Dracaenogenins A and B, new spirostanols from the red resin of Dracaena cochinchinensis

Medicinal plant resin natural products: structural diversity and biological activities

Covering: up to the mid of 2023Plants secrete defense resins rich in small-molecule natural products under abiotic and biotic stresses. This comprehensive review encompasses the literature published up to mid-2023 on medicinal plant resin natural products from six main contributor genera, featuring 275 citations that refer to 1115 structurally diverse compounds. The scope of this review extends to include essential information such as the racemic nature of metabolites found in different species of plant resins, source of resins, and revised structures. Additionally, we carefully analyze the reported biological activities of resins, organizing them based on the their structures. The findings offer important insights into the relationship between their structure and activity. Furthermore, this detailed examination can be valuable for researchers and scientists in the field of medicinal plant resin natural products and will promote continued exploration and progress in this area.

Dragon's Blood from Dracaena Worldwide: Species, Traditional Uses, Phytochemistry and Pharmacology

Dragon's blood (DB) refers mainly to the crimson resin of many Dracaena spp. DB has been used by different traditional medicine systems worldwide, including Arabic medicine, African medicine, traditional Chinese medicine, Thai medicine, etc. DB are mainly used to heal wounds, kill pain, stop bleeding, and cure various diseases such as diarrhea, dysentery and ulcers for over 1000 years. 11 Dracaena spp. and 3 subspecies are reported to be able to produce red resin. However, the resources are extremely deficient. Several Dracaena spp. are in threatened status. Over 300 compounds have been isolated from Dracaena spp., mainly including flavonoids, steroids, and phenolics. DB exhibits anti-inflammatory, analgesic, antithrombotic, anti-oxidant, antimicrobial, antidiabetic, and anticancer properties, which explain its wound healing effects, preventive effects on cardiovascular and cerebrovascular diseases, dual-directional regulation of blood flow, neuroprotection and radioprotective effects. No apparent side effects or toxicity have been reported. DB are restricted from being exploited due to limited resources and unclear resin formation mechanism. It is necessary to expand the cultivation of Dracaena spp. and fully understand the mechanism underlying the resin formation process to develop an effective induction method for the sustainable utilization of DB.

Transcriptome profiling reveals candidate flavonoid-related genes during formation of dragon's blood from Dracaena cochinchinensis (Lour.) S.C.Chen under conditions of wounding stress

ETHNOPHARMACOLOGICAL RELEVANCE

Dragon's Blood (Resina Draconis) is a red resin that has been used in traditional medicine to promote blood circulation, regenerate muscles, reduce swelling and pain, stop bleeding, etc., and its main chemical constituents are flavonoids. Dracaena cochinchinensis (Lour.) S.C.Chen is the only plant defined by the Pharmacopoeia of the People's Republic of China as a source of dragon's blood.

AIM OF THE STUDY

We aimed to reveal genes involved in the biosynthesis and accumulation of flavonoids of D. cochinchinensis which is under wounding stress by performing a de novo transcriptome analysis.

MATERIALS AND METHODS

D. cochinchinensis samples were collected for transcriptome sequencing and bioinformatics analysis at 0 days (0 d), 3 days (3 d), 6 days (6 d), and 10 days (10 d) after induction wounding stress, and tissues were microscopically observed after wounding stress.

RESULTS

A total of 63,244 unigenes were obtained through bioinformatics analysis, and genes associated with the biosynthesis of flavonoids were identified. Through the analysis of DEGs after wounding stress in D. cochinchinensis, based on gene expression consistent with flavonoid accumulation levels, 20 genes in connection with the flavonoid synthesis pathway and 56 genes that may be responsible for flavonoid modification and transport, and also revealed TFs (MYB, bHLH) that may be responsible for flavonoid biosynthesis. Analysis of DEGs between the four periods revealed that after wounding stress, the greatest number of significant DEGs were enriched during the first 3 days, while fewer DEGs were enriched after day 3, which corresponding to only about 1/10 (353/3883) the number of DEGs during the first 3 days. In addition, putative unigenes involved in lignin biosynthesis, such as CSE, HCT, CCR, F5H, and CAD, were significantly down-regulation after D. cochinchinensis wounding stress, but the putative unigenes responsible for flavonoid biosynthesis, such as CHS, CHI, DFR, F3'5'H, F3H, ANR, FLS, and ANS were significantly up-regulation.

