compared, the difference were in or not among these samples. Comparingthe CPT and HCPT concentration in fruit (pericarp and seed), it showed that most of CPT was distributed in seed, and HCPT were distributed averagely in pericarp and seed.The development of young stems and leaves were investigated using optical, fluorescence and scanning electron microscopy and the camptothecin content in Camptotheca acuminata was analyzed by HPLC. Secretory structure, especially secretory canals were found. A linear relationship (1^=0.9257) was found between CPT content and secretory canal density of stem. The secretion in canals and glandular trichomes showed intense blue autofluorescence under 360nm UV light. The results showed that camptothecin was primarily accumulated in glandular trichomes and secretory canals of stems and leaves.