Camptotheca Acuminata Decne Research Articles

Characteristics of forest understory herbaceous vegetation and its influencing factors in biodiversity hotspots in China

Forest ecosystems, especially within biodiversity hotspots, heavily rely on the often-overlooked understory herbaceous communities (USHC) for their structural integrity and ecological functions. Because of their modest stature, these communities have garnered insufficient attention from researchers. Therefore, in this study attention is focused on USHC, which attempts to fill this research gap. To achieve this, we established 105 sample plots in 2022 within forest ecosystems situated in the biodiversity hotspot of southwest China. Our investigation unveiled a rich biodiversity tapestry, identifying 424 plant species from 108 families and 284 genera. Notable were the 217 herbaceous species identified in the understory layer, representing 67 families and 163 genera. These understory herbaceous species accounted for 51.2 % of the overall species count. Through a detailed analysis, the sample plots were categorized into eight distinct communities using a two-way indicator species analysis. These communities exhibited diverse variations in species composition, diversity, biomass, and nutrient characteristics. Notably, community I (Eucalyptus robusta Smith + Rubus corchorifolius L. f. + Alternanthera philoxeroides (Mart.) Griseb.), V (Camptotheca acuminata Decne + Rubus parkeri Hance + Iris tectorum Maxim), VIII (Platycladus orientalis (L.) Franco + Viburnum dilatatum Thunb. + Cyclosorus interruptus (Willd.) H. Ito) stood out for their exceptional species diversity and productivity. Moreover, correlation analyses highlighted the substantial impact of topographic and soil factors on USHC. Altitude, soil water content, and total carbon content emerged as the primary determinants of species diversity. Biomass demonstrated close associations with total soil carbon and nitrogen. Furthermore, the nutrient characteristics displayed significant correlations with soil nutrient contents. These findings underscore the critical importance of prioritizing USHC attention in forest conservation and management strategies within biodiversity hotspots. The implications strongly advocate for the inclusion of these communities in planning and decision-making processes, emphasizing their pivotal role in maintaining structural and functional diversity in ecosystems.

Efficient ultrasonic extraction of alkaloids and glycosides from Camptotheca acuminata Decne via deep eutectic solvents: Kinetics and mechanisms

The study investigated the extraction of alkaloids and glycosides from the Camptotheca acuminata Decne using deep eutectic solvent (DES). 18 types of deep eutectic solvents (DESs) were prepared, and it was found that the extraction performance of choline chloride (ChCl)-formic acid (FA) was optimal, surpassing traditional solvents such as methanol/70 % methanol. In comparison to methanol, the extracted amount of compounds by DES was 2–3 times higher. The extraction processes involving the molar ratio of ChCl-FA, pH, DES/H2O mass ratio, solid/liquid ratio, as well as ultrasonic power were optimized. A mathematical model for solid/liquid extraction kinetics from Camptotheca acuminata Decne was developed. The extraction mechanism was investigated using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and 1H nuclear magnetic resonance(1H NMR). The results revealed that the DES caused dissociation in Camptotheca acuminata Decne and formed hydrogen bonds with Camptothecin (CPT). Meanwhile, density functional theory (DFT) calculations verified that FA-based exhibited the highest extracted amount for CPT. In addition, this study investigated the recovery rate of DES, and the results showed that after 10 cycles, the DES system remained effective for the extraction of alkaloids and glycosides.

Influence of tree size on the scaling relationships of lamina and petiole traits: A case study using Camptotheca acuminata Decne.

