Correlation of non-crocin components of Gardeniae Fructus with its external properties

Abstract

This study aimed to explore the correlation of the content of 15 non-crocin components of Gardeniae Fructus with its external properties(shape and color). The fruit shape was quantified according to the length/diameter measured by ruler and vernier calliper and the chromaticity values L~*, a~*, b~*, and ΔE~* of all samples were determined by chroma meter. Chromatographic separation was conducted on a Welch Ultimate XB C_(18) column(4.6 mm×250 mm, 5 μm) under gradient elution with acetonitrile solution(A) and 0.1% formic acid aqueous solution(B) as the mobile phase at a flow rate of 1.0 mL·min~(-1). The column temperature was 30 ℃ and the detection wavelength was 238 nm. The high-performance liquid chromatography(HPLC) method was established for simultaneous determination of the content of eight iridoid glycosides, six phenolic acids, and one flavonoid in 21 batches of Gardeniae Fructus samples. The correlation of the content of the 15 components with shapes and chromaticity values in each sample was analyzed by multivariate statistical analysis. According to the circulation situation and traditional experience, 21 batches of Gardeniae Fructus samples were divided into three categories, namely 14 batches of Jiangxi products(small and round, red and yellow), 4 batches of Fujian products(oval, red) and 3 batches of Shuizhizi(Gardenia jasminoides, longest, reddest). The Gardeniae Fructus samples were sequenced as Jiangxi products(1.71) < Fujian products(1.99) < Shuizhizi(2.55) in terms of the length/diameter average, Jiangxi products(17.7) < Fujian products(19.7) ≈ Shuizhizi(19.6) in terms of average value of a~*(red and green), Jiangxi products(24.4) > Fujian products(19.2) ≈ Shuizhizi(19.3) in terms of b~*(yellow and blue), and Jiangxi products(49.8) > Fujian products(48.0) ≈ Shuizhizi(47.8) in terms of L~*(brightness). The total content of the 15 components, 8 iridoid glycosides, 6 phenolic acids, and rutin in Jiangxi products was in the ranges of 65.53-99.64, 52.15-89.16, 6.10-11.83, and 0.145-1.81 mg·g~(-1), respectively. The total amount of the 15 components, 8 iridoid glycosides, 6 phenolic acids, and rutin in Fujian products was in the ranges of 69.33-94.35, 63.52-85.19, 5.39-8.41, and 0.333-0.757 mg·g~(-1), respectively. In Shuizhizi, the total content of the 15 components, 8 iridoid glycosides, 6 phenolic acids, and rutin was in the ranges of 77.35-85.98, 68.69-76.56, 7.30-9.05, and 0.368-0.697 mg·g~(-1), respectively. Pearson correlation analysis revealed that Gardeniae Fructus with leaner and longer fruit shape possessed lower content of total phenolic acids(the sum of the six phenolic acids) and rutin, but the correlation with iridoid glycosides was not high. Additionally, the higher content of total phenolic acids and rutin denoted the yellow coloration of Gardeniae Fructus, and the higher content of cryptochlorogenic acid, chlorogenic acid, and rutin meant the brighter color of Gardeniae Fructus. However, the higher content of geniposide and neochlorogenic acid and the lower content of deacetyl asperulosidic acid methyl ester led to the red coloration of Gardeniae Fructus. The results indicated that the morphological characters of Gardeniae Fructus were closely related to its chemical components. The more round shape and the yellower color reflected the higher content of phenolic acids and flavonoid, and Gardeniae Fructus with redder color had higher content of geniposide. OPLA-DA showed that the length/diameter and the content of six iridoid glycosides(gardoside, shanzhiside, gardenoside, genipin 1-gentiobioside, 6β-hydroxy geniposide, and deacetyl asperulosidic acid methyl ester), two phenolic acids(neochlorogenic acid and cryptochlorogenic acid) and rutin could be used as markers to distinguish three types of samples. This study provided experimental data for the scientific connotation of "quality evaluation through morphological identification" of Gardeniae Fructus.