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Rationale: Isopsoralen (ISO), a quality control marker (Q‐marker) in Psoraleae Fructus, is proven to present an obvious anti‐osteoporosis effect. Until now, the metabolism and anti‐osteoporosis mechanisms of ISO have not been fully elucidated, greatly restricting its drug development. Methods: The metabolites of ISO in rats were profiled by using ultrahigh‐performance liquid chromatography coupled with time‐of‐flight mass spectrometry. The potential anti‐osteoporosis mechanism of ISO in vivo was predicted by using network pharmacology. Results: A total of 15 metabolites were characterized in rats after ingestion of ISO (20 mg/kg/day, by gavage), including 2 in plasma, 12 in urine, 6 in feces, 1 in heart, 3 in liver, 1 in spleen, 1 in lung, 3 in kidney, and 2 in brain. The pharmacology network results showed that ISO and its metabolites could regulate AKT1, SRC, NFKB1, EGFR, MAPK3, etc., involved in the prolactin signaling pathway, ErbB signaling pathway, thyroid hormone pathway, and PI3K‐Akt signaling pathway. Conclusions: This is the first time for revealing the in vivo metabolism features and potential anti‐osteoporosis mechanism of ISO by metabolite profiling and network pharmacology, providing data for further verification of pharmacological mechanism. [ABSTRACT FROM AUTHOR]

Rationale: Eucommia cortex is the core herb in traditional Chinese medicine preparations for the treatment of osteoporosis. Pinoresinol diglucoside (PDG), the quality control marker and the key pharmacodynamic component in Eucommia cortex, has attracted global attention because of its definite effects on osteoporosis. However, the in vivo metabolic characteristics of PDG and its anti‐osteoporotic mechanism are still unclear, restricting its development and application. Methods: Ultra‐high‐performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry was used to analyze the metabolic characteristics of PDG in rats, and its anti‐osteoporosis targets and mechanism were predicted using network pharmacology. Results: A total of 51 metabolites were identified or tentatively characterized in rats after oral administration of PDG (10 mg/kg/day), including 9 in plasma, 28 in urine, 13 in feces, 10 in liver, 4 in heart, 3 in spleen, 11 in kidneys, and 5 in lungs. Furan‐ring opening, dimethoxylation, glucuronidation, and sulfation were the main metabolic characteristics of PDG in vivo. The potential mechanism of PDG against osteoporosis was predicted using network pharmacology. PDG and its metabolites could regulate BCL2, MARK3, ALB, and IL6, involving PI3K‐Akt signaling pathway, estrogen signaling pathway, and so on. Conclusions: This study was the first to demonstrate the metabolic characteristics of PDG in vivo and its potential anti‐osteoporosis mechanism, providing the data for further pharmacological validation of PDG in the treatment of osteoporosis. [ABSTRACT FROM AUTHOR]

N2 adsorption is a prerequisite for activation and transformation. Time-of-flight mass spectrometry experiments show that the Nb2C6H4+ cation, resulting from the gas-phase reaction of Nb2+ with C6H6, is more favorable for N2 adsorption than Nb+ and Nb2+ cations. Density functional theory calculations reveal the effect of the ortho-C6H4 ligand on N2 adsorption. In Nb2C6H4+, interactions between the Nb-4d and C-2p orbitals enable the Nb2+ cation to form coordination bonds with the ortho-C6H4 ligand. Although the ortho-C6H4 ligand in Nb2C6H4+ is not directly involved in the reaction, its presence increases the polarity of the cluster and brings the highest occupied molecular orbital (HOMO) closer to the lowest occupied molecular orbital (LUMO) of N2, thereby increasing the N2 adsorption energy, which effectively facilitates N2 adsorption and activation. This study provides fundamental insights into the mechanisms of N2 adsorption in "transition metal–organic ligand" systems. [ABSTRACT FROM AUTHOR]

Rationale: Tetrandrine, the Q‐marker in Stephaniae Tetrandrae Radix, was proven to present an obvious antitumor effect. Until now, the metabolism and antitumor mechanism of tetrandrine have not been fully elucidated. Methods: The metabolites of tetrandrine in rats were profiled using ultra‐high‐performance liquid chromatography coupled with time‐of‐flight mass spectrometry. The potential antitumor mechanism of tetrandrine in vivo was predicted using network pharmacology. Results: A total of 30 metabolites were characterized in rats after ingestion of tetrandrine (10 mg/kg), including 0 in plasma, 7 in urine, 11 in feces, 9 in liver, 8 in spleen, 4 in lung, 5 in kidney, 5 in heart, and 4 in brain. This study was the first to show the metabolic processes demethylation, hydroxylation, and carbonylation in tetrandrine. The pharmacology network results showed that tetrandrine and its metabolites could regulate AKT1, TNF, MMP9, MMP2, PAK1, and so on by involving in proteoglycan tumor pathway, PI3K‐Akt signaling pathway, tumor pathway, MAPK signaling pathway, and Rap1 signaling pathway. Conclusions: The metabolism features of tetrandrine and its potential antitumor mechanism were summarized, providing data for further pharmacological validation. [ABSTRACT FROM AUTHOR]

Rationale: Salvianolic acid B (Sal B), the Q‐marker in Salvia miltiorrhiza, was proved to present an obvious anti‐diabetes effect when treated as a food intake. Until now, the metabolism feature, tissue distribution and anti‐diabetes mechanism of Sal B have not been fully elucidated. Methods: The metabolites of Sal B in rats were profiled using ultrahigh‐performance liquid chromatography coupled with time‐of‐flight mass spectrometry. The potential anti‐diabetes mechanism of Sal B was predicted by network pharmacology. Results: A total of 31 metabolites were characterized in rats after ingestion of Sal B at a dosage of 40 mg/kg, including 1 in plasma, 19 in urine, 31 in feces, 0 in heart, 0 in liver, 0 in spleen, 1 in lung, 1 in kidney and 0 in brain. Among them, 18 metabolites were reported for the first time. Phase I reactions of hydrolysis, hydrogenation, dehydroxylation, hydroxylation, decarboxylation and isomerization, and phase II reactions of methylation were found in Sal B. Notably, decarboxylation and dehydroxylation were revealed in Sal B for the first time. The pharmacology network results showed that Sal B and its metabolites could regulate ALB, PLG, ACE, CASP3, MMP9, MMP2, MTOR, etc. The above targets were involved in insulin signaling pathway, PI3K‐Akt signaling pathway, HIF‐1 signaling pathway, TNF signaling pathway, etc. Conclusions: The metabolism feature of Sal B in vivo was systematically revealed, and its anti‐diabetes mechanism for further pharmacological validations was predicted based on metabolite profiling and network pharmacology for the first time. [ABSTRACT FROM AUTHOR]