Reaction mechanism of the farnesyl pyrophosphate C-methyltransferase towards the biosynthesis of pre-sodorifen pyrophosphate by Serratia plymuthica 4Rx13

Classical terpenoid biosynthesis involves the cyclization of the linear prenyl pyrophosphate precursors geranyl-, farnesyl-, or geranylgeranyl pyrophosphate (GPP, FPP, GGPP) and their isomers, to produce a huge number of natural compounds. Recently, it was shown for the first time that the biosynthesis of the unique homo-sesquiterpene sodorifen by Serratia plymuthica 4Rx13 involves a methylated and cyclized intermediate as the substrate of the sodorifen synthase. To further support the proposed biosynthetic pathway, we now identified the cyclic prenyl pyrophosphate intermediate pre-sodorifen pyrophosphate (PSPP). Its absolute configuration (6R,7S,9S) was determined by comparison of calculated and experimental CD-spectra of its hydrolysis product and matches with those predicted by semi-empirical quantum calculations of the reaction mechanism. In silico modeling of the reaction mechanism of the FPP C-methyltransferase (FPPMT) revealed a S_N2 mechanism for the methyl transfer followed by a cyclization cascade. The cyclization of FPP to PSPP is guided by a catalytic dyad of H191 and Y39 and involves an unprecedented cyclopropyl intermediate. W46, W306, F56, and L239 form the hydrophobic binding pocket and E42 and H45 complex a magnesium cation that interacts with the diphosphate moiety of FPP. Six additional amino acids turned out to be essential for product formation and the importance of these amino acids was subsequently confirmed by site-directed mutagenesis. Our results reveal the reaction mechanism involved in methyltransferase-catalyzed cyclization and demonstrate that this coupling of C-methylation and cyclization of FPP by the FPPMT represents an alternative route of terpene biosynthesis that could increase the terpenoid diversity and structural space.

Ethnobotanical survey of medicinal plants used for pregnant women׳s health conditions in Menoua division-West Cameroon

ETHNOPHARMACOLOGICAL RELEVANCE

In Cameroon, most women use traditional medicine for the treatment of pregnancy and childbirth complaints. In order to identify some of the medicinal plants locally used to alleviate these complaints, an ethnobotanical survey was undertaken in five villages of Menoua Division (West-Cameroon).

MATERIALS AND METHODS

Interviews were conducted through structured questionnaires among 24 traditional healers and 179 women living either in the town of Dschang or in 4 neighboring villages. After having recorded the interviewee personal information on issues related to medicinal plants utilization, a literature investigation on their therapeutic or pharmacological effects and phytochemical composition was conducted.

RESULTS

A total of 88 medicinal plants species used to treat 24 conditions occurring during or after pregnancy and belonging to 70 genera or 34 families were recorded. Maximum medicinal uses of plants are reported for the treatment of the following ailments: swelling of legs and ankles (23%), facilitation of delivery (22%), cleaning of the baby (12%). Most herbal remedies are prepared with the leaves (30%), leaves+stems (28%) and whole plant (23%) as maceration (76%). The majority of women who used medicinal plants were very satisfied (75 %) and it is reported that most of these plants are used in the treatment of women health conditions.

CONCLUSION

Many herbal remedies used for the treatment of pregnant women׳s health conditions in Menoua division-West Cameroon have been revealed. It would therefore be judicious for our government and research institution to evaluate the therapeutic and toxicological potentials of these plants in order to valorize their use.

mVOC: a database of microbial volatiles

Scents are well known to be emitted from flowers and animals. In nature, these volatiles are responsible for inter- and intra-organismic communication, e.g. attraction and defence. Consequently, they influence and improve the establishment of organisms and populations in ecological niches by acting as single compounds or in mixtures. Despite the known wealth of volatile organic compounds (VOCs) from species of the plant and animal kingdom, in the past, less attention has been focused on volatiles of microorganisms. Although fast and affordable sequencing methods facilitate the detection of microbial diseases, however, the analysis of signature or fingerprint volatiles will be faster and easier. Microbial VOCs (mVOCs) are presently used as marker to detect human diseases, food spoilage or moulds in houses. Furthermore, mVOCs exhibited antagonistic potential against pathogens in vitro, but their biological roles in the ecosystems remain to be investigated. Information on volatile emission from bacteria and fungi is presently scattered in the literature, and no public and up-to-date collection on mVOCs is available. To address this need, we have developed mVOC, a database available online at http://bioinformatics.charite.de/mvoc.

Ethnopharmacological survey of plants used for the treatment of female infertility in Baham, Cameroon

ETHNOPHARMACOLOGICAL RELEVANCE

Infertility affects many women in Cameroon, with a rate of about 25%. This study aimed at collecting and documenting information on herbal remedies traditionally used for the treatment of women infertility in Baham subdivision (Western Region of Cameroon).

MATERIALS AND METHODS

Fieldwork was undertaken as an ethnopharmacological survey involving thirty-two traditional medicine practitioners interviewed in 8 villages of the Baham sub-division. Personal information on interviewees as well as issues related to medicinal use of plants were recorded using structured questionnaires. A literature investigation on the therapeutic or pharmacological properties of recorded medicinal plants was further undertaken.

RESULTS

From this inventory, a total of 46 plant species belonging to 43 genera and 26 families have been registered. These plants are used in 32 recipes and prepared as maceration (43%) or decoction (40%) of only one plant (25%) or of the mixture of two (22%), three (28%), four (22%) or even seven (3%) medicinal plants. Globally, they are given orally during 30 days, at an average dosage of two glasses per day. The literature confirms the use of the majority of these plants for the treatment of the woman infertility and illnesses that are associated to it.

CONCLUSION

This research shows that traditional healers of the Baham subdivision use various recipes of medicinal plants for the treatment of female infertility. The valorization of this potential could be important for the conservation of these plants and the improvement of women reproductive health.