A simple synthesis of four stereoisomers of roseoside and their inhibitory activity on leukotriene release from mice bone marrow-derived cultured mast cells

The discovery of an anti-inflammatory monoterpenoid, neoroseoside from the Zea mays

A new monoterpenoid, neoroseoside (1), along with two previously reported compounds, 2″-O-α-l-rhamnosyl-6-C-fucosylluteolin (2) and farobin A (3) were isolated from the Zea mays. The structure of compound 1 was determined through the analysis spectroscopic data, including mass spectrometry (MS), infrared (IR) spectroscopy, and nuclear magnetic resonance (NMR) data. The absolute configurations of 1 were deduced from the comparing the values of optical rotations and from the interpretation of electronic circular dichroism (ECD) spectra. Compounds 2 and 3 displayed moderate antibacterial activity against Streptococcus mutans ATCC 25175 (inhibition rates 24 % and 28 %, respectively) and Streptococcus sobrinus ATCC 33478 (inhibition rate of 26 %), at a concentration of 100 μg/mL, whereas compound 1 did not have any significant antibacterial activities. The compounds 1-3 also showed anti-inflammatory activity on cytokine IL-6 and TNF-α.

Climate-Affected Australian Tropical Montane Cloud Forest Plants: Metabolomic Profiles, Isolated Phytochemicals, and Bioactivities

The Australian Wet Tropics World Heritage Area (WTWHA) in northeast Queensland is home to approximately 18 percent of the nation's total vascular plant species. Over the past century, human activity and industrial development have caused global climate changes, posing a severe and irreversible danger to the entire land-based ecosystem, and the WTWHA is no exception. The current average annual temperature of WTWHA in northeast Queensland is 24 °C. However, in the coming years (by 2030), the average annual temperature increase is estimated to be between 0.5 and 1.4 °C compared to the climate observed between 1986 and 2005. Looking further ahead to 2070, the anticipated temperature rise is projected to be between 1.0 and 3.2 °C, with the exact range depending on future emissions. We identified 84 plant species, endemic to tropical montane cloud forests (TMCF) within the WTWHA, which are already experiencing climate change threats. Some of these plants are used in herbal medicines. This study comprehensively reviewed the metabolomics studies conducted on these 84 plant species until now toward understanding their physiological and metabolomics responses to global climate change. This review also discusses the following: (i) recent developments in plant metabolomics studies that can be applied to study and better understand the interactions of wet tropics plants with climatic stress, (ii) medicinal plants and isolated phytochemicals with structural diversity, and (iii) reported biological activities of crude extracts and isolated compounds.

Investigating the in vitro mode of action of okra (Abelmoschus esculentus) as hypocholesterolemic, anti-inflammatory, and antioxidant food

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Okra leaf butanol extract and fruit extract induce the LDLR expression in human hepatoma cell line Huh7.

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Okra leaf butanol extract reduced the mRNA levels of proinflammatory cytokines IL-1β, IL-6 and TNF-α in THP1-derived macrophages.

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Okra fruit extract showed a sequestering ability of cholic acid providing an additional mechanism of hypocholesterolemic activity.

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Leaf ethyl acetate extract exerted significant antioxidant activity with IC₅₀ comparable to ascorbic acid.

Okra (Abelmoschus esculentus) have been introduced as food relatively recently in Europe. It is native to India and one of the most important vegetables in Nigeria. The leaves can be consumed but also the fruit is rich in nutrients and bioactive compounds (i.e., dietary fiber, vitamins, oils, polysaccharides, polyphenols) and several health promoting actions have been ascribed, including a lipid-lowering properties. In this work the effects of fruit and leaf extracts on expression of key mediators of cholesterol metabolism, i.e., the low-density lipoprotein receptor (LDLR) and proprotein convertase subtilisin/kexin type 9 (PCSK9), were investigated in human hepatoma cell line Huh7. Furthermore, effects on proinflammatory cytokines (IL-1β, IL-6 and TNF-α) expressed by THP1-derived macrophages were studied to assess potential anti-inflammatory actions.

