ISO 21370:2019

INTERNATIONAL ISO
STANDARD 21370
First edition
2019-02
Traditional Chinese medicine —
Dendrobium officinale stem
Médecine traditionnelle chinoise — Tige de Dendrobium officinale
Reference number
©
ISO 2019
© ISO 2019
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ii © ISO 2019 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Descriptions . 2
5 Requirements . 2
5.1 General characteristics . 2
5.2 Dendrobium officinale stem . 3
5.2.1 Morphological features . 3
5.2.2 Thin-layer chromatogram (TLC) identification . 3
5.2.3 Moisture . 3
5.2.4 Total ash . 3
5.2.5 Ethanol-soluble extractives . 3
5.2.6 Marker compounds . 3
5.2.7 Heavy metals . 3
5.2.8 Pesticide residues . 4
6 Sampling . 4
7 Test methods . 4
7.1 Macroscopic identification . 4
7.2 TLC identification . 4
7.3 Determination of moisture content . 4
7.4 Determination of total ash . 4
7.5 Determination of ethanol-soluble extractives . 4
7.6 Determination of marker compounds . 4
7.7 Determination of heavy metals . 4
7.8 Determination of pesticide residues . 4
8 Test report . 4
9 Packaging, storage and transportation . 5
10 Marking and labelling . 5
Annex A (informative) TLC identification. 6
Annex B (informative) Determination of ethanol-soluble extractives . 8
Annex C (informative) Determination of polysaccharides . 9
Annex D (informative) Determination of mannose and peak area ratio of mannose to glucose .11
Annex E (informative) Reference values of national and regional limits of moisture, total
ash, ethanol-soluble extractives, polysaccharides, mannose and peak area ratio of
mannose to glucose in Dendrobium officinale stem .14
Bibliography .15
Foreword
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iv © ISO 2019 – All rights reserved

Introduction
Dendrobium officinale stem, the dried stem of Dendrobium officinale Kimura et Migo, is a widely used
herb medicine in China and many other Asian countries. In traditional Chinese medicine, this herb is
used to treat fever, retching and excessive thirst. Modern pharmacological studies also demonstrate
its great potential in diabetes treatment and immuno-enhancement. Therefore, the market for
Dendrobium officinale has developed very rapidly, as indicated by the increase in yield, production
output and trade volume.
However, there remain many challenges, such as adulteration of similar species and lack of suitable
testing methods for quality assessment. In addition, though Dendrobium officinale has been recorded in
[4]
several pharmacopoeias and standards, such as Chinese Pharmacopoeia , Hong Kong Chinese Materia
[5] [6]
Medica Standards and Taiwan Herbal Pharmacopoeia , specifications and quality requirements of
these standards vary, thus there is a clear and urgent need to develop an international standard for
harmonizing the existing standards, as well as ensuring the safety and effectiveness of Dendrobium
officinale.
As national implementation may differ, National Standards Bodies are invited to modify the values
given in 5.2.3, 5.2.4 and 5.2.5 in their national standards. Examples of national and regional values are
given in Annex E.
INTERNATIONAL STANDARD ISO 21370:2019(E)
Traditional Chinese medicine — Dendrobium officinale
stem
1 Scope
This document specifies minimum requirements and test methods for Dendrobium officinale stem that
is derived from cultivated Dendrobium officinale Kimura et Migo.
It is applicable to Dendrobium officinale stem that is sold and used as Chinese materia medica (whole
medicinal materials) and decoction pieces derived from this plant.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 1575, Tea — Determination of total ash
ISO 18664, Traditional Chinese Medicine — Determination of heavy metals in herbal medicines used in
Traditional Chinese Medicine
ISO 20409, Traditional Chinese medicine — Panax notoginseng root and rhizome
ISO 21371, Traditional Chinese medicine — Labelling requirements of products intended for oral or topical use
CAC/MRL01, Maximum Residue Limits for Pesticides in Foods
CODEX STAN 229, Analysis of pesticide residues: Recommended methods
World Health Organization. Quality control methods for herbal materials, General advice on sampling, 2011
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1
fresh stem
stem that is newly harvested and has not undergone any processing
3.2
dried stem
stem prepared by cleaning, cutting and then heating or sun-drying
3.3
processed stem
stem processed by trimming off the fibrous root and leaves, stir-baking while twisting to a spiral or
spring form and drying
Note 1 to entry: This is the common trade form of dried stem of Dendrobium officinale. It is usually called Tie Pi
Feng Dou in Chinese.
4 Descriptions
Dendrobium officinale stem generally has three trade forms, including fresh stem, dried stem and
processed stem (Tie Pi Feng Dou), as shown in Figure 1.
a) Fresh stem b) Dried stem c) Processed stem (Tie Pi
Feng Dou)
Key
1 node
2 leaf sheath
Figure 1 — Structure of Dendrobium officinale
5 Requirements
5.1 General characteristics
The following requirements shall be met before sampling:
a) Dendrobium officinale stem shall be clean and free from foreign matter.
2 © ISO 2019 – All rights reserved

b) The presence of living insects, moulds and external contaminants which are visible to the naked
eye shall not be permitted.
5.2 Dendrobium officinale stem
5.2.1 Morphological features
5.2.1.1 Fresh stem
Cylindrical, circular for cross section. Nodes distinct, unbranched. Purple-dotted leaf sheath. Externally
yellowish-green, striated longitudinally. Odour slight. Taste mild, then sweet and viscous on chewing.
5.2.1.2 Dried stem
Cylindrical, differ in length. Externally greyish-green, yellowish-green or golden yellow, striated
longitudinally, sometimes grey leaf sheath remained. Odour slight. Taste mild, then viscous on chewing.
5.2.1.3 Processed stem
Spiral or spring-like, usually with two to six spires. Texture compact, easily broken, fracture even, grey
to greyish-green. Externally yellowish-green or golden yellow, striated longitudinally, sometimes grey
leaf sheath remained. Odour slight. Taste mild, then viscous on chewing.
5.2.2 Thin-layer chromatogram (TLC) identification
The identification of Dendrobium officinale stem by thin-layer chromatogram (TLC) shall present spots
or bands with the same colour and position corresponding to those of reference standard solution.
5.2.3 Moisture
The mass fraction of moisture should not be more than 14,0 %.
NOTE The fresh stem is exempt from this test.
5.2.4 Total ash
The mass fraction of total ash should not be more than 7,0 %.
NOTE The fresh stem is exempt
...