Berchemiosides A-C, 2-Acetoxy-ω-phenylpentaene Fatty Acid Triglycosides from the Unripe Fruits of Berchemia berchemiifolia

Five new compounds from the stems of Ephedra equisetina

Five new compounds were identified from the stems of Ephedra equisetina Bunge. Their structures were elucidated by spectroscopic methods, involving UV, IR, NMR spectrum and HRESIMS analyses. The absolute configuration of compound 2 was proved by comparing their experimental and calculated ECD spectrum. The vitro bioactive assay of all compounds suggested that compound 1, 3, 4, 5 and 6 may have potential anti-asthmatic activities.

Flavonoids and phenols from the stems of Ephedra equisetina

Twelve undescribed compounds, including five flavonoids and seven phenols, were isolated from the stems of Ephedra equisetina Bunge. Their structures were elucidated by spectroscopic methods, including NMR spectroscopy and HRESIMS analysis. Their absolute configurations were elucidated by comparing their experimental and calculated ECD spectra. In the in vitro bioactive assay, all compounds were tested for their anti-asthmatic activities by releasing β-Hex in C48/80-induced RBL-2H3 cells. The β-Hex release rates of compounds 3, 8, 10, and 11 were 0.8502 ± 0.0231, 0.8802 ± 0.0805, 0.7850 ± 0.0593, and 0.8361 ± 0.0728, respectively, suggesting that compounds 3, 8, 10, and 11 have potential anti-asthmatic activities.

Perplexing Polyphenolics: The Isolations, Syntheses, Reappraisals, and Bioactivities of Flavonoids, Isoflavonoids, and Neoflavonoids from 2016 to 2022

Flavonoids, isoflavonoids, neoflavonoids, and their various subcategories are polyphenolics-an extensive class of natural products. These compounds are bioactive and display multiple activities, including anticancer, antibacterial, antiviral, antioxidant, and neuroprotective activities. Thus, these compounds can serve as leads for therapeutic agents or targets for complex synthesis; they are coveted and routinely isolated, characterized, biologically evaluated, and synthesized. However, data regarding the compounds' sources, isolation procedures, structural novelties, bioactivities, and synthetic schemes are often dispersed and complex, a dilemma this review aims to address. To serve as an easily accessible guide for researchers wanting to apprise themselves of the latest advancements in this subfield, this review summarizes seventy-six (76) articles published between 2016 and 2022 that detail the isolation and characterization of two hundred and forty-nine (249) novel compounds, the total and semisyntheses of thirteen (13) compounds, and reappraisals of the structures of twenty (20) previously reported compounds and their bioactivities. This article also discusses new synthetic methods and enzymes capable of producing or modifying flavonoids, isoflavonoids, or neoflavonoids.

Lignans and terpenoids from the stem of Ephedra equisetina Bunge

Seven undescribed lignans, equiselignan A-F, and six undescribed terpenoids, equiseterpenoid A-E (including two pairs of enantiomers, (+/-)-equiselignan A and (+/-)-equiseterpenoid E), were isolated from the stems of Ephedra equisetina Bunge. Their structures were elucidated by spectroscopic methods, and the absolute configurations of the undescribed compounds were determined by interpretation of their electronic circular dichroic (ECD) and optical rotation data. In β-hexosaminidase (β-Hex) release assay, anti-asthmatic activities of all of the compounds were evaluated by releasing β-Hex in C48/80-induced RBL-2H3 cells. The β-Hex release rates of equiselignan B and equiseterpenoid B were 0.86 ± 0.094 and 0.86 ± 0.012 by comparing with model group, whereupon equiselignan B and equiseterpenoid B exhibited significant anti-asthmatic activities.

LC-MS-based identification and antioxidant evaluation of small molecules from the cinnamon oil extraction waste

Cinnamon oil is obtained by steam distillation from cinnamon leaves and is usually considered highly cost-effective compared to bark oil, however, which results in tons of waste cinnamon leaves (WCL) discarded annually. By using MS/MS molecular networking (MN) assisted profiling, six main chemical diversities including flavonols and flavones, phenolic acids, lactones, terpenoids, phenylpropanoids and flavanols were rapid revealed from WCL aqueous extract. 101 compounds were tentatively identified by assigning their MS/MS fragments within typical pathways under ESI-MS/MS dissociation. The featured phenolic acids, terpenoids and their glycosides in cinnamon species were recognized as the main constituents of WCL. The hydrophilic lactones, lignans and flavanols were reported for the first time in cinnamon leaves. Furthermore, ABTS and FRAP assays integrated with MN analysis were conducted to uncover an antioxidant fraction, from which 40 potential antioxidant compounds were rapidly annotated. This fundamental information will help expand the utilization of WCL from cinnamon oil industry.

