Ent-clerodane and ent-trachylobane diterpenoids from Croton dictyophlebodes

Joan J E Munissi; Sani M Isyaka; Eduard Mas-Claret; Molly Brabner; Moses K Langat; Stephen S Nyandoro; Dulcie A Mulholland

doi:10.1016/j.phytochem.2020.112487

Ent-clerodane and ent-trachylobane diterpenoids from Croton dictyophlebodes

Phytochemistry. 2020 Nov:179:112487. doi: 10.1016/j.phytochem.2020.112487. Epub 2020 Aug 22.

Authors

Joan J E Munissi¹, Sani M Isyaka², Eduard Mas-Claret², Molly Brabner², Moses K Langat³, Stephen S Nyandoro⁴, Dulcie A Mulholland⁵

Affiliations

¹ Chemistry Department, College of Natural and Applied Sciences, University of Dar es Salaam, P.O.Box 35061, Dar es Salaam, Tanzania.
² Natural Products Research Group, Department of Chemistry, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, GU2 7XH, UK.
³ 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.
⁴ Chemistry Department, College of Natural and Applied Sciences, University of Dar es Salaam, P.O.Box 35061, Dar es Salaam, Tanzania. Electronic address: nyandoro@udsm.ac.tz.
⁵ 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: 32847772
DOI: 10.1016/j.phytochem.2020.112487

Abstract

The stem bark and root bark extracts of Croton dictyophlebodes (Euphorbiaceae) yielded seven undescribed ent-clerodanes: 15,16-epoxy-17,12(S)-olide-ent-cleroda-1,3,13(16),14-tetraen-18-oic acid methyl ester (crotodictyo A), 3β,4β:15,16-diepoxy-ent-cleroda-13(16),14-dien-20-al (crotodictyo B), 3β,4β:15,16-diepoxy-ent-cleroda-13(16),14-dien-19,20-dioic acid (crotodictyo C), 3β,4β:15,16-diepoxy-ent-cleroda-13(16),14-dien-20,19-olide (crotodictyo D), 3β,4β:15,16-diepoxy-20,12(R)-olide ent-cleroda-13(16),14-dien-19-oic acid methyl ester (crotodictyo E), 15,16-epoxy-ent-cleroda-3,13(16),14-trien-12-oxo-18-oic acid (crotodictyo F) and 15,16-epoxy-ent-cleroda-1,3,13(16),14-tetraen-12-oxo-18-oic acid (crotodictyo G), in addition to 15,16-epoxy- ent-cleroda-3,13(16),14-trien-12-oxo-18-oic acid methyl ester (crotodictyo H), reported previously as a synthetic derivative, and acetyl aleuritolic acid. The root extract yielded two ent-trachylobanes, ent-trachylobane-18,19-diol, the undescribed ent-trachylobane-2α,19-diol, along with ent-kaur-16-en-19-oic acid and 2-methoxybenzyl benzoate. Compounds were evaluated against the NCI 60 panel of human tumour cell lines at a single dose of 10^-5 M, but showed no significant activity.

Keywords: Croton dictyophlebodes; Cytotoxicity screening; Electronic circular dichroism; Ent-clerodane; Ent-trachylobane; Euphorbiaceae.

MeSH terms

Cell Line, Tumor
Croton*
Diterpenes
Diterpenes, Clerodane*
Euphorbiaceae*
Humans
Molecular Structure

Substances

Diterpenes
Diterpenes, Clerodane