https://chemistry.mdma.ch/hiveboard/rhodium/pdf/piper.phytochemistry.pdf

Phytochemistry of the genus Piper

The insecticidal activity of materials derived from the fruits of Piper nigrum against third instar larvae of Culex pipiens pallens, Aedes aegypti, and A. togoi was examined and compared with that of commercially available piperine, a known insecticidal compound from Piper species. The biologically active constituents of P. nigrum fruits were characterized as the isobutylamide alkaloids pellitorine, guineensine, pipercide, and retrofractamide A by spectroscopic analysis. Retrofractamide A was isolated from P. nigrum fruits as a new insecticidal principle. On the basis of 48-h LC(50) values, the compound most toxic to C. pipiens pallens larvae was pipercide (0.004 ppm) followed by retrofractamide A (0.028 ppm), guineensine (0.17 ppm), and pellitorine (0.86 ppm). Piperine (3.21 ppm) was least toxic. Against A. aegypti larvae, larvicidal activity was more pronounced in retrofractamide A (0.039 ppm) than in pipercide (0.1 ppm), guineensine (0.89 ppm), and pellitorine (0.92 ppm). Piperine (5.1 ppm) was relatively ineffective. Against A. togoi larvae, retrofractamide A (0.01 ppm) was much more effective, compared with pipercide (0.26 ppm), pellitorine (0.71 ppm), and guineensine (0.75 ppm). Again, very low activity was observed with piperine (4.6 ppm). Structure-activity relationships indicate that the N-isobutylamine moiety might play a crucial role in the larvicidal activity, but the methylenedioxyphenyl moiety does not appear essential for toxicity. Naturally occurring Piper fruit-derived compounds merit further study as potential mosquito larval control agents or as lead compounds.

Larvicidal activity of isobutylamides identified in Piper nigrum fruits against three mosquito species

Piper crassinervium, P aduncum, P hostmannianum, and P gaudichaudianum contain the new benzoic acid derivatives crassinervic acid (1), aduncumene (8), hostmaniane (18), and gaudichaudianic acid (20), respectively, as major secondary metabolites Additionally, 19 known compounds such as benzoic acids, chromenes, and flavonoids were isolated and identified The antifungal activity of these compounds was evaluated by bioautographic TLC assay against Cladosporium cladosporioides and C sphaerospermum

Benzoic Acid Derivatives from Piper Species and Their Fungitoxic Activity against Cladosporium cladosporioides and C. sphaerospermum

Constituents of Chinese Piper species and their inhibitory activity on prostaglandin and leukotriene biosynthesis in vitro.

/pdf/piper-a-model-genus-for-studies-of-phytochemistry-ecology-3eoj94d9b6.pdf

Piper: A Model Genus for Studies of Phytochemistry, Ecology, and Evolution

Structural and synthetic studies on the retrofractamides—amide constituents of Piper retrofractum

Amides from Piper brachystachyum and Piper retrofractum.

Three unsaturated amides, designated brachystamides-C, D and E have been characterised from Piper brachystachyum Wall. Brachystamide-C, shown to be N-isobutyl-15-(3',4'-methylenedioxyphenyl)-2E,4E,13E-pentadecatrienamide, was unusual in having a non-conjugated double bond. Piper retrofractum Vahl. yielded retrofractamide-D, which has been fully characterised.

Amides from Piper brachystachyum and Piper retrofractum

Background: Myofascial pain syndrome (MPS) is common among females between ages 20-40 years. Psychosomatic and mechanical reasons are attributed as causative factors. Female health care workers (FHW) in hospitals with rapid patient turn over are vulnerable to develop MPS. Our aim was to ascertain the prevalence of MPS in married FHW working in various departments of the hospital and its association with poor sleep and work stress.
Methods: We selected married FHWs in 20-50 years age group and divided them into two groups, medical and paramedical (those involved directly and indirectly with patient care respectively). MPS was diagnosed after detailed personal interview and clinical examination. Sleep duration was divided into less than 5 hours and more than 5hours. Presence of work-related stress and other medical parameters were also recorded.
Results: A total of 150 medical and 150 paramedical FHWs were included in the study. Overall prevalence of MPS among FHWs was 42%, of which, medical group was 32% and paramedical was 52%. The paramedical group showed significantly higher prevalence of MPS (p: 0.02). Sleep was less than 5 hours in 29.3% of medical FHW and 13.3% of paramedical. This difference didn’t show any association to MPS (p=0.8). 38% FHW perceived excessive work stress, 40% were paramedical and 36% were medical. This didn’t correlate with prevalence of MPS (p=0.2) among them.
Conclusions: Paramedical FHW experienced more MPS than medical and it was more of mechanical type and not due to work stress or sleep deprivation.

/pdf/assessment-of-myofascial-pain-syndrome-among-married-female-k93fw5mm.pdf

Koshy Abraham

Papers

Structural and synthetic studies on the retrofractamides—amide constituents of Piper retrofractum

Amides from Piper brachystachyum and Piper retrofractum.

Amides from Piper brachystachyum and Piper retrofractum

Assessment of myofascial pain syndrome among married female healthcare workers: a cross sectional comparative study in a tertiary care centre