There is a lack of research on whether tree size affects lamina and petiole biomass allocation patterns, whereas the trade-off between leaf biomass allocated to the lamina and the petiole is of significance when considering the hydraulic and mechanical function of the leaf as a whole. Here, Camptotheca acuminata Decne was selected for study because of the availability of trees differing in size growing under the same conditions. A total of 600 leaves for two tree size groups and 300 leaves per group differing in height and trunk diameter were collected. The lamina fresh mass (LFM), lamina dry mass (LDM), lamina area (LA), petiole fresh mass (PFM), and petiole length (PL) of each leaf was measured, and reduced major axis regression protocols were used to determine the scaling relationships among the five functional traits. The bootstrap percentile method was used to determine if the scaling exponents of the traits differed significantly between the two tree size groups. The results indicated that (i) there was a significant difference in the LFM, LDM, PFM, PL, LMA, LFMA and PFM/LFM between large and small trees, but no significant difference in LA; (ii) the LA versus LFM, LA versus LDM, LFM versus PFM, LA versus PFM, and PL versus PFM scaling relationships of the two groups were allometric (i.e., not isometric); (iii) there were significant differences in the scaling exponents of LA versus LFM, LA versus PFM, PL versus PFM between the two groups, but there was no significant difference in the LFM versus PFM scaling relationship between the two groups of trees. The data were also consistent with the phenomenon known as "diminishing returns". These data indicate that tree size influences leaf biomass allocation patterns in ways that can potentially influence overall plant growth, and therefore have an important bearing on life-history strategies.

Promotion Effects of Taxus chinensis var. mairei on Camptotheca acuminata Seedling Growth in Interplanting Mode

Wild Camptotheca acuminata Decne (C. acuminata) resources are becoming endangered and face poor growth. Preliminary investigation results found that the growth of C. acuminata in an artificial mixed forest of Taxus chinensis var. mairei (Lemee et Levl.), Cheng et L. K. Fu (T. chinensis var. mairei) and C. acuminata was significantly higher than that in pure forests. Understanding the reasons for the above differences can help create a mixed forest of T. chinensis var. mairei and C. acuminata to solve the problem of depleting C. acuminata resources. In this study, the growth and soil indexes under two different modes (C. acuminata/T. chinensis var. mairei interplanted and monocultured C. acuminata seedlings) were compared. The results showed that plant height, basal diameter, photosynthesis rate and chlorophyll content of C. acuminata under the interplanting mode were higher than those under monoculture. The growth rates of plant height and basal diameter that were calculated from interplanted specimens increased by 25% and 40%, respectively, compared with those from specimens that were monocultured. Photosynthetic rates from different light intensities under interplanting were higher than those in seedlings under monoculture. The contents of chlorophylls a and b and total chlorophyll under interplanting were 1.50, 1.59, and 1.47 times higher than those under monoculture, respectively. The numbers of bacteria and fungi in the interplanted culture were higher than those in the monoculture. Furthermore, the differences in microbial diversity under different planting modes were analyzed via the amplicon sequencing method. Soil enzyme activities increased under interplanting compared with that in the monoculture. Taxane allelochemicals were detected in the range of 0.01–0.67 μg/g in the interplanting mode from April to September. T. chinensis var. mairei may increase the establishment and productivity of C. acuminata seedlings under interplanting mode through improvements in enzyme activity, changes in microorganism population structure, and release of allelochemicals.

Biotechnology of camptothecin production in Nothapodytes nimmoniana, Ophiorrhiza sp. and Camptotheca acuminata.

Cancer is probably the deadliest human disease in recent years. In the past few years, rapid clinical progress has been made in the field of anticancer drug development. Plant secondary metabolites have been noted as extremely efficacious as promising natural source for anticancer therapy for many years. Camptothecin (CPT) is one of the popularly used anti-tumor drugs possessing clinically proven properties against a plethora of human malignancies that include ovarian and colorectal cancers. For the first time, CPT was obtained from the extracts of a Chinese medicinal tree, Camptotheca acuminata Decne. from the family Cornaceae. Subsequently, CPT was also isolated from the bark of Nothapodytes foetida (Wight) Sleumer (Icacinaceae). However, the availability of enough natural sources for obtaining CPT is a major constraint. Due to overexploitation and harvesting, loss of habitat, excessive trading, and unfavorable environmental factors, the natural source of CPT has become extinct or extremely limited and hence they are red listed under endangered species. Conventional propagation has also failed to meet the ever-expanding demand for CPT production. With this, biotechnological toolkits have constantly been used as a boon to produce sustainable source, utilization, and ex situ conservation of medicinal plants. The approaches serve as a supplement to traditional agriculture in the mass production of plant metabolites with potent bioactivities. Non-availability of enough anticancer medicine and the requirement to satisfy current demands need a sustainable source of CPT. With this background, we present a comprehensive review on CPT discovery, its occurrence in the plant kingdom, biosynthesis, phytochemistry, pharmacological properties, clinical studies, patterns of CPT accumulation, and biotechnological aspects of CPT production in three plants, viz., N. nimmoniana, Ophiorrhiza species, and C. acuminata.Key points• Biotechnological approaches on production of camptothecin from Nothapodytes nimmoniana, Ophiorrhiza species, and Camptotheca acuminata• In vitro propagation of camptothecin-producing plants• Genetic diversity and transgenic research on camptothecin-producing plants.