Widely targeted metabolic analysis revealed the changed pigmentation and bioactive compounds in the ripening Berchemia floribunda (Wall.) Brongn. fruit

Berchemia plants were important materials for Chinese traditional medicines due to their special secondary metabolites. Unlike the root, stem and leaf tissues, Berchemia floribunda (Wall.) Brongn. fruit was lacked of systematic metabolic investigation. Biochemical analysis found that the total flavonoid and total phenolic content of Berchemia fruit pulp showed a peak value at red ripe stage, and then decreased, but the total anthocyanin content sharply increased along with the coloration. By widely targeted metabolomic analysis, 644 metabolites were identified and categorized into 23 groups mainly including flavonoid, organic acids, amino acids, lipids, phenylpropanoid, nucleotides, alkaloids, carbohydrates, alcohols, anthocyanins & proanthocyanidins, vitamins, terpenes, polyphenols, phenolamides, quinones, indole derivatives, and sterides. Among them, 111 metabolites and 123 metabolites respectively showed up- and down-regulation from break stage to full mature. KEGG enrichment analysis indicated that active secondary metabolism such as biosynthesis of phenylpropanoids, flavonoid, and alkaloids happened during Berchemia fruit ripening. More importantly, Cyanidin-3-O-galactoside and other 3 cyanidins were found to be the predominant pigments in mature Berchemia fruit and increased cyanidins and pelargonidins but decreased anthocyanins might be contributed to the purple pigmentation of Berchemia fruit. Interestingly, 29 pharmaceutical compounds previously reported in other Berchemia tissues were also detected in ripening Berchemia fruit pulp: 8 flavonoid, 2 quinones & sucrose showed up-regulated accumulation while 6 polyphenols, 5 flavonoid, 3 phenylpropanoid, 2 organic acids, 1 quinones and β-sitosterol showed down-regulated accumulation In conclusion, our first comprehensive metabolic fingerprint will promote the further study of B. floribunda fruit and its medical and food application.

Highly regio- and stereoselective synthesis of bis-sulfanyl substituted conjugated dienes by copper–palladium cooperative catalysis

An efficient one-pot method for the synthesis of (Z,Z)-isomers of 1,4-bis(sulfanyl)-1,4-diaryl-1,3-butadienes by the cooperative catalysis of Cu(Xantphos)I/Pd(OAc)₂ and a base has been developed.

Renoprotective Mono- and Triterpenoids from the Fruit of Gardenia jasminoides

This paper describes the isolation and characterization of 17 new and 12 known terpenoids from the fruit of Gardenia jasminoides. The structures of eight new triterpenoids and nine new monoterpenoids, including their absolute configurations, were defined by spectroscopic analysis in combination of quantum chemical electronic circular dichroism (ECD), vibrational circular dichroism (VCD), and gauge-independent atomic orbital (GIAO) NMR calculations. The cytoprotective effects of the isolated compounds against lipopolysaccharide (LPS)-induced apoptosis in normal rat kidney tubule epithelioid (NRK 52e) cells were investigated in vitro. Compounds 10, 18, 20, 21, 24, and 26 exhibited significant protective effects with EC₅₀ values from 14.2 nM to 1.6 μM.

Unraveling Plant Natural Chemical Diversity for Drug Discovery Purposes

The screening and testing of extracts against a variety of pharmacological targets in order to benefit from the immense natural chemical diversity is a concern in many laboratories worldwide. And several successes have been recorded in finding new actives in natural products, some of which have become new drugs or new sources of inspiration for drugs. But in view of the vast amount of research on the subject, it is surprising that not more drug candidates were found. In our view, it is fundamental to reflect upon the approaches of such drug discovery programs and the technical processes that are used, along with their inherent difficulties and biases. Based on an extensive survey of recent publications, we discuss the origin and the variety of natural chemical diversity as well as the strategies to having the potential to embrace this diversity. It seemed to us that some of the difficulties of the area could be related with the technical approaches that are used, so the present review begins with synthetizing some of the more used discovery strategies, exemplifying some key points, in order to address some of their limitations. It appears that one of the challenges of natural product-based drug discovery programs should be an easier access to renewable sources of plant-derived products. Maximizing the use of the data together with the exploration of chemical diversity while working on reasonable supply of natural product-based entities could be a way to answer this challenge. We suggested alternative ways to access and explore part of this chemical diversity with in vitro cultures. We also reinforced how important it was organizing and making available this worldwide knowledge in an "inventory" of natural products and their sources. And finally, we focused on strategies based on synthetic biology and syntheses that allow reaching industrial scale supply. Approaches based on the opportunities lying in untapped natural plant chemical diversity are also considered.

