Absorption, distribution, and metabolism of pyrrolizidine alkaloids in tea plants: Insights from hydroponic exposure and molecular simulations.

Pyrrolizidine alkaloids (PAs) secreted by weeds in tea gardens are absorbed by tea plants, but their distribution and metabolism remain unclear. Here, different types of PAs were soaked from Ageratum conyzoides L. and used in hydroponic experiments.

Progress on targeted discovery of microbial natural products based on the predictions of both structure and activity.

Covering: up to 2025Microbial natural products (NPs) with diverse structures and fascinating activities are a fertile source of drug discovery. Genomic and metagenomic data have revealed that there are abundant valuable resources to be explored. With the advancement in technology, methods for discovering NPs from microorganisms are undergoing notable changes.

Isolation and identification of triterpenoid saponins with antiproliferative and hemolytic activities from Camellia oleifera Abel seeds.

Seven previously undescribed triterpenoid saponins, oleiferasaponins G-G (1-7), along with two known congeners (8 and 9) were isolated from seeds of Camellia oleifera Abel. Their structures were determined by extensive spectroscopic data. All isolated compounds are decorated with an aglycone and tetrasaccharide moiety.

Two New Triterpenoid Saponins with Antifungal Activity from Flowers.

Two new triterpenoid saponins, namely camsinsaponins A and B (, ), along with two known congeners (, ) were isolated from flowers. Their structures were determined by extensive spectroscopic data. All compounds were assessed for antifungal bioactivity against , , and .

Production improvement of an antioxidant in cariogenic Streptococcus mutans UA140.

Aims: This study aimed to improve the production of mutantioxidin, an antioxidant encoded by a biosynthetic gene cluster (mao) in Streptococcus mutans UA140, through a series of optimization methods.

Method And Results: Through the construction of mao knockout strain S. mutans UA140∆mao, we identified mutantioxidin as the antioxidant encoded by mao and verified its antioxidant activity through a reactive oxygen species (ROS) tolerance assay.

Fungicide-tolerant persister formation during cryptococcal pulmonary infection.

Bacterial persisters, a subpopulation of genetically susceptible cells that are normally dormant and tolerant to bactericides, have been studied extensively because of their clinical importance. In comparison, much less is known about the determinants underlying fungicide-tolerant fungal persister formation in vivo. Here, we report that during mouse lung infection, Cryptococcus neoformans forms persisters that are highly tolerant to amphotericin B (AmB), the standard of care for treating cryptococcosis.

Rapid identification of the geographic origin of Taiping Houkui green tea using near-infrared spectroscopy combined with a variable selection method.

Background: Most studies focus on the geographically larger production areas in tea traceability. However, famous high-quality tea is often produced in a narrow range of origins, which makes traceability a challenge. In this study, Taiping Houkui (TPHK) green tea of narrow geographical origin was rapidly identified using Fourier-transform near-infrared (FT-NIR) spectroscopy.

Polyprenylated acylphloroglucinol meroterpenoids with PTP1B inhibition from Hypericum forrestii.

Three new polyprenylated acylphloroglucinol meroterpenoids, hyperiforins A-C (1-3), were isolated from Hypericum forrestii (Chittenden) N. Robson, together with twelve known analogues (4-15). Their structures were established by extensive physical and spectroscopic data analysis.

Hyperprins A and B, Two Complex Meroterpenoids from .

Hyperprins A () and B (), two polyprenylated acylphloroglucinol related meroterpenoids with undescribed carbon skeletons, were isolated from . Compound possesses a new 6/6/6/6/5/5 hexacyclic system with an unprecedented tetracyclo[10.3.

[Studies on alkaloid constituents of Fritillaria yuminensis].