Okra fruit extract significantly induced the mRNA and protein levels of the LDLR by 1.4 ± 0.3 and 4.8 ± 1.5-fold, respectively without any significant modification of PCSK9 expression. In addition, fruit extract showed a significant sequestering ability of cholic acid. Leaf butanol extract exerted similar action by inducing the expression of both the LDLR (+3.1 ± 1.6-fold vs control) and PCSK9 (+1.3 ± 0.4-fold vs control). The evaluation of the potential anti-inflammatory effect revealed a significant action of leaf butanol extract with reduced mRNA levels of IL-1β (−28 ± 8 % vs control), IL-6 (−11 ± 1 % vs control) and TNF-α (−43 ± 8 % vs control), while fruit extract did not show any anti-inflammatory activity. Finally, leaf ethyl acetate extract showed a significant antioxidant capacity comparable to ascorbic acid. Taken together, we provided evidence that leaf butanol extract and, more effectively, fruit extract induced the LDLR expression, effect that may explain the previously reported hypocholesterolemic action of okra. In addition, okra’s extracts reduced the expression of pro-inflammatory cytokines from THP1-derived macrophages, an effect that may suggest a vascular protective action of okra.

First Occurrence of Megastigmane Glucosides in a Plant of Retama Genus

Chemical investigation of Retama sphaerocarpa collected in Algeria resulted in the isolation of two megastigmane glucosides, compounds 1 and 2, along with a series of isoflavones and phenol derivatives. Compound 1, named retamoside, was new and its structure was determined by extensive application of spectroscopic methods, including HRMS, 1D and 2D NMR and CD. The anti-inflammatory properties of co-occurring main megastigmane, saurobaccioside B (2) and structurally related vomifoliol (3) on LPS-stimulated murine macrophages RAW 274.7 have been evaluated.

Anti-inflammatory properties of novel galloyl glucosides isolated from the Australian tropical plant Uromyrtus metrosideros

Two new galloyl glucosides, galloyl-lawsoniaside A (4) and uromyrtoside (6), were isolated from the polar fraction of Uromyrtus metrosideros leaf extract along with another four previously identified phytochemicals (1, 2, 3, and 5). The structures of these six compounds were characterised using low and high-resolution mass spectrometry (L/HRMS) and 1D and 2D Nuclear Magnetic Resonance (NMR) spectroscopy. These compounds were not toxic to human peripheral blood mononuclear cells (PBMCs) at 10 μg/mL over 24 h, yet showed significant in vitro suppression of proinflammatory cytokines involved in the pathogenesis of inflammatory bowel disease (IBD). Specifically, the release of interferon γ (IFN-γ), interleukin (IL)-17A, and IL-8 from phorbol myristate acetate/ionomycin (P/I) and anti-CD3/anti-CD28-activated cells were significantly suppressed by compounds 4 and 5. Interestingly, no effect on tumour necrosis factor (TNF) release was observed. These results show that the newly characterised compound 4 has promising cytokine suppressive properties, which could be further investigated as a candidate for IBD treatment.

Total Synthesis and Biological Evaluation of Mutolide and Analogues

The convergent total syntheses of three 14-membered macrolide natural products, mutolide, nigrosporolide and (4S,7S,13S)-4,7-dihydroxy-13-tetradeca-2,5,8-trienolide have been achieved. The key synthetic features include Shiina macrolactonization to assemble the 14-membered macrocyclic core, Wittig or Still-Gennari olefination and selective reduction of propargylic alcohol to construct the E- or Z-olefins. Cross metathesis was also highlighted as an efficient tool to forge the formation of E-olefin. The three synthetic macrolides were evaluated for their cytotoxic activity against three human cancer cell lines as well as for inhibitory effect on CFTR-mediated chloride secretion in human intestinal epithelial (T84) cells. Mutolide displayed significant cytotoxic activity against HCT116 colon cancer cells with an IC₅₀ of ∼12 μM as well as a potent CTFR inhibitory effect with an IC₅₀ value of ∼1 μM.

Glycosylated constituents isolated from the trunk of Abies holophylla and their anti-inflammatory and neurotrophic activity

Eleven previously undescribed glycosylated compounds with phenolic (abeoside A-F), monoterpenyl (abeoside G and H), or 2-heptanyl (abeoside I-K) aglycone, and twenty one reported compounds were isolated from the trunk of Abies holophylla. The structures of the previously undescribed compounds were elucidated on the basis of the conventional NMR and HRMS data analysis, and the absolute configuration of sugar units were assigned by chiral derivatization and LC-MS analysis. All the isolated compounds were evaluated for their anti-neuroinflammatory and neurotrophic activities. Among the evaluated compounds, twelve compounds including abeoside A, B, E, G, H, J, and K exhibited strong anti-neuroinflammatory activities with IC₅₀ values of 4.6-18.2 μM by inhibiting production of LPS-induced NO levels, and abeoside C and 1-O-[(S)-oleuropeyl]-β-D-glucoside showed powerful effects on the stimulation of NGF secretion levels with 157.09 ± 8.53% and 154.74 ± 1.24%, respectively.

