Proe. Indian Acad. Sci. ( Sci.), Vol. 97, No. 4, August 1987, pp. 315-323. 9 Printedin India.

Chemosystematics of some Indian members of the

M DANIEL and S D SABNIS Phytochemistry Laboratory, Department of Botany, Faeulty of Science, The MS University of Baroda, Baroda 390 002, India Abslraet. Fifty-eighttaxa belonging to 3 subfamiliesof Acanthaceae have been screened for leal"flavonoids, phenolie acids and aucubins. The patterns of distribution of leal"pheno- lics among the taxa invr suggest that: (i) there ate 3 well-definedtaxonomie groups; (ii) the treatment of Thunbergiaceae as distinct from Acanthaceae(Sensu stricto) is justified; (iii) Nelsonioidear appean to be an intermediatelink between Thunbergiaceae and Acan- thaceae, and its inelusion within Aeanthaee.ae is justilicd and (iv) Thunbergiacear is relatively more primitive than Aeanthaeeae. KeywortLs. Chemotaxonomy;flavonoids: acanthaeeae.

1. Introduction

The circumscription of Acanthaceae--a predominantly tropical and subtropical family is a subject of controversy (Nees Von Esenbeck 1847; Lindau 1895). Mohan Raro and Wadhi (1965) elevated Thunbergioideae to a distinct family status on mor- phological grounds. This proposition was ably supported by Chaubal (1966) and Sahi and Dixit (1969). Cronquist (1981) does not support this contention, but finds Mendoncioideae more distinctive than the Nelsonioideae and Thunbergioideae and prefers to keep the two latter subfamilies within Acanthaceae while elevating the former subfamily to a distinct family Mendonciaceae. Bremekamp (1953) transferred Nelsonioideae to the Scrophulariaceae and kept it near the tribe Rhinantheae. Paly- nological evidences (Chaubal 1966; Raj 1961) supported Bremekamp's view, but embryological (Mohan Raro and Wadhi 1965; Johri and Singh 1959) and morpho- anatomical characters (Ahmed 1974a) do suggest the elose affinity of Nelsonioideae to Acanthaceae. Except Nair et al (1965), Govindachari et al (1965) and Harborne (1967) on the phenolic chemistry of the family Acanthaceae, there is no comparative account on the patterns of distfibution of phenolics in the family. The present paper reports the patterns of distribution of leal phenolics and aucubins among 58 taxa of the family Acanthaceae and their systematie significance.

2. Materials and methods

The were collected from various localities in Gujarat, Madhya Pradesh and Kerala. The voueher specimens have been deposited in the University Herbarium. The methods followed for the extraction, isolation and characterisation of flavonoids and phenolic acids have been described elsewhere (Daniel and Sabnis 1977). Aucubins were tested using Trim-Hill colour test (Harborne 1973).

315 316 M Daniel and S D Sabnis

3. Resuits

The distribution of various flavones, flavonols, glycoflavones, proanthocyanins, phenolic acids and aucubins aro presented in tables 1 and 2. Of the 58 taxa screened, 47 contained flavones, flavonols, glycoflavones and proanthocyanins. Thirty five species contained flavones as o-glycosides. Apigenin, luteolin and/or their mono-, bi- or trimetboxy derivatives were the common flavones in most of the taxa investigated. 6-Hydroxy or 6-methoxy flavones were found in 7 taxa. Glycoflavones were isolated from 15 species. Vitexin and iso-vitexin were the most common glycoflavones. 4'-OMe Vitexin was confined to Bremekampia neilgherryensis, Haplanthus verticiUaris and linneanum. 6-Methoxy Vitexin was restricted to procumbens var. simplex. In at least 6 species, flavone-o- glycosides and glycoflavones were found together. In Adhatoda zeylanica glycofla- vones were found in association with flavonols and they were the solo flavonoids in 8 taxa. The subfamilies Nelsonioideae and Thunbergioideae were rich in glycoflavones but poor in flavones. 6-Oxygenated flavones were entirely absent from these sub- families, but were conŸ237 to the subfamily . Flavonols, kaempferol, quercetin, my¡ and their monomethoxy derivatives were found in 4 species of the tribes Odontonemeae and Justicieae. In no plant flavones and flavonols did eccur together. Proanthocyanins were raro and restricted to the 3 taxa; in auriculata and ilicifolius they were found alongwith flavones and in crenata with glycoflavones. Of the 19 phenolic acids identified from the extracts, 14 were benzoic acids and the rest were cinnamic acids. Vanillic and syringic acids were present in more than 60~ of the taxa studied, p-OH Benzoic acid was recorded in about 50~ of the taxa. This compound was not observed in any member of the Nelsonioideae and Thunber- gioideae, whereas vanillic acid and any of the cinnamic acids were also not found in the latter subfamily. Gentisic and protocatechuic acids were found in all the members of Thunbergioideae studied. Aucubins were found only in glutinosa and prionitis.

