Two New Anti-Proliferative C18 -Norditerpenes from the Roots of Podocarpus macrophyllus

Phytochemical analysis and quality assessment of Podocarpus macrophyllus by UHPLC-DAD-ESI-MS and UHPLC-MS/MS MRM methods

The concern about the quality of medicinal herbs is becoming important due to the poor quality of commercial products like cosmetics, functional foods, and natural medicine produced from them. However, there is a lack of modern analytical methods to evaluate the constituents of P. macrophyllus until the moment. This paper reports an analytical method based on UHPLC-DAD and UHPLC-MS/MS MRM methods to evaluate the ethanolic extracts of P. macrophyllus leaves and twigs. 15 main constituents were identified using a UHPLC-DAD-ESI-MS/MS profiling. Subsequently, a reliable analytical method was established and successfully used to quantitate the constituent's content using four marker compounds in leaf and twig extracts of this plant. The result obtained from the current study demonstrated the secondary metabolites and the variety of their derivatives in this plant. The analytical method can help evaluate the quality of P. macrophyllus and develop high-value functional materials.

A Comprehensive Review of the Classification, Sources, Phytochemistry, and Pharmacology of Norditerpenes

Norditerpenes are considered to be a common and widely studied class of bioactive compounds in plants, exhibiting a wide array of complex and diverse structural types and originating from various sources. Based on the number of carbons, norditerpenes can be categorized into C19, C18, C17, and C16 compounds. Up to now, 557 norditerpenes and their derivatives have been found in studies published between 2010 and 2023, distributed in 51 families and 132 species, with the largest number in Lamiaceae, Euphorbiaceae, and Cephalotaxaceae. These norditerpenes display versatile biological activities, including anti-tumor, anti-inflammatory, antimicrobial, and antioxidant properties, as well as inhibitory effects against HIV and α-glucosidase, and can be considered as an important source of treatment for a variety of diseases that had a high commercial value. This review provides a comprehensive summary of the plant sources, chemical structures, and biological activities of norditerpenes derived from natural sources, serving as a valuable reference for further research development and application in this field.

A comprehensive review on the medicinal usage of Podocarpus species: Phytochemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Plants of the Podocarpus species belong to the Podocarpaceae family and are largely distributed in the southern hemisphere. Beside the commercially and ecologically valuable, plants of the Podocarpus species are also used in traditional medicines in some countries for treating asthma, fever, venereal diseases, eye diseases, etc. AIM OF THE STUDY: In recent decades, the identities and pharmacological activities of phytochemicals extracted from Podocarpus plants have been widely studied. However, there have been no comprehensive and systematic reviews. This article aims to systematically review the latest research on the putative mechanisms underlying pharmacological actions of phytochemicals from the Podocarpus species, as well as to lay a foundation for promoting the development of plant resources from this genus, further drug research, and product development.

MATERIALS AND METHODS

A comprehensive search of PubMed, Google Scholar, Web of Science, Elsevier and CNKI databases was conducted using the keywords "Podocarpus", "traditional usage", "phytochemistry", "pharmacology", "nagilactone", etc. Related papers published among July 1964 to February 2023 were collected to summarize the research progress. All plant names were determined through the "The Plant List" (http://www.theplantlist.org/).

RESULTS

To date, 262 chemical constituents have been isolated and identified from 26 Podocarpus plants; among these, norditerpene bilactone is the main pharmacologically active component. Norditerpene bilactones are reported to have anti-cancer, anti-inflammatory, antioxidant, antibacterial, anti-tyrosinase, neuroprotective, anti-plasmodial, anti-mutagenic, and anti-atherosclerotic properties as well as other pharmacological activities, which support its traditional uses.

CONCLUSION

Extensive studies on phytochemistry and pharmacology of Podocarpus species lead to discovery of a series of hopeful leading compounds with unique chemical structure, especially the nor- and bis-norditerpenoid dilactones with four isoprene units. These compounds have been proved to possess various pharmacological activities. This review will provide a reference for further research and promote the idea of combining modern research with traditional medicinal applications of Podocarpus plants.