Twelve alkaloids were isolated from the bulbs of Fritillaria yuminensis by column chromatography over silica gel, ODS, and Sephadex LH-20, as well as RP-HPLC. Their structures were identified mainly by NMR and MS analyses as yubeinine(1), imperialine(2), delavinone(3), tortifoline(4), hupehenizioiside(5), imperialine-β-D-glucoside(6), kuroyurinidine(7), pengbeisine A(8), walujewine A(9), peimisine-3-O-β-D-glucopyranoside(10), solanidine-3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside(11), and solanidine-3-O-α-L-rhamnopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→4)]-β-D-glucopyranoside(12). Compounds 4-12 were obtained from F.

Anticancer activity and mechanism of total saponins from the residual seed cake of Camellia oleifera Abel. in hepatoma-22 tumor-bearing mice.

We have previously demonstrated that several new saponins from the seed cake of Camellia oleifera Abel. exhibited antiproliferative activity against human tumor cells in vitro. The current study investigated the effect of total saponins from the residual seed cake of Camellia oleifera Abel.

Isosteroidal alkaloids from the bulbs of Fritillaria tortifolia.

Three new isosteroidal alkaloids, frititorines A-C (1-3), were isolated from the bulbs of Fritillaria tortifolia, together with ten known ones (4-13). Their structures were elucidated by extensive spectroscopic analyses, chemical methods, and single-crystal X-ray crystallographic analysis. Compound 1 is the first 5β-cevanine alkaloid with a cis A/B ring junction from the Fritillaria genus.

Triterpenoid saponins from the genus Camellia: structures, biological activities, and molecular simulation for structure-activity relationship.

This review summarizes the isolation, chemical identification, and biochemical activities of Camellia triterpenoid saponins, updating a previous review and encompassing all new studies through September 2017. Further, molecular simulations of the interaction between several known cytotoxic oleiferasaponin monomers and Interleukin-6 are discussed, demonstrating that molecular modeling is a convenient method to obtain structure-activity information.

Two New Oleanane-Type Saponins with Anti-Proliferative Activity from Camellia oleifera Abel. Seed Cake.

Two new oleanane-type saponins, named oleiferasaponins C₄ (1) and C₅ (2), were isolated from Camellia oleifera Abel. seed cake residue. Their respective structures were identified as 16α-hydroxy-22α-O-angeloyl-23α-aldehyde-28-dihydroxymethylene-olean-12-ene-3β-O-[β-d-galacto-pyranosyl-(1→2)]-[β-d-glucopyranosyl-(1→2)-β-d-galactopyranosy-(1→3)]-β-d-glucopyranosid-uronic acid methyl ester (1) and 16α-hydroxy-22α-O-angeloyl-23α-aldehyde-28-dihydroxy-methylene-olean-12-ene-3β-O-[β-d-galactopyranosyl-(1→2)]-[β-d-galactopyranosyl-(1→3)]-β-d-glucopyranosiduronic acid methyl ester (2) through 1D- and 2D-NMR, HR-ESI-MS, and GC-MS spectroscopic methods.

Novel triterpenoid saponins from residual seed cake of Camellia oleifera Abel. show anti-proliferative activity against tumor cells.

Four oleanane-type triterpenoid saponins were isolated from the seed cake of Camellia oleifera Abel.: camelliasaponin B1 and three new saponins, oleiferasaponin C1-C3 (1-3). Their structures were identified as 22-O-angeloyl-camelliagenin B 3-O-[β-d-galactopyranosyl-(1→2)]-[β-d-galactopyranosyl-(1→2)-α-l-arabinopyranosyl-(1→3)]-β-d-glucopyranosiduronic acid methyl ester (1); 22-O-angeloyl-camelliagenin A 3-O-[β-d-galactopyranosyl-(1→2)]-[β-d-glucopyranosyl-(1→2)-β-d-galactopyranosyl-(1→3)]-β-d-glucopyranosiduronic acid methyl ester (2); and 28-O-cinnamoyl-camelliagenin B 3-O-[β-d-galactopyranosylz-(1→2)] [β-d-galactopyranosyl(1→2)-α-l-arabinopyranosyl-(1→3)]-β-d-glucopyranosiduronic acid methyl ester (3) through 1D and 2D NMR, HR-ESI-MS, as well as GC-MS spectroscopic methods.