Of pinocembrin

Bogdanov, S. (1989). Determination of pinocembrin in honey using HPLC. /. Apicult. Res. 28, 55-57. 

Vakhabov, A.A., C.D. Aminov, and R.K. Hasanova Antiinflammatory Activity of Pinocembrin. Dokl. Akad. Nauk Resp. Uzb. (USSR), 1993, 43 Chem. Abstr., 122, 96053f (1995). 

In a similar study, different phenylpropanoid acids, such as cinnamic acid (32), p-coumaric acid (33), caffeic acid (34), and ferulic acid (35), were fed to recombinant yeast containing four different initial flavanone biosynthetic plant genes, C4H, 4CL, CHS, and CHI, at different time intervals to produce flavanones. In cinnamic acid-supplemented culture, 16.3 mg 1 of pinocembrin (31) and 0.2 mg 1 of naringenin (30) were produced. Naringenin (28.3 mg 1 ) and (2S)-eriodictyol (6.5 mg 1 ) were detected in p-coumaric acid- and caffeic acid-supplemented cultures, respectively. No flavanones were produced with ferulic acid precursor substrate [33]. The production of pinocembrin and naringenin in S. cerevisiae was 22- and 62-fold higher compared to that of respective flavanones in E. coli [34]. 

Each plant tissue tends to have an obviously distinctive profile of flavonoids. The flavonoid content can reach about 0.5% in pollen, 10% in propolis, and about 6 mg/kg in honey. Havonoid aglycones appear to be present only in propolis and honey, while pollen contains flavanols in herosidic forms. The flavonoids in honey and propolis have been identified as flavanones and flavanones/flavanols (Campos et ah, 1990). The antimi-crobially active flavanone pinocembrine was foimd to be a major flavonoid in honey (Bogdanov, 1989). Amiot et ah (1989) studied two blossom and two honeydew Swiss honey samples and foimd that pinocembrine was the main flavonoid. Pinocembrine concentration varied between 2 and 3 mg/kg (Bogdanov, 1989). Berahia et ah (1993) analyzed sunflower honey samples and detected six flavone/flavols, four flavanone/ flavols, and pinocembrin, of which pinocembrin is the main flavonoid. The flavonoids in sunflower honey and propolis were characterized and assessed for their effects on hepatic drug-metabolizing enzymes and benzo [fl]pyrene-DNA adduct formation (Sabatier et ah, 1992 Siess et ah, 1996). 

Some phenolic acids such as ellagic acid can be used as floral markers of heather honey (Cherchi et al., 1994 Ferreres et al., 1996a,b), and the hydroxyciimamates (caffeic, p-coumaric, and ferulic acids) as floral markers of chestnut honey (Cherchi et al., 1994). Pinocembrin, pinobanksin, and chrysin are the characteristic flavonoids of propolis, and these flavo-noid compounds have been found in most European honey samples (Tomas-Barberan et al., 2001). However, for lavender and acacia honeys, no specific phenolic compoimds could be used as suitable floral markers (Tomas-Barberan et al., 2001). Other potential phytochemical markers like abscisic acid may become floral markers in heather honey (Cherchi et al., 1994). Abscisic acid was also detected in rapeseed, lime, and acacia honey samples (Tomas-Barberan et al., 2001). Snow and Manley-Harris (2004) studied antimicrobial activity of phenolics. 

Honey contains an extensive diversity of phenolic compounds as secondary constituents, notably flavonoids and phenolic acids (Arraez-Roman et al., 2006 Baltrusaityte et al., 2007 Estevinho et al., 2008). The flavonoid content reaches about 6000 mg/kg, consisting mainly of flavanones and flavones (Anklam, 1998). The main flavonoids are myricetin, tricetin, quercetin, hesperidin, luteolin, kaempferol, pinocembrin, chrysin, pinobanksin,... 

From the roots of B. oxydonta, Bohlmann et al. [39] isolated the flavanones pinocembrin, Fig. (45) and pinobanksin, Fig. (46), while the aerial parts of Baccharis varians Gardn. afforded two 3-acetoxyflavanones, Fig. (47) [25],... 

Essential oil from the seeds of A. katsumadai, a Chinese drug "caodoukou", was analyzed by GLC and 22 components were detected [35]. Three main constituents were isolated and identified as 1,8-cineol, a-humulene and trans,trans- ameso. From the seed residue, after removal of the essential oil by steam, alpinetin and cardamonin were isolated [36]. Together with trans,trans-fameso, rrawj-cinnamaldehyde and three flavonoids, alpinetin, cardamonin and pinocembrin, six diarylheptanoids 34-39 were isolated from the seeds of A. katsumadai and identified on the basis of chemical and spectral evidence [37]. 

Pinocembrin (50) has been implicated as an attractant to a bark beetles feeding on fruit trees (Harbome, 1991). In contrast, the flavonoid aglycone, morin (39) [as well as iso-quercitrin (51) and several essential oils], is involved in feeding of silkworm larvae Bombyx mod) on mulberry plants Morus nigra) (Harbome, 1991). 

---