A New Lignan from the Roots of Ginkgo biloba

Anti-BPH lignans from Urtica triangularis subsp. pinnatifida (Hand.-Mazz.) C.J.Chen

A new lignan named (-)-ginkgool-9-O-β-glucopyranoside (1) together with eight known lignans (2-9) were isolated from Urtica triangularis subsp. pinnatifida (Hand.-Mazz.) C.J.Chen. According to the mass spectrometry and spectroscopic analyses, the gross structure and absolute configuration of the new lignan were elucidated. The cytotoxic effects of compounds 1-9 on BPH-1 cells and the docking results on type II 5α-reductase were analysed to evaluate their anti-BPH activity. The results showed better anti-BPH activity that compound 4 displaying an IC50 of 79.75 ± 3.68 μM than finasteride presenting an IC50 of 91.8 ± 3.74 μM. Compounds 1, 2 and 5 had moderate anti-BPH activity compared with finasteride.

The Potential of Ginkgo biloba as a Source of Biologically Active Compounds-A Review of the Recent Literature and Patents

Ginkgo biloba is a relict tree species showing high resistance to adverse biotic and abiotic environmental factors. Its fruits and leaves have high medicinal value due to the presence of flavonoids, terpene trilactones and phenolic compounds. However, ginkgo seeds contain toxic and allergenic alkylphenols. The publication revises the latest research results (mainly from 2018-2022) regarding the chemical composition of extracts obtained from this plant and provides information on the use of extracts or their selected ingredients in medicine and food production. A very important section of the publication is the part in which the results of the review of patents concerning the use of Ginkgo biloba and its selected ingredients in food production are presented. Despite the constantly growing number of studies on its toxicity and interactions with synthetic drugs, its health-promoting properties are the reason for the interest of scientists and motivation to create new food products.

Extraction Techniques and Analytical Methods for Isolation and Characterization of Lignans

Lignans are a group of natural polyphenols present in medicinal plants and in plants which are a part of the human diet for which more and more pharmacological activities, such as antimicrobial, anti-inflammatory, hypoglycemic, and cytoprotective, are being reported. However, it is their cytotoxic activities that are best understood and which have shed light on this group. Two anticancer drugs, etoposide, and teniposide, were derived from a potent cytotoxic agent—podophyllotoxin from the roots of Podophyllum peltatum. The evidence from clinical and observational studies suggests that human microbiota metabolites (enterolactone, enterodiol) of dietary lignans (secoisolariciresinol, pinoresinol, lariciresinol, matairesinol, syringaresinol, medioresinol, and sesamin) are associated with a reduced risk of some hormone-dependent cancers. The biological in vitro, pharmacological in vivo investigations, and clinical studies demand significant amounts of pure compounds, as well as the use of well-defined and standardized extracts. That is why proper extract preparation, optimization of lignan extraction, and identification are crucial steps in the development of lignan use in medicine. This review focuses on lignan extraction, purification, fractionation, separation, and isolation methods, as well as on chromatographic, spectrometric, and spectroscopic techniques for their qualitative and quantitative analysis.

Lignans and sesquiterpenoids from the stems of Schisandra bicolor var. tuberculate

A pair of new tetrahydrofuran lignan enantiomers, (±)-schibiculatin A [(±)-1], a new enedione lignan, schibiculatin B (2), two new cadinane-type sesquiterpenoids, schibiculatins C (3) and D (4), along with two known seco-cadinane-type sesquiterpenoids (5 and 6) and seven known miscellaneous lignans (7-13) were isolated from the stems of Schisandra bicolor var. tuberculate. The structures of 1-4 were elucidated by comprehensive analysis of their spectroscopic data, quantum chemical calculations, as well as single-crystal X-ray diffraction. A few isolated compounds were tested for their protective activities against corticosterone-induced apoptosis in PC12 cells. Among them, compounds 5 and 6 showed moderate activities.

Distribution of lignans and lignan mono/diglucosides within Ginkgo biloba L. stem

To investigate the biosynthetic pathways and regulatory mechanisms of lignans in plants, the actual distributions of lignans and lignan glucosides in flash-frozen stems of Ginkgo biloba L. (Ginkgoaceae) were studied using cryo time-of-flight secondary ion mass spectrometry coupled with scanning electron microscopy (cryo-TOF-SIMS/SEM). Four lignans and four lignan glucosides were successfully characterized. Quantitative HPLC measurements were conducted on serial tangential sections of freeze-fixed ginkgo stem to determine the amount and approximate distribution of lignan and lignan glucosides. (-)-Olivil 4,4'-di-O-β-d-glucopyranoside (olivil DG) was the most abundant lignan glucoside in ginkgo and was distributed mainly in the phloem, ray parenchyma cells, and pith. The comparative accumulation of olivil DG revealed its possible transport pathways and storage sites in ginkgo. Although not all relevant enzymes have been identified, understanding the distributions of lignan and lignan glucosides in ginkgo stems provides significant insight into their biological functions.

