Cytotoxic nor-dammarane triterpenoids from Dysoxylum hainanense

Triterpenoids from Dysoxylum genus and their biological activities

This study aims to analyze the ethnobotanical, chemical, and biological activities of triterpenoid compounds isolated from the Dysoxylum genus of the Meliaceae family between 1974 and 2021. The species are mainly distributed in Africa, Asia, and Australia, and used as a traditional medicine to treat various diseases. Triterpenoid was first isolated in 1976 and as tetranortriterpenoid or limonoid, it was named dysobinin. Several studies were conducted for more than 40 years on the plants' stems, bark, and leaves, where approximately 279 triterpenoid compounds from several groups such as dammarane, nortriterpenoid, oleanane, lupane, tirucallane, cyclolanostane, or cycloartane, glabretal, and cycloapoeuphane-types were isolated with some synthetic products. In addition, the hypothetical route of triterpenes biosynthesis from this genus was identified, and tirucallane-type were reported to be 37.6% of the total compounds. The anti-malarial, anti-feedant, antimicrobial, anti-inflammatory, antioxidant, vasodilative effect, anti-viral, cortisone reductase, and cytotoxic activities of the extract were also evaluated. The results showed the necessity of using the triterpenoid compounds from the Dysoxylum genus in traditional medicine and the discovery of new drugs.

Cytotoxic nor-dammarane triterpenes from Viburnum hainanense Merr. et Chun

Five new nor-dammarane triterpenes, 12β-O-acetyl-17β-hydoxy-3,15-dioxo-20,21,22,23,24,25,26,27-octanordammanran (1), 12β-hydoxy-17β-methoxy-3,15-dioxo-20,21,22,23,24,25,26,27-octanordammanran (2), 12β-O-acetyl-3,15-dioxo-17-en-20,21,22,23,24,25,26,27-octanordammanran (3), 12β-hydoxy-15α-O-acetyl-3-oxo-17-en-20,21,22,23,24,25,26,27-octanordammanran (4) and 3β-hydoxy-17-oxo-12-en-20,21,22,23,24,25,26,27-octanordammanran (5), were obtained from the ethanol extract of the whole plants of Viburnum hainanense Merr. et Chun. Structural elucidation of all the compounds was performed by spectral methods such as 1D and 2D NMR, IR, UV, and HRESIMS. The isolated compounds were tested in vitro for cytotoxic potential against seven tumor cell lines (Hep-2, SCL-1, CAL-27, UMSCC-1, Detroit-562, SCC-PKU, and TCA-83). As result, compounds 1 and 2 exhibited cytotoxic activities with IC50 values less than 10 μM.

Limonoids and Triterpenoids from Dysoxylum mollissimum var. glaberrimum

Seven new limonoids, dysomollides A-G (1-7), and two new cycloapotirucallane-type triterpenoids, dysomollins A and B (8 and 9), together with three known compounds, dysoxylumin A (10) and toonapubesins A (11) and B (12), were isolated from the twigs of Dysoxylum mollissimum var. glaberrimum. The structures of 1-9 were elucidated on the basis of spectroscopic methods. Compound 10 showed inhibitory activity against A549 cells with an IC50 value of 2.1 μM, and compound 11 exhibited activity against P388 cells with an IC50 value of 6.7 μM.

Hupehenols A-E, selective 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) inhibitors from Viburnum hupehense

Five selective 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) competitive inhibitors, hupehenols A-E (1-5), were isolated from Viburnum hupehense. The structure elucidation indicated that compounds 1-5 are new 20,21,22,23,24,25,26,27-octanordammarane triterpenoids. Their structures were established on the basis of NMR spectroscopic and mass spectrometric analysis. Hupehenols A-E (1-5) showed inhibition against human 11β-HSD1, with hupehenols B (2) and E (5) having IC50 values of 15.3 and 34.0 nM, respectively. Moreover, hupehenols C (3) and D (4) are highly selective inhibitors of human 11β-HSD1 when compared to murine 11β-HSD1.

Triterpenoids

This review covers the isolation and structure determination of triterpenoids reported during 2012 including squalene derivatives, lanostanes, holostanes, cycloartanes, cucurbitanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, quassinoids, lupanes, oleananes, friedelanes, ursanes, hopanes, serratanes, isomalabaricanes and saponins; 348 references are cited.

Chemical components of Dysoxylum densiflorum

Three new diterpenoids, including two halimanes, 5(10),13E-halimadiene-3α,15-diol (1), and 5(10),14-halimadiene-3α,13ξ-diol (2), one labdane, 12-(3-methyl-furan)-labd-8(17)-en-19-oic acid (3), together with sixteen known compounds were isolated from the barks of Dysoxylum densiflorum. All compounds were elucidated by extensive spectroscopic analysis.

Three new nor-dammarane triterpenoids from Dysoxylum hainanense with particular cytotoxicity against glioma cell line

Three new nor-dammarane triterpenoids, 12β-O-acetyl-15α-hydoxy-3-oxo-17-en-20,21,22-23,24,25,26,27-octanordammanran (1), 12β,28-O-diacetyl-15α-hydoxy-3-oxo-17-en-20,21,22-23,24,25,26,27-octanordammanran (2), 12β-hydoxy-3,15-dioxo-20,21,22-23,24,25,26,27-octanordammanran (3), together with one known compound, 12β-O-acetyl-15α,28-dihydoxy-3-oxo-17-en-20,21,22-23,24,25,26,27-octanordammanran (4), were isolated from the 95 % EtOH extract of Dysoxylum hainanense. The structures of the new compounds were elucidated by spectral methods. All the triterpenoids were in vitro evaluated for their cytotoxic activities against four tumor cell lines (BGC-823, U251, HepG2 and SGC-7901). All the three nor-dammarane triterpenoids exhibited particular significant cytotoxic activities against glioma cell line.

Cytotoxic and radical scavenging nor-dammarane triterpenoids from Viburnum mongolicum

The ethanol extract of the whole plants of Viburnum mongolicum afforded six new nor-dammarane triterpenoids: 3β,12β-dihydroxy-25,26,27-trinordammara-22-en -24,20-olide (1), 3β,12β-dihydroxy-24α-methoxy-25,26,27-trinordammara-20,24-epoxy (2), 3β-O-acetyl-12β-hydroxy-23,24,25,26,27-hexanordammarane-20-one (3), 12β-O- acetyl-15α-hydroxy-17β-methoxy-3-oxo-20,21,22-23,24,25,26,27-octanordammanrane (4), 12β-O-acetyl-15α,17β-dihydroxy-3-oxo-20,21,22-23,24,25,26,27-octanordammanrane (5), and 12β,15α-dihydroxy-3-oxo-17-en-20,21,22-23,24,25,26,27-octanordammanrane (6), together with two known nor-dammarane triterpenoids, 12β-hydroxy-3-oxo-24α-methoxy- 25,26,27-trinordammara-20,24-epoxy (7) and 3β,12β-dihydroxy-23,24,25,26,27- hexanordammarane-20-one (8). The structures of the isolated compounds were established based on 1D and 2D (¹H-¹H COSY, HMQC, and HMBC) NMR spectroscopy, in addition to high resolution mass spectrometry. The isolated compounds were tested in vitro for cytotoxic potential against seven tumor cell lines and radical scavenging activities. Compounds 4-6 exhibited significant cytotoxic activities against all tested tumor cell lines and radical scavenging activities against ABTS·+ radicals comparable with the standard drug Trolox.