Cytotoxic leuconoxine-type diazaspiroindole alkaloids isolated from Cryptolepis dubia.

Two leuconoxine-type diazaspiroindole alkaloids, the known compound, (+)-melodinine E (1), and its new analogue, (+)-11-chloromelodinine E (2), were isolated from the stems of Cryptolepis dubia (Burm.f.) M.

The Cytotoxic Cardiac Glycoside (-)-Cryptanoside A from the Stems of and Its Molecular Targets.

A cardiac glycoside epoxide, (-)-cryptanoside A (), was isolated from the stems of collected in Laos, for which the complete structure was confirmed by analysis of its spectroscopic and single-crystal X-ray diffraction data, using copper radiation at a low temperature. This cardiac glycoside epoxide exhibited potent cytotoxicity against several human cancer cell lines tested, including HT-29 colon, MDA-MB-231 breast, OVCAR3 and OVCAR5 ovarian cancer, and MDA-MB-435 melanoma cells, with the IC values found to be in the range 0.1-0.

Strategies for the discovery of potential anticancer agents from plants collected from Southeast Asian tropical rainforests as a case study.

Covering up to early 2023The present review summarizes recent accomplishments made as part of a multidisciplinary, multi-institutional anticancer drug discovery project, wherein samples comprising higher plants were collected primarily from Southeast Asia, and also from Central America, and the West Indies. In the introductory paragraphs, a short perspective is provided on the current importance of plants in the discovery of cancer therapeutic agents, and the contributions of other groups working towards this objective are mentioned. For our own investigations, following their collection, tropical plants have been subjected to solvent extraction and biological evaluation for their antitumor potential.

Cytotoxic constituents of Glycosmis ovoidea collected in Vietnam.

Compounds derived from natural sources have been major contributors to the area of cancer chemotherapy for decades. As part of an ongoing effort to discover anticancer drug leads from tropical plants, a large-scale collection of Glycosmis ovoidea Pierre (Rutaceae), was made at Nui Chua National Park, Vietnam. Activity-guided fractionation of the chloroform-soluble fractions led to the isolation of nine coumarins, including the new compound, 1-(7-methoxy-2-oxo-2H-chromen-8-yl)-3-methyl-1-oxobut-2-en-2-yl (S)-2-methylbutanoate (1).

Isolation and elucidation of two isoflavonoids from an American Indian plant, Pursh, using Magnetic Microbead Affinity Selection Screening (MagMASS) for estrogen receptor alpha ligands.

A new isoflavonoid, xanthocerin J, along with previously described xanthocerin A, were isolated from a methanol extract of aerial parts of a traditional American Indian herb, Pursh (Asteraceae). The structures of these compounds were characterized using mass spectrometry and NMR based on an isolation protocol using magnetic microbead affinity selection screening (MagMASS) for ligands to the estrogen receptor alpha (ERα). These compounds bound to ERα from an active fraction that exhibited dose-dependent antiestrogenic activity in the Ishikawa assay.

Discovery of Anticancer Agents of Diverse Natural Origin.

Research progress from mainly over the last five years is described for a multidisciplinary collaborative program project directed toward the discovery of potential anticancer agents from a broad range of taxonomically defined organisms. Selected lead compounds with potential as new antitumor agents that are representative of considerable structural diversity have continued to be obtained from each of tropical plants, terrestrial and aquatic cyanobacteria, and filamentous fungi. Recently, a new focus has been on the investigation of the constituents of U.

Bioactive small-molecule constituents of Lao plants.

Laos has a rich plant diversity, and medicinal plants are used extensively in Lao traditional medicine for the treatment of a variety of human diseases. However, only a relatively small number of these plants have been investigated for their major components with potential antitumor, anti-infective, and other types of bioactivities. These species include , , , , , , , and .

Spermidine alkaloid and glycosidic constituents of Vietnamese .

Phytochemical investigation of the aerial parts of led to the isolation of secondary metabolites belonging to the spermidine alkaloid, glycoside, depsidone and phenol classes. Of the eleven secondary metabolites isolated in this study, two spermidine alkaloids, dovyalicins H () and I (), which belong to a rare group among this class, and six glycosides () are previously undescribed. The structures of all new isolates were determined by interpretation of spectroscopic and spectrometric data.

Update on Phytochemical and Biological Studies on Rocaglate Derivatives from Aglaia Species.

With about 120 species, is one of the largest genera of the plant family Meliaceae (the mahogany plants). It is native to the tropical rainforests of the Indo-Australian region, ranging from India and Sri Lanka eastward to Polynesia and Micronesia. Various species have been investigated since the 1960s for their phytochemical constituents and biological properties, with the cyclopenta[]benzofurans (rocaglates or flavaglines) being of particular interest.