Cell death-inducing activities via P-glycoprotein inhibition of the constituents isolated from fruits of Nandina domestica

Two new pyrrole alkaloids methyl-E-mangolamide (1) and methyl-Z-mangolamide (2), four new megastigmane glycosides nandinamegastigmanes I-IV (3-6), and eight known compounds (7-14) were isolated from the methanol extract of the fruits of Nandina domestica. The structures of the new compounds were elucidated based on chemical and spectroscopic evidence. The absolute stereochemistry of nandinamegastigmane I (3) was established upon comparing the experimental and predicted electronic circular dichroism (ECD) data. Among the isolated compounds, 1 and 2 showed cell death-inducing activity on the Adriamycin-treated HeLa cells. In addition, one of the mechanisms for cell death-inducing activity of 1 and 2 was suggested as inhibition of P-glycoprotein.

Agallochin P, a new diterpene from Vietnamese mangrove Excoecaria agallocha L

A new diterpene (1) along with eight known compounds (2-9) were isolated from Excoecaria agallocha leaves. The structure and relative configuration of new compound were established on the basis of spectroscopic data analysis and confirmed by NMR chemical shifts calculation with DP4+ probability. Cytotoxicity of the isolated compounds were also evaluated.

Comparative metabolites profiling of Caryota mitis & Caryota urens via UPLC/MS and isolation of two novel in silico chemopreventive flavonoids

Caryota mitis and Caryota urens (F. Arecaceae) are well reported in Ayurvedic medicine and involved in several edible food products. Herein, the first comparative profiling of their leaf and fruit metabolites of both species via HR-UPLC/PDA/ESI-MS and multivariate data analyses is presented. A total of 142 metabolites were detected with seven reported for the first time in F. Arecaceae and a novel O-caffeoylshikimic acid conjugate. Screening of plants' leaf crude extracts via in vitro DCPIP kinetic assay revealed the induction of phase II cytoprotective enzyme NQO1 by 4.5- to 5-fold versus control, suggestive of potential chemopreventive activity. Two novel sulfated flavonols that is quercetin-3-O-sulfate-4'-O-rhamnosyl (1→6)-β-d-glucoside (F1) and kaempferol-3-O-sulfate-4'-O-rhamnosyl(1→6)-β-d-glucoside (F3) in addition to another five known flavonoids were isolated from C. mitis ethanol extract and identified via MS and NMR spectroscopic techniques. Among isolated compounds, F1 and F3 exhibited the highest docking score as KEAP-1 inhibitors and Nrf2 activators posing them as potential chemopreventive drug leads. PRACTICAL APPLICATIONS: The study extends the usages of this edible less explored Caryota species to a potential cancer chemopreventive action. Guided by the extensive chemical information presented herein, additional uses could be suggested for these plants with 142 identified metabolites including androst-en-diol that has aphrodisiac and muscle building effects. The presented multivariate data analyses could aid phytochemists in plants classification and mapping (chemotaxonomy) since several metabolites are reported herein for the first time either in family or genus.

Stem Lettuce and Its Metabolites: Does the Variety Make Any Difference?

The objective of the present study was to characterize chemical composition of hitherto unexamined aerial parts of Lactuca sativa var. angustana cv. Grüner Stern. In contrast to leafy and head varieties of the lettuces, asparagus lettuce grown in Europe is much less studied. Fractionation of a methanolic extract from leaves of L. sativa cv. Grüner Stern, supported with HPLC/DAD and 1H NMR analysis, led to the isolation and/or identification of numerous terpenoid and phenolic compounds, including five apocarotenoids-(-)-loliolide, (+)-dehydrovomifoliol, blumenol A, (6S,9S)-vomifoliol, and corchoionoside C; three sesquiterpene lactones; two lignans-((+)-syringaresinol and its 4-O-β-glucoside); five caffeic acid derivatives; and three flavonoids. Some of the compounds, to the best of our knowledge, have never been isolated from L. sativa before. Moreover, monolignols, phenolic acids and a tryptophan-derived alkaloid were found in the analyzed plant material. Stems, leaves and shoot tips of the asparagus lettuce were examined to assess their phenolics and sesquiterpene lactone content as well as DPPH scavenging activity. Another stem lettuce-L. sativa var. angustana cv. Karola, two cultivars of leafy lettuces and one species of wild lettuce-L. serriola, were also examined as a reference material using HPLC/DAD. The results have been discussed regarding our previous studies and the literature data available.