Discovery of the new Coptotriche species in China revealed two novel host-plant families and host-plant orders for Tischeriidae, a family of stenophagous, leaf-mining lepidopterans.

The article describes three new species of Coptotriche Walsingham, 1890 from China and adjacent northern Vietnam: C. camptotheca Xu Dai, sp. nov. feeding on Camptotheca acuminata Decne. (Nyssaceae); C. turpinia Xu Dai, sp. nov. feeding on Turpinia arguta (Lindl.) Seem. (Staphyleaceae); and C. asiana Dikus Stonis, sp. nov. The latter appeared to be a narrow oligophagous species feeding on various Symplocos Jacq.: S. sumuntia Buch.-Ham. ex D. Don, S. poilanei Guill., and Symplocos glauca (Thunb.) Koidz. (Symplocaceae). Nyssaceae and Staphyleaceae are novel host-plant families of Tischeriidae. The new species are illustrated with photographs of adults, male and female genitalia, and leaf mines. The article also briefly discusses about the proportion of monophagous and oligophagous species of Tischeriidae.

Enhanced production of camptothecin by immobilized callus of Ophiorrhiza mungos and a bioinformatic insight into its potential antiviral effect against SARS-CoV-2

Camptothetin (CPT) is a quinoline alkaloid originally isolated from the Chinese tree, Camptotheca acuminata Decne. CPT was found to have anticancerous and antiviral properties. Derivatives of natural CPT, including topothecan and irinotecan are used clinically to treat a variety of cancers. Apart from Camptotheca acuminata Decne, CPT production was also found in the perennial plant Ophiorrhiza mungos. In this study we attempted the immobilization of the tissue culture grown callus of Ophiorrhiza mungos for the continuous production of a higher concentration of CPT. As evident from previous studies about the antiviral effects of CPT, we wanted to bioinformatically analyze the binding potential of CPT towards two important proteins of SARS-CoV-2, protease (Mpro) and RNA dependent RNA polymerase (RdRp). Further docking analysis of the CPT against the exterior spike glycoprotein of SARS-CoV-2 was also done to determine their potential interaction. The immobilized callus of Ophiorrhiza mungos produced CPT at a concentration of 420 µg/l by the end of 12 days of growth. The HPLC analysis was done to determine the purity of the CPT synthesized by the immobilization technique. The bioinformatic analysis revealed a higher binding efficiency of CPT and its derivatives, toptecan and irinotecan against Mpro and RdRp. The docking analysis of CPT against the spike glycoprotein of SARS-CoV-2 showed hydrogen bonding with the amino acids at K466 with a bond distance of 2.56A° and K355 with a bond distance of 2.40A°. This finding was of particular importance that other compounds including hydroxychloroquine sulphate, lopinavir and ivermectin could bind with the spike protein only by weak Vander wall bonds and no hydrogen bond formation was noticed. Our studies hence evaluate the efficiency of CPT against SARS-CoV-2, by potentially blocking the interaction of the spike glycoprotein with the angiotensin-converting enzyme 2 (ACE2) receptor found on host cells.

