Magnolia officinalis Rehd. et Wils. and Magnolia officinalis Rehd. et Wils. var. biloba Rehd. et Wils, as the legal botanical origins of Magnoliae Officinalis Cortex, are almost impossible to distinguish according to their appearance traits with respect to medicinal bark. The application of AFLP molecular markers for differentiating the two origins has not yet been successful. In this study, a combination of e-nose measurements, e-tongue measurements, and chemical analyses coupled with multiple-source data fusion was used to differentiate the two origins. Linear discriminant analysis (LDA) and quadratic discriminant analysis (QDA) were applied to compare the discrimination results. It was shown that the e-nose system presented a good discriminant ability with a low classification error for both LDA and QDA compared with e-tongue measurements and chemical analyses. In addition, the discriminating capacity of LDA for low-level fusion with original data, similar to a combined system, was superior or equal to that acquired individually with the three approaches. For mid-level fusion, the combination of different principals extracted by PCA and variables obtained on the basis of PLS-VIP exhibited an analogous discrimination ability for LDA (classification error 0.0%) and was significantly superior to QDA (classification error 1.67–3.33%). As a result, the combined e-nose, e-tongue, and chemical analysis approach proved to be a powerful tool for differentiating the two origins of Magnoliae Officinalis Cortex.
Actinosynnema is a small but well-known genus of actinomycetes for production of ansamitocin, the payload component of antibody-drug conjugates against cancers. However, the secondary metabolite production profile of Actinosynnema pretiosum ATCC 31565, the most famous producer of ansamitocin, has never been fully explored. Our antiSMASH analysis of the genomic DNA of Actinosynnema pretiosum ATCC 31565 revealed a NRPS–PKS gene cluster for polyene macrolactam. The gene cluster is very similar to gene clusters for mirilactam and salinilactam, two 26-membered polyene macrolactams from Actinosynnema mirum and Salinispora tropica, respectively. Guided by this bioinformatics prediction, we characterized a novel 26-membered polyene macrolactam from Actinosynnema pretiosum ATCC 31565 and designated it pretilactam. The structure of pretilactam was elucidated by a comprehensive analysis of HRMS, 1D and 2D-NMR, with absolute configuration of chiral carbons predicted bioinformatically. Pretilactam features a dihydroxy tetrahydropyran moiety, and has a hexaene unit and a diene unit as its polyene system. A preliminary antibacterial assay indicated that pretilactam is inactive against Bacillus subtilis and Candida albicans.
Objective: This study aimed to provide data for the type and content of linear furocoumarins (FCs) in Angelica dahurica (AD) in order to assess their cumulative risks and provide a scientific basis for the rational use and quality evaluation of the medicinal AD to improve public health. Methods: A UPLC method was developed for the simultaneous determination of nine FCs initially by using imperatorin (Im) as the internal standard substance, including Im, phellopterin (Ph), isoimperatorin (Is), oxypeucedanin hydrate (Oh), byakangelicin (Bn), xanthotoxin (8-MOP), bergapten (5-MOP), byakangelicol (Bl), and oxypeucedanin (Op) in two species of Angelica dahurica (AD). And, the risk assessment for the total FCs in AD was explored using the hazard index combined with the toxic equivalency factor (TEF-HI) strategy for the first time. Results: The established method revealed acceptable applicability, and there were no significant differences compared with the external standard method (ESM). The quantitative results demonstrated that the total content of FCs in Angelica dahurica (BZ) were higher than that in Angelica dahurica var. formosana (HBZ), and there was a great difference between the Bl and Op. Moreover, the risk assessment data revealed that the risk of total FCs in AD to human health was low. Conclusions: The established UPLC method that determined nine FCs in AD using a single marker could solve the problem of difficulty in obtaining a chemical reference substance with high purity and requiring a long determination time. And, the TEF-HI risk assessment approach associated with FCs in ADs could guide the rational utilization of toxic FCs in ADs in the progress of improving public health safety. In short, the whole systematic strategy provides a scientific basis for rational quality evaluation and the healthy use of related herbal medicines.