Alkaloids and lignans with acetylcholinesterase inhibitory activity from the flower buds of Magnolia biondii Pamp

Sixteen compounds, including two new alkaloids and three new lignans, were isolated and their AChE inhibitory activities were evaluated.

Two new phenylpropanoids and a new dihydrostilbenoid from the flower buds of Magnolia biondii pamp and their acetylcholinesterase inhibitory activities

Two new phenylpropanoids, named (2'R*,3'R*)-2',3'-dihydroxy-4'-methoxy-caffeoyl butyrate (1), 9-acetoxy syringin (2), and a new dihydrostilbene, named (8'R)-4',5-dihydroxy-4,8'-dimethoxy-2-hydroxyethyl diphenylethane (3), together with five analogues (4-8), were isolated from the flower buds of Magnolia biondii Pamp. Their structures were elucidated by extensive spectroscopic analyses and comparison with literature data. The absolute configurations were deduced by comparison of experimental and calculated gauge-independent atomic orbital (GIAO) 1 D NMR data. Moreover, the isolated compounds (1-8) were evaluated in vitro for their acetylcholinesterase (AChE) inhibitory activities.

New xanthine oxidase inhibitors from the fruiting bodies of Tyromyces fissilis

Excessive uric acid production, which causes gout and hyperuricemia, can be blocked by inhibiting xanthine oxidase (XO). However, some agents to block on XO often cause side effects, thereby necessitating the identification of new inhibitors. During the screening of XO inhibitors from various mushroom extracts, we found that a methanolic extract of the fruiting bodies of Tyromyces fissilis, an inedible and non-toxic fungus, showed inhibitory activity. Both n-hexane and ethyl acetate layers, obtained by partitioning this extract exhibited XO inhibitory activity. Subsequently, using an activity-guided separation method, eight active compounds (1-8) were isolated. The structures of five of the new compounds, 2-4, 6, and 7, were elucidated by spectral analysis and chemical derivatization. All compounds had a salicylic acid moiety with an aliphatic group at the C-6 position. Notably, 2-hydroxy-6-pentadecylbenzoic acid (1) showed the highest level of XO noncompetitive inhibition (58.9 ± 2.2% at 25 µM).

Survey of natural products reported by Asian research groups in 2017

The new natural products reported in 2017 in peer-reviewed articles in journals with good reputations were reviewed and analyzed. The advances made by Asian research groups in the field of natural products chemistry in 2017 were summarized. Compounds with unique structural features and/or promising bioactivities originating from Asian natural sources were discussed based on their structural classification.

Targeted Isolation of Neuroprotective Dicoumaroyl Neolignans and Lignans from Sageretia theezans Using in Silico Molecular Network Annotation Propagation-Based Dereplication

The integration of LC-MS/MS molecular networking and in silico MS/MS fragmentation is an emerging method for dereplication of natural products. In the present study, a targeted isolation of natural products using a new in silico-based annotation tool named Network Annotation Propagation (NAP) is described. NAP improves accuracy of in silico fragmentation analyses by reranking candidate structures based on the network topology from MS/MS-based molecular networking. Annotation for the MS/MS spectral network of the Sageratia theezans twig extract was performed using NAP, and most molecular families within the network, including the known triterpenoids 1-7, could be putatively annotated, without relying on any previous reports of molecules from this species. Based on the in silico dereplication results, molecules were prioritized for isolation. In total, six dicoumaroyl 8- O-4' neolignans (8-13) and three dicoumaroyl lignans (14-16) were isolated from the twigs of S. theezans and structurally characterized by spectroscopic analyses. Isolates were evaluated for their neuroprotective activity, and compounds 14-16 showed potent protective effects against glutamate-induced oxidative stress in mouse HT22 cells at a concentration of 12.5 μM.

Rhamnellosides A and B, ω-Phenylpentaene Fatty Acid Amide Diglycosides from the Fruits of Rhamnella franguloides

Two new ω-phenylpentaene fatty acid amide diglycosides, rhamnellosides A (1) and B (2), were isolated from the fruits of Rhamnella franguloides (Rhamnaceae). These compounds were prioritized using LC-MS/MS molecular networking dereplication based on our previous discovery of 2-acetoxy-ω-phenylpentaene fatty acid triglycosides berchemiosides A−C from a phylogenetically related species, Berchemia berchemiifolia. The structures of the isolated compounds were elucidated by spectroscopic analyses in combination with chemical derivatization. The pentaene groups of 1 and 2 were found to have (6E, 8E, 10Z, 12Z, 14E)-geometry, which is the same as that found in berchemioside A.