Publications by authors named "Yunbao Ma"

Artemyriantholidimers A-G (1-7), seven undescribed guaiane-type sesquiterpenoid dimers (GSDs), and 27 known compounds (8-34) were isolated from Artemisia myriantha (Asteraceae). Their structures and relative configurations were elucidated based on the comprehensive analyses of UV, IR, MS, NMR data, quantum chemical NMR calculations with DP4+ probability analyses, and the absolute configurations were elucidated by ECD calculations. The undescribed GSDs (1-7) were presumably formed via Diels-Alder reactions, and compounds 5-7 were rare GSDs with α-configuration of H-6'.

View Article and Find Full Text PDF

Diabetes mellitus (DM) is a chronic metabolic disorder characterized by elevated blood glucose levels, generally due to defects of insulin action or secretion. Inhibition of α-glucosidase, an enzyme responsible for carbohydrate degradation, is a promising strategy for managing postprandial hyperglycemia in diabetic patients. In this study, two new C-linked diarylheptanoid dimers, kaemgalanganols A (1) and B (2), were isolated from K.

View Article and Find Full Text PDF

Two unprecedented sesquiterpene and monoterpene heterodimers and ten previously undescribed sesquiterpenoids, artemordosins A-L (1-12), as well as ten known sesquiterpenoids (13-22), were obtained from Artemisia ordosica. Their structures were elucidated based on comprehensive analyses of NMR, IR, HRESIMS, GIAO NMR calculations with DP4+ probability analysis, and ECD calculations. Notably, artemordosins A and B (1 and 2) were the first examples of cadinane-monoterpene dimers, and artemordosin A (1) was a cadinane-myrceane heterodimer with a 6/6/6/6 ring system formed by [4 + 2] cycloaddition, while artemordosin B (2) was a 4,5-seco-cadinane-artemisane dimer connected through a C-5-O-C-4' linkage.

View Article and Find Full Text PDF
Article Synopsis
  • Alpinia oxyphylla (AOF) is an important medicinal fruit in China, studied for its potential benefits in addressing cognitive disorders related to type 2 diabetes mellitus (T2DM).
  • Researchers isolated 24 compounds from AOF, including three new substances, identifying several that showed activity in inhibiting the enzyme BACE1, which is linked to T2DM-associated cognitive issues.
  • Key compounds demonstrated neuroprotective effects against amyloid β damage in cells, with certain diarylheptanoids and sesquiterpenoids found to both inhibit BACE1 and modulate related protein expressions to mitigate cognitive decline.
View Article and Find Full Text PDF

Three uncommon isospongian diterpenoids including a new one, 3-epi-kravanhin A (2), were isolated from the leaves of Amomum tsao-ko. Compounds 2 and 3 dose-dependently promoted GLP-1 secretion on STC-1 cells with promotion ratios of 109.7 % and 186.

View Article and Find Full Text PDF

Glucagon-like peptide-1 (GLP-1) secretagogues are fascinating pharmacotherapies to overcome the defects of GLP-1 analogs and dipeptidyl peptidase-4 (DPP-4) inhibitors in treating diabetes and obesity. To discover new GLP-1 secretagogues from natural sources, alpigalangols A-Q (1-17), 17 new labdane diterpenoids including four unusual nor-labdane and N-containing ones, were isolated from the fruits of Alpinia galanga. Most of the isolates showed GLP-1 promotive effects in NCl-H716 cells, of which compounds 3, 4, 12, and 14-17 were revealed with high promoting rates of 246.

View Article and Find Full Text PDF

Artemisia annua L. ("Qinghao" in Chinese) is a famous traditional Chinese medicinal herb and has been used to treat malaria and various tumors. Our preliminary screening indicated that the EtOAc extract of A.

View Article and Find Full Text PDF

Artemyriantholides A-K (1-11) as well as 14 known compounds (12-25) were isolated from Artemisia myriantha var. pleiocephala (Asteraceae). The structures and absolute configuration of compounds 2 and 8-9 were confirmed by the single crystal X-ray diffraction analyses, and the others were elucidated by MS, NMR spectral data and electronic circular dichroism calculations.

