Oxindole and Benzoxazinone Alkaloids from the Seeds of (Avocado) and Their SIRT1 Stimulatory Activity.

Mill. (Lauraceae), commonly known as avocado, is a well-known food because of its nutrition and health benefits. The seeds of avocado are major byproducts, and thus their phytochemicals and bioactivities have been of interest for study.

Linderanidins A-F: Rare oligomeric flavonoids with an unusual C-3-C-4 linkage from the roots of Lindera erythrocarpa and their inhibitory activities on autophagy.

Autophagy is a crucial process for maintaining cellular homeostasis by degrading and recycling unnecessary or damaged cellular components. In the process of exploring autophagy regulators in plants, unique nine oligomeric flavonoids linked by the bonding of C-3 and C-4, consisting of three pairs of biflavonoids, linderanidins A-C [(+)-1/(-)-1, (+)-2/(-)-2, and (+)-3/(-)-3], and three trimeric A-type proanthocyanidins, linderanidins D-F (4-6), were isolated from the roots of Lindera erythrocarpa. The structures and absolute configurations of these compounds were determined using various techniques, such as 1D and 2D NMR, mass spectrometry, X-ray crystallography, and electronic circular dichroism.

Properties of Configurationally Stable Atropoenantiomers in Macrocyclic Natural Products and the Chrysophaentin Family.

development of antibiotics, antineoplastics, and therapeutics for other diseases. Natural products are unique among all other small molecules in that they are produced by dedicated enzymatic assembly lines that are the protein products of biosynthetic gene clusters. As the products of chiral macromolecules, natural products have distinct three-dimensional shapes and stereochemistry is often encoded in their structures through the presence of stereocenters, or in the case of molecules that lack a stereocenter, the presence of an axis or plane of chirality.

Antiviral activity of CAVAC-1901, a combination of 3 standardized medicinal plants, against highly pathogenic influenza A virus in chickens.

Three different medicinal plants that consisted of the formulated mixture (CAVAC-1901) have been traditionally used for distinct medicinal purposes in different areas. Angelica dahurica has been used as an important ingredient of a prescription, Gumiganghwal-tang, for the common cold and influenza. Curcuma longa has been utilized for the treatment of asthma, and jaundice.

Unique guanidine-conjugated catechins from the leaves of Alchornea rugosa and their autophagy modulating activity.

Natural guanidines, molecules that contain the guanidine moiety, are structurally unique and often exhibit potent biological activities. A phytochemical investigation of the leaves of Alchornea rugosa (Lour.) Müll.

Insulin-mimetic activity of 23-glycosyl oleanane triterpenoids isolated from Gymnema latifolium.

Chemical investigation of the plant Gymnema latifolium led to the isolation of seven undescribed 23-glycosyl oleanane triterpenoids, gymlatinosides GLF1-GLF7, and two known compounds, gymnemosides D and E. The structures of the isolated compounds were elucidated using diverse spectroscopic methods. The extract of G.

Benzylisoquinoline Alkaloids from the Stems of and Their Potential as Autophagy Inhibitors.

is traditionally used to treat depression and affective disorders in Malaysia. The chemical compositions have been reported to include bisbenzylisoquinoline and aporphine-type alkaloids in the genus Lour., but studies on the components of have rarely been reported.

Heliciopsides A-E, Unusual Macrocyclic and Phenolic Glycosides from the Leaves of and Their Stimulation of Glucose Uptake.

Ten phenolic constituents, including three new macrocyclic glycosides (-), a new phenolic glycoside (), a new biphenyl glycoside (), and five known compounds (, -), were isolated from a 70% MeOH extract of the leaves of by liquid chromatography-tandem mass spectrometry (LC-MS/MS)-guided molecular networking. The chemical structures of new compounds -, and were established based on comprehensive spectroscopic data analysis, including 1D and 2D NMR and HRESIMS techniques. All isolated compounds (-) were evaluated for their stimulation of glucose uptake in differentiated 3T3-L1 adipocytes using 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]-d-glucose (2-NBDG) as a fluorescent glucose analog.

Inhibition of a broad range of SARS-CoV-2 variants by antiviral phytochemicals in hACE2 mice.

Although several vaccines and antiviral drugs against SARS-CoV-2 are currently available, control and prevention of COVID-19 through these interventions is limited due to inaccessibility and economic issues in some regions and countries. Moreover, incomplete viral clearance by ineffective therapeutics may lead to rapid genetic evolution, resulting in the emergence of new SARS-CoV-2 variants that may escape the host immune system as well as currently available COVID-19 vaccines. Here, we report that phytochemicals extracted from Chlorella spp.