4. Discussion

The patterns of distribution of flavonoids and phenolic acids do suggest the recog- nition of 3 distinct taxonomic groups. Thunbergioideae is characte¡ by the uniform presence of glycoflavones and absence of 6-oxygenated flavones, proantho- cyanins, aucubins, vanillic, p-OH benzoic and cinnamic acids. Flavones are also raro in this group. The chemical characteristics, together with other characters such as climbing habit, prominent bracteoles, absence of cystoliths, presence of axillary , a smaU sized calyx, panduraeform glandular hairs (Ahmed 1974b) and cus- hion shaped funiculus forming a sort of obturator, justify the recognition of Thunbergioideae asa distinct family related to Acanthaceae--a view also expressed by Mohan Ram and Wadhi (1965) and Bremekamp (1953). The chemical data on the two representatives of the subfamily Nelsonioideae indi- cato that it is intermediate between Thunbergiaceae and Acanthaceae (Sensu stricto) and perhaps forms a connecting link between the two closely related families. This subfamily is similar to Thunbergiaceae in the absence of flavonols, 6-oxygenated 'l'able I, The distrihulion of flaw~noids aml aucubins in some members of the aeanthaceae (afler Lindau 1895). 1 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 17 18 19 20 21 22 23

Subfainily Nelsonioideae Elytraria crenuta Vahl + + t + Slaurogyne glutinosa O. Kuntze + "t- + Subfamily Thunbergioideae erecta T. Anders. t,,S 7: fragrans Wall. T. grandiflora Roxb. T. mysorensis T. Anders. Subfamily Acanlhoideae Tribe Hygrophilaeae Hemiadelphis polysperma Nees Hy#rophila auriculata Heine + + E" H. quadrivalvis Nees H. serpyllum T. Anders. + + Tribe Strobilantheae Gantelbaa urens Bremek. + ele.oans var. crenata Clarke + r t~ H. hirta T. Anders. H. latebrosa var. heyneana Bremek. + Strobilanthus callosus Nees S. scaber Nees + S. wiyhtianus Nees Tribe Ruellieae Daedalacanthus" nervosus T. Anders. Dipteracamhus patulus var. alba Bhandari D. prostratuL~ Nees + roseum Br. + + + haikiei Woodr. + R. colorata Wall. + R. taberosa Linn.

".-..3 Table 1. (Contd.) ,...,to, oo 1 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 17 18 19 20 21 22 23

Tribe Barlerieac + Barleria crlstata Linn. + + B. grandiflora Dalz. e,, B. prattensis Sant. + + B. prionitis Linn. B. strioosa Willd. g~ cuspidata Nees + ~t L. bandraensis Biatter Neuracanthus sphaerostachyus Dalz. Tribe Acantheae + q~ Acanthus iliclfollus Linn. asperrima Nr162 ha B. linearifolia Pers. B. madaraspawnsis (L.) Heyne + B. repens Roth -4- + undulaefolia Salisb. + Tribe Andrographideae + Bremekampia neiloherryensls Srer + Haplanthus verticillaris Nees + Indonessiella echioides Sreem. Tribe Asystasiear Asyslasia dalzelliana SanL + + A. ganfletica T. Anders. A. travancoria Bedd. Tribe Odontoneaear verticillata Christr Ecbolium linneanum Kurz + bicalyculta Nees + l~hinacanthus r Nees + + § Runoia pectinata Nees ~+ + R. repens Nees t~

Table I. (Contd.)

I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 17 18 19 20 21 22 23 ~" Tribe Justicieae Adhatoda zeylanica Medic. + + + Beloperone gultata Brandegce. B. violacea Planch. and Linden Jacobinia bolit,iensis Woodr. + t% ,1usticia betonica Linn. +

J. neesii Ramam. g~ .I. procumbens var. simplex Yamazaki r J. trinervia Vahl !, Echioidin; 2, Apigenin; 3, 4'-OMe Apigenin; 4, 7-OMe ApiBenin; 5, Luteolin; 6, 7-OMe Luteolin; 7, Y-OMe Luleolin; 8, 7, 4'-DiOMe Luteolin; 9, 7, Y, 4"-TriOMe Luteolin; 10, Scutellarein; I 1, 6-OMe Scutellarein; 12, 6-OH Luteolin; 13, 6-OMe Luteolin; 14, Kaempferol; 15, 7-OMe Kaempferol; 16, Quereetin; 17, 3'-OMe Quercetin; 18, Myricetin; 19, Vitexin and lsovitexin; 20, 4-OMe Vitexin; 21, 6-OMe Vitexin; 22, Proanthocyanins; 23, Aucubins. t-~ Table 2. The distribution of phenolic acids in some members of Acanthaceae. o