CONCLUSION

We performed de novo transcriptome analysis of D.cochinchinensis under wounding stress, candidate genes and TFs involved in the biosynthesis and accumulation of flavonoids were identified, which is the first report on the transcript variants in flavonoid form accumulation in D. cochinchinensis under wounding stress. According to the results of DEGs analysis, wounding stress attenuated lignin biosynthesis meanwhile promoted flavonoid biosynthesis. In addition, we also compared the transcriptomics of the two different original plants (D.cochinchinensis and D.cambodiana) that form dragon's blood in order to provide further understanding of the formation of dragon's blood.

What We Know and What We Do Not Know about Dragon Trees?

This article is a broad review focused on dragon trees—one of the most famous groups of trees in the world, well known from ancient times. These tertiary relicts are severely endangered in most of the area where they grow. The characteristic features of the dragon tree group are described and the species belonging to this group are listed. This review gathers together current knowledge regarding the taxonomy, evolution, anatomy and morphology, physiology, and ontogeny of arborescent dragon tree species. Attention is also paid to the composition, harvesting, medicinal, and ethnobotanical use of the resin (dragons’ blood). An evaluation of population structure, distribution, ecology, threats, and nature conservation forms the final part of the review. In the conclusions we recommend further avenues of research that will be needed to effectively protect all dragon tree species.

A unique C-linked chalcone-dihydrochalcone dimer from Dracaena cinnabari resin

A new C-linked chalcone-dihydrochalcone dimer, named dracidione, was isolated from the ethyl acetate extract of dragon's blood resin of Dracaena cinnabari Balf. f. Structure elucidation of the new compound was carried out by means of one- and two-dimensional NMR spectroscopy in addition to high resolution mass spectrometry. The unique structure incorporated a chalcone and a dihydrochalcone, which is reported for the first time from nature. Furthermore, dracidione showed moderate α-glucosidase inhibitory activity with IC₅₀= 40.27 µg/ml.

Homoisoflavonoid derivatives from the red resin of Dracaena cochinchinensis

Five new homoisoflavonoid derivatives, including three meta-homoisoflavanes (1-3), one homoisoflavanone (4), and one homoisoflavan (5), along with five known analogues (6-10), were isolated from the red resin of Dracaena cochinchinensis (Chinese dragon's blood). Their structures were elucidated by analysis of spectroscopic data (1D and 2D NMR, IR, and HRESIMS). The absolute configuration of compound 1 was determined by single-crystal X-ray crystallographic analysis, and those of 2-5 were established on the basis of experimental and computed ECD data. Compounds 4, 6, and 9 exhibited moderate inhibition of nitric oxide production in lipopolysaccharide-stimulated BV-2 microglial cells with IC₅₀ values of 60.4-75.6 μM.

De Novo transcriptome characterization of Dracaena cambodiana and analysis of genes involved in flavonoid accumulation during formation of dragon's blood

Dragon’s blood is a red resin mainly extracted from Dracaena plants, and has been widely used as a traditional medicine in East and Southeast Asia. The major components of dragon’s blood are flavonoids. Owing to a lack of Dracaena plants genomic information, the flavonoids biosynthesis and regulation in Dracaena plants remain unknown. In this study, three cDNA libraries were constructed from the stems of D. cambodiana after injecting the inducer. Approximately 266.57 million raw sequencing reads were de novo assembled into 198,204 unigenes, of which 34,873 unique sequences were annotated in public protein databases. Many candidate genes involved in flavonoid accumulation were identified. Differential expression analysis identified 20 genes involved in flavonoid biosynthesis, 27 unigenes involved in flavonoid modification and 68 genes involved in flavonoid transport that were up-regulated in the stems of D. cambodiana after injecting the inducer, consistent with the accumulation of flavonoids. Furthermore, we have revealed the differential expression of transcripts encoding for transcription factors (MYB, bHLH and WD40) involved in flavonoid metabolism. These de novo transcriptome data sets provide insights on pathways and molecular regulation of flavonoid biosynthesis and transport, and improve our understanding of molecular mechanisms of dragon’s blood formation in D. cambodiana.