New Diterpenes with Potential Antitumoral Activity Isolated from Plants in the Years 2017-2022

Diterpenes represent a wider class of isoprenoids, with more than 18,000 isolated compounds, and are present in plants, fungi, bacteria, and animals in both terrestrial and marine environments. Here, we report on the fully characterised structures of 251 new diterpenes, isolated from higher plants and published from 2017, which are shown to have antitumoral activity. An overview on the most active compounds, showing IC50 < 20 μM, is provided for diterpenes of different classes. The most active compounds were extracted from 29 different plant families; particularly, Euphorbiaceae (69 compounds) and Lamiaceae (54 compounds) were the richest sources of active compounds. A better activity than the positive control was obtained with 33 compounds against the A549 cell line, 28 compounds against the MCF-7 cell line, 9 compounds against the HepG2 cell line, 8 compounds against the Hep3B cell line, 19 compounds against the SMMC-7721 cell line, 9 compounds against the HL-60 cell line, 24 compounds against the SW480 cell line, and 19 compounds against HeLa.

Naturally Occurring 8ß,13ß-kaur-15-en-17-al and Anti-Malarial Activity from Podocarpus polystachyus Leaves

Despite much interest and studies toward the genus Podocarpus, the anti-malarial evaluation of Podocarpus polystachyus’s phytoconstituents remains lacking. Herein, the phytoconstituents of P. polystachyus leaves and their anti-malarial effect against Plasmodium falciparum were investigated for the first time. One new natural product, 8ß,13ß-kaur-15-en-17-al (1), along with three known compounds, 8ß,13ß-kaur-15-en-17-ol (2) and 13ß-kaur-16-ene (3), and α-tocopherol hydroquinone (4) were isolated via HR-ESI-MS and NMR analyses. Compounds 1 and 2 inhibited P. falciparum growth at 12 and 52 µM of IC₅₀, respectively. Their anti-malarial activity was associated with the in silico P. falciparum lactate dehydrogenase (PfLDH) inhibition. Molecular docking of ligands 1 and 2 with the putative target PfLDH revealed ~−2 kcal/mol of binding energies more negative than the control. Molecular dynamic simulations (100 ns) showed equal or smaller deviation values (RMSD, RMSF, Rg) and stronger interactions of PfLDH-1 and PfLDH-2 complexes via at least one consistent H-bond than the control. Additionally, a slightly increased PfLDH H-bond profile in their interactions improved the PfLDH dynamic and structural stabilities. Overall, this study supports the relevance of 1 and 2 as plasmodial growth inhibitors with their putative anti-PfLDH activity, which could be a potential scaffold for developing anti-malarial drugs.

The complete chloroplast genome sequence of Podocarpus macrophyllus (Podocarpaceae) and phylogenetic analysis

The complete chloroplast genome sequence of Podocarpus macrophyllus was determined in this study. According to the results, the genome is 134,239 bp in length. The GC content of the whole chloroplast genome is 37.0%. The complete chloroplast genome of P. macrophyllus encodes a total of 120 genes, including 34 tRNA genes, 4 rRNA genes and 82 protein-coding genes. Like other conifers chloroplast genomes, P. macrophyllus has no inverted repeat sequences. To reveal the phylogenetic relationship of P. macrophyllus, we constructed phylogenetic trees using other species of Podocarpaceae, and the phylogenetic analysis showed that P. macrophyllus is evolutionarily closest to Podocarpus longifoliolatus.

De novo transcriptome analysis provides insights into the salt tolerance of Podocarpus macrophyllus under salinity stress

BACKGROUND

Soil salinization is causing ecosystem degradation and crop yield reduction worldwide, and elucidation of the mechanism of salt-tolerant plants to improve crop yield is highly significant. Podocarpus macrophyllus is an ancient gymnosperm species with a unique environmental adaptation strategy that may be attributed to its lengthy evolutionary process. The present study investigated the physiological and molecular responses of P. macrophyllus plants to salt stress by analyzing its photosynthetic system and antioxidant enzyme activity. We also analyzed the differentially expressed genes (DEGs) in P. macrophyllus under salt stress using RNA sequencing and de novo transcriptome assembly.

RESULTS

Salt treatment significantly affected the photosynthetic system in P. macrophyllus seedlings, which decreased chlorophyll content, altered chloroplast ultrastructure, and reduced photosynthesis. The activities of antioxidant enzymes increased significantly following salt stress treatment. Transcriptome analysis showed that salt stress induced a large number of genes involved in multiple metabolic and biological regulation processes. The transcription levels of genes that mediate phytohormone transport or signaling were altered. K⁺ and Ca²⁺ transporter-encoding genes and the MYB transcription factor were upregulated under salt stress. However, the genes involved in cell wall biosynthesis and secondary metabolism were downregulated.

