# New Cleistanthane Diterpenoids from Vellozia pyrantha A.A.Conc and Their Cytotoxic Activity

## TL;DR

Researchers discovered new plant compounds from Vellozia pyrantha that show some ability to kill cancer cells.

## Contribution

Four new cleistanthane diterpenoids with cytotoxic activity against lung and liver carcinoma cells were identified and structurally characterized.

## Key findings

- Pyranthanol B and pyranthanones A–B showed cytotoxic effects against lung and liver carcinoma cell lines.
- Moderate toxicity was observed against normal lung cells for pyranthanol B and pyranthanone A.
- The compounds may be potential candidates for drug development targeting carcinoma cells.

## Abstract

Four new cytotoxic cleistanthane diterpenoids, named
pyranthanols
A–B (1–2) and pyranthanones
A (3–4), were isolated from Vellozia
pyrantha A.A.Conc resin, along with four known compounds
(5–8). These compounds show varying degrees of
oxidation with hydroxyl and carbonyl groups at different positions
of the cleistanthane core skeleton. Their structures were proposed
after careful analysis of 1H and 13C NMR, HMBC,
HMQC, and COSY and NOESY 1D data and comparison with the literature.
Pyranthanol B (2) and pyranthanones A–B (3–4) were active against a lung carcinoma cell line
(H-1299) with IC50 values varying from 27.57 ± 6.89
to 99.96 ± 22.64 μM, whereas pyranthanol B (2) and pyranthanone B (4) were active against a human
liver carcinoma cell line (HepG2) with IC50 values of 36.21
± 11.97 and 43.63 ± 25.53 μM, respectively. Pyranthanol
B (2) and pyranthanone A (3) were also toxic
against a normal lung cell line (MRC-5) with IC50 values
of 49.99 ± 19.98 and 43.63 ± 43.63 ± 20.25 μM,
respectively. The moderate activity observed may suggest these compounds
as potential candidates for drug development against carcinoma cell
lines.