Sesquiterpene lactone and its unique proaporphine hybrids from Magnolia grandiflora L. and their anti-inflammatory activity.

Two undescribed sesquiterpene lactone-proaporphine hybrid skeletons, two undescribed sesquiterpenes, and four known compounds were isolated from the aerial part of Magnolia grandiflora L. The structures of isolated compounds were unambiguously determined based on the interpretation of a combination of NMR spectroscopy, HRESIMS, DP4+ probability calculation of carbon data, X-ray crystallographic analyses, and ECD calculation. The isolated compounds were investigated for their anti-inflammatory activity against nitric oxide production and the protein expression of COX-2 in LPS-stimulated RAW 264.

Flavonostilbenes Isolated from the Stems of as Potential SIRT1 Activators.

The cumulative effects of cell damage result in aging, which gradually decreases human function in various aspects and leads to multiple age-related chronic diseases. To overcome the adverse effects of aging, silent mating type information regulation 2 homologue (SIRT1) activators are promising bioactive compounds that mimic calorie restriction to improve quality of life and prevent aging. In this study, 11 new flavonostilbenes (-) and three known compounds (-) were purified from stems of .

Rugonidines A-F, Diastereomeric 1,6-Dioxa-7,9-diazaspiro[4.5]dec-7-en-8-amines from the Leaves of .

Rugonidines A-F (-), three pairs of novel configurationally semistable diastereomers featuring an unprecedented 1,6-dioxa-7,9-diazaspiro[4.5]dec-7-en-8-amine scaffold, were isolated from based on MS/MS-based molecular networking analysis. Their structures were elucidated by NMR spectroscopy in combination with quantum-chemical calculations.

Triterpenoid saponins from the leaves and stems of Pericampylus glaucus and their insulin mimetic activities.

During an attempt to discover insulin mimetics, thirteen new triterpenoid saponins (1-13), including three phytolaccagenic acids (1, 2, and 12) and ten serjanic acids (3-11 and 13), as aglycones were isolated from a 70% ethanol extract of leaves and stems from Pericampylus glaucus. The chemical structures of compounds 1-13 were determined through spectroscopic data analysis, including NMR, IR, and HRESIMS. All isolated compounds (1-13) were evaluated using 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]-d-glucose (2-NBDG) as a fluorescent-tagged glucose probe to determine their stimulatory effects on glucose uptake in differentiated 3 T3-L1 adipocyte cells.

Flavanonol Glycosides from the Stems of and Their Neuroprotective Activities.

The accumulation of amyloid beta (A) peptides is common in the brains of patients with Alzheimer's disease, who are characterized by neurological cognitive impairment. In the search for materials with inhibitory activity against the accumulation of the A peptide, seven undescribed flavanonol glycosides (-) and five known compounds (-) were isolated from stems of by HPLC-qTOF MS/MS-based molecular networking. Interestingly, this plant has been used as a folk medicine for the treatment of various inflammatory conditions.

SIRT1 Activation Enhancing 8,3'-Neolignans from the Twigs of Uyeki.

Three undescribed 8,3'-neolignans, corynol (), 3-methoxy-corynol () and 3'-deoxy-corynol (), together with two bergenin derivatives, three flavonoids, two hydrolysable tannins and six simple phenolic compounds, were isolated from the twigs of Uyeki. The structures of the 8,3'-neolignans were elucidated by analyzing their NMR, HRESIMS and ECD spectra. All the isolated compounds were evaluated for their SIRT1 stimulatory activity, and 3'-deoxy-corynol () showed SIRT1 stimulation activity.

Meroterpenoids from the leaves of Psidium guajava (guava) cultivated in Korea using MS/MS-based molecular networking.

MS/MS-based molecular networking showed differences in the chemical profiles, especially the terpenoid-coupled-phloroglucinol clusters, of Psidium guajava grown in Jeju Island of South Korea ("Jejuguava"), Vietnam and China. A chemical investigation of the 95% EtOH extract of Jejuguava leaves revealed meroterpenoids characterized by a dihydropyran ring junction between an acylphloroglucinol structure and terpenoid, and named jejuguajavones A-J (1-10). Compounds (±)-8-(±)-10 are racemic mixtures that were separated using a chiral HPLC column.