CONCLUSION

Our research identified some important pathways and putative genes involved in salt tolerance in P. macrophyllus and provided clues for elucidating the mechanism of salt tolerance and the utilization of the salt tolerance genes of P. macrophyllus for crop improvement.

Natural and Synthetic Lactones Possessing Antitumor Activities

Cancer is one of the leading causes of death globally, accounting for an estimated 8 million deaths each year. As a result, there have been urgent unmet medical needs to discover novel oncology drugs. Natural and synthetic lactones have a broad spectrum of biological uses including anti-tumor, anti-helminthic, anti-microbial, and anti-inflammatory activities. Particularly, several natural and synthetic lactones have emerged as anti-cancer agents over the past decades. In this review, we address natural and synthetic lactones focusing on their anti-tumor activities and synthetic routes. Moreover, we aim to highlight our journey towards chemical modification and biological evaluation of a resorcylic acid lactone, L-783277 (4). We anticipate that utilization of the natural and synthetic lactones as novel scaffolds would benefit the process of oncology drug discovery campaigns based on natural products.

Development of Potential Antitumor Agents from the Scaffolds of Plant-Derived Terpenoid Lactones

Naturally occurring terpenoid lactones and their synthetic derivatives have attracted increasing interest for their promising antitumor activity and potential utilization in the discovery and design of new antitumor agents. In the present perspective article, selected plant-derived five-membered γ-lactones and six-membered δ-lactones that occur with terpenoid scaffolds are reviewed, with their structures, cancer cell line cytotoxicity and in vivo antitumor activity, structure-activity relationships, mechanism of action, and the potential for developing cancer chemotherapeutic agents discussed in each case. The compounds presented include artemisinin (ART, 1), parthenolide (PTL, 2), thapsigargin (TPG, 3), andrographolide (AGL, 4), ginkgolide B (GKL B, 5), jolkinolide B (JKL B, 6), nagilactone E (NGL E, 7), triptolide (TPL, 8), bruceantin (BRC, 9), dichapetalin A (DCT A, 10), and limonin (LMN, 11), and their naturally occurring analogues and synthetic derivatives. It is hoped that this contribution will be supportive of the future development of additional efficacious anticancer agents derived from natural products.

Anticancer Activities and Mechanism of Action of Nagilactones, a Group of Terpenoid Lactones Isolated from Podocarpus Species

Nagilactones are tetracyclic natural products isolated from various Podocarpus species. These lactone-based compounds display a range of pharmacological effects, including antifungal, anti-atherosclerosis, anti-inflammatory and anticancer activities reviewed here. The most active derivatives, such as nagilactones C, E and F, exhibit potent anticancer activities against different cancer cell lines and tumor models. A comprehensive analysis of their mechanism of action indicates that their anticancer activity mainly derives from three complementary action: (i) a drug-induced inhibition of cell proliferation coupled with a cell cycle perturbation and induction of apoptosis, (ii) a blockade of the epithelial to mesenchymal cell transition contributing to an inhibition of cancer cell migration and invasion and (iii) a capacity to modulate the PD-L1 immune checkpoint. Different molecular effectors have been implicated in the antitumor activity, chiefly the AP-1 pathway blocked upon activation of the JNK/c-Jun axis. Nag-C is a potent inhibitor of protein synthesis binding to eukaryotic ribosomes and inhibition of different protein kinases, such as RIOK2 and JAK2, has been postulated with Nag-E. The literature survey on nagilactones highlights the therapeutic potential of these little-known terpenoids. The mechanistic analysis also provides useful information for structurally related compounds (podolactones, oidiolactones, inumakilactones) isolated from Podocarpus plants.

Four Natural Compounds Separated from Folium Isatidis: Crystal Structures and Antibacterial Activity

Four natural compounds were obtained by concentrating, separating and purifying from the Folium isatidis. These natural compounds have been characterized by elemental analysis, IR spectrum, NMR and single-crystal X-ray diffraction analysis. The results show that these natural compounds are 4(3H)-quinazolinone (I), 2,4(1H,3H)-quinazolinedione (II), methyl 3,4-dihydro-4-oxoquinazoline-2-carboxylate (III) and ethyl 3,4-dihydro-4-oxoquinazoline-2-carboxylate (IV). The antibacterial activity experiment showed that I and II had better activity against Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Salmonella than III, IV and other multiple components, because III and IV have long branches and steric hindrance effect. Compounds I and II have planar structure, which can more easily combine with these bacteria and kill them. The above results have good guiding significance for studying the antibacterial activity for single components or mixtures from natural origin.