Natural potential therapeutic agents of neurodegenerative diseases from the traditional herbal medicine Chinese dragon's blood

ETHNOPHARMACOLOGICAL RELEVANCE

Dragon's blood has been used as a famous traditional medicine since ancient times by many cultures. It is a deep red resin, obtained from more than 20 different species of four distinct genera. Red resin of Dracaena cochinchinensis S.C. Chen, known as Chinese dragon's blood or Yunnan dragon's blood, has been shown to promote blood circulation, alleviate inflammation, and to treat stomach ulcers, diarrhea, diabetes, and bleeding. This study investigated an effective approach to identify natural therapeutic agents for neurodegeneration from herbal medicine. The dichloride extract and isolated effective constituents of Chinese dragon's blood showed quinone oxidoreductase 1 (NQO1) inducing activity and anti-inflammatory effect significantly, which are therapy targets of various neurodegenerative diseases.

MATERIALS AND METHODS

Multiple chromatography and spectra analysis were utilized to afford effective constituents. Then Hepa 1c1c7 and BV-2 cells were employed to assay their NQO1 inducing and anti-inflammatory activities, respectively.

RESULTS

Bioactivities guided isolation afforded 21 effective constituents, including two new polymers cochinchinenene E (1), cochinchinenene F (2) and a new steroid dracaenol C (16). The main constituent 3 (weight percent 0.2%), 5 (weight percent 0.017%), 4 (weight percent 0.009%), 9 (weight percent 0.094%), 10 (weight percent 0.017%) and 8 (weight percent 0.006%) are responsible for the anti-inflammatory activities of Chinese dragon's blood. While, new compounds 1, 2 and known compounds 5, 11 showed good NQO1 inducing activities. The brief feature of the activities and structures was discussed accordingly.

CONCLUSION

Overviewing the bioactivities and phytochemical study result, 4'-hydroxy-2,4-dimethoxydihydrochalcone (3) and pterostilbene (5) as effective constituents of Chinese dragon's blood, were found to be potential candidate therapeutic agents for neurodegenerative diseases.

Antibacterial Activity against Ralstonia solanacearum of Phenolic Constituents Isolated from Dragon's Blood

Ralstonia solanacearum is a worldwide and devastating plant pathogen infesting over 200 host species. Synthetic bactericides against the pathogen have only achieved limited success and always cause both crop contamination and environmental pollution. However, natural bactericides are effective for protecting cultivated crops from destruction by disease, without the adverse effects of chemical bactericides. In this paper, fifteen phenolic constituents from dragon's blood were screened for their antimicrobial activity against Ralstonia solanacearum, and all exhibited inhibitory activity. These compounds are potential leading compounds for the development of bactericides against wilt diseases caused by Ralstonia solanacearum.

Influence of treatment with loureirin on rat hepatic stellate cells in vitro

AIM: To investigate the effects of treatment with loureirin A/B on rat hepatic stellate cells (HSCs) in vitro.

METHODS: HSC-T6 cells were cultured in 96-well plates for 24 h and then incubated with different concentrations of loureirin A/B for 48 h. MTT assay was used to assess the proliferation of HSCs. The contents of hyaluronic acid, laminin and collagen type IV in culture supernatants were measured by radioimmunoassay. The mRNA expression of blood vessel endothelium (VEGF₁₆₅) and histoplasma tissue inhibitory factor (HIF-1) was detected by real-time fluorescence quantitative PCR.

RESULTS: The half maximal inhibitory concentrations (IC₅₀) of loureirin A/B were 0.3 and 0.1 µg/µL respectively. Treatment with loureirin A/B significantly inhibited HSC proliferation, the secretion of hyaluronic acid, laminin and collagen type IV (31.1 ± 4.32 vs 43.05 ± 4.96, 441.28 ± 25.38 vs 302.98 ± 29.59, 17.96 ± 3.00 vs 25.23 ± 4.96, all P < 0.05), and the mRNA expression of VEGF₁₆₅ and HIF-1. The effects of loureirin B were stronger than those of loureirin A.

CONCLUSION: Treatment with loureirin A/B could significantly inhibit the proliferation of HSCs, the secretion of hyaluronic acid, laminin and collagen type IV, and the mRNA expression of VEGF₁₆₅ mRNA and HIF-1 mRNA, and the effects of loureirin B were stronger than those of loureirin A.

