Cytochrome P450 3A4 inhibitory constituents of the wood of Taxus yunnanensis

A comprehensive review of Shengdeng in Tibetan medicine: textual research, herbal and botanical distribution, traditional uses, phytochemistry, and pharmacology

"Shengdeng", a group of Tibetan medicines with diverse biological origins, has long been utilized in Tibet for the treatment of rheumatoid arthritis. It showcases remarkable efficacy in alleviating rheumatism, reducing swelling, and relieving pain. This study aimed to clarify the plant species used as "Shengdeng" and summarize their botanical distribution, traditional uses, phytochemistry, and pharmacology to promote its utilization and development. "Shengdeng" is derived from a remarkable collection of 14 plant species belonging to six distinct families. Extensive phytochemical investigations have led to the identification of 355 chemical constituents within "Shengdeng". Pharmacological studies conducted on "Shengdeng" have revealed a wide range of beneficial properties, including antioxidant, anticancer, antimicrobial, antiviral, antiparasitic, anti-inflammatory, and anti-arthritic activities. Notably, flavonoids and triterpenoids emerge as the predominant groups among these constituents, contributing to the therapeutic potential and diverse applications of "Shengdeng". The present review provides a concise summary of the recent advancements in textual research concerning the herbal and botanical distribution, traditional uses, phytochemistry, and pharmacological activities of "Shengdeng". It is crucial to note that future research on "Shengdeng" should prioritize the analysis of its active ingredients and the establishment of rigorous quality standards. These aspects are essential for ensuring consistency, efficacy, and safety in its clinical application.

Recent strategies and tactics for the enantioselective total syntheses of cyclolignan natural products

Covering: 2000 to 2021Lignan natural products are found in many different plant species and possess numerous useful biological properties, such as anti-inflammatory, antiviral, antioxidant, antibacterial, and antitumor activities. Their utility in both traditional and conventional medicine, coupled with their structural diversity has made them popular synthetic targets over many decades. This review specifically addresses the cyclolignan subclass of the family, which possess both a C8-C8' and a C2-C7' linkage between two different phenylpropene units. We present a comprehensive overview of the diverse strategies employed by chemists to achieve enantioselective total syntheses of cyclolignans covering: 2000 to 2021.

α-Conidendrin inhibits the expression of intercellular adhesion molecule-1 induced by tumor necrosis factor-α in human lung adenocarcinoma A549 cells

α-Conidendrin is a lignan isolated from Taxus wallichiana and other species. In the present study, we demonstrated that α-conidendrin inhibited the cell-surface expression of intercellular adhesion molecule-1 (ICAM-1) induced by tumor necrosis factor-α (TNF-α) at an IC₅₀ value of 40-60 μM in human lung adenocarcinoma A549 cells. α-Conidendrin decreased ICAM-1 protein and mRNA expression levels at concentrations of 40-100 μM in TNF-α-stimulated A549 cells. The TNF-α-induced mRNA expression of vascular cell adhesion molecule-1, E-selectin, and cyclooxygenase-2 was also reduced by α-conidendrin. In the TNF-α-induced nuclear factor κB (NF-κB) signaling pathway, α-conidendrin did not influence the translocation of the NF-κB subunit RelA from the cytoplasm to the nucleus at concentrations up to 100 μM. A chromatin immunoprecipitation assay revealed that α-conidendrin at 100 μM reduced the binding of RelA to the ICAM-1 promoter in response to a stimulation with TNF-α. Collectively, these results indicated that α-conidendrin interfered with the DNA binding of RelA to the ICAM-1 promoter, thereby reducing ICAM-1 transcription.

Syntheses of all eight stereoisomers of conidendrin

All eight stereoisomers of conidendrin were synthesized from (1 R,2 S,3 S)-1-(4-benzyloxy-3-methoxyphenyl)-3-(4-benzyloxy-3-methoxybenzyl)-2- hydroxymethyl-1,4-butanediol ((+)-4) and its enantiomer with high optical purity. The configurations at 4-positions of the conidendrin stereoisomers were constructed by intramolecular Friedel-Crafts reaction of protected 4. After conversion to tetrahydronaphthalene intermediate 7a, the 2- and 3-position of tetrahydronaphthalene structure 7a were converted to 3a- and 9a-position of (+)-α-conidendrin (3a), respectively. By the epimerization process of 2- or 3-position of 7a, the other diastereomers were obtained. All enantiomers were also synthesized from (-)-4.

