Ocimum is considered the largest genus
in the
Lamiacea family. The genus includes basil, a group of aromatic plants
with a wide range of culinary uses that nowadays draws attention for
its medicinal and pharmaceutical potential. This systematic review
intends to explore the chemical composition of nonessential oils and
their variation across different Ocimum species.
Moreover, we aimed to identify the state of knowledge regarding the
molecular space in this genus as well as the different methods of
extraction/identification and geographical location. Seventy-nine
eligible articles were selected for the final analysis, from which
we extracted more than 300 molecules. We found that the countries
with the highest number of studies into Ocimum species
are India, Nigeria, Brazil, and Egypt. However, from all known species
of Ocimum, only 12 were found to have an extensive
chemical characterization, particularly Ocimum basilicum and
Ocimum tenuiflorum. Our study focused especially on alcoholic,
hydroalcoholic, and water extracts, in which the main techniques for
compound identifications are GC-MS, LC-MS, and LC-UV. Across the compiled
molecules, we found a wide variety of compounds, especially flavonoids,
phenolic acids, and terpenoids, suggesting that this genus could be
a very useful source of possible bioactive compounds. The information
collected in this review also emphasizes the huge gap between the
vast number of Ocimum species discovered and the
number of studies in each of them that determined the chemical characterization.