Ophiorrhiza, a promising herbaceous source of the anticancer compound camptothecin

Camptothecin is an important source for the synthesis of some of the major anti-cancer agents such as irinotecan and topotecan. Traditional source of camptothecin are prominently woody plants such as Camptotheca acuminata Decne. and Nothopodytes nimmoniana (Graham) Mabb., and the increasing demand for camptothecin leads to the level of threatening their existence. Ophiorrhiza species composed of herbaceous plants with quick growth characteristics which are reported as alternative source of camptothecin. The present review focus on taxonomical status, traditional uses, biological activities and phytochemical constituents with a special attention in bioproduction of camptothecin from Ophiorrhiza species and its future prospects.

Synthesis and biological activities of two camptothecin derivatives against Spodoptera exigua

Camptothecin (CPT), a natural alkaloid isolated from Camptotheca acuminata Decne, is found to show potential insecticidal activities with unique action mechanisms by targeting at DNA-topoisomease I (Top1) complex and inducing cell apoptosis. To improve the efficacy against insect pests, two camptothecin (CPT) derivatives were synthesized through introducing two functional groups, 2-nitroaminoimidazoline and 1-chloro-2-isocyanatoethane by esterification reaction. The insecticidal activities of these two derivatives were evaluated at contact toxicity, cytotoxicity and topoisomerase I (Top1) inhibitory activities comparing with CPT and hydroxyl-camptothecin (HCPT). Results showed that compound a, synthesized by introducing 2-nitroaminoimidazoline to CPT, apparently increased contact toxicity to the third larvae of beet armyworm, Spodoptera exigua, and cytotoxicity to IOZCAS-Spex-II cells isolated from S. exigua. However, the inhibition on DNA relaxation activity of Top1 was reduced to less than 5 percentage even at high concentrations (50 and 100 μM). For introducing 1-chloro-2-isocyanatoethane to HCPT, the contact toxicity, cytotoxicity and Top1 inhibitory activity of synthesized compound b were increased significantly compared to CPT and HCPT. These results suggested that both synthesized compounds possessed high efficacy against S. exigua by targeting at Top1 (compound b) or novel mechanism of action (compound a).

Effects of experimental defoliation on resource allocation using integrated physiological units in the andromonoecious Camptotheca acuminata

The resource allocation of individual plants is a relatively complex process. Trade-off exists between vegetative growth and reproduction, male and female characteristics in monoecious plant. Camptotheca acuminata Decne. (Nyssaceae) is a perennial woody plant that annually forms short shoots that contain an apex cyme consisting of four to six capitula and four to eight (usually six) alternate leaves. We regard these short shoots as integrated physiological units (IPUs). Three levels of defoliation treatments were applied to the IPUs: 100%, 50% and 0% (control). The results showed that in the primary capitula the male input (pollen production) decreased and the change of female function (pistil weight) was not statistically significant. In contrast, the secondary capitula exhibited a plastic shift toward maleness and stopped producing pistils but increased pollen production. Due to the inherent inflorescence structures and flowering time sequence of the cymes, the effects of defoliating different capitulum positions were diverse, and the secondary and tertiary capitula suffered greater effects than those in the primary position. Moreover, the effects of 100% defoliation were more significant than those of 50% defoliation. Furthermore, no new leaves were produced within the IPUs after defoliation, but the photosynthetic capacities of the remaining leaves were enhanced. The results of this study revealed that defoliation on IPUs had different impacts on the reproductive and vegetative traits, and caused a trade-off between male and female functions in C. acuminata. These findings indicated that defoliation on IPUs can help to explain sex allocation in the andromonoecious C. acuminata, and resource limitations further intensify intra-inflorescense sex allocation.