View Article and Find Full Text PDF
Article Synopsis
  • - Guaianolide dimers, a class of natural products with potential anticancer properties, have been limited in study due to their low presence in plants; lavandiolide I, sourced from Artemisia, was synthesized and tested for antihepatoma effects, showing promising results against various liver cancer cell lines.
  • - A total of 33 derivatives of lavandiolide I were created and evaluated, with 10 showing superior activity compared to both lavandiolide I and the common medication sorafenib in inhibiting liver cancer cells.
  • - The study identified that modifying the dimer's structure by adding specific functional groups significantly increased antihepatoma effects, resulting in several derivatives exhibiting 1.2
View Article and Find Full Text PDF

Artemdubosides A-E (1-5), the first examples of natural polyacetylenes substituted by 6'-O-crotonyl β-glucopyranoside, and artemdubosides F-G (6-7) that were two unusual polyacetylenes featuring a 6'-O-acetyl β-glucopyranoside moiety, were isolated from Artemisia dubia var. subdigitata. Their structures were elucidated based on the spectral data including HRESIMS, UV, IR, 1D and 2D NMR, and ECD calculations.

View Article and Find Full Text PDF

In pursuit of effective agents for hepatocellular carcinoma derived from the Artemisia species, this study built upon initial findings that an ethanol (EtOH) extract and ethyl acetate (EtOAc) fraction of the aerial parts of Artemisia dubia Wall. ex Bess. exhibited cytotoxicity against HepG2 cells with inhibitory rates of 57.

View Article and Find Full Text PDF

The ethanol and EtOAc extracts of Artemisia sacrorum exhibited inhibitory effect against HepG2, Huh7, and SK-Hep-1 cell lines with inhibitory ratios of 65.5%, 28.1%, 84.

View Article and Find Full Text PDF

Artemongolins A-K (1-11), which are undescribed sesquiterpenoid dimers, were obtained from Artemisia mongolica and characterized through comprehensive spectral data, including HRESIMS, IR, 1D and 2D NMR, and ECD calculations. The absolute configurations of compounds 1, 4, and 7 were undoubtedly determined by a single-crystal X-ray crystallography. Artemongolins A-K (1-11) featured a rare 5/7/5/5/5/10 hexacyclic system composed of a germacrene and a guaianolide by a fused 2-oxaspiro[4,4]nonane-1-one ring system.

View Article and Find Full Text PDF

Artemeriosides A-F (1-6), six novel sesquiterpenoids containing a 6'-O-crontonyl β-glucopyranoside, were isolated from Artemisia annua L. Their structures were determined by spectral data including HRESIMS, IR, UV, 1D and 2D NMR, and ECD calculations. Compounds 1-6 represented the first examples of natural sesquiterpenoid substituted by 6'-O-crontonyl β-glucopyranoside.

View Article and Find Full Text PDF

Inspired by our previous finding that disesquiterpenoids showed more potent antihepatoma cytotoxicity than their corresponding parent monomers, natural product-like guaianolide-germacranolide heterodimers were designed and synthesized from guaianolide diene and germacranolides via a biomimetic Diels-Alder reaction to provide three antihepatoma active dimers with novel scaffolds. To explore the structure-activity relationship, 31 derivatives containing ester, carbamate, ether, urea, amide, and triazole functional groups at C-14' were synthesized and evaluated for their cytotoxic activities against HepG2, Huh7, and SK-Hep-1 cell lines. Among them, 25 compounds were more potent than sorafenib against HepG2 cells, 15 compounds were stronger than sorafenib against Huh7 cells, and 17 compounds were stronger than sorafenib against SK-Hep-1 cells.

View Article and Find Full Text PDF

, also known as "Qinghao" in Chinese, is a famous traditional Chinese medicine and has been used for the treatment of malaria and various tumors. In this study, three novel sesquiterpenoid-flavonol hybrids, artemannuols A-C (1-3), were isolated and elucidated by extensive spectral data and ECD calculations. Structurally, artemannuols A-C (1-3) are the first examples of sesquiterpenoid-flavonol hybrids fused by an ether bond, among which artemannuols A and B (1 and 2) are composed of bisabolane-type sesquiterpenoid and flavonol moieties, and artemannuol C (3) is composed of humulane-type sesquiterpenoid and flavonol moieties.