Bioactivity-guided isolation of cyclooxygenase-2 inhibitors from Saussurea obvallata (DC.) Edgew. Using affinity solid phase extraction assay

ETHNOPHARMACOLOGICAL RELEVANCE

Saussurea obvallata (DC.) Edgew. is a traditional Tibetan medicine used for the treatment of inflammation-related diseases, but the scientific validation was very limited.

AIM OF THE STUDY

This study aimed to rapid screen and targeted isolate cyclooxygenase-2 (COX-2) inhibitors from S. obvallata extract.

MATERIALS AND METHODS

An efficient ligand-fishing method based on affinity solid phase extraction (A-SPE) combining with HPLC was developed. The identified COX-2 inhibitors were separated using preparative liquid chromatography. In vitro COX-2 inhibition assays were employed to confirm the inhibitory activities of the isolated compounds. In addition, the effect of the isolated compounds on the production of prostaglandin E2 (PGE2) and the expression of COX-2 in LPS-induced RAW 264.7 were evaluated.

RESULTS

A total of four phenylpropanoids, isolariciresinol, syringaresinol, pinoresinol and balanophonin were targeted isolated as COX-2 inhibitors with IC₅₀ values of 36.4 ± 2.6 μM, 23.1 ± 1.8 μM, 3.6 ± 0.3 μM and 12.1 ± 0.9 μM, respectively. The isolated compounds significantly inhibited LPS-induced NO production in a dose-dependent manner. And, the results of the inhibitory effect on the release of PGE₂ and the expression of COX-2 in LPS-induced macrophages were consistent with A-SPE analysis.

CONCLUSION

The present work demonstrated that the developed A-SPE-HPLC method could successfully targeted isolated COX-2 inhibitors from S. obvallata extract. And, the isolation results indicated that the therapeutic effect of S. obvallata on inflammation-related diseases was partly based on the COX-2 active ingredients.

Structure, synthesis, biosynthesis, and activity of the characteristic compounds from Ginkgo biloba L

Covering: 1928-2021Ginkgo biloba L. is one of the most distinctive plants to have emerged on earth and has no close living relatives. Owing to its phylogenetic divergence from other plants, G. biloba contains many compounds with unique structures that have served to broaden the chemical diversity of herbal medicine. Examples of such compounds include terpene trilactones (ginkgolides), acylated flavonol glycosides (ginkgoghrelins), biflavones (ginkgetin), ginkgotides and ginkgolic acids. The extract of G. biloba leaf is used to prevent and/or treat cardiovascular diseases, while many ginkgo-derived compounds are currently at various stages of preclinical and clinical trials worldwide. The global annual sales of G. biloba products are estimated to total US$10 billion. However, the content and purity of the active compounds isolated by traditional methods are usually low and subject to varying environmental factors, making it difficult to meet the huge demand of the international market. This highlights the need to develop new strategies for the preparation of these characteristic compounds from G. biloba. In this review, we provide a detailed description of the structures and bioactivities of these compounds and summarize the recent research on the development of strategies for the synthesis, biosynthesis, and biotechnological production of the characteristic terpenoids, flavonoids, and alkylphenols/alkylphenolic acids of G. biloba. Our aim is to provide an important point of reference for all scientists who research ginkgo-related compounds for medicinal or other purposes.

Advances in the chemical constituents and chemical analysis of Ginkgo biloba leaf, extract, and phytopharmaceuticals

Ginkgo biloba leaf (GBL) is an important botanical drug that can be used for treating many diseases. This review summarizes the reported chemical constituents from GBL or Ginkgo biloba extract (GBE) to date, as well as the recent advances in the extraction, purification, qualitative and quantitative analysis methods (from 2015 to 2020). To date, about 110 flavonoids have been reported to have unambiguous structures, including flavonol and its glycosides, flavone and its glycosides, flavanone and its glycosides, isoflavone and its glycosides, flavan-3-ols, bioflavonoids, and biginkgosides. In recent years, in addition to new flavonoids, new terpenoids and lignan have been also isolated from GBL. Further, several extraction and purification methods have been described and compared. Quantitative analysis of the constituents have been mainly carried out by high-performance liquid chromatography with different detector methods. Many studies have focused on variations of compounds contents in GBL from different regions, tree ages, or collection times, which provide references for the selection of GBL. Liquid chromatography-mass spectrometry coupled with activity assay methods were used to on-line screen the bioactive compounds from GBL or its phytopharmaceuticals. The application of other analytical technologies such as MS imaging, supercritical fluid chromatography, capillary electrophoresis, quantitative nuclear magnetic resonance, and spectroscopy, has also been discussed. This review of the chemical constituents and analytical methods of Ginkgo will provide a reference for the research on the quality control and discovery of effective constituents for GBL and its related phytopharmaceuticals.