A pentamethoxylated flavone from Glycosmis ovoidea promotes apoptosis through the intrinsic pathway and inhibits migration of MCF-7 breast cancer cells.

The rare flavone 5,3'-dihydroxy-3,6,7,8,4'-pentamethoxyflavone (PMF) has been isolated from several plant species, and its cytotoxic activity has been reported against many types of cancer cells. In this study, PMF was purified from Glycomis ovoidea collected in Vietnam, and its antiproliferative effects and underlying mechanism of action were investigated against MCF-7 cells. PMF inhibited growth in MCF-7 > MCF-10A > MDA-MB-231 cells after 72 hr treatment, with IC values of 1.

Cytotoxic and non-cytotoxic cardiac glycosides isolated from the combined flowers, leaves, and twigs of Streblus asper.

A new non-cytotoxic [(+)-17β-hydroxystrebloside (1)] and two known cytotoxic [(+)-3'-de-O-methylkamaloside (2) and (+)-strebloside (3)] cardiac glycosides were isolated and identified from the combined flowers, leaves, and twigs of Streblus asper collected in Vietnam, with the absolute configuration of 1 established from analysis of its ECD and NMR spectroscopic data and confirmed by computational ECD calculations. A new 14,21-epoxycardanolide (3a) was synthesized from 3 that was treated with base. A preliminary structure-activity relationship study indicated that the C-14 hydroxy group and the C-17 lactone unit and the established conformation are important for the mediation of the cytotoxicity of 3.

Structurally Modified Cyclopenta[]benzofuran Analogues Isolated from .

Four new cyclopenta[]benzofuran derivatives based on an unprecedented carbon skeleton (-), with a dihydrofuran ring fused to dioxanyl and aryl rings, along with a new structural analogue () of 5‴-episilvestrol (episilvestrol, ), were isolated from an aqueous extract of a large-scale re-collection of the roots of collected in Vietnam. Compound demonstrated mutarotation in solution due to the presence of a hydroxy group at C-2‴, leading to the isolation of a racemic mixture, despite being purified on a chiral-phase HPLC column. Silvestrol () and episilvestrol () were isolated from the most potently cytotoxic chloroform subfraction of the roots.

Highly sweet compounds of plant origin: From ethnobotanical observations to wide utilization.

Ethnopharmacological Relevance: Ethnobotanical studies have been of very great importance in recognizing plants that contain substances that modulate the heterodimer T1R2-T1R3 sweet taste receptor, inclusive of Stevia rebaudiana (Asteraceae) and Siraitia grosvenorii (Cucurbitaceae).

Aim Of The Review: In addition to reviewing relevant ethnobotanical literature, inclusive of original field work conducted, the authors have provided a progress report on the ultimate regulatory acceptance of highly sweet ent-kaurane (steviol) diterpene glycosides from S. rebaudiana leaves ("stevia") and cucurbitane triterpene glycosides (mogrosides) from the fruits of S.

Caspase-Dependent Apoptosis in Prostate Cancer Cells and Zebrafish by Corchorusoside C from Streptocaulon juventas.

Corchorusoside C (1), isolated from Streptocaulon juventas collected in Vietnam, was found to be nontoxic in a zebrafish ( Danio rerio) model and to induce cytotoxicity in several cancer cell lines with notable selective activity against prostate DU-145 cancer cells (IC 0.08 μM). Moreover, corchorusoside C induced DU-145 cell shrinkage and cell detachment.

Potential Anticancer Agents Characterized from Selected Tropical Plants.

Higher plants are well known for their value in affording clinically useful anticancer agents, with such compounds acting against cancer cells by a range of mechanisms of action. There remains a strong interest in the discovery and development of plant secondary metabolites as additional cancer chemotherapeutic lead compounds. In the present review, progress on the discovery of plant-derived compounds of the biflavonoid, lignan, sesquiterpene, steroid, and xanthone structural types is presented.

Bioactivity-Guided Isolation of Totarane-Derived Diterpenes from Podocarpus neriifolius and Structure Revision of 3-Deoxy-2α-hydroxynagilactone E.

Bioactivity-guided phytochemical investigation of Podocarpus neriifolius D. Don. (Podocarpaceae) has led to the isolation of one new (2) and three known (1, 3, and 4) B-type podolactones, along with three totarane-type diterpenes (5-7).

Non-Destructive Chemical Analysis of a L. (Mangosteen) Herbarium Voucher Specimen.

Herbarium voucher specimens are used primarily for taxonomic confirmation. However, they also afford a record of the metabolic profile of a plant, potentially at the time it was collected, or at the very least, at the time of analysis. Even with the enhanced sensitivity of modern analytical techniques, analysis of the metabolites of a herbarium voucher requires removal and consumption of at least part of an entire specimen.

The Search for Anticancer Agents from Tropical Plants.