View Article and Find Full Text PDF
Article Synopsis
  • Researchers synthesized 51 derivatives of AH, finding that 34 were more effective against the same cancer cell lines, with compound 25 displaying the best activity (IC values of 0.6-1.3 µM), significantly outperforming both AH and the known drug sorafenib.
  • Compound 25 not only effectively stops cancer cell division and induces apoptosis but also improves safety in normal liver cells, while showing potential binding targets identified through bioinformatics as
View Article and Find Full Text PDF
Article Synopsis
  • * The bioactivity tests showed that some of these compounds exhibited significant cytotoxicity against liver cancer cell lines HepG2, Huh7, and SK-Hep-1, with IC values better than the commonly used drug sorafenib.
  • * Compound 1 demonstrated notable effects such as inhibiting cell migration, inducing cell cycle arrest, and triggering apoptosis, indicating its potential as a therapeutic agent against liver cancer linked to strong binding with a specific protein (PR
View Article and Find Full Text PDF

Twelve undescribed and 13 known eudesmane-type sesquiterpenoids were obtained from Artemisia leucophylla, and structurally elucidated based on comprehensive analyses of spectral data, including HRESIMS, IR, 1D and 2D NMR, and ECD calculation. The absolute configuration of compound 1 was determined by a single X-ray single crystal diffraction. Chemically, compounds 1-5 featured unprecedented 1,2-seco-1-nor-eudesmane-type skeleton with a cis-fused 6/5 bicyclic system.

View Article and Find Full Text PDF
Article Synopsis
  • A study on the plant Artemisia dubia Wall. showed that its ethanol extract and ethyl acetate fraction were effective in killing HepG2 cancer cells, achieving 57.1% and 84.2% inhibition at 100.0 μg/mL concentration, respectively.
  • Researchers isolated 20 new compounds called artemidubolides A-T and identified their structures using advanced techniques like X-ray diffraction and spectral analysis.
  • Among these compounds, 18 demonstrated significant cytotoxicity against three types of liver cancer cells, with some, like artemidubolides B, D, and M, showing the strongest effects and influencing cell growth and survival mechanisms in HepG2 cells.
View Article and Find Full Text PDF

Our previous study demonstrated that guaiane-type sesquiterpenoid ludartin showed potent antihepatoma activity against two human hepatocellular carcinoma cell lines, HepG2 and Huh7, with IC values of 32.7 and 34.3 μM, respectively.

View Article and Find Full Text PDF

Ten new germacrane-type sesquiterpenoids, artemyrianosins A-J (1-10), were isolated from the aerial parts of Artemisia myriantha. Their structures were elucidated by spectral analyses including UV, IR, HRESIMS, 1D and 2D NMR, ECD and the absolute configurations of compounds 1 and 7-9 were characterized using X-ray crystallography. All isolates were tested their cytotoxicity against three human hepatoma cell lines (HepG2, Huh7, and SK-Hep-1), and compounds 1-3, 7, and 10 showed cytotoxicity with IC values ranging from 43.

View Article and Find Full Text PDF

The dried fruit of Amomum villosum (Amomi Fructus) is an important spices and traditional Chinese medicine. In this study, the EtOH extract of Amomi Fructus was revealed with hypoglycemic effects on db/db mice by increasing plasma insulin levels. After extracted with EtOAc, the EtOAc fraction showed increased activity in stimulating glucagon-like peptide-1 (GLP-1) secretion compared with the EtOH extract.

View Article and Find Full Text PDF

The biomimetic synthesis of guaianolide dimers lavandiolides H, I, and K and artematrolide F containing a spirolactone moiety has been accomplished for the first time from naturally abundant arglabin in four to six steps with an overall yield up to 60%, and a series of natural product-like guaianolide dimers, trimer, and tetramer were also successfully synthesized. Notably, the trimeric compound exhibited antihepatoma cytotoxicity more potent than that of sorafenib with IC values of 6.2 μM (HepG2), 6.

View Article and Find Full Text PDF