The biological activities of the spiderworts (Tradescantia)

Widely used throughout the world as traditional medicine for treating a variety of diseases ranging from cancer to microbial infections, members of the Tradescantia genus show promise as sources of desirable bioactive compounds. The bioactivity of several noteworthy species has been well-documented in scientific literature, but with nearly seventy-five species, there remains much to explore in this genus. This review aims to discuss all the bioactivity-related studies of Tradescantia plants and the compounds discovered, including their anticancer, antimicrobial, antioxidant, and antidiabetic activities. Gaps in knowledge will also be identified for future research opportunities.

Chemical constituents from the roots of Kadsura coccinea with their protein tyrosine phosphatase 1B and acetylcholinesterase inhibitory activities

Kadsura coccinea (Lem.) A. C. Smith has been used as a tonic, decongestant, and digestive agent. The roots are also employed in traditional medicine to treat chronic enteritis, acute gastritis, duodenal ulcers, rheumatic pain in bone, and traumatic injuries. In the present study, we have described the biological evaluation of constituents from the roots of K. coccinea with PTP1B and AChE inhibitory activities for the first time in literature. A new compound (1), kadcoccilactone T, and 24 known ones (2‒25) were isolated and identified using spectroscopic methods. All the isolates were examined for PTP1B and AChE inhibitory activities. Compounds 4 and 8 expressed strong PTP1B inhibition with IC₅₀ values of 1.57 ± 0.11 and 3.99 ± 1.08 μM, respectively. Apparently, these compounds were further studied for PTP1B enzyme kinetic analysis. The result indicated that compounds 4 and 8 exhibited mixed-type inhibition with the Κ_i values of 4.97 and 3.26 µM, respectively.

Norsesquiterpenoids and triterpenoids from strawberry cv. Falandi

Falandi is a common strawberry (Fragaria × ananassa Duch.) cultivar in southern China. Further study of the chemical constituents in Falandi fruit led to the isolation of nine norsesquiterpenoids and three triterpenoids. Falandioside D (1) and falandins A (2) and B (3) were new norsesquiterpenoids, and the others excluding tormentic acid (11) were found in strawberry for the first time. Compounds 1 and 11 exhibited potent α-glucosidase inhibitory activity with the half maximal inhibitory concentration (IC50) values of 565.0 and 27.4 μM in comparison to acarbose (619.9 μM). Compounds 3, 7 (blumenol C glucoside), and 11 showed cytotoxicity against human nasopharyngeal carcinoma cell line CNE1 with the IC50 values of 57.6, 56.4, and 36.0 μM, respectively. Among new compounds, 1 showed 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical cation scavenging capacity (IC50=36.2 μM). These results suggested that non-phenolic constituents were also involved in the antidiabetic, antitumour, and antioxidant effects of strawberry fruit.

Chemical constituents from Kandelia candel with their inhibitory effects on pro-inflammatory cytokines production in LPS-stimulated bone marrow-derived dendritic cells (BMDCs)

Chemical investigation of Kandelia candel resulted in the isolation of 19 compounds (1-19), including one new sesquiterpene glycoside, kandelside (1), three megastigman glycoside compounds (7-9), 16 known phenolic compounds (2-6 and 10-19). Structures of the isolated compounds were elucidated based on spectral data comparison with reported values. Isolated compounds were also evaluated for their inhibitory effects on the production of pro-inflammatory cytokines interleukin (IL)-12 p40, IL-6, and tumor necrosis factor α (TNF-α) in lipopolysaccharide (LPS)-stimulated bone marrow-derived dendritic cells. Among these compounds, compound 9 exhibited strong inhibitory activity against IL-6 production (IC50=0.07 ± 0.05 μM) and moderate inhibitory activity against TNF-α production (IC50=49.86 ± 1.02 μM), but exhibited no activity on IL-12 p40 production. Compounds 5 and 6 significantly inhibited IL-12 p40, IL-6, and TNF-α production with IC50 values of 11.68 ± 0.38, 44.52 ± 1.08, and 28.73 ± 0.96 μM, respectively.