Many of the clinically used anticancer agents in Western medicine are derived from secondary metabolites found in terrestrial microbes, marine organisms, and higher plants, with additional compounds of this type being currently in clinical trials. If plants are taken specifically, it is generally agreed that the prospects of encountering enhanced small organic-molecule chemical diversity are better if tropical rather than temperate species are investigated in drug discovery efforts. Plant collection in tropical source countries requires considerable preparation and organization to conduct in a responsible manner that abides by the provisions of the 1992 Rio Convention of Biological Diversity and the 2010 Nagoya Protocol on Access to Genetic Resources.

Cytotoxic and NF-κB and mitochondrial transmembrane potential inhibitory pentacyclic triterpenoids from Syzygium corticosum and their semi-synthetic derivatives.

Syzygium is a large genus of flowering plants, with several species, including the clove tree, used as important resources in the food and pharmaceutical industries. In our continuing search for anticancer agents from higher plants, a chloroform extract of the leaves and twigs of Syzygium corticosum collected in Vietnam was found to be active toward the HT-29 human colon cancer cell line. Separation of this extract guided by HT-29 cells and nuclear factor-kappa B (NF-κB) inhibition yielded 19 known natural products, including seven triterpenoids, three ellagic acid derivatives, two methylated flavonoids, a cyclohexanone, four megastigmanes, a small lactone, and an aromatic aldehyde.

Revisiting the linkage between ethnomedical use and development of new medicines: A novel plant collection strategy towards the discovery of anticancer agents.

The Vietnam-Laos International Cooperative Biodiversity Group (ICBG) based at the University of Illinois at Chicago (UIC) catalyzed a country-wide network of medicinal plant preserves (MPP) and medicinal biodiversity preserves (MBP) now established in ten provinces of the Lao People's Democratic Republic (Lao PDR), which are relied upon as protected sources of ethnomedicines for local villagers and traditional healers. In collaboration with the Lao PDR's Institute of Traditional Medicine (ITM), our ongoing P01 Program Project (Ohio State University) examined the anticancer bioprospecting potential for two of the most exhaustively inventoried of these sites: the Bolikhamxay MPP and the Xiengkhouang MBP. Guided by prior voucher specimens sourced from these preserves with an overwhelming emphasis on plants employed in traditional medicine, 201 distinct samples from 96 species were collected along with proper herbarium documentation.

Potent Inhibitor of Drug-Resistant HIV-1 Strains Identified from the Medicinal Plant Justicia gendarussa.

Justicia gendarussa, a medicinal plant collected in Vietnam, was identified as a potent anti-HIV-1 active lead from the evaluation of over 4500 plant extracts. Bioassay-guided separation of the extracts of the stems and roots of this plant led to the isolation of an anti-HIV arylnaphthalene lignan (ANL) glycoside, patentiflorin A (1). Evaluation of the compound against both the M- and T-tropic HIV-1 isolates showed it to possess a significantly higher inhibition effect than the clinically used anti-HIV drug AZT.

Anti-HIV diphyllin glycosides from Justicia gendarussa.

In a search for new anti-HIV active leads from over several thousands of plant extracts, we have identified a potent plant lead. The active plant is determined as Justicia gendarussa (Acanthaceae), a medicinal plant that has been used for the treatment of injury, arthritis and rheumatism in Asia including China. Our bioassay-guided fractionation of the methanol extract of the stems and barks of the plant led to the isolation of two anti-HIV compounds, justiprocumins A and B.

Cardiac Glycoside Constituents of Streblus asper with Potential Antineoplastic Activity.

Three new (1-3) and two known (4 and 5) cytotoxic cardiac glycosides were isolated and characterized from a medicinal plant, Streblus asper Lour. (Moraceae), collected in Vietnam, with six new analogues and one known derivative (5a-g) synthesized from (+)-strebloside (5). A preliminary structure-activity relationship study indicated that the C-10 formyl and C-5 and C-14 hydroxy groups and C-3 sugar unit play important roles in the mediation of the cytotoxicity of (+)-strebloside (5) against HT-29 human colon cancer cells.

Discovery of Bioactive Compounds by the UIC-ICBG Drug Discovery Program in the 18 Years Since 1998.

The International Cooperative Biodiversity Groups (ICBG) Program based at the University of Illinois at Chicago (UIC) is a program aimed to address the interdependent issues of inventory and conservation of biodiversity, drug discovery and sustained economic growth in both developing and developed countries. It is an interdisciplinary program involving the extensive synergies and collaborative efforts of botanists, chemists and biologists in the countries of Vietnam, Laos and the USA. The UIC-ICBG drug discovery efforts over the past 18 years have resulted in the collection of a cumulative total of more than 5500 plant samples (representing more than 2000 species), that were evaluated for their potential biological effects against cancer, HIV, bird flu, tuberculosis and malaria.