Flavonoid oligomers from Chinese dragon’s blood, the red resins of Dracaena cochinchinensis

A detailed chemical investigation of the red resins from Dracaena cochinchinensis (Chinese dragon’s blood) yielded five new flavonoid oligomers, named cochinchinenins D-H (1–5), together with a known biflavonoid, cinnabarone (6), and a mixture of two known biflavonoids, socotrin-4′-ol (7) and homoisosocotrin-4′-ol (8). Of these new compounds, 1–3 were biflavonoids and 4 and 5 were triflavonoids. Their structures were determined on the basis of spectroscopic analysis. The isolated compounds were tested for cytotoxicity (Cdc25), antibacterial (PEPT) and antifungal (YNG) activities.

Steroidal saponins from fresh stems of Dracaena angustifolia

Six new steroidal saponins (1-6), angudracanosides A-F, were isolated from fresh stems of Dracaena angustifolia, together with eight known compounds. The structures of compounds 1-6 were determined by detailed spectroscopic analyses and chemical methods. Antifungal testing of all compounds showed that 6 and 7 were active against Cryptococcus neoformans with IC(50)s of 9.5 and 20.0 μg/mL, respectively.

Auroside, a Xylosyl-sterol, and Patusterol A and B, two Hydroxylated Sterols, from two Soft Corals Eleutherobia aurea and Lobophytum patulum

A new sterol glycoside, auroside (1) and two new hydroxylated sterols, patusterol A and B (2, 3) have been isolated from the South African soft coral Eleutherobia aurea and from the Kenyan soft coral Lobophytum patulum. The structure elucidation was achieved from extensive 1D- and 2D- NMR and MS data, and in the case of auroside also by chemical reactions. In addition, from Lobophytum patulum, was also isolated a known nitrogen containing compound (Z)-N-[2-(4-hydroxyphenyl)ethyl]-3-methyldodec-2-enamide, and from Eleutherobia aurea several, earlier reported, diterpenoids. Compound 2 was found to be toxic to brine shrimp embryos with an LC50 value of 2.30 μM.

Unusual 22S-spirostane Steroids from Dracaena cambodiana

From the methanol extract of Dracaena cambodiana roots two unusual 22S-spirostane steroids (1β,3β,14α,20R,22S,25R)-spirost-5-ene-1,3, 14-triol (1) and (1β,3β,14α,15α,20R,22S,25R)-spirost-5-ene-tetrol (2) have been isolated, together with a known 22R-spirostane compound, namogenin B (3). Their structures were elucidated by spectroscopic and spectrometric methods, including HRMS and extensive 1D and 2D NMR spectroscopy. Compound 1 showed significant antimicrobial activity against Pseudomonas aeruginosa, Staphylococcus aureus and Fusarium oxysporum, with MIC values of 45.0, 25.0 and 50.0 μg/mL, respectively.

Dragon's blood: botany, chemistry and therapeutic uses

Dragon's blood is one of the renowned traditional medicines used in different cultures of world. It has got several therapeutic uses: haemostatic, antidiarrhetic, antiulcer, antimicrobial, antiviral, wound healing, antitumor, anti-inflammatory, antioxidant, etc. Besides these medicinal applications, it is used as a coloring material, varnish and also has got applications in folk magic. These red saps and resins are derived from a number of disparate taxa. Despite its wide uses, little research has been done to know about its true source, quality control and clinical applications. In this review, we have tried to overview different sources of Dragon's blood, its source wise chemical constituents and therapeutic uses. As well as, a little attempt has been done to review the techniques used for its quality control and safety.

Steroidal Saponins and Sapogenins from the Agavaceae Family

Plants belonging to the family Agavaceae are used in folkloric medicinal practices worldwide and chemical investigations of these plants have shown that they are an abundant source of steroidal saponins and sapogenins. Despite the large number of secondary metabolites isolated from this family so far, there have been few reports on the bioactivity of these compounds. This article provides a comprehensive review of the steroidal constituents of plants from the genera Agave, Cordyline, Dracaena, Furcraea, Nolina, Sansevieria and Yucca up to June 2006, and reports on the bioactivity of these compounds where available.