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Four previously undescribed diterpenoids including two crotofolanes, crotodichogamoin A and B, and two halimanes, crothalimene A and B, a new sesquiterpenoid, and fifteen previously reported compounds, including the crotofolane, crotohaumanoxide, the casbane, depressin, a further seven furanohalimane diterpenoids, three patchoulane and two further cadinane sesquiterpenoids and aleuritolic acid were isolated from the root of Croton dichogamus. Crotodichogamoin B is an important biosynthetic intermediate of the crotofolane class and this is the first report of patchoulene sesquiterpenoids from the genus. Compounds were tested at one concentration, 1 × 10 M, in the NCI59 cell one-dose screen but did not show significant activity snd were also evaluated for their cytotoxicity against Caco-2 cell lines using the neutral red assay. 10-epi-Maninsigin D reduced Caco-2 cell viability at 10, 30 and 100 μM, with values of decreased viability of 28%, 48% and 43% respectively. None of the other tested compounds showed significant activity.

The roots of the endangered medicinal plant Croton megalocarpoides collected in Kenya were investigated and twenty-two compounds isolated. Among them were twelve new ent-clerodane (1-12) and a new abietane (13) diterpenoids, alongside the known crotocorylifuran (4 a), two known abietane and four known ent-trachylobane diterpenoids, and the triterpenoids, lupeol and acetyl aleurotolic acid. The structures of the compounds were determined using NMR, HRMS and ECD. The isolated compounds were evaluated against a series of microorganisms (fungal and bacteria) and also against Plasmodium falciparum, however no activity was observed.

Two novel compounds, alienusolin, a 4α-deoxyphorbol ester (1), crotonimide C, a glutarimide alkaloid derivative (2), and ten known compounds, julocrotine (3), crotepoxide (4), monodeacetyl crotepoxide (5), dideacetylcrotepoxide, (6), β-senepoxide (7), α-senepoxide (8), (+)-(2S,3R-diacetoxy-1-benzoyloxymethylenecyclohex-4,6-diene (9), benzyl benzoate (10), acetyl aleuritolic (11), and 24-ethylcholesta-4,22-dien-3-one (12) were isolated from the Kenyan Croton alienus. The structures of the compounds were determined using NMR, GCMS, and HRESIMS studies.

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Kenyan Croton sylvaticus Hochst. ex Krauss gave four clerodane diterpenoids, the new ent–3,13 E-clerodadiene-15-formate (1), the known 15-acetoxy- ent-3,13 E-clerodadiene (2), ent-3,13 E-clerodadien-15-ol (3) and hardwickiic acid (4), two known halimane diterpenoids, penduliflaworosin (5) and crotohalimaneic acid (6) and one labdane diterpenoid, labda-13 E-ene-8α,15-diol (7). The compounds, when tested for their anti-microbial activities against Bacillus subtilis, Xanthomonas campestris and Candida albicans, were found to be inactive.

Five previously undescribed compounds, megalocarpoidolide I (1), megalocarpoidolide J (3), 12-epi-crotonzambefuran A (4), megalocarpoidolide K (5), 1-trans-p-hydroxycoumaroylgeranylgerani-1-ol (6) were isolated from the stem bark of Croton megalocarpoides Friis & M. G. Gilbert. The known ent-trachyloban-18-ol, megalocarpoidolide B, megalocarpoidolide C (2), megalocarpoidolide H, crotocorylifuran, 7,8-dehydrocrotocorylifuran, 1,2dehydrocrotocorylifuran-2-one, acetyl aleuritolic acid, lupeol, N-trans-p-coumaroyl-3',4'dihydroxyphenylethylamine, dodecyl trans-ferulate and lignoceryl trans-ferulate were also isolated. The structures of the compounds were determined using NMR and IR spectroscopy and HRMS. The structure of compound 1 was determined using Logic for Structural Determination (LSD). Compounds 1, 2 and 3 were evaluated against the NCI60 panel of human tumour cell lines at 10µM level but found to be inactive.

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