Phytochemistry最新文献

Phytochemical investigation of the whole plants of Helleborus niger L. (Ranunculaceae) resulted in the isolation of five undescribed compounds, including one bufadienolide (1), two bufadienolide rhamnosides (2 and 3), and two ecdysteroids (12 and 13), along with eight known compounds (4–11). The chemical structures of 1–3, 12, and 13 were determined by spectroscopic studies, including 2D NMR, and chromatographic and spectroscopic analyses of the hydrolyzed products. Compounds 1–13 were evaluated for their cytotoxic activity against HL-60 human leukemia cells, A549 human lung adenocarcinoma cells, SBC-3 human small-cell lung cancer cells, and TIG-3 human normal diploid lung cells. Compounds 1–12 showed cytotoxic activity against HL-60, A549, and SBC-3 cells, with IC₅₀ values ranging from 0.0016 to 6.1 μM. Bufadienolide rhamnoside 2 exhibited potent cell proliferation inhibitory activity against SBC-3 cells after 24–48 h of treatment and apoptosis-inducing activity in SBC-3 cells via an intrinsic pathway after 72 h of treatment. The JFCR39 panel screening of 2 suggests that the molecular target of 2 is Na⁺,K⁺-ATPase.

Chemical investigation of the acid hydrolysate of Cynanchum bungei roots led to the isolation of eleven undescribed steroids, namely cynbungenins A-K (1–11), and seven previously described analogues (12–18). The complete structures of these compounds were elucidated using the comprehensive spectroscopic analyses and reference data. Structurally, compounds 1 and 2 represent the first example of androstane-type steroids found in the Cynanchum plants, and compounds 3–6 and 12 are characterized as pregnane-type steroids with a rare 8,14-seco-steroid core. In the cytotoxic activity assay, compound 16 displayed the strongest cytotoxic effect against MCF-7, HCT-116, HeLa, and HepG2 cancer cell lines, with IC₅₀ values of 9.98-16.42 μM, and further research indicated that it induced both apoptosis and cell cycle arrest in the G0/G1 phase in a dose-dependent manner toward HepG2 cells.

Phenolamides are specialized metabolites widely distributed in the plant kingdom. Their structure is composed by the association of hydroxycinnamic acid derivatives to mono-/poly-amine through an amination catalyzed by N-hydroxycinnamoyltransferases enzymes. Tomato plants accumulate putrescine-derived phenolamides in their vegetative parts. Recently, two first genes coding for putrescine-hydroxycinnamoyltransferase (PHT, Solyc11g071470 and Solyc11g071480) were identified in tomato and demonstrated to control the leaf accumulation of caffeoylputrescine in response to leafminer infestation. In this study, two additional genes (Solyc06g074710 and Solyc11g066640) were functionally characterized as new tomato PHT. The substrate specificity and the expression pattern in planta were determined for the four tomato PHT. Taken together the results give a comprehensive view of the control of the putrescine-derived phenolamide accumulation in tomato plant through the biochemical specificity and the spatial expression of this small family of PHT.

Achillea alpina L. (Alpine yarrow) is a noteworthy herb in the genus Achillea with many uses in vegetables and traditionally used to treat stomach disorders. In our continuous research on the chemical constituents and biological activities of medicinal plants, ten previously undescribed terpenoids including eight eudesmane-type sesquiterpenes (1–8), one nor-eudesmane-type sesquiterpene (9), one cyclo-geraniol derivative (10), and twenty-one known compounds were isolated and structurally elucidated from the aerial parts of A. alpina. Structures and absolute configurations of the undescribed terpenoids were identified using comprehensive spectroscopic analysis (NMR, HRESI-MS, and CD data) and computational methods (ECD and NMR calculation). Enzyme inhibitory assays showed that the isolated sesquiterpene (19), triterpene (22), and sterol (26) were protein tyrosine phosphatase 1B (PTP1B) inhibitors with IC₅₀ values ranging from 14.87 to 23.09 μM in comparison with positive control - ursolic acid, showing IC₅₀ value of 5.93 ± 0.16 μM. Further enzyme kinetics and molecular docking studies were performed to provide valuable insights into their mechanism of action.

Two undescribed isoquinolines (1–2), including one undescribed carbon skeleton isoquinoline together with six known ones (4–9) as well as an undescribed amide (3) and three known ones (10–12) were isolated from C. tomentella. Their planar structures and absolute configurations were elucidated by extensive analyses of UV, NMR, HRESIMS, DP4+ statistical analysis and ECD calculations, respectively. Tomentediline A (1) is an isoquinoline alkaloid dimer that forms an undescribed carbon carbon bond at the C-13 position of (2H)-protoberberine in a natural product discovered for the first time. Meantime, 1 exerted moderate cytotoxicity against the U251 cell lines, indicating that the undescribed dimer skeleton of isoquinoline compound has the potential for anti-glioma.