Camptotheca acuminata Decne residue after camptothecin extract as a substrate to produce mushroom spawn

Currently in China, no technically and economically viable methods exist to handle large quantities of Camptotheca acuminata Decne residue (CA residue) after camptothecin extract while there is a great demand for low cost alternatives to replace the cottonseed hull-based materials used in commercial mushroom culture. Hence, it is of importance for camptothecin extract factories and mushroom producers to explore the utilization of CA residue in mushroom industry. We conducted a research to study how partially or completely substituting traditional mushroom substrate by CA residue would influence the mycelial growth in mushroom spawn production. 5 mushroom strains from 4 species were used in the test, i.e., oyster mushroom (Pleurotus ostreatu) strains, Zayou No. 1 and Xide 33, needle mushroom (Flammulina velutipes) strain ChuanjinNo. 3, hairy wood ear (Auricularia polytricha) strain Huang Er No. 10, and shiitake (Lentinula edodes) strain Wuxiang. The nutrient element composition and heavy metal contents of CA residue were determined to ensure its safety and to determine its appropriate component in the substrate formulation for mushroom spawn production. The four substrate formulations (one control — CK, and three treatments, named, T1, T2, T3,) contained 0%, 40%, 79%, and 100% CA residue, respectively, to allow comparison of the fungal mycelial growth. The control (CK) was the popularly used formulation in Chinese commercial mushroom production, comprising of 73% cottonseed hulls, 10% sawdust, 15% wheat bran, 1% lime, 1% white sugar (percentage by weight). All mushroom spawns of the five strains in the four treatments were incubated under the same conditions. The results showed that mycelia of the five mushroom strains grew significantly faster on the substrates containing CA residue than on the substrate with no CA residue (CK). There were no significant differences in the mycelial growth rate among treatments containing CA residue for the two oyster mushrooms and the needle mushroom, but mycelial growth rate in treatments T2 and T3 was significantly higher than in treatment T1 for hairy wood ear and shiitake. The results suggest that CA residue can be used to culture oyster mushroom, needle mushroom, hairy wood ear, and shiitake spawn, and the medium containing CA residue can stimulate their mycelial growth. The commercial production of mushroom spawn using CA residue not only brings better economical benefits including lower cost to mushroom producers, but also reduces environmental pollution by providing a means to reduce dumping and piling of CA residue.

Propagation and chlorophyll fluorescence of Camptotheca acuminata cuttings

The Chinese happy tree, Camptotheca acuminata Decne, is grown extensively in plantations for harvest and extraction of its anti-cancer and potentially anti-viral compound, camptothecin. This study determined whether C. acuminata was amenable to clonal propagation as rooted cuttings and whether application of the rooting hormone, indole-3-butyric acid (IBA), affected chlorophyll fluorescence (FV/FM) or the percentage of cuttings that formed roots. The species was found highly amenable to vegetative propagation because a consistently high percentage of cuttings formed roots when treated with 3 or 8 g IBA / kg powder. IBA application was unnecessary in spring when more than 90% of untreated cuttings formed roots, but the highest IBA dose increased the number of plants produced by 18 and 82% (from tip cuttings) and by 46 and 102% (from node cuttings) in two later collections when rooting of untreated cuttings had declined. IBA treatments did not affect chlorophyll fluorescence. Industrial deployment of C. acuminata is entirely feasible using rooted cuttings, allowing clonal multiplication of genotypes that contain high levels of camptothecin.

Laticifers in Camptotheca acuminata Decne: distribution and structure

In this paper, a system of laticifers in Camptotheca acuminata Decne (Nyssaceae) is described. Laticifers were already present in the leaf primordia of the shoot apex. In the mature leaves, laticifers were found in the midrib and in the larger veins, both in the parenchymatic region delimited by vascular bundles and in the cortex just external to the phloem. In the stem, laticifers were present in both the primary and secondary body, running parallel to the longitudinal axis. They were located in the pith and in the cortex proximal to the phloem. No laticifers were found in the roots. The histochemical analyses indicated that the main compounds accumulated in laticifers were phenols. Neutral lipids and fatty acids were also present. Ultrastructural observations showed osmiophilic globules both in the vacuoles and in the peripheral regions of the cytoplasm of the laticifer cells. Plastids were present, although altered, with some parallel membranes and lacking starch grains. The discovery in C. acuminata of a laticifer system, which had never been described for the order Cornales, could be of taxonomic value, also considering that this order has traditionally represented one of the most problematic groups of flowering plants.