Melicopteline A-E, Unusual Cyclopeptide Alkaloids with Antiviral Activity against Influenza A Virus from .

In the search for antiviral cyclopeptides against influenza A virus, five unprecedented Caryophyllaceae-type cyclopeptides (-) were isolated from the leaves of . Their chemical structures and absolute configurations were unambiguously determined by means of advanced Marfey's analysis and comprehensive spectroscopic analyses including two-dimensional nuclear magnetic resonance and MS/MS fragmentation. Interestingly, compounds - contain an unusual heterocycle, a 3a-hydroxypyrroloindole moiety, which was biosynthetically formed by a nucleophilic cyclization from the least abundant amino acid, tryptophan, precursor and has aroused a great interest in the aspect of chemical diversity and biological activity.

Phenolic Constituents of the Roots of with Senolytic Activity.

With the advent of senolytic agents capable of selectively removing senescent cells in old tissues, the perception of age-associated diseases has been changing from being an inevitable to a preventable phenomenon of human life. In the search for materials with senolytic activity from natural products, six new flavonostilbenes (-), three new phenylethylchromanones (-), three new phenylethylchromones (-), and four known compounds (-) were isolated from the roots of . The chemical structures of these isolated compounds were determined based on the interpretation of spectroscopic data, including 1D and 2D NMR, ECD, and HRMS.

Glucose Uptake-Stimulating Galloyl Ester Triterpenoids from .

Using molecular networking-guided isolation, three new galloyl ester triterpenoids (-), two new hexahydroxydiphenic acid-conjugated triterpenoids ( and ), and four known compounds (, , , and ) were isolated from the fruits and leaves of . The chemical structures of -, , and were elucidated on the basis of interpreting their NMR, HRESIMS, and ECD spectra. All compounds (-) were evaluated for their glucose uptake-stimulating activities in differentiated adipocytes using 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]-d-glucose as a fluorescent-tagged glucose probe.

Neuroprotective Effects of Triterpenoids from against Amyloid β-Induced Neuronal Damage.

Alzheimer's disease (AD), a neurocognitive impairment affecting human mental capacity, is related to the accumulation of amyloid-β peptide (Aβ) and the hyperphosphorylation of tau protein. In addition to modern therapies approved for AD treatment, natural products with antioxidant and anti-inflammatory properties have been studied for their potential to prevent AD pathogenesis. Six new noroleanane triterpenoids from the fruit peels of were isolated, and their structures were determined by diverse spectroscopic methods.

Metabolite Profiling of Rambutan ( L.) Seeds Using UPLC-qTOF-MS/MS and Senomorphic Effects in Aged Human Dermal Fibroblasts.

(rambutan) is an edible tropical fruit that is widely grown in Southeast Asia. In general, the seeds contain high nutrients, but rambutan seeds are thrown out during processing. In this study, the anti-aging activity of rambutan seeds was evaluated with a new approach through the selective inhibition of the senescence-associated secretory phenotype (senomorphics).

Antiviral activity of furanocoumarins isolated from Angelica dahurica against influenza a viruses H1N1 and H9N2.

Ethnopharmacological Relevance: Angelica dahurica (Hoffm.) Benth. & Hook.

Antiviral Activities of Compounds Isolated from (Pine Tree) against the Influenza A Virus.

was screened in an ongoing project to discover anti-influenza candidates from natural products. An extensive phytochemical investigation provided 26 compounds, including two new megastigmane glycosides ( and ), 21 diterpenoids (), and three flavonoids (). The chemical structures were elucidated by a series of chemical reactions, including modified Mosher's analysis and various spectroscopic measurements such as LC/MS and 1D- and 2D-NMR.

Oleanane Triterpenoids from the Leaves of and Their Insulin Mimetic Activities.

During an effort to find insulin mimetic compounds, the leaves of were shown to have a stimulatory effect on glucose uptake in 3T3-L1 adipocyte cells. Bioassay-guided fractionation on a 70% ethanol extract of was applied to yield two new ( and ) and two known ( and ) oleanane triterpenoids with a methyl anthranilate moiety together with five further new oleanane triterpenoids (-). The chemical structures of all isolates were determined based on their spectroscopic data, including IR, UV, NMR, and mass spectrometric analysis.

Oleanane hemiacetal glycosides from Gymnema latifolium and their inhibitory effects on protein tyrosine phosphatase 1B.

Gymnema sylvestre (Retz.) R. Br.