Chemical investigations of a methanolic extract of the twigs of Vernonia amygdalina Delile (Asteraceae) resulted in the isolation and identification of three previously undescribed highly oxygenated Δ^7,9(11) stigmastane-type steroids namely vernonins U–W (1−3) along with six known compounds (4−9). The structural characterization of all the isolated compounds has been conducted via comprehensive 1D and 2D-NMR spectroscopy as well as HRMS. The seven steroidal derivatives 1−7 were evaluated for their antiplasmodial activity against the chloroquine-resistant strain P. falciparum Dd2 (PfDd2) and their hemolytic effect on human red blood cells (RBCs). Vernonins U (1), A (4) and stigmasterol-3-O-β-d-glucopyranoside (7) showed the highest activity with IC₅₀ values of (5.47 ± 0.01) μg/mL, (6.02 ± 0.13) μg/mL and (6.34 ± 0.80) μg/mL, respectively, against PfDd2, while vernonin W (3) showed moderate activity of (21.20 ± 0.40) μg/mL. None of the tested compounds displayed hemolytic effects on human RBCs up to 100 μg/mL indicating their safety. These results enrich the known chemistry of V. amygdalina and support its use in folk medicine for the treatment of malaria. This encourages further research towards new antiplasmodial drug candidates from this plant.

Five previously undescribed compounds, including three 12-nor-rotenoids, were isolated from Pachyrhizus erosus seeds. A brief survey on the dealkylation of selected rotenoids with BBr₃ was undertaken. Spectroscopic data of these previously undescribed compounds and reaction products are reported. The proposal of absolute configurations at stereocenters in the isolates and reaction products was based on NMR and ECD data. Most of the isolates and reaction products were evaluated for their growth inhibitory activities against four cancer cell lines and a Vero cell line. Many compounds exhibited strong to moderate activities with IC₅₀ values ranging from 0.06 to 20.9 μM, and their structure-activity relationships were evaluated.

Three previously undescribed pyrrolizidinone alkaloids, penicipyrrolizidinones A and B (1 and 2), possessing an unprecedented 2-methyl-2-(oct-6-enoyl)pyrrolizidin-3-one skeleton, and penicipyrrolizidinone C (3), featuring a rare 1-alkenyl-2-methyl-pyrrolizidin-3,7-dione skeleton, together with four known pyrrolidine derivatives (4−7) were isolated from the mangrove-derived fungus Penicillium sp. DM27. Their structures were elucidated through comprehensive spectroscopic analysis, theoretical calculations of ECD spectra, and the modified Mosher's method. A plausible biosynthetic pathway for penicipyrrolizidinones A−C (1−3) was proposed. Compounds 4 and 5 exhibited moderate cytotoxicity against B16-F10 melanoma cells with IC₅₀ values of 10.5 μM and 15.5 μM, respectively.

The genus Valeriana is used in traditional Chinese medicine to treat nervous disorders, sleep disorders, epilepsy and skin diseases. A large number of sesquiterpenoids from this genus have been found to exhibit anti-inflammatory, antiproliferative, anti-influenza virus and neuroprotective activities. In order to discover more sesquiterpenoids with structural diversity and bioactivity from Valeriana plants, fifteen sesquiterpenoids, including ten undescribed ones, valernaenes A−J (1, 5−7, 9−11 and 13−15), were isolated from the roots and rhizomes of Valeriana officinalis var. latifolia. Their structures were elucidated by extensive spectroscopic techniques (1D, 2D NMR and HRESIMS) and electronic circular dichroism (ECD) calculation. Structurally, valernaenes C (6) and D (7) were two caryophyllane-type norsesquiterpenoids. In addition, valernaenes A (1) and F (10) exhibited anti-influenza virus activity with EC₅₀ values of 38.76 ± 1.44 and 23.01 ± 4.89 μM, respectively. Furthermore, caryophyllenol A (2) showed promoting effect on nerve growth factor (NGF)-mediated neurite outgrowth in PC12 cells with differentiation rate of 12.26% at a concentration of 10 μM. This study not only enriched the structural diversity of sesquiterpenoids in the genus Valeriana, but also provided theoretical basis for the discovery of anti-influenza virus and neuroprotective agents from this genus.

Cancer poses a significant global public health challenge, with commonly used adjuvant or neoadjuvant chemotherapy often leading to adverse side effects and drug resistance. Therefore, advancing cancer treatment necessitates the ongoing development of novel anticancer agents with diverse structures and mechanisms of action. Natural products remain crucial in the process of drug discovery, serving as a primary source for pharmaceutical leads and therapeutic advancements. Triterpenoids are particularly compelling due to their complex structures and wide array of biological activities. Recent research has demonstrated that naturally occurring triterpenes and their derivatives have the potential to serve as promising candidates for new drug development. This review aims to comprehensively explore the anticancer properties of triterpenoids and their synthetic analogs, with a focus on recent advancements. Various aspects, such as synthesis, phytochemistry, and molecular simulation for structure-activity relationship analyses, are summarized. It is anticipated that triterpenoid derivatives will emerge as notable anticancer agents following further investigation into their mechanisms of action and in vivo studies.