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Subfamily Nelsonioideae Elytraria crenata Vahl + + + + + + -[- Staurogyne glutinosa O. Kuntze + + + q- + Subfamily Thunbergioideae Thunbergia erecta T. Anders, + + + + T. fra.qrans Watl. + + T. orandiflora Roxb. + q- -I- + T. mysorensis T. Anders. + -I- "t- + + Subfamily Acanthoideae Tribe Hygrophileae Hemiadelphis polyspermus Nees Hyorophila auriculata Heine + + + + + tt. quadrivalvis Nees q- + + + 4- + H. serpyllum T. Anders. + Tribe Strobilantheae Gantelbua urens Bremek. 4- + + Hemigraphis elegans var. crenata Ciarke + + + + H. hirta T. Anders. + q- + + H. latebrosa var. heyneana Bremek. + Strobilanthus callosus Nees -I- + "1- + q- S. scaber Nees S. wightianus Nees + + + + + Tribe R uellieae Daedalacanthus nervosus T. Anders. + + + Dipteracamhu.~ patulus var. alba Bhandari + + D. prostratus Nees + Erantl, emum roseum Br. + + + + Ruellia baikiei Woodr. R. colorata WaU. "t- -I- R. tuberosa Linn. + + Table 2. (Contd.)

I 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Tribe Barlerieae Barleria cristata Linn. + + + ac B. grandiflora Dalz. + 4- + + + B. prattensis Sant. + + -I- + + B. prionitis Linn. + + + + -t- B. strigosa Willd. + + + ac Lepidagathis cuspidata Nees + + + ac + + L. bandraensis Blatter + ac + Neuracanthus sphaerostachyus Dalz. + -t- ac Tribe Acantheae ,a, Acanthus ilicifolius Linn. + + + ac Blepharis asperrima Nees + ac + g~ B. linearifolia Pers + ac + B. madaraspaten,sis (L.) Heyne ac + + + B. repens Roth ~- + + g~ + Crox.sandra undulaefolia Salisb. + + + Tribe Andrographideae + + + ac Bremekampia neilgherryensis Sreem. + o~ Haplanthus verticillaris Nees ac + lndonessiella echioides Sreem. + + + Tribe Asystasieae dulzelliana Sant. + A. gangetica T. Anders. + + + A. trat~ancoria Bedd. + + Tribe Odontonemeae Dicliptera t~erticillata Christens. + Ecobolium linneanum Kurz + + + Peristrophe bicalyculata Nees + + + + communis Nees ac + + + Run#ia pectinata Nees + + + ac R. repens Nees + + + + + Rg. t~ Tablr 2. (Contd.)

I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 17 18 19 20

Tribe Justicieae Adhatoda zeylanica Medie. + -4- + + ~t Beloperone guttata Brandegce + + B. violacea Planeh and Linden. + + + + J acobinia boliviensis Woodr. + + Justicia betonica Linn. + + + J. neesli Ramam. + + + J. procumbens var. simplex Yamazaki -I- + + + + J. trinervia Vahl. + 1~ Salicylic acid; 2, p-Hydroxybenzoie acid; 3, o-Pyrocateehuie aeid; 4, Gentisic acid; 5, Protocatechuic aeid; 6, a-Resorcylic acick 7, 2-OH, 4-OCH3-Benzoic acid; 8, 2-OH, 5-OCH~-Benzoie acid; 9, Vanillie acid; 10, Syringie aeid; 11, 3-OH, 4-OCH3-Benzoie a.cid; 12, 3-OH, 5-OCH3-Benzoie aeid; 13, Phloretie aeid; 14, Meliiotic aeid; 15, p-Coumaric acid; 16, o-Coumarie aeid; 17, Caffeie aeid; 18, Ferulie aeid; 19, Sinapie aeid. Chemosystematics of lndian Acanthaceae 323 flavones and p-hydroxy benzoic acid. Both Thunbergiaceae and Nelsonioideae possess panduraeform glandular hairs and do not contain the characteristic cysto- liths of Acanthoideae (Ahmed 1974a). But Nelsonioideae differ from Thunbergiaceae in having aucubins, proanthocyanins and cinnamic acids, all of which are charac- teristic to Acanthoideae. It may be noted that Bremekamp (1953) transferred this subfamily to Scrophulariaceae and placed near the tribe Rhinantheae, based on the presence of well-deve[oped endosperm, the type of placentation and the nature of dehiscence of the fruit. The subfamily Acanthoideae is relative|y homogeneous, and together with Nelsonioideae constitute a well-defined family Acanthaceae. The family Thunbergiaceae is more primitive than the Acanthaceae in the absence of 6-oxygenation, cinnamic acids and in the rarity of flavones. The family Acantha- ceae (containing Nelsonioideae and Acanthoideae), with its predominance of fla- vones especially 6-oxygenated compounds and reduction in flavonols, glycoflavones and proanthocyanins is chemically advanced over Thunbergiaceae. Within Acan- thaceae, Nelsonioideae appears to be more primitive than Acanthoideae because of the absence of 6-hydroxylation in the Nelsonioideae.

References

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