Cytotoxic diterpenoids from the leaves and stem bark of Croton haumanianus (Euphorbiaceae)

Sani M Isyaka; Eduard Mas-Claret; Moses K Langat; Thomas Hodges; Bethany Selway; Blaise M Mbala; Bienvenu K Mvingu; Dulcie A Mulholland

doi:10.1016/j.phytochem.2020.112455

Cytotoxic diterpenoids from the leaves and stem bark of Croton haumanianus (Euphorbiaceae)

Phytochemistry. 2020 Oct:178:112455. doi: 10.1016/j.phytochem.2020.112455. Epub 2020 Jul 20.

Authors

Sani M Isyaka¹, Eduard Mas-Claret¹, Moses K Langat², Thomas Hodges¹, Bethany Selway¹, Blaise M Mbala³, Bienvenu K Mvingu³, Dulcie A Mulholland⁴

Affiliations

¹ Natural Products Research Group, Department of Chemistry, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, GU2 7XH, UK.
² Natural Products Research Group, Department of Chemistry, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, GU2 7XH, UK; Jodrell Laboratory, Natural Capital and Plant Health Department, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3DS, United Kingdom.
³ Departement de Chimie et Industry, Faculte des Sciences, Universite de Kinshasa, B.P.190 Kin XI, Democratic Republic of the Congo.
⁴ Natural Products Research Group, Department of Chemistry, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, GU2 7XH, UK; School of Chemistry and Physics, University of KwaZulu-Natal, Durban, 4041, South Africa. Electronic address: d.mulholland@surrey.ac.uk.

PMID: 32692659
DOI: 10.1016/j.phytochem.2020.112455

Abstract

The leaf extract of Croton haumanianus J. Léonard (Euphorbiaceae) yielded twenty-six compounds, including eight previously reported ent-kauranes and an ent-labdane and eight undescribed ent-kauranes, ent-16R-kauran-17-al, ent-3β-hydroxy-16R-kauran-17-al, ent-16S,17-epoxykauran-19-ol, ent-16S,17-epoxykauran-3β-ol, ent-17-palmityloxykaurane-3β,16β-diol, ent-17-palmityloxykauran-16β-ol, ent-3α,18-cyclokaurane-16β,17-diol and 19-nor-16α,17-dihydroxy-ent-kaur-4(18)-ene and three undescribed ent-clerodanes, dimethyl ent-15,16-epoxy-6β-hydroxy-1,3,13(16),14-clerodatetraen-20,12S-olide-18,19-dioate (saniolide A), dimethyl ent-15,16-epoxy-6β-hydroxy-1,3,13(16),14-clerodatetraen-20,12R-olide-18,19-dioate (12-epi-saniolide A), methyl ent-15,16-epoxy-1,3,13(16),14-clerodatetraen-18,6R:20,12S-diolide-19-oate (saniolide B). The stem bark extract yielded the ent-clerodane crotocorylifuran, and five undescribed ent-isopimaranes, ent-isopimara-8(14),15-dien-18-al, ent-18-hydroxyisopimara-8(14),15-dien-7-one, ent-isopimara-7,15-dien-18-oic acid, ent-isopimara-7,15-dien-18-ol and ent-isopimara-8,15-dien-7-oxo-18-oic acid. Three compounds, ent-kaurane-3β,16β,17-triol, ent-17-palmityloxykaurane-3β,16β-diol and ent-17-palmityloxykauran-16β-ol, showed selective activity against three of the NCI 60 cancer cell lines, the colon (HCT-116), the melanoma (M14) and the renal (786-0) cancer cell lines at a concentration of 10^-5 M.

Keywords: Anti-proliferative activity; Croton haumanianus; Ent-clerodane; Ent-isopimarane; Ent-kaurane; Euphorbiaceae.

MeSH terms

Croton*
Diterpenes*
Diterpenes, Kaurane*
Euphorbiaceae*
Molecular Structure
Plant Bark

Substances

Diterpenes
Diterpenes, Kaurane