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<b>Caragana korshinskii</b> Kom. (CK), one of afforestation tree species, is widely planted in northwest region of China. To compare the constituents as references for further utilization of CK, <b>C. microphyll</b> Lam. (CM) and <b>C. jubata</b> L. (CJ), been used as traditional Chinese medicine, were taken into consideration. To obtain more information on CK for further utilization, a sensitive and stable pre-column derivatization method for the analysis of fatty acids (FAs) was established using a novel labeling reagent 2-(5H-benzo[a]-carbazol-11(6H)-yl)ethyl hydrazine-carboxylate (BCEHC) by HPLC with fluorescence detector. The derivatives exhibit predominant fluorescence property at excitation and emission wavelengths of 330 nm and 380 nm, respectively. 16 derivatives of FAs including 13 saturated FAs and 3 unsaturated FAs are separated on a reversed-phase column with gradient elution within 30 min. The validation of method indicated that all FAs were given excellent linear responses with good linear coefficient of correlation being equal to or greater than 0.9985. The limits of detection (LODs) at a signal-to-noise ratio of 3 varied from 63.12 to 116.21 ng L−1. The developed method was successfully applied to determine the contents of free FAs (FFAs) in flowers, leaves and bark of CK and the samples were extracted by a green and simple method of gas purge microsyringe extraction. The results show that the contents of linoleic acid and linolenic acid are high in flowers and leaves while the bark is rich in linoleic acid. The total content of FFAs in all parts of CK is higher than that of CM. The distribution of FFAs in plants is obviously different even in the congeneric among different species.

• Extracts from <b>Lycium ruthenicum</b> Murr. fruit were obtained by UAE. • Phenolic compounds and antioxidant activities of obtained extracts were simultaneously optimized by RSM. • Optimum parameters: time 30 min, power 100 W, solvent-sample ratio 40 mL/g, ethanol 33%. • The extracts contained phenolic acids, identified and quantified by HPLC.<br><b>Lycium ruthenicum</b> Murr. (LR) is a functional food that plays an important role in anti-oxidation due to its high level of phenolic compounds. This study aims to optimize ultrasound-assisted extraction (UAE) of phenolic compounds and antioxidant activities of obtained extracts from LR using response surface methodology (RSM). A four-factor-three-level Box-Behnken design (BBD) was employed to discuss the following extracting parameters: extraction time (<b>X</b> 1), ultrasonic power (<b>X</b> 2), solvent to sample ratio (<b>X</b> 3) and solvent concentration (<b>X</b> 4). The analysis of variance (ANOVA) results revealed that the solvent to sample ratio had a significant influence on all responses, while the extraction time had no statistically significant effect on phenolic compounds. The optimum values of the combination of phenolic compounds and antioxidant activities were obtained for <b>X</b> 1 = 30 min, <b>X</b> 2 = 100 W, <b>X</b> 3 = 40 mL/g, and <b>X</b> 4 = 33% (v/v). Five phenolic acids, including chlorogenic acid, caffeic acid, syringic acid, <b>p</b>-coumaric acid and ferulic acid, were analyzed by HPLC. Our results indicated that optimization extraction is vital for the quantification of phenolic compounds and antioxidant activity in LR, which may be contributed to large-scale industrial applications and future pharmacological activities research.

<br>Display Omitted<br>• A new protocol of synchronous determination of phenolic acids (PAs) was proposed by RP-HPLC-UV with double-wavelength. • The validated results demonstrated that the proposed method was feasible to determine PAs in plant samples. • The protocol was applied for analysis PAs in <b>Caragana korshinskii</b> Kom. which was mainly rich in chlorogenic acid, vanillic acid, caffeic acid and rosmarinic acid. • Total content of PAs in leaves was the highest compared with that of flowers and bark.<br>The utilization of <b>Caragana korshinskii</b> Kom. (CK) is currently concentrated on its ecological and fuel functions. Little attention has been devoted to the analysis of their phenolic acid (PA) components. To obtain more data for further utilization of CK, a new analysis protocol was tested to determine PAs synchronously by RP-HPLC-UV with double-wavelength (280 nm and 320 nm) detection. Specifically, separation of PA components was performed on a Hypersil Gold C18 reverse phase column with gradient elution. A four-factor-three-level Box-Behnken design was implemented for optimization of PA extraction. The results demonstrated that CK were rich primarily in chlorogenic acid, vanillic acid, caffeic acid and rosmarinic acid. The total content of PAs in CK leaves was the highest compared with its other parts. The distribution of total flavonoid content of CK was leaves > flowers > bark, while that of the total phenolic content of CK was flowers > leaves > bark.