A new megastigmane glycoside from Akebia quinata

A new megastigmane glycoside, 8S*,9R*-megastigman-3-one-4,6-diene-8,9-diol-9-O-β-D-glucopyranoside, named akequintoside D (1), as well as six known compounds, roseoside II (2), 3-O-caffeoylquinic acid (3), methyl-3-O-caffeoylquinate (4), 3,4,5-trimethoxyphenyl-β-D-glucopyranoside (5), cuneataside D (6), 3,4-dimethoxyphenyl-6-O-(α-L-rhamnopyranosyl)-β-D-glucopyranoside (7) were isolated from the stem of Akebia quinata. The structures of compounds (1-7) were identified based on 1D and 2D NMR, including (1)H-(1)H COSY, HSQC, HMBC and NOESY spectroscopic analyses. The inhibitory activity of these isolated compounds against interleukin-6 (IL-6) production in TNF-α stimulated MG-63 cells was also examined.

Concise synthesis and biological assessment of (+)-neopeltolide and a 16-member stereoisomer library of 8,9-dehydroneopeltolide: identification of pharmacophoric elements

We describe herein a concise synthesis of (+)-neopeltolide, a marine macrolide natural product that elicits a highly potent antiproliferative activity against several human cancer cell lines. Our synthesis exploited the powerful bond-forming ability and high functional group compatibility of olefin metathesis and esterification reactions to minimize manipulations of oxygen functionalities and to maximize synthetic convergency. Our findings include a chemoselective olefin cross-metathesis reaction directed by H-bonding, and a ring-closing metathesis conducted under non-high dilution conditions. Moreover, we developed a 16-member stereoisomer library of 8,9-dehydroneopeltolide to systematically explore the stereostructure-activity relationships. Assessment of the antiproliferative activity of the stereoisomers against A549 human lung adenocarcinoma, MCF-7 human breast adenocarcinoma, HT-1080 human fibrosarcoma, and P388 murine leukemia cell lines has revealed marked differences in potency between the stereoisomers. This study provides comprehensive insights into the structure-activity relationship of this important antiproliferative agent, leading to the identification of the pharmacophoric structural elements and the development of truncated analogues with nanomolar potency.

Chemical Constituents from the Aerial Parts of Gynura Bicolor

Gynura bicolor (Willd.) DC., is used in folk recipes for the treatment of diabetes mellitus in Jiangsu, Zhejiang and Sichuan province in the south of China. A previous pharmacological study proved that the plant showed significant hypoglycemic activity on normal and alloxan-diabetic mice. In this study, two terpenes, four megastigmane-type norisoprenoids and two glycosides were isolated from the aqueous ethanolic extract of the aerial parts of Gynura bicolor and characterized mainly by NMR spectroscopy and mass spectrometry. These compounds were isolated for the first time from this plant, and no evidence could be found for the previous reported presence of megastigmane-type norisoprenoids in the genus Gynura.

α-Glucosidase inhibitory hydrolyzable tannins from Eugenia jambolana seeds

Three new hydrolyzable tannins including two gallotannins, jamutannins A (1) and B (2), and an ellagitannin, iso-oenothein C (3), along with eight known phenolic compounds were isolated from the seeds of Eugenia jambolana fruit. The structures were elucidated on the basis of spectroscopic data analysis. All compounds isolated were evaluated for α-glucosidase inhibitory effects compared to the clinical drug acarbose.

A new sulfated alpha-ionone glycoside from Sonchus erzincanicus Matthews

Sonchus erzincanicus (Asteraceae) is an endemic species in Turkey, where six Sonchus species grow. In this study, a phytochemical study was performed on the aerial parts of the plant. The study describes the isolation and structure elucidation of five flavonoids and two a-ionone glycosides from S. erzincanicus. The compounds were isolated using several and repeated chromatographic techniques from ethyl acetate and aqueous phases that were partitioned from a methanol extract obtained from the plant. 5,7,3',4'-Tetrahydroxy-3-methoxyflavone (1) and quercetin 3-O-beta-D-glucoside (2) were isolated from the ethyl acetate phase, while corchoionoside C 6'-O-sulfate (3), corchoionoside C (4), luteolin 7-O-glucuronide (5) and luteolin 7-O-beta-D-glucoside (6), apigenin 7-O-glucuronide (7) were isolated from the aqueous phase. Corchoionoside C 6'-O-sulfate (3), isolated for the first time from a natural source, was a new compound. The structures of the compounds were elucidated by means of 1H-NMR, 13C-NMR, 2D-NMR (COSY, HMQC, HMBC) and ESI-MS.