Anticancer activity and molecular mechanisms of α-conidendrin, a polyphenolic compound present in Taxus yunnanensis, on human breast cancer cell lines

α-Conidendrin is a polyphenolic compound found mainly in Taxus yunnanensis, as the source of chemotherapy drug paclitaxel, which has been used in traditional medicine for treatment of cancer. This study aimed to investigate the anticancer activity and molecular mechanisms of α-conidendrin on breast cancer cell lines. The results of the present study show that α-conidendrin possesses potent antiproliferative effects on breast cancer cell lines MCF-7 and MDA-MB-231. α-Conidendrin significantly induced apoptosis in breast cancer cells via reactive oxygen species generation, upregulation of p53 and Bax, downregulation of Bcl-2, depolarization of mitochondrial membrane potential (MMP), release of cytochrome c from mitochondria, and activation of caspases-3 and -9. α-Conidendrin remarkably inhibited the proliferation of breast cancer cells through induction of cell cycle arrest by upregulating p53 and p21 and downregulating cyclin D1 and CDK4. Unlike breast cancer cells, the antiproliferative effect of α-conidendrin on human foreskin fibroblast cells (normal cells) was very small. In normal cells, reactive oxygen species levels, loss of MMP, release of cytochrome c, mRNA expression of p53, p21, cyclin D1, CDK4, Bax, and Bcl-2 as well as mRNA expression and activity of caspases-3 and -9 were significantly less affected by α-conidendrin compared with cancer cells. These results suggest that α-conidendrin can be a promising agent for treatment of breast cancer with little or no toxicity against normal cells.

In(OTf)3-catalyzed intramolecular hydroarylation of α-phenylallyl β-ketosulfones – synthesis of sulfonyl 1-benzosuberones and 1-tetralones

In(OTf)₃-catalyzed intramolecular hydroarylation of α-phenylallyl β-ketosulfones provides sulfonyl 1-benzosuberones and 1-tetralones in moderate to good yields in refluxing (CH₂Cl)₂ under open-vessel and easy-operation reaction conditions. A plausible mechanism is proposed and discussed. This highly regioselective protocol provides an atom-economic ring-closure route.

In(OTf)₃-catalyzed intramolecular hydroarylation of α-phenylallyl β-ketosulfones provides sulfonyl 1-benzosuberones and 1-tetralones in moderate to good yields in refluxing (CH₂Cl)₂ under open-vessel and easy-operation reaction conditions.

Extraction, Purification, and Biological Activities of Polysaccharides from Branches and Leaves of Taxus cuspidata S. et Z

Taxus cuspidata S. et Z. is an excellent natural source of bioactive polysaccharides and has various biological activities. The objective of this study was to evaluate the effect of antidiabetic and antitumor activities of polysaccharides from Taxus cuspidata branches and leaves (TCBL) and to determine the optimum extraction technology of TCBL using a low-temperature and high-efficiency enzyme and ultrasound-assisted coupled extraction (EUCE) method. Optimal technology parameters were determined as follows: an extraction temperature of 51 °C, an extraction time of 33 min, a ratio of material to liquid of 1:19 (g:mL), and an enzyme concentration of 0.10 mg·mL⁻¹. Under the optimized conditions, the polysaccharide yield from TCBL obtained by EUCE was 4.78% ± 0.18%. The four purified polysaccharides (Pe1, Pe2, Pe3, Pe4) from TCBL are mainly composed of arabinose, galactose, glucose, a small amount of xylose, and mannose. This composition was assessed by HPIC analysis. The antidiabetic activity and antitumor activity of polysaccharides from TCBL were assayed in vitro. Among the four purified polysaccharides from TCBL, purified Pe4 had the highest inhibitory capacity against α-glucosidase, and its IC₅₀ value was 123.0 µg·mL⁻¹. Pe1 had the highest antitumor capacity against MCF7 cells and HepG2 cells, with IC₅₀ values of 169.0 and 132.0 µg·mL⁻¹. Pe4 had the highest antitumor effect on human cervical cancer cells (Hela), and its IC₅₀ value was 89.9 µg·mL⁻¹. Pe4 polysaccharide demonstrated a good α-glucosidase inhibitory activity and antitumor capacity against Hela cells. Therefore, Pe4 polysaccharide from TCBL is a beneficial source of potential inhibitors of type II diabetes and human cervical cancer activity.

Bright Side of Lignin Depolymerization: Toward New Platform Chemicals

Lignin, a major component of lignocellulose, is the largest source of aromatic building blocks on the planet and harbors great potential to serve as starting material for the production of biobased products. Despite the initial challenges associated with the robust and irregular structure of lignin, the valorization of this intriguing aromatic biopolymer has come a long way: recently, many creative strategies emerged that deliver defined products via catalytic or biocatalytic depolymerization in good yields. The purpose of this review is to provide insight into these novel approaches and the potential application of such emerging new structures for the synthesis of biobased polymers or pharmacologically active molecules. Existing strategies for functionalization or defunctionalization of lignin-based compounds are also summarized. Following the whole value chain from raw lignocellulose through depolymerization to application whenever possible, specific lignin-based compounds emerge that could be in the future considered as potential lignin-derived platform chemicals.

Pharmacokinetic synergy from the taxane extract of Taxus chinensis improves the bioavailability of paclitaxel

BACKGROUND

Taxus chinensis (Pilger) Rehd is widely distributed in China and the northern hemisphere, and the most popular medicinal component isolated from Taxus chinensis is paclitaxel (PTX), which has now become the first-line chemotherapeutic drug for breast cancer and ovarian cancer. Oral administration of pure PTX as a potential anti-cancer agent is compromised by low bioavailability.

HYPOTHESIS/PURPOSE

In the clinical practice of traditional Chinese medicine, drug co-administration in the form of mixtures or formula could achieve pharmacokinetic/pharmacodynamic synergies. In this study, we aimed to investigate whether there exist any 'inherent' phytochemical synergy from Taxus chinensis extract that could improve PTX bioavailability.

STUDY DESIGN

Pharmacokinetic study of PTX after oral administration of Taxus chinensis extracts or single PTX was performed. In addition, comparative cytotoxic studies were carried out on the MCF-7 breast cancer cell lines.

METHODS

The plasma concentrations of PTX were determined using a validated high performance chromatography tandem mass spectrometry method. The cytotoxicity was compared using the MTT assay.

RESULTS

Oral administration of taxane fractions isolated from Taxus chinensis (containing 17.2% PTX) could achieve remarkably higher blood concentration and systemic exposure of PTX in rats, while the retention of PTX was significantly improved. Further tissue distribution analysis revealed that the penetration of PTX into major tissues was drastically increased compared with that of single PTX. In addition, in MCF-7 cells, the co-existing components in taxane mixtures could strengthen the inhibitory effects of PTX on tumor cell proliferation.

CONCLUSION

Together, these results support that administration of PTX in the form of taxane mixtures may become a novel approach to improve the poor bioavailability of PTX. Moreover, the inherent synergy from Taxus chinensis taxane extracts promises a novel strategy to strengthen PTX efficacy.

New lignans and their biological activities

Lignans, which are widely distributed in higher plants, represent a vast and rather diverse group of phenylpropane derivatives. They have attracted considerable attention due to their pharmacological activities. Some of the lignans have been developed approved therapeutics, and others are considered as lead structures for new drugs. This article is based on our previous review of lignans discovered in the period 2000-2004, and it provides a comprehensive compilation of the 354 new naturally occurring lignans obtained from 61 plant families between 2005 and 2011. We classified five main types according to their structural features, and provided the details of their sources, some typical structures, and diverse biological activities. A tabular compilation of the novel lignans by species is presented at the end. A total of 144 references were considered for this review.

Hepatoprotective activity of twelve novel 7'-hydroxy lignan glucosides from Arctii Fructus

Twelve novel 7'-hydroxy lignan glucosides (1-12), including two benzofuran-type neolignans, two 8-O-4' neolignans, two dibenzylbutyrolactone lignans, and six tetrahydrofuranoid lignans, together with six known lignan glucosides (13-18), were isolated from the fruit of Arctium lappa L. (Asteraceae), commonly known as Arctii Fructus. Their structures were elucidated using spectroscopy (1D and 2D NMR, MS, IR, ORD, and UV) and on the basis of chemical evidence. The absolute configurations of compounds 1-12 were confirmed using rotating frame nuclear overhauser effect spectroscopy (ROESY), the circular dichroic (CD) exciton chirality method, and Rh2(OCOCF3)4-induced CD spectrum analysis. All of the isolated compounds were tested for hepatoprotective effects against D-galactosamine-induced cytotoxicity in HL-7702 hepatic cells. Compounds 1, 2, 7-12, and 17 showed significantly stronger hepatoprotective activity than the positive control bicyclol at a concentration of 1 × 10(-5) M.

Cytotoxic oxepinochromenone and flavonoids from the flower buds of Rosa rugosa

A new oxepinochromenone, rugosachromenone A (1), seven new flavonoids, rugosaflavonoids A-G (2-8), and 11 known compounds (9-19) were isolated from the flower buds of Rosa rugosa. Compound 1 is found from Nature for the first time. Compound 2 displayed cytotoxicity against NB4, SHSY5Y, and MCF7 cells with IC50 values of 2.2, 2.5, and 2.3 μM, respectively, and 3 was toxic to A549 and MCF7 cells with IC50 values of 1.2 and 2.8 μM, respectively.