Authentication of Two Different Chemical Types of Cinnamomum Camphora Leaves by Microscopic Technique with GC-MS and GC Analysis

Abstract

Cinnamomum camphora Chvar. Borneol (CCCB) and Cinnamomum camphora Chvar. Cineol (CCCC) are two different chemical types of C. camphora. The clinical application of these chemical types of CC shows big differences, but sometimes they are confused because of the similarity of morphological features. To identify the two types of CC and to analyze the differences of compositions, their morphological characteristics were investigated by microscopic techniques and the chemical components were determined by GC-MS analysis and GC internal standard method. Distinguishing features of morphological characteristics were the shape, petiol, gland, and smell. Microscopic study of the transverse sections of leaves showed 13 – 15 columns xylem vessel in the leaves of CCCB, 11 – 13 columns xylem vessel, and more obvious and thicker cell walls of fiber cells in the leaves of CCCC. From this research, GC-MS analysis of essential oil of the leaves could provide mainly differential characteristics to distinguish between CCCB and CCCC. The total of 33 compounds were identified in the essential oil of CCCB leaves and the main component was d-borneol (55.11%), while d-borneol in CCCC leaves was not the main component and the amount of d-borneol might be related to the microstructure of gland. L(-)-camphor and d-borneol were quantitatively analyzed by GC with FID detector, using methyl salicylate as the internal standard. Each gram of the total essential oil contains 0.68 g of d-borneol in CCCB, and each gram of the total essential oil contains 0.150 and 0.015 g of L(-)-camphor in CCCB and CCCC, respectively, from Hunan province. Other habitats showed the same trend. This research was aimed to establish a method based on the microscopic, GC-MS, and GC techniques to identify and quantify CCCB and CCCC compositions, for providing scientific data to ensure with accuracy the origin of CCCB and CCCC plant material.