[Fruit variation and geographical distribution of citron].

The ripe dried fruit of citron(Citrus medica) is one of the important sources of Chinese herb Citri Fructus. At the same time, it is also grown for edible and ornamental uses. There are many species and abundant genetic variation. To clarify the intraspecific variation and resource distribution of citron, this study investigated the variation in 11 citron fruits, basically covering the main species in China, including Xiaoguo citron(C. medica var. ethrog), Goucheng(C. medica var. yunnanensis), Muli citron(C.medica var. muliensis), Dehong citron(C.medica×Citrus spp.), Fuzhou citron(C.medica×C.grandis?), Mawu(C.medica×C.grandis?), Cangyuan citron, Binchuan citron, Sweet citron, Big citron, and Small citron. The natural communities of citron were proved to be mainly distributed in the southwestern and western Yunnan and southeastern Tibet of China, with Yunnan, Sichuan, Guangxi, Chongqing, Hubei, and Zhejiang identified as the main production areas. Citron has also been widely grown in India, the Mediterranean region, and the Caribbean coast countries. The field investigation revealed the large-scale intraspecific variation of citron fruits. Most of the fruits are oval-like or sphere-like in shape. The fruits are green when raw and yellow when ripe, with oil cell dots on the skin, stripe-likes running from top to bottom, and bulge at the top. Usually, in the smaller citron fruits, the pulp and juice vesicles are better developed and the central columella is tighter. By contrast, the juice vesicles and central columella in larger fruits became more vacant, with carpels visible, and the apex segregation and development of the carpels is one of the reasons for variation. These variations should be given top priority in the future variety selection and breeding, and the quality differences of different citron species and their mechanisms should be further studied. In particular, variety selection and classification management according to their medicinal or edible purposes will provide scientific and technological supports for the orderly, safe, and effective production of citron products consumed as food and medicine.

Rapid characterization of the absorbed chemical constituents of Tangzhiqing formula following oral administration using UHPLC-Q-TOF-MS.

Tangzhiqing formula, a Chinese herbal formula, is used for the treatment of type II diabetes and prediabetes. Although its effectiveness has been certified by clinical use, its absorbed chemical constituents are not comprehensively represented. Thence, in order to reveal potential bioactive components and metabolism of Tangzhiqing formula, an ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry method was developed. A total of 86 absorbed components, including 38 prototype compounds and 48 metabolites, were identified in rat plasma, urine, and feces after oral administration of Tangzhiqing formula. This was the first systematic study on the chemical constituents and metabolic profiling of Tangzhiqing formula. The results indicated that alkaloids and flavonoids were main absorbed components, and glucuronidation and sulfation were the major metabolites. Moreover we concluded that alkaloids and flavonoids first underwent demethylation and hydrolysis reactions before biotransformed to phase II metabolites. This study provided valuable data for safety estimation of Tangzhiqing formula, which will be advantageous for clinical application.

Highly sensitive and quantitative profiling of acidic phytohormones using derivatization approach coupled with nano-LC-ESI-Q-TOF-MS analysis.

In current study, we developed a highly sensitive method for the quantitative profiling of acidic phytohormones. Tandem solid-phase extraction (SPE) and liquid-liquid extraction (LLE) was employed to efficiently purify acidic phytohormones, which were further derived by 3-bromoactonyltrimethylammonium bromide (BTA) to increase the ionization efficiency in electrospray ionization-mass spectrometry detection. Additionally, fifteen BTA-derived acidic phytohormones, including ten gibberellins (GAs), were well separated with a salt gradient on poly(methacrylic acid-co-ethylene glycol dimethacrylate) (MAA-co-EDMA) monolithic column. By employing online trapping system, the signal intensities of the analytes were significantly improved. The limits of detection (LODs, Signal/Noise=3) of targeted phytohormones ranged from 1.05 to 122.4 pg/mL, which allowed the highly sensitive determination of low abundant acidic phytohormones with tiny amount plant sample. Good reproducibility was obtained by evaluating the intra- and inter-day precisions with relative standard deviations (RSDs) less than 10.9 and 11.9%, respectively. Recoveries of the target analytes from spiked rice leave samples ranged from 88.3 to 104.3%. By employing the method developed here, we were able to simultaneously determine 11 endogenous acidic phytohormones from only 5mg of rice leave sample, which dramatically decreased the required sample amount (three orders of magnitude lower) for the profiling of low abundant acidic phytohormones compared to previous reports. Taken together, the method provided a good solution for the highly sensitive and quantitative profiling of